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Sample records for radiosterilized freeze-dried human

  1. Moisture sorption characteristics of freeze-dried human platelets

    Institute of Scientific and Technical Information of China (English)

    Meng-jie XU; Guang-ming CHEN; Ju-li FAN; Jin-hui LIU; Xian-guo XU; Shao-zhi ZHANG

    2011-01-01

    Freeze-drying is a promising method for a long-term storage of human platelets. The moisture sorption characteristics of freeze-dried human platelets (FDHPs) were studied in this paper. The moisture sorption isotherms of FDHPs and freeze-dried lyophilization buffer (FDLB) were measured at 4, 25, and 37 ℃. The experimental data were fitted to Brunauer-Emmett-Teller (BET) and Guggenheim-Anderson-de Boer (GAB) equations. There were no significant statistical differences (P>0.05) between the sorption characteristics of FDHPs and FDLB at 4 and 25 ℃, while FDHPs absorbed more water at 37 ℃. The net isosteric heat of sorption was derived. The heat for FDHPs showed an abnormal negative value at low moisture contents when 25 and 37 ℃ data were used. Dynamic sorption experiments were carried out at 25 ℃ with environmental water activity controlled at 0.75, 0.85, and 0.90. The moisture diffusion coefficient was fitted to be 8.24x 10-12 m2/s when experimental data at initial time were used. These results would be helpful in choosing prehydration and storage condition for FDHPs.

  2. Freeze-drying as a preserving preparation technique for in vitro testing of human skin.

    Science.gov (United States)

    Franzen, Lutz; Vidlářová, Lucie; Kostka, Karl-Heinz; Schaefer, Ulrich F; Windbergs, Maike

    2013-01-01

    In vitro testing of drugs with excised human skin is a valuable prerequisite for clinical studies. However, the analysis of excised human skin presents several obstacles. Ongoing drug diffusion, microbial growth and changes in hydration state influence the results of drug penetration studies. In this work, we evaluate freeze-drying as a preserving preparation method for skin samples to overcome these obstacles. We analyse excised human skin before and after freeze-drying and compare these results with human skin in vivo. Based on comprehensive thermal and spectroscopic analysis, we demonstrate comparability to in vivo conditions and exclude significant changes within the skin samples due to freeze-drying. Furthermore, we show that freeze-drying after skin incubation with drugs prevents growth of drug crystals on the skin surface due to drying effects. In conclusion, we introduce freeze-drying as a preserving preparation technique for in vitro testing of human skin.

  3. Intracellular trehalose improves the survival of human red blood cells by freeze-drying

    Institute of Scientific and Technical Information of China (English)

    HE Hui; LIU Baolin; HUA Zezhao; LI Chuan; WU Zhengzheng

    2007-01-01

    Freeze-drying of human red blood cells has a potential important application for blood transfusion.The aim of this study was to investigate the effects ofintracellular trehalose on the survival of red blood cells after freeze-drying and rehydration.Fresh red blood cells were incubated in trehalose solutions of various concentrations at 37℃ for 7 h following freeze-drying.Polyvinylpyrrolidone,Trehalose,sodium citrate,and human serum albumin were used as extracellular protective agents for the freeze-drying of red blood cells.The results indicated that the intracellular trehalose concentration was increased with increasing concentration of extracellular trehalose solution,and the maximum concen tration of intracellular trehalose reached 35 mmol/L.The viability of freeze-dried red blood cells increased with the increment of intracellular trehalose concentration.

  4. TEMPERATURE-DEPENDENCE OF WATER TRANSPORT INTO THE MINERALIZED MATRIX OF FREEZE-DRIED HUMAN DENTIN

    NARCIS (Netherlands)

    VANDERGRAAF, ER; TENBOSCH, JJ

    1991-01-01

    Ten dentine sections cut perpendicular to the dentinal tubules from human mature non-carious third molars, were freeze-dried and then rehydrated by immersion in water at four temperatures, 10, 25, 40 and 70-degrees-C. The uptake of water by the sections was assessed as a function of rehydration time

  5. Vitamins, fatty acids, and antioxidant capacity stability during storage of freeze-dried human milk.

    Science.gov (United States)

    Lozano, Blanca; Castellote, Ana Isabel; Montes, Rosa; López-Sabater, M Carmen

    2014-09-01

    Although freezing is the most common method used to preserve human milk, nutritional and immunological components may be lost during storage. Freeze-drying could increase the shelf life of human milk, while preserving its original characteristics. Seventy-two samples of freeze-dried human milk were stored for different periods of time, up to a maximum of 3 months, at 4 °C or 40 °C. Vitamin C, tocopherols, antioxidant capacity, and fatty acids composition were analyzed. A new HILIC-UHPLC method improving vitamin C determination was also validated. Ascorbic acid and total vitamin C concentrations significantly decreased at both temperatures, while antioxidant capacity only decreased at 40 °C. Fatty acids composition and both γ-tocopherol and δ-tocopherol contents remained unaltered. The stability after storage of freeze-dried milk was higher than that reported for frozen or fresh milk indicating that freeze-drying is a promising option to improve the preservation of human milk in banks.

  6. In Vitro Impact of Conditioned Medium From Demineralized Freeze-Dried Bone on Human Umbilical Endothelial Cells.

    Science.gov (United States)

    Harnik, Branko; Miron, Richard J; Buser, Daniel; Gruber, Reinhard

    2017-03-01

    Angiogenesis is essential for the consolidation of bone allografts. The underlying molecular mechanism, however, remains unclear. Soluble factors released from demineralized freeze-dried bone target mesenchymal cells; however, their effect on endothelial cells has not been investigated so far. The aim of the present study was therefore to examine the effect of conditioned medium from demineralized freeze-dried bone on human umbilical endothelial cells in vitro. Conditioned medium was first prepared from demineralized freeze-dried bone following 24 hours incubation at room temperature to produce demineralized bone conditioned media. Thereafter, conditioned medium was used to stimulate human umbilical vein endothelial cells in vitro by determining the cell response based on viability, proliferation, expression of apoptotic genes, a Boyden chamber to determine cell migration, and the formation of branches. The authors report here that conditioned medium decreased viability and proliferation of endothelial cells. Neither of the apoptotic marker genes was significantly altered when endothelial cells were exposed to conditioned medium. The Boyden chamber revealed that endothelial cells migrate toward conditioned medium. Moreover, conditioned medium moderately stimulated the formation of branches. These findings support the concept that conditioned medium from demineralized freeze-dried bone targets endothelial cells by decreasing their proliferation and enhancing their motility under these in vitro conditions.

  7. Freeze-drying of HI-6-loaded recombinant human serum albumin nanoparticles for improved storage stability.

    Science.gov (United States)

    Dadparvar, Miriam; Wagner, Sylvia; Wien, Sascha; Worek, Franz; von Briesen, Hagen; Kreuter, Jörg

    2014-10-01

    Severe intoxications with organophosphates require the immediate administration of atropine in combination with acetyl cholinesterase (AChE) reactivators such as HI-6. Although this therapy regimen enables the treatment of peripheral symptoms, the blood-brain barrier (BBB) restricts the access of the hydrophilic antidotes to the central nervous system which could lead to a fatal respiratory arrest. Therefore, HI-6-loaded albumin nanoparticles were previously developed to enhance the transport across this barrier and were able to reactivate organophosphate-(OP)-inhibited AChE in an in vitro BBB model. Since HI-6 is known to be moisture-sensitive, the feasibility of freeze-drying of the HI-6-loaded nanoparticles was investigated in the present study using different cryo- and lyoprotectants at different concentrations. Trehalose and sucrose (3%, w/v)-containing formulations were superior to mannitol concerning the physicochemical parameters of the nanoparticles whereas trehalose-containing samples were subject of a prolonged storage stability study at temperatures between -20°C and +40°C for predetermined time intervals. Shelf-life computations of the freeze-dried HI-6 nanoparticle formulations revealed a shelf-life time of 18 months when stored at -20°C. The formulations' efficacy was proven in vitro by reactivation of OP-inhibited AChE after transport over a porcine brain capillary endothelial cell layer model.

  8. Pore architecture and cell viability on freeze dried 3D recombinant human collagen-peptide (RHC)–chitosan scaffolds

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jing; Zhou, Aimei; Deng, Aipeng [School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094 (China); Yang, Yang [Faculty of Engineering, University of Nottingham, Nottingham NG7 2RD (United Kingdom); Gao, Lihu; Zhong, Zhaocai [School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094 (China); Yang, Shulin, E-mail: yshulin@njust.edu.cn [School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094 (China)

    2015-04-01

    Pore architecture of 3D scaffolds used in tissue engineering plays a critical role in the maintenance of cell survival, proliferation and further promotion of tissue regeneration. We investigated the pore size and structure, porosity, swelling as well as cell viability of a series of recombinant human collagen-peptide–chitosan (RHCC) scaffolds fabricated by lyophilization. In this paper, freezing regime containing a final temperature of freezing (T{sub f}) and cooling rates was applied to obtain scaffolds with pore size ranging from 100 μm to 120 μm. Other protocols of RHC/chitosan suspension concentration and ratio modification were studied to produce more homogenous and appropriate structural scaffolds. The mean pore size decreased along with the decline of T{sub f} at a slow cooling rate of 0.7 °C/min; a more rapid cooling rate under 5 °C/min resulted to a smaller pore size and more homogenous microstructure. High concentration could reduce pore size and lead to thick well of scaffold, while improved the ratio of RHC, lamellar and fiber structure coexisted with cellular pores. Human umbilical vein endothelial cells (HUVECs) were seeded on these manufactured scaffolds, the cell viability represented a negative correlation to the pore size. This study provides an alternative method to fabricate 3D RHC–chitosan scaffolds with appropriate pores for potential tissue engineering. - Highlights: • Fabrication of recombinant human collagen-chitosan scaffolds by freezing drying • Influence of freeze drying protocols on lyophilized scaffolds • Pore size, microstructure, porosity, swelling and cell viability were compared. • The optimized porous scaffold is suitable for cell (HUVEC) seeding.

  9. Synergetic effect of freeze-drying and gamma irradiation on the mechanical properties of human cancellous bone.

    Science.gov (United States)

    Cornu, Olivier; Boquet, Jérome; Nonclercq, Olivier; Docquier, Pierre-Louis; Van Tomme, John; Delloye, Christian; Banse, Xavier

    2011-11-01

    Freeze-drying and irradiation are common process used by tissue banks to preserve and sterilize bone allografts. Freeze dried irradiated bone is known to be more brittle. Whether bone brittleness is due to irradiation alone, temperature during irradiation or to a synergetic effect of the freeze-drying-irradiation process was not yet assessed. Using a left-right femoral head symmetry model, 822 compression tests were performed to assess the influence of sequences of a 25 kGy irradiation with and without freeze-drying compared to the unprocessed counterpart. Irradiation of frozen bone did not cause any significant reduction in ultimate strength, stiffness and work to failure. The addition of the freeze-drying process before or after irradiation resulted in a mean drop of 35 and 31% in ultimate strength, 14 and 37% in stiffness and 46 and 37% in work to failure. Unlike irradiation at room temperature, irradiation under dry ice of solvent-detergent treated bone seemed to have no detrimental effect on mechanical properties of cancellous bone. Freeze-drying bone without irradiation had no influence on mechanical parameters, but the addition of irradiation to the freeze-drying step or the reverse sequence showed a detrimental effect and supports the idea of a negative synergetic effect of both procedures. These findings may have important implications for bone banking.

  10. Development of freeze dried vegetables

    Science.gov (United States)

    Larson, R. W.

    1970-01-01

    The development of freeze dried vegetables to be used in the Apollo food system is discussed. After the initial selection and screening of vegetables, several types of freeze dried vegetables were prepared in small batches. From these small batches, two vegetables were judged satisfactory for further testing and evaluation. These vegetables, mashed potatoes and asparagus, were subjected to storage at 100 deg plus or minus 5 F. for two weeks and then taste tested. The vegetables were also tested to determine if they complied with the microbiological requirements for Apollo food. The space food prototype production guide for the vegetables is submitted.

  11. Preparation of redispersible liposomal dry powder using an ultrasonic spray freeze-drying technique for transdermal delivery of human epithelial growth factor

    Directory of Open Access Journals (Sweden)

    Yin F

    2014-03-01

    Full Text Available Fei Yin,1 Shiyan Guo,2 Yong Gan,2 Xinxin Zhang21Department of Pharmacy, Liaoning Cancer Hospital and Institute, Shenyang, 2Shanghai Institute of Materia Medica, Chinese Academy of Science, Shanghai, People's Republic of ChinaAbstract: In this work, an ultrasonic spray freeze-drying (USFD technique was used to prepare a stable liposomal dry powder for transdermal delivery of recombinant human epithelial growth factor (rhEGF. Morphology, particle size, entrapment efficiency, in vitro release, and skin permeability were systematically compared between rhEGF liposomal dry powder prepared using USFD and that prepared using a conventional lyophilization process. Porous and spherical particles with high specific area were produced under USFD conditions. USFD effectively avoided formation of ice crystals, disruption of the bilayer structure, and drug leakage during the liposome drying process, and maintained the stability of the rhEGF liposomal formulation during storage. The reconstituted rhEGF liposomes prepared from USFD powder did not show significant changes in morphology, particle size, entrapment efficiency, or in vitro release characteristics compared with those of rhEGF liposomes before drying. Moreover, the rhEGF liposomal powder prepared with USFD exhibited excellent enhanced penetration in ex vivo mouse skin compared with that for powder prepared via conventional lyophilization. The results suggest that ultrasonic USFD is a promising technique for the production of stable protein-loaded liposomal dry powder for application to the skin.Keywords: spray freeze-drying, recombinant human epithelial growth factor, liposomes, skin permeability, transdermal drug delivery

  12. Fundamentals of freeze-drying.

    Science.gov (United States)

    Nail, Steven L; Jiang, Shan; Chongprasert, Suchart; Knopp, Shawn A

    2002-01-01

    Given the increasing importance of reducing development time for new pharmaceutical products, formulation and process development scientists must continually look for ways to "work smarter, not harder." Within the product development arena, this means reducing the amount of trial and error empiricism in arriving at a formulation and identification of processing conditions which will result in a quality final dosage form. Characterization of the freezing behavior of the intended formulation is necessary for developing processing conditions which will result in the shortest drying time while maintaining all critical quality attributes of the freeze-dried product. Analysis of frozen systems was discussed in detail, particularly with respect to the glass transition as the physical event underlying collapse during freeze-drying, eutectic mixture formation, and crystallization events upon warming of frozen systems. Experiments to determine how freezing and freeze-drying behavior is affected by changes in the composition of the formulation are often useful in establishing the "robustness" of a formulation. It is not uncommon for seemingly subtle changes in composition of the formulation, such as a change in formulation pH, buffer salt, drug concentration, or an additional excipient, to result in striking differences in freezing and freeze-drying behavior. With regard to selecting a formulation, it is wise to keep the formulation as simple as possible. If a buffer is needed, a minimum concentration should be used. The same principle applies to added salts: If used at all, the concentration should be kept to a minimum. For many proteins a combination of an amorphous excipient, such as a disaccharide, and a crystallizing excipient, such as glycine, will result in a suitable combination of chemical stability and physical stability of the freeze-dried solid. Concepts of heat and mass transfer are valuable in rational design of processing conditions. Heat transfer by conduction

  13. Freeze-drying as an alternative method of human sclera preservation Liofilização como alternativa à preservação de esclera humana

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    Ana Carolina de Arantes Frota

    2008-04-01

    Full Text Available PURPOSE: To compare the effect of preserving sclera samples in either 95% ethanol or freeze-dried. METHODS: Ninety-six samples of human sclera were studied. Half of them were freeze-dried and half preserved in 95% ethanol. Preservation periods of 18, 45, 90 or 174 days were studied. Automated immunostaining was carried out in the Ventana BenchMarkR LT platform using collagen 1 and fibronectin antibodies. Histological staining was also performed with hematoxilin-eosin and Masson trichrome. Samples were classified according to the degree of collagen fiber parallelism (0-2, intensity of Masson staining (0-2, and the expression of both antibodies (0-3. Friedman and Wilcoxon tests were applied to compare preservation methods and p-values below 0.05 were considered to ensure statistical significance. RESULTS: Relevant results were found in three situations: (i Friedman's test showed better collagen fiber integrity in the freeze-dried group rehydrated after 174-days as compared to the 90-day group; (ii Wilcoxon's test showed better collagen fiber integrity in the freeze-dried group after 18 and 174 days as compared to the ethanol group; (iii the freeze-dried group disclosed higher immunohistochemical expression for COL-1 antibody in the sclera samples rehydrated after 45, 90 and 174 days as compared to the ones rehydrated after 18 days. CONCLUSION: Histological and immunohistochemical analysis showed freeze-drying to be a superior method for sclera preservation as compared to 95% ethanol. This technique provides an easy method to manipulate tissue, with longer shelf life, and storage at room temperature.OBJETIVO: Comparar dois métodos de preservação de esclera humana, liofilização e álcool 95%, em diferentes períodos de tempo. MÉTODOS: Foram avaliados 96 fragmentos de seis escleras humanas. Metade das amostras foi submetida ao processo de liofilização e metade conservada em álcool 95%. Dois fragmentos de cada grupo foram avaliados pelas

  14. A Mathematical Model for Freeze-Drying

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Based on the experiments on freeze-drying carrot and potato slabs, the effects of some parameters, such as heating temperature and pressure on the freeze-drying process are examined. A simple model of freeze-drying is established to predict drying time and the mass variations of materials during the drying. The experimental results agree well with those calculated by the model.

  15. Preparation of redispersible liposomal dry powder using an ultrasonic spray freeze-drying technique for transdermal delivery of human epithelial growth factor.

    Science.gov (United States)

    Yin, Fei; Guo, Shiyan; Gan, Yong; Zhang, Xinxin

    2014-01-01

    In this work, an ultrasonic spray freeze-drying (USFD) technique was used to prepare a stable liposomal dry powder for transdermal delivery of recombinant human epithelial growth factor (rhEGF). Morphology, particle size, entrapment efficiency, in vitro release, and skin permeability were systematically compared between rhEGF liposomal dry powder prepared using USFD and that prepared using a conventional lyophilization process. Porous and spherical particles with high specific area were produced under USFD conditions. USFD effectively avoided formation of ice crystals, disruption of the bilayer structure, and drug leakage during the liposome drying process, and maintained the stability of the rhEGF liposomal formulation during storage. The reconstituted rhEGF liposomes prepared from USFD powder did not show significant changes in morphology, particle size, entrapment efficiency, or in vitro release characteristics compared with those of rhEGF liposomes before drying. Moreover, the rhEGF liposomal powder prepared with USFD exhibited excellent enhanced penetration in ex vivo mouse skin compared with that for powder prepared via conventional lyophilization. The results suggest that ultrasonic USFD is a promising technique for the production of stable protein-loaded liposomal dry powder for application to the skin.

  16. Impregnation of leather during "freeze-drying"

    DEFF Research Database (Denmark)

    Storch, Mikkel; Vestergaard Poulsen Sommer, Dorte; Hovmand, Ida

    2016-01-01

    Freeze-drying is a recognized method for the preservation of waterlogged objects. Naturally, freeze-drying has also been used for waterlogged archaeological leather often after treatment with Na2.EDTA and impregnation with PEG; but the treated leather sometimes suffers from “excessive drying......” becoming too stiff and brittle. The aim of this study was to examine the effect of a conventional freeze-drying method against an alternative freeze-drying method that preserves the natural moisture content of the leather. Both new and archaeological waterlogged leather were included in the study...... suggest that the process which takes place within the leather during the freeze-drying in not actual freeze-drying, but rather a sophisticated way of distributing the impregnating agent. The pure ice phase freezes out, but the impregnating agent remains liquid as the temperature does not become low enough...

  17. Hypoxia Enhances Chondrogenic Differentiation of Human Cord Blood Multilineage Progenitor Cells Seeded on a Novel Scaffold of Freeze Dried Polycaprolactone

    DEFF Research Database (Denmark)

    Munir, Samir; Figueroa, Ryan Jude; Koch, Thomas Gadegaard

    Background Cartilage defects are common and causes osteoarthritis. Articular chondrocytes or bone marrow-derived stromal cells are presently the favoured cells for cartilage tissue engineering. Human umbilical cord blood multilineage progenitor cells (MLPCs) are easily harvested and have capability...... blue. Sulphated glycosaminoglycans (sGAG) and secreted CD-RAP were assessed as markers of cartilage anabolism. Results MLPCs pellets and scaffolds induced in 5% O2 showed increased cellularity and matrix deposition compared with induction in 21% O2. Matrix deposition in pellets was observed in a zonal...

  18. Proteomic characterization of freeze-dried human plasma: providing treatment of bleeding disorders without the need for a cold chain.

    Science.gov (United States)

    Steil, Leif; Thiele, Thomas; Hammer, Elke; Bux, Jürgen; Kalus, Monika; Völker, Uwe; Greinacher, Andreas

    2008-11-01

    Transfusion of human plasma is a basic treatment for severe coagulopathies, especially in major bleeding. The required logistics to provide plasma is challenging because of the need to maintain a cold chain. This disadvantage could be overcome by lyophilized plasma. However, it is unknown to what extent lyophilization alters plasma proteins. Quantitative proteomic technologies were applied to monitor protein changes during production of lyophilized, solvent/detergent (S/D)-treated plasma. The impact of S/D treatment and lyophilization on the plasma proteome was evaluated by differential in-gel electrophoresis (2D-DIGE), and proteins were characterized by mass spectrometry. Clotting factor activities were determined in lyophilized S/D-treated plasma after 24 months of storage at room temperature. By 2D-DIGE, 600 individual protein spots were compared. Lyophilization did not change any of the 600 spots, whereas pathogen inactivation caused significant changes of 38 spots including alpha1-antitrypsin, alpha1-antichymotrypsin, and alpha2-antiplasmin. Clotting factor activities remained stable over 24 months of storage. Lyophilization of human plasma neither alters its protein composition nor impairs its clotting capacity. It does not require cost-intensive logistics for storage and transport and can be quickly reconstituted. It is suggested that lyophilized, pathogen-inactivated plasma is an attractive option to provide the most important basic treatment for severe coagulopathies in areas without cold chain and to provide plasma with reduced time delay in emergency situations.

  19. Mechanisms of deterioration of nutrients. [of freeze dried foods

    Science.gov (United States)

    Karel, M.; Flink, J. M.

    1976-01-01

    Methods which produce freeze dried foods of improved quality were examined with emphasis on storage stability. Specific topics discussed include: microstructure of freeze dried systems, investigation of structural changes in freeze dried systems, artificial food matrices, osmotic preconcentration to yield improved quality freeze dried fruits, and storage stability of osmotically preconcentrated freeze dried fruits.

  20. Well-plate freeze-drying

    DEFF Research Database (Denmark)

    Trnka, Hjalte; Rantanen, Jukka; Grohganz, Holger

    2015-01-01

    due to increasing amount of amorphous matter in the samples was observed in both vials and well plates. Cake collapse was found to be representative in well plates and could be effectively quantified using image analysis. Reconstitution time was also found to be equal in all three platforms. Finally......Abstract Context: Freeze-drying in presence of excipients is a common practice to stabilize biomacromolecular formulations. The composition of this formulation is known to affect the quality of the final product. Objective: The aim of this study was to evaluate freeze-drying in well-plates...... as a high throughput platform for formulation screening of freeze-dried products. Methods: Model formulations consisting of mannitol, sucrose and bovine serum albumin were freeze-dried in brass well plates, plastic well plates and vials. Physical properties investigated were solid form, residual moisture...

  1. Freeze-dried bone in pulpotomy procedures in monkey.

    Science.gov (United States)

    Fadavi, S; Anderson, A W; Punwani, I C

    1989-01-01

    The purpose of this study was to evaluate the effect of freeze-dried bone on amputated pulps. Fifteen primary and one permanent monkey teeth were treated with freeze-dried bone. As the control group, another fifteen primary teeth were treated with calcium hydroxide and fifteen primary and one permanent teeth with formocresol. Four other primary teeth pulps were amputated and sealed with tin foil and IRM as controls. Twelve mandibular incisors were left intact. Histologically all but three teeth treated with human freeze-dried bone after three months showed a complete or partial calcific barrier directly below the amputation site. Normal appearing odontoblastic cells were noted below the calcific barrier. The apical third was vital with an occasional chronic inflammatory cell visible. The histological findings of teeth treated with calcium-hydroxide were very similar to freeze-dried bone. All but four teeth showed a complete calcific barrier at the amputation site. The odontoblastic cells were normal in appearance and the inflammatory cell reactions decreased from the middle portion toward the apical region. The histological evaluation of the formocresol-treated teeth was comparable with previously published studies.

  2. Freeze-drying of lactic acid bacteria.

    Science.gov (United States)

    Fonseca, Fernanda; Cenard, Stéphanie; Passot, Stéphanie

    2015-01-01

    Lactic acid bacteria are of great importance for the food and biotechnology industry. They are widely used as starters for manufacturing food (e.g., yogurt, cheese, fermented meats, and vegetables) and probiotic products, as well as for green chemistry applications. Freeze-drying or lyophilization is a convenient method for preservation of bacteria. By reducing water activity to values below 0.2, it allows long-term storage and low-cost distribution at suprazero temperatures, while minimizing losses in viability and functionality. Stabilization of bacteria via freeze-drying starts with the addition of a protectant solution to the bacterial suspension. Freeze-drying includes three steps, namely, (1) freezing of the concentrated and protected cell suspension, (2) primary drying to remove ice by sublimation, and (3) secondary drying to remove unfrozen water by desorption. In this chapter we describe a method for freeze-drying of lactic acid bacteria at a pilot scale, thus allowing control of the process parameters for maximal survival and functionality recovery.

  3. Sperm Preservation using Freeze-Drying Method

    Directory of Open Access Journals (Sweden)

    TAKDIR SAILI

    2005-03-01

    Full Text Available Since the discovery of cryopreservation method for bull semen, cryopreservation become an alternative method for maintaining gamet resources of certain animal which is threatened or near extinction. This technology was then applied to the preservation of embryo, oocyte, ovary and testis. The application of intracytoplasmic sperm injection (ICSI for which sperm motility is unnecessary had supported the effort to create simplified method such as freeze-drying for sperm preservation. Due to the benefit of ICSI over the conventional in vitro fertilization (IVF the spermatozoon could be mechanically driven to pass through the zona pellucida and entering the cytoplasm of oocytes prior to fertilization. The freeze-drying method is an alternative method in sperm preservation which ignored the motility of sperm. The sperm resulted from this technique is in drying state, therefore, it might be stored in room temperature or in refrigerator. Many reports have claimed that freeze-dried sperm which is not motile but has an intact DNA was able to fertilize oocytes, even produced offspring in mouse.

  4. Nasal dorsal augmentation with freeze-dried allograft bone.

    Science.gov (United States)

    Clark, Richard P; Wong, Granger; Johnson, Loche M; Hagge, Rosalie J; Ciminello, Frank; Lee, John; Stone, Kiki I; Clark, Isabel A

    2009-10-01

    Properly prepared freeze-dried bone has been used with impunity by orthopedic surgeons since 1992 without a single report of disease transmission. The aim of this study was to evaluate freeze-dried cortical allograft bone for nasal dorsal augmentation. Freeze-dried human cortical bone was obtained from DCI Donor Services, Nashville, Tennessee. Standards recommended by the American Association of Tissue Banks, the U.S. Food and Drug Administration, and the Centers for Disease Control and Prevention were followed. Objective evaluation of the persistence of graft volume was obtained by cephalometric radiography. Vascularization and incorporation of new bone elements within the grafts were demonstrated by using fluorine-18 sodium fluoride positron emission tomographic/computed tomographic scanning. The average persistence of projection in 18 patients was 87 percent at 6 months. Thereafter, 10 patients showed 100 percent maintenance of projection at 12 to 36 months. Vascularization and incorporation of new bone elements within the grafts were demonstrated by using fluorine-18 sodium fluoride positron emission tomographic/computed tomographic scanning in four patients. The initial loss of 13 percent of projection is most likely attributable to resolution of early surgical edema. The authors postulate that there are two pathways based on whether the recipient bed allows vascular access to the graft. The revascularization or inductive pathway involves stem cell conversion to eventual osteoblasts. The scar bed barrier or noninductive pathway involves the preservation of the graft as an unchanged alloimplant. This report is the first of a series that will include a 5-year and a 10-year follow-up.

  5. Spray freeze drying of YSZ nanopowder

    Science.gov (United States)

    Raghupathy, Bala P. C.; Binner, J. G. P.

    2012-07-01

    Spray freeze drying of yttria stabilised zirconia nanopowders with a primary particle size of 16 nm has been undertaken using different solids content starting suspensions, with the effect of the latter on the flowability and crushability of the granules being investigated. The flowability and fill density of the granules increased with an increase in the solid content of the starting suspension, whilst the crushability decreased. The powder flowability, measured using a Hall flowmeter and model shoe-die filling tests, showed that the flowability of otherwise poorly flowable nanopowders can be improved to match that of the commercial spray dried submicron powder. The 5.5 vol.% solid content based suspension yielded soft agglomerates whilst a 28 vol.% solid content suspension formed hard agglomerates on spray freeze drying; the granule relics were visible in the fracture surface of the die pressed green compact in the latter case. The increase in granule strength is explained by the reduction in inter-particle distance based on the theories developed by Rumpf and Kendall. The flaw sizes computed using the Kendall model are comparable with those seen in the micrographs of the granule. With an optimum solid content, it is possible to have a granulated nanopowder with reasonable flowability and compactability resulting in homogeneous green bodies with 54 % of theoretical density.

  6. Freeze-drying of live virus vaccines: A review.

    Science.gov (United States)

    Hansen, L J J; Daoussi, R; Vervaet, C; Remon, J-P; De Beer, T R M

    2015-10-13

    Freeze-drying is the preferred method for stabilizing live, attenuated virus vaccines. After decades of research on several aspects of the process like the stabilization and destabilization mechanisms of the live, attenuated viruses during freeze-drying, the optimal formulation components and process settings are still matter of research. The molecular complexity of live, attenuated viruses, the multiple destabilization pathways and the lack of analytical techniques allowing the measurement of physicochemical changes in the antigen's structure during and after freeze-drying mean that they form a particular lyophilization challenge. The purpose of this review is to overview the available information on the development of the freeze-drying process of live, attenuated virus vaccines, herewith focusing on the freezing and drying stresses the viruses can undergo during processing as well as on the mechanisms and strategies (formulation and process) that are used to stabilize them during freeze-drying.

  7. A clinical and radiological evaluation of the relative efficacy of demineralized freeze-dried bone allograft versus anorganic bovine bone xenograft in the treatment of human infrabony periodontal defects: A 6 months follow-up study

    Directory of Open Access Journals (Sweden)

    Vikram Blaggana

    2014-01-01

    Full Text Available Background: The ultimate goal of periodontal therapy entails regeneration of the periodontal tissues lost as a consequence of periodontitis. Predictable correction of vertical osseous defects has however posed as a constant therapeutic challenge. The aim of our present study is to evaluate the relative efficacy of demineralized freeze-dried bone allograft (DFDBA vs anorganic bovine bone xenograft (ABBX in the treatment of human infrabony periodontal defects. Materials and Methods: 15 patients with 30 bilaterally symmetrical defect sites in either of the arches, in the age group of 25-50 years were selected as part of split-mouth study design. Defect-A (right side was grafted with DFDBA while Defect-B (left side was grafted with ABBX. Various clinical and radiographic parameters viz. probing depth(PD, clinical attachment level(CAL and linear bone fill were recorded preoperatively, 12- & 24-weeks postoperatively. Results: Both defect-A & defect-B sites exhibited a highly significant reduction in probing depth, and gain in clinical attachment level and linear bone fill at 12-weeks & at the end of 24-weeks. Comparative evaluation between the study groups revealed a statistically non-significant reduction in probing depth (P<0.1 and mean gain in linear bone fill (P<0.1. However, there was a statistically significant gain in clinical attachment level (P <0.05 in Defect-A (CD=0.356 as compared to Defect-B (CD=0.346. Conclusions: Within the limits of this study, both the materials viz. ABBX and DFDBA are beneficial for the treatment of periodontal infrabony defects. Both the materials were found to be equally effective in all respects except the gain in attachment level, which was found to be more with DFDBA. Long-term studies are suggested to evaluate further the relative efficacy of the two grafts.

  8. Experimental study on rehydration conditions of freeze-dried platelets

    Institute of Scientific and Technical Information of China (English)

    Ju-li FAN; Xian-guo XU; Shao-zhi ZHANG; Fa-ming ZHU; Guang-ming CHEN; Li-xing YAN

    2009-01-01

    A rehydration process for freeze-dried human platelets was studied on 1 ml of samples.The effects of prehydration duration,prehydration temperature,an rehydration solution on the recovery rate,mean platelet volume(MPV),and platelet distribution width(PDW)were investigated.The mass changes during the prehydration process were also studied.Three prehydration durations:0,1.5,and 3.5 h,and two rehydration solutions:platelet-poor plasma and phosphate-buffered saline(PBS),were tested.It was found that:(1)the prehydration was of significance;(2)1.5 h of prehydration had better effects than 3.5 h of prehydration;(3)as a rehydration solution,the platelet-poor plasma behaved better than the PBS.The impacts of prehydration duration and temperature on the results were studied.There was almost no difference between 35 and 37℃.Among all the prehydration durations tested,15,30,60,90,and 120 min,the best result was achieved with the time duration of 15 min.The weights of prehydrated platelets at the end of each test were measured and the water contents were calculated.Atier 15 min of prehydration,the water contents in the samples were about(4.8±0.01)%and(5.27±0.29)%(w/w)corresponding to the conditions of 35 and 37 ℃.respectively.These results will be helpful for further studies on the freeze-drying of mammalian cells.

  9. Microwave Enhanced Freeze Drying of Solid Waste Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The development of advanced methods for Microwave Enhanced Freeze Drying of Solid Waste (MEFDSW) is proposed. Methods for the recovery of relatively pure water as a...

  10. Microwave Enhanced Freeze Drying of Solid Waste Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Development of technology for Microwave Enhanced Freeze Drying of Solid Waste (MEFDSW) is proposed. The present state of the art for solid waste stabilization using...

  11. Amnion s and radio-sterilized porcine skin use as potential matrices for the development of human skin substitutes; Uso de amnios y piel porcina radioesterilizados como matrices potenciales para el desarrollo de sustitutos de piel humana

    Energy Technology Data Exchange (ETDEWEB)

    Martinez P, M. E.; Reyes F, M. L.; Reboyo B, D. [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Velasquillo M, M. C.; Sanchez S, R.; Brena M, A. M.; Ibarra P, J. C., E-mail: esther.martinez@inin.gob.mx [Instituto Nacional de Rehabilitacion, Calz. Mexico-Xochimilco No. 289, Col. Arenal de Guadalupe, 14389 Mexico D. F. (Mexico)

    2014-10-15

    The injuries by burns constitute a primordial problem of public health; they cause a high mortality index, severe physical and psychological disability, etc. The autologous skin transplant is the replacement therapy recommended for its treatment, but in patients that present a high percentage of burnt skin; this is not possible to carry out. Another strategy is the transplant of donated skin; however, due to the little donation that exists in our country is not very feasible to apply this treatment. A challenge of the tissues engineering is to develop biological skin substitutes, based on cells and amnion s, favoring the cutaneous regeneration and quick repair of injuries, diminishing this way the hospitalization expenses. At present skin substitutes that can equal to the same skin do not exist. On the other hand, the mesenchymal stromal cells (Msc) represent an alternative to achieve this objective; since has been demonstrated that the Msc participate in the tissue repair by means of inhibition of pro-inflammatory cytokines and differentiation to dermal fibroblasts and keratinocytes. To apply the Msc in cutaneous injuries a support material is required that to allow transplanting these cells to a lesion or burn. The radio-sterilized human amnion and the radio-sterilized porcine skin, processed by the Radio-Sterilized Tissues Bank of the Instituto Nacional de Investigaciones Nucleares (ININ), are biomaterials that are used as temporary cutaneous coverings. We suppose that these two matrices will be appropriate for the growth and maintenance in cultivation of the Msc, to generate two biological skin substitutes, in collaboration with the Biotechnology Laboratory of the Instituto Nacional de Rehabilitacion. (Author)

  12. Sucrose Diffusion in Decellularized Heart Valves for Freeze-Drying.

    Science.gov (United States)

    Wang, Shangping; Oldenhof, Harriëtte; Goecke, Tobias; Ramm, Robert; Harder, Michael; Haverich, Axel; Hilfiker, Andres; Wolkers, Willem Frederik

    2015-09-01

    Decellularized heart valves can be used as starter matrix implants for heart valve replacement therapies in terms of guided tissue regeneration. Decellularized matrices ideally need to be long-term storable to assure off-the-shelf availability. Freeze-drying is an attractive preservation method, allowing storage at room temperature in a dried state. However, the two inherent processing steps, freezing and drying, can cause severe damage to extracellular matrix (ECM) proteins and the overall tissue histoarchitecture and thus impair biomechanical characteristics of resulting matrices. Freeze-drying therefore requires a lyoprotective agent that stabilizes endogenous structural proteins during both substeps and that forms a protective glassy state at room temperature. To estimate incubation times needed to infiltrate decellularized heart valves with the lyoprotectant sucrose, temperature-dependent diffusion studies were done using Fourier transform infrared spectroscopy. Glycerol, a cryoprotective agent, was studied for comparison. Diffusion of both protectants was found to exhibit Arrhenius behavior. The activation energies of sucrose and glycerol diffusion were found to be 15.9 and 37.7 kJ·mol(-1), respectively. It was estimated that 4 h of incubation at 37°C is sufficient to infiltrate heart valves with sucrose before freeze-drying. Application of a 5% sucrose solution was shown to stabilize acellular valve scaffolds during freeze-drying. Such freeze-dried tissues, however, displayed pores, which were attributed to ice crystal damage, whereas vacuum-dried scaffolds in comparison revealed no pores after drying and rehydration. Exposure to a hygroscopic sucrose solution (80%) before freeze-drying was shown to be an effective method to diminish pore formation in freeze-dried ECMs: matrix structures closely resembled those of control samples that were not freeze-dried. Heart valve matrices were shown to be in a glassy state after drying, suggesting that they can

  13. The impact of vacuum freeze-drying on collagen sponges after gas plasma sterilization.

    Science.gov (United States)

    Markowicz, M; Koellensperger, E; Steffens, G C M; Frentz, M; Schrage, N; Pallua, N

    2006-01-01

    The sterilization of porous collagen sponges remains a challenging procedure. Gamma irradiation denatures collagen, resulting in dramatic changes to its structure. Ethylene oxide leaves toxic residues requiring weeks to evaporate. This study investigated the impact on cell behavior of gas plasma treatment when combined with vacuum freeze-drying. The goal of this procedure is to eliminate the molecules of hydrogen peroxide remaining after the sterilization process, together with their decomposition products, from the scaffolds. These molecules hinder the immediate use of the porous designs. Collagen and EDC/NHS-heparinized collagen scaffolds were sterilized with gas plasma. H2O2 released by the collagen specimens was measured by peroxidase test both immediately and also 1 week after the plasma treatment. Further measurements were done 24, 36, 48 and 72 h after vacuum freeze-drying. The activity of these scaffolds was further evaluated in relation to the proliferation, migration and differentiation of human umbilical vein endothelial cells (HUVECs). Both immediately after exposure to gas plasma and also 1 week later, the collagen designs contained significantly higher concentrations of H2O2 than scaffolds having also undergone vacuum freeze-drying. This procedure achieved faster decontamination of the remaining H2O2. Following vacuum freeze-drying, sponges already allowed HUVEC proliferation after 48 h, but in non-lyophilized specimens after gas plasma treatment alone, cell death occurred as early as only 1 week later. These data highlight the advantages of carrying out vacuum freeze-drying following gas plasma sterilization. The results show the substantial impact of sterilization of porous materials made for tissue engineering.

  14. Freeze-drying applied to radioactive source preparation.

    Science.gov (United States)

    de Sanoit, J; Leprince, B; Bobin, Ch; Bouchard, J

    2004-12-01

    In the framework of R&D studies for the improvement of radioactive source efficiencies prepared on thin films for 4pibeta-gamma coincidence counting, a comparative study on two drying methods has been undertaken in our laboratory (BNM-Laboratoire National Henri Becquerel, France). The standard method of evaporation at atmospheric pressure and a method based on freeze-drying using commercial equipment are compared. The preliminary results of this study obtained with 65Zn sources are presented and a significant improvement of the detection efficiencies to the electron emission for freeze-dried sources is shown. In the course of validation of this method, other radionuclides were studied and, up to now, the results confirm the better crystallization homogeneity achieved for freeze-dried sources.

  15. Economic aspects of radiosterilization; Aspekty ekonomiczne sterylizacji radiacyjnej

    Energy Technology Data Exchange (ETDEWEB)

    Zimek, Z. [Institute of Nuclear Chemistry and Technology, Warsaw (Poland)

    1997-10-01

    The economic analysis of radiosterilization have been done. The costs have been estimated on the example of Electron Accelerator Irradiation Plant for Radiosterilization working in Institute of Nuclear Chemistry and Technology, Warsaw. 3 tabs.

  16. Optimizing the Chemical Compositions of Protective Agents for Freeze-drying Bifidobacterium longum BIOMA 5920

    Institute of Scientific and Technical Information of China (English)

    杨婵媛; 朱晓丽; 范代娣; 米钰; 骆艳娥; 惠俊峰; 苏然

    2012-01-01

    Freeze drying has a deleterious effect on the viability of microorganisms. In front of this difficulty, the present study adopts response surface methodology to optimize the chemical compositions of protective agents to seek for maximum viability of Bifidobacterium longum BIOMA 5920 during freeze-drying. Through the compara- tive analysis of single protectant, the complex protective agents show better effect on the Bifidobacterium viability. Human-like collagen (HLC), trehalose and glycerol are confirmed as significant factors by Box-Behnken Design. The optimized formula for these three variables is tested as follows: HLC 1.23%, trehalose 11.50% and glycerol 4.65%. Under this formula, the viability is 88.23%, 39.67% higher in comparison to the control. The viable count is 1.07×10 9 cfu·g-1 , greatly exceeding the minimum viable count requirement (10 6 cfu·g-1 ).

  17. A novel approach to sterile pharmaceutical freeze-drying.

    Science.gov (United States)

    Cherry, Christopher Lee Albert; Millward, Huw; Cooper, Rose; Landon, John

    2014-02-01

    A novel approach has been developed that enables sterile pharmaceutical products to be freeze-dried in the open laboratory without specialist facilities. The product is filled into vials, semi-stoppered and sealed inside one, followed by a second, sterilization pouch under class 100 conditions. The product is then freeze-dried in the laboratory where the vials are shelf-stoppered before being returned to class 100, unwrapped and crimped. The sterilization pouches increased the resistance to water vapor movement during sublimation, thereby increasing the sublimation time and product temperature. Ovine immunoglobulins were double wrapped and lyophilized (as above) adjusting the primary drying time and shelf temperature for increased product temperature and, therefore, prevention of collapse. Ovine immunoglobulin G formulations freeze-dried to ≤ 1.1% residual moisture with no effect on protein aggregation or biological activity. The process was simulated with tryptone soya broth and no growth of contaminating microbial cells was observed after incubation at 35 °C for 2 weeks. Although increasing lyophilization time, this approach offers significant plant and validation cost savings when sterile freeze-drying small numbers of vials thereby making the manufacture of treatments for neglected and orphan diseases more viable economically.

  18. Stability of Freeze-Dried Sera Stored at Different Temperatures for the Detection of Anti-Leishmania infantum Antibodies Using Direct Agglutination Test.

    Directory of Open Access Journals (Sweden)

    Zahra Kakooei

    2014-11-01

    Full Text Available This study aimed to evaluate freeze-dried sera as an alternative to non-freeze dried for detection of anti-Leishmania infantum antibodies over the course of 11 months using the direct agglutination test (DAT.Altogether, 60 serum samples (30 from humans and 30 from dogs were collected from various geographical locations in Iran. All the collected sera were pooled and each pooled serum sample contained 10 different sera. In the beginning, the human and dog pooled sera were categorized as positive (weak and strong and negative based on anti-L. infantum antibodies using the DAT. All the freeze-dried and non-freeze-dried sera were stored at -70°C, -20°C, 4°C, 22-28°C and 56°C for 11 months. The positive and negative human and dog pooled sera were separately tested using the DAT each month and the results were compared to non-freeze-dried sera kept under the same conditions.We found strong agreement (100% between the results obtained from freeze-dried human and dog in strong DAT positive sera kept at -70°C, -20°C, 4°C and 22-28°C during this study. The human and dog pooled sera stored at 56°C were corrupted after 2 weeks. The DAT results were highly reproducible using freeze-dried human pooled sera in the beginning and month 11 of this study (CV = 0.036.Freeze-dried human and dog strong DAT positive sera are highly stable under different temperature conditions, are easy to transport and are safe for use as positive and negative serum controls in laboratories.

  19. Antioxidant, antiproliferative and antimicrobial activity of freeze-dried raspberry

    Directory of Open Access Journals (Sweden)

    Vulić Jelena J.

    2014-01-01

    Full Text Available The main chemical composition, i.e. the total content of bioactive compounds (phenolics 2209.86 ± 70.32 mg GAE/100g FDR, flavonoids 831.87 ± 12.61 mg R/100g FDR and anthocyanins 144.55 ± 0.39 mg CGE/100g FDR, in freeze-dried raspberry (FDR was evaluated spectrophotometrically. Vitamin C content was determined by HPLC analysis (88.81 ± 4.38 mg vit C/100g FDR. Antioxidant activities of FDR extract were evaluated spectrophotometrically on stable 2,2-diphenyl-1-picrylhydrazyl (DPPH free radicals and by electron spin resonance spectroscopy (ESR method on hydroxyl radicals (•OH. EC50 values were evaluated. EC50 DPPH• was 0.127 ± 0.013 mg/ml, while EC50 •OH was 1.366 ± 0.026 mg/ml. Antiproliferative activity of the FDR extract was evaluated in vitro in three human cell lines by colorimetric sulphorhodamine B (SRB assay. The most pronounced effects were obtained in the breast adenocarcinoma cell line (MCF7. EC50 value was 395.07 ± 96.38 μg/ml. Antimicrobial activity was determined by disk diffusion method. The FDR extract produced a clear inhibition zone (without visible colonies only toward Staphylococcus aureus. The minimal inhibitory (MIC and minimal bactericidal (MBC concentrations of FDR extract were evaluated. The values MIC were in the range of 4.7 - 100 mg/ml, and of MBC in the range of 6.3 - > 100 mg/ml.[ Projekat Ministarstva nauke Republike Srbije, br. TR 31044

  20. Characterization of freeze dried egg melange long stored after irradiation

    Science.gov (United States)

    Bakalivanov, Stefan; Tsvetkova, Eli; Bakalivanova, Todorka; Tsvetkov, Tsvetan; Kaloyanov, Nikolay; Grigorova, Stoyanka; Alexieva, Vanja

    2008-01-01

    During the 4-year period of storage at room temperature of the freeze-dried (control group) and the freeze-dried and gamma-irradiated (2.0 and 3.5 kGy) whole hen's egg mélange, no significant changes were found into the sensory and functional characteristics till the 28th month. The change in the number of SH groups was not unidirectional up to the 28th month and then it started to decrease in all investigated samples. During the entire period of investigation the amount of malondialdehyde in all three groups of egg mélange was considerably below the allowed limit for foodstuffs. The most significant fractions of the protein spectra showed a general tendency of decrease during the storage.

  1. Encapsulation of black carrot juice using spray and freeze drying.

    Science.gov (United States)

    Murali, S; Kar, Abhijit; Mohapatra, Debabandya; Kalia, Pritam

    2015-12-01

    Black carrot juice extracted using pectinase enzyme was encapsulated in three different carrier materials (maltodextrin 20DE, gum arabic and tapioca starch) using spray drying at four inlet temperatures (150, 175, 200 and 225 ℃) and freeze drying at a constant temperature of - 53 ℃ and vacuum of 0.22-0.11 mbar with the constant feed mixture. The products were analyzed for total anthocyanin content, antioxidant activity, water solubility index, encapsulation efficiency and total colour change. For both the drying methods followed in this study, maltodextrin 20DE as the carrier material has proven to be better in retaining maximum anthocyanin and antioxidant activity compared to gum arabic and tapioca starch. The best spray dried product, was obtained at 150 ℃. The most acceptable was the freeze dried product with maximum anthocyanin content, antioxidant activity, water solubility index, encapsulation efficiency and colour change.

  2. Heat and Mass Transfer Model in Freeze-Dried Medium

    Science.gov (United States)

    Alfat, Sayahdin; Purqon, Acep

    2017-07-01

    There are big problems in agriculture sector every year. One of the major problems is abundance of agricultural product during the peak of harvest season that is not matched by an increase in demand of agricultural product by consumers, this causes a wasted agricultural products. Alternative way was food preservation by freeze dried method. This method was already using heat transfer through conduction and convection to reduce water quality in the food. The main objective of this research was to design a model heat and mass transfer in freeze-dried medium. We had two steps in this research, the first step was design of medium as the heat injection site and the second was simulate heat and mass transfer of the product. During simulation process, we use physical property of some agriculture product. The result will show how temperature and moisture distribution every second. The method of research use finite element method (FEM) and will be illustrated in three dimensional.

  3. Improving the Quality of Freeze Dried Rice: Initial Evaluations

    Science.gov (United States)

    2015-05-01

    CRP. Improvement themes are product texture following rehydration, alternatives to plain FD rice, and fortification with vitamins and minerals. Phase...cm, placed in a –20 °C blast freezer and held overnight, then transferred to the production scale freeze dryer (Pilot Freeze Drying Plant , Budge... vitamins ) upon washing3 and cooking in excess water which is then discarded4, with these losses increasing when the rice was cooked with a greater

  4. The impact of freeze-drying infant fecal samples on measures of their bacterial community profiles and milk-derived oligosaccharide content

    Directory of Open Access Journals (Sweden)

    Zachery T. Lewis

    2016-01-01

    Full Text Available Infant fecal samples are commonly studied to investigate the impacts of breastfeeding on the development of the microbiota and subsequent health effects. Comparisons of infants living in different geographic regions and environmental contexts are needed to aid our understanding of evolutionarily-selected milk adaptations. However, the preservation of fecal samples from individuals in remote locales until they can be processed can be a challenge. Freeze-drying (lyophilization offers a cost-effective way to preserve some biological samples for transport and analysis at a later date. Currently, it is unknown what, if any, biases are introduced into various analyses by the freeze-drying process. Here, we investigated how freeze-drying affected analysis of two relevant and intertwined aspects of infant fecal samples, marker gene amplicon sequencing of the bacterial community and the fecal oligosaccharide profile (undigested human milk oligosaccharides. No differences were discovered between the fecal oligosaccharide profiles of wet and freeze-dried samples. The marker gene sequencing data showed an increase in proportional representation of Bacteriodes and a decrease in detection of bifidobacteria and members of class Bacilli after freeze-drying. This sample treatment bias may possibly be related to the cell morphology of these different taxa (Gram status. However, these effects did not overwhelm the natural variation among individuals, as the community data still strongly grouped by subject and not by freeze-drying status. We also found that compensating for sample concentration during freeze-drying, while not necessary, was also not detrimental. Freeze-drying may therefore be an acceptable method of sample preservation and mass reduction for some studies of microbial ecology and milk glycan analysis.

  5. Computational analysis of fluid dynamics in pharmaceutical freeze-drying.

    Science.gov (United States)

    Alexeenko, Alina A; Ganguly, Arnab; Nail, Steven L

    2009-09-01

    Analysis of water vapor flows encountered in pharmaceutical freeze-drying systems, laboratory-scale and industrial, is presented based on the computational fluid dynamics (CFD) techniques. The flows under continuum gas conditions are analyzed using the solution of the Navier-Stokes equations whereas the rarefied flow solutions are obtained by the direct simulation Monte Carlo (DSMC) method for the Boltzmann equation. Examples of application of CFD techniques to laboratory-scale and industrial scale freeze-drying processes are discussed with an emphasis on the utility of CFD for improvement of design and experimental characterization of pharmaceutical freeze-drying hardware and processes. The current article presents a two-dimensional simulation of a laboratory scale dryer with an emphasis on the importance of drying conditions and hardware design on process control and a three-dimensional simulation of an industrial dryer containing a comparison of the obtained results with analytical viscous flow solutions. It was found that the presence of clean in place (CIP)/sterilize in place (SIP) piping in the duct lead to significant changes in the flow field characteristics. The simulation results for vapor flow rates in an industrial freeze-dryer have been compared to tunable diode laser absorption spectroscopy (TDLAS) and gravimetric measurements.

  6. Technology Advances and Mechanistic Modelling in Freeze-drying and Dehydration of Food

    Directory of Open Access Journals (Sweden)

    Wanren Chen

    2015-08-01

    Full Text Available Aim of study is to introduce some advanced freeze-drying technology and mechanistic modelling in freeze-drying and dehydration of food, freeze-drying is based on the dehydration by sublimation of a frozen product, due to very low temperature, all the deterioration activity and microbiological activity are stopped and provide better quality to the final product. Meanwhile the main problems of the freeze-dried food were proposed and its prospect and outlook was also analyzed, expecting to obtain technical and theoretical support for the production of freeze-drying food.

  7. Physical Stability of Freeze-Dried Isomalt Diastereomer Mixtures

    DEFF Research Database (Denmark)

    Koskinen, Anna-Kaisa; Fraser-Miller, Sara J.; Bøtker, Johan P.

    2016-01-01

    of the diastereomer compositions showed signs of physical instability when stored in the highest relative humidity condition. The four different crystalline diastereomer mixtures showed specific identifiable solid state properties. Conclusions Isomalt was shown to be a suitable excipient for freeze-drying. Preferably...... a mixture of the diastereomers should be used, as the mixture containing only one of the isomers showed physical instability. A mixture containing a 1:1 ratio of the two diastereomers showed the best physical stability in the amorphous form....

  8. Electrochemical properties of carbon aerogels with freeze - drying

    Science.gov (United States)

    Xu, Yuelong; Yan, Meifang; Liua, Zhenfa

    2017-09-01

    Carbon aerogels (CAs) were prepared via a sol–gel process by polymerization of phloroglucinol, resorcinol and formaldehyde using 2,4-dihydroxybenzoic acid as catalyst with freeze-drying. The electrochemical properties were characterized using cyclic voltammetry, galvanostatic charge–discharge measurements and electrochemical impedance spectroscopy (EIS). The specific capacitance of corresponding CAs was up to 131 F g‑1 and 105 F g‑1 at the density of 0.5 A g‑1 and 1.0 A g‑1, respectively.

  9. Calorimetric analysis of cryopreservation and freeze-drying formulations.

    Science.gov (United States)

    Sun, Wendell Q

    2015-01-01

    Differential scanning calorimetry (DSC) is a commonly used thermal analysis technique in cryopreservation and freeze-drying research. It has been used to investigate crystallization, eutectic formation, glass transition, devitrification, recrystallization, melting, polymorphism, molecular relaxation, phase separation, water transport, thermochemistry, and kinetics of complex reactions (e.g., protein denaturation). Such information can be used for the optimization of protective formulations and process protocols. This chapter gives an introduction to beginners who are less familiar with this technique. It covers the instrument and its basic principles, followed by a discussion of the methods as well as examples of specific applications.

  10. Impact of the freeze-drying process on product appearance, residual moisture content, viability, and batch uniformity of freeze-dried bacterial cultures safeguarded at culture collections.

    Science.gov (United States)

    Peiren, Jindrich; Hellemans, Ann; De Vos, Paul

    2016-07-01

    In this study, causes of collapsed bacterial cultures in glass ampoules observed after freeze-drying were investigated as well as the influence of collapse on residual moisture content (RMC) and viability. Also, the effect of heat radiation and post freeze-drying treatments on the RMC was studied. Cake morphologies of 21 bacterial strains obtained after freeze-drying with one standard protocol could be classified visually into four major types: no collapse, porous, partial collapse, and collapse. The more pronounced the collapse, the higher residual moisture content of the freeze-dried product, ranging from 1.53 % for non-collapsed products to 3.62 % for collapsed products. The most important cause of collapse was the mass of the inserted cotton plug in the ampoule. Default cotton plugs with a mass between 21 and 30 mg inside the ampoule did not affect the viability of freeze-dried Aliivibrio fischeri LMG 4414(T) compared to ampoules without cotton plugs. Cotton plugs with a mass higher than 65 mg inside the ampoule induced a full collapsed product with rubbery look (melt-back) and decreasing viability during storage. Heat radiation effects in the freeze-drying chamber and post freeze-drying treatments such as exposure time to air after freeze-drying and manifold drying time prior to heat sealing of ampoules influenced the RMC of freeze-dried products. To produce uniform batches of freeze-dried bacterial strains with intact cake structures and highest viabilities, inserted cotton plugs should not exceed 21 mg per ampoule. Furthermore, heat radiation effects should be calculated in the design of the primary drying phase and manifold drying time before heat sealing should be determined as a function of exposure time to air.

  11. Design of freeze-dried Soluplus/polyvinyl alcohol-based film for the oral delivery of an insoluble drug for the pediatric use.

    Science.gov (United States)

    Shamma, Rehab; Elkasabgy, Nermeen

    2016-01-01

    Spironolactone (SL) is a poorly water-soluble drug. Being poorly soluble affects its dissolution rate which in turn affects its oral bioavailability. This work aimed to prepare freeze-dried SL-Soluplus/polyvinyl alcohol (PVA) oral thin film in an attempt to enhance the drug solubility on one hand and at the same time prepare a solid dosage form convenient for the pediatric use. SL-Soluplus/PVA films were prepared using polyethylene glycol 400 (PEG 400) as a plasticizer applying the solvent-casting technique. The prepared films were evaluated for their thickness, tensile strength, and in vitro dissolution studies. Box-Behnken design (17 runs) was applied to optimize the effects of the formulation variables on the film properties. The optimized film formulation was freeze-dried after casting so as to enhance the drug dissolution. Moreover, the optimized freeze-dried film was re-characterized in vitro and evaluated in vivo in human volunteers to investigate its palatability and satisfaction. The results showed that the optimized formulation composed of 10% polymer concentration containing Soluplus:PVA (0.33:0.66) and plasticized with 30% PEG 400 possessed the highest desirability value (0.836). Freeze-drying of the optimized formulation succeeded to improve SL in vitro dissolution due to the preparation of a more porous film compared to the non-freeze-dried one. In vivo evaluation of the optimized freeze-dried film showed high satisfaction among the participating volunteers concerning the ease of administration and sensation thereafter, where all the film specimens dissolved without the need for water and no film residues remained in the mouth following film dissolution. In conclusion, freeze-dried Soluplus®/PVA-based oral thin film proved to be a successful carrier for the oral delivery of insoluble drugs like SL for pediatrics.

  12. Infrared Thermography for Monitoring of Freeze-Drying Processes: Instrumental Developments and Preliminary Results

    Science.gov (United States)

    Emteborg, Håkan; Zeleny, Reinhard; Charoud-Got, Jean; Martos, Gustavo; Lüddeke, Jörg; Schellin, Holger; Teipel, Katharina

    2014-01-01

    Coupling an infrared (IR) camera to a freeze dryer for on-line monitoring of freeze-drying cycles is described for the first time. Normally, product temperature is measured using a few invasive Pt-100 probes, resulting in poor spatial resolution. To overcome this, an IR camera was placed on a process-scale freeze dryer. Imaging took place every 120 s through a Germanium window comprising 30,000 measurement points obtained contact-free from −40°C to 25°C. Results are presented for an empty system, bulk drying of cheese slurry, and drying of 1 mL human serum in 150 vials. During freezing of the empty system, differences of more than 5°C were measured on the shelf. Adding a tray to the empty system, a difference of more than 8°C was observed. These temperature differences probably cause different ice structures affecting the drying speed during sublimation. A temperature difference of maximum 13°C was observed in bulk mode during sublimation. When drying in vials, differences of more than 10°C were observed. Gradually, the large temperature differences disappeared during secondary drying and products were transformed into uniformly dry cakes. The experimental data show that the IR camera is a highly versatile on-line monitoring tool for different kinds of freeze-drying processes. © 2014 European Union 103:2088–2097, 2014 PMID:24902839

  13. Optimization of freeze drying conditions for purified pectinase from mango (Mangifera indica cv. Chokanan) peel

    National Research Council Canada - National Science Library

    Mehrnoush, Amid; Mustafa, Shuhaimi; Yazid, Abdul Manap Mohd

    2012-01-01

    Response surface methodology (RSM) along with central composite design (CCD) was applied to optimize the freeze drying conditions for purified pectinase from mango (Mangifera indica cv. Chokanan) peel...

  14. Folic acid content in thermostabilized and freeze-dried space shuttle foods

    Science.gov (United States)

    Lane, H. W.; Nillen, J. L.; Kloeris, V. L.

    1995-01-01

    This study was designed to determine whether freeze-dried and thermostabilized foods on a space shuttle contain adequate folate and to investigate any effects of freeze-drying on folacin. Frozen vegetables were analyzed after three states of processing: thawed; cooked; and rehydrated. Thermostabilized items were analyzed as supplied with no further processing. Measurable folate decreased in some freeze-dried vegetables and increased in others. Folacin content of thermostabilized food items was comparable with published values. We concluded that although the folacin content of some freeze-dried foods was low, adequate folate is available from the shuttle menu to meet RDA guidelines.

  15. Electron accelerators for radiosterilization; Akceleratory elektronow dla potrzeb sterylizacji radiacyjnej

    Energy Technology Data Exchange (ETDEWEB)

    Zimek, Z. [Institute of Nuclear Chemistry and Technology, Warsaw (Poland)

    1997-10-01

    The applications of electron accelerators in commercial plants for radiosterilization have been shown. Advantages of such irradiation source have been presented. The types and parameters of accelerators being installed in worldwide irradiation plants for radiosterilization have been listed as well. 2 tabs.

  16. CFD modelling of condensers for freeze-drying processes

    Indian Academy of Sciences (India)

    Miriam Petitti; Antonello A Barresi; Daniele L Marchisio

    2013-12-01

    The aim of the present research is the development of a computational tool for investigating condensation processes and equipment with particular attention to freeze-dryers. These condensers in fact are usually operated at very low pressures, making it difficult to experimentally acquire quantitative knowledge of all the variables involved. Mathematical modelling and CFD (Computational Fluid Dynamics) simulations are used here to achieve a better comprehension of the flow dynamics and of the process of ice condensation and deposition in the condenser, in order to evaluate condenser efficiency and gain deeper insights of the process to be used for the improvement of its design. Both a complete laboratory-scale freeze-drying apparatus and an industrial-scale condenser have been investigated in this work, modelling the process of water vapour deposition. Different operating conditions have been considered and the influence exerted by the inert gas as well as other parameters has been investigated.

  17. The effect of dryer load on freeze drying process design.

    Science.gov (United States)

    Patel, Sajal M; Jameel, Feroz; Pikal, Michael J

    2010-10-01

    Freeze-drying using a partial load is a common occurrence during the early manufacturing stages when insufficient amounts of active pharmaceutical ingredient (API) are available. In such cases, the immediate production needs are met by performing lyophilization with less than a full freeze dryer load. However, it is not obvious at what fractional load significant deviations from full load behavior begin. The objective of this research was to systematically study the effects of variation in product load on freeze drying behavior in laboratory, pilot and clinical scale freeze-dryers. Experiments were conducted with 5% mannitol (high heat and mass flux) and 5% sucrose (low heat and mass flux) at different product loads (100%, 50%, 10%, and 2%). Product temperature was measured in edge as well as center vials with thermocouples. Specific surface area (SSA) was measured by BET gas adsorption analysis and residual moisture was measured by Karl Fischer. In the lab scale freeze-dryer, the molar flux of inert gas was determined by direct flow measurement using a flowmeter and the molar flux of water vapor was determined by manometric temperature measurement (MTM) and tunable diode laser absorption spectroscopy (TDLAS) techniques. Comparative pressure measurement (capacitance manometer vs. Pirani) was used to determine primary drying time. For both 5% mannitol and 5% sucrose, primary drying time decreases and product temperature increases as the load on the shelves decreases. No systematic variation was observed in residual moisture and vapor composition as load decreased. Further, SSA data suggests that there are no significant freezing differences under different load conditions. Independent of dryer scale, among all the effects, variation in radiation heat transfer from the chamber walls to the product seems to be the dominant effect resulting in shorter primary drying time as the load on the shelf decreases (i.e., the fraction of edge vials increases).

  18. A novel collagen film with micro-rough surface structure for corneal epithelial repair fabricated by freeze drying technique

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yang [School of Materials Science and Engineering, South China University of Technology, Guangzhou 510641 (China); National Engineering Research Center for Tissue Restoration and Reconstruction, Guangzhou 510006 (China); Guangdong Province Key Laboratory of Biomedical Engineering, South China University of Technology, Guangzhou 510006 (China); Ren, Li, E-mail: psliren@scut.edu.cn [School of Materials Science and Engineering, South China University of Technology, Guangzhou 510641 (China); National Engineering Research Center for Tissue Restoration and Reconstruction, Guangzhou 510006 (China); Guangdong Province Key Laboratory of Biomedical Engineering, South China University of Technology, Guangzhou 510006 (China); Wang, Yingjun, E-mail: imwangyj@163.com [School of Materials Science and Engineering, South China University of Technology, Guangzhou 510641 (China); National Engineering Research Center for Tissue Restoration and Reconstruction, Guangzhou 510006 (China); Guangdong Province Key Laboratory of Biomedical Engineering, South China University of Technology, Guangzhou 510006 (China)

    2014-05-01

    Highlights: • Collagen film with micro-rough surface is fabricated by freeze drying technique. • The film has suitable water uptake capability and toughness performance. • The film has good optical performance. • Human corneal epithelial cells studies confirmed the biocompatibility of the film. - Abstract: Corneal epithelial defect is a common disease and keratoplasty is a common treatment method. A collagen film with micro-rough surface was fabricated through a simple freeze drying technique in this study. Compared with the air-dried collagen film (AD-Col), this freeze-dried collagen film (FD-Col) has a more suitable water uptake capability (about 85.5%) and toughness performance. Both of the two films have good optical properties and the luminousness of them is higher than 80%. Besides, the adhesion and proliferation rate of human corneal epithelial cells on the micro-rough surface of FD-Col film is higher than that on the smooth surface of AD-Col film. The results indicate that this FD-Col film may have potential applications for corneal epithelial repair.

  19. Application of freeze-drying technology in manufacturing orally disintegrating films.

    Science.gov (United States)

    Liew, Kai Bin; Odeniyi, Michael Ayodele; Peh, Kok-Khiang

    2016-01-01

    Freeze drying technology has not been maximized and reported in manufacturing orally disintegrating films. The aim of this study was to explore the freeze drying technology in the formulation of sildenafil orally disintegrating films and compare the physical properties with heat-dried orally disintegrating film. Central composite design was used to investigate the effects of three factors, namely concentration of carbopol, wheat starch and polyethylene glycol 400 on the tensile strength and disintegration time of the film. Heat-dried films had higher tensile strength than films prepared using freeze-dried method. For folding endurance, freeze-dried films showed improved endurance than heat-dried films. Moreover, films prepared using freeze-dried methods were thicker and had faster disintegration time. Formulations with higher amount of carbopol and starch showed higher tensile strength and thickness whereas formulations with higher PEG 400 content showed better flexibility. Scanning electron microscopy showed that the freeze-dried films had more porous structure compared to the heat-dried film as a result of the release of water molecule from the frozen structure when it was subjected to freeze drying process. The sildenafil film was palatable. The dissolution profiles of freeze-dried and heat-dried films were similar to Viagra® with f2 of 51.04 and 65.98, respectively.

  20. Characteristics of sugar surfactants in stabilizing proteins during freeze-thawing and freeze-drying.

    Science.gov (United States)

    Imamura, Koreyoshi; Murai, Katsuyuki; Korehisa, Tamayo; Shimizu, Noriyuki; Yamahira, Ryo; Matsuura, Tsutashi; Tada, Hiroko; Imanaka, Hiroyuki; Ishida, Naoyuki; Nakanishi, Kazuhiro

    2014-06-01

    Sugar surfactants with different alkyl chain lengths and sugar head groups were compared for their protein-stabilizing effect during freeze-thawing and freeze-drying. Six enzymes, different in terms of tolerance against inactivation because of freeze-thawing and freeze-drying, were used as model proteins. The enzyme activities that remained after freeze-thawing and freeze-drying in the presence of a sugar surfactant were measured for different types and concentrations of sugar surfactants. Sugar surfactants stabilized all of the tested enzymes both during freeze-thawing and freeze-drying, and a one or two order higher amount of added sugar surfactant was required for achieving protein stabilization during freeze-drying than for the cryoprotection. The comprehensive comparison showed that the C10-C12 esters of sucrose or trehalose were the most effective through the freeze-drying process: the remaining enzyme activities after freeze-thawing and freeze-drying increased at the sugar ester concentrations of 1-10 and 10-100 μM, respectively, and increased to a greater extent than for the other surfactants at higher concentrations. Results also indicate that, when a decent amount of sugar was also added, the protein-stabilizing effect of a small amount of sugar ester through the freeze-drying process could be enhanced. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association.

  1. Model of Mass and Heat Transfer during Vacuum Freeze-Drying for Cornea

    Directory of Open Access Journals (Sweden)

    Zou Huifen

    2012-01-01

    Full Text Available Cornea is the important apparatus of organism, which has complex cell structure. Heat and mass transfer and thermal parameters during vacuum freeze-drying of keeping corneal activity are studied. The freeze-drying cornea experiments were operated in the homemade vacuum freeze dryer. Pressure of the freeze-drying box was about 50 Pa and temperature was about −10°C by controlled, and operating like this could guarantee survival ratio of the corneal endothelium over the grafting normal. Theory analyzing of corneal freeze-drying, mathematical model of describing heat and mass transfer during vacuum freeze-drying of cornea was established. The analogy computation for the freeze-drying of cornea was made by using finite-element computational software. When pressure of the freeze-drying box was about 50 Pa and temperature was about −10°C, time of double-side drying was 170 min. In this paper, a moving-grid finite-element method was used. The sublimation interface was tracked continuously. The finite-element mesh is moved continuously such that the interface position always coincides with an element node. Computational precision was guaranteed. The computational results were agreed with the experimental results. It proved that the mathematical model was reasonable. The finite-element software is adapted for calculating the heat and mass transfer of corneal freeze-drying.

  2. Model-based optimization of the primary drying step during freeze-drying

    DEFF Research Database (Denmark)

    Mortier, Séverine Thérèse F.C.; Van Bockstal, Pieter-Jan; Nopens, Ingmar;

    2015-01-01

    Since large molecules are considered the key driver for growth of the pharmaceutical industry, the focus of the pharmaceutical industry is shifting from small molecules to biopharmaceuticals: around 50% of the approved biopharmaceuticals are freeze-dried products. Therefore, freeze- drying is an ...

  3. Encapsulation and subsequent freeze-drying of Lactobacillus reuteri CRL 1324 for its potential inclusion in vaginal probiotic formulations.

    Science.gov (United States)

    Juárez Tomás, María Silvina; De Gregorio, Priscilla Romina; Leccese Terraf, María Cecilia; Nader-Macías, María Elena Fátima

    2015-11-15

    Probiotic formulations must include a high number of viable and active microorganisms. In this work, the survival of human vaginal Lactobacillus reuteri CRL 1324 during encapsulation, lyophilization and storage, and the activity of encapsulated and/or freeze-dried bacterial cells were evaluated. Extrusion-ionic gelation technique was applied to encapsulate L. reuteri CRL 1324, using xanthan and gellan. Encapsulated and free bacterial cells were freeze-dried with or without lactose and skim milk as lyoprotectors. The different systems obtained were stored at room temperature and at 4°C for 150days. The following determinations were performed: L. reuteri CRL 1324 viability, microorganism released from capsules, survival in a medium simulating the vaginal fluid and maintenance of beneficial properties (growth inhibition of opportunistic pathogenic Streptococcus agalactiae NH 17 and biofilm formation). L. reuteri CRL 1324 encapsulation was efficient, allowing the recovery of a high number of entrapped lactobacilli. The survival of encapsulated L. reuteri during lyophilization and storage was significantly higher in the presence of lyoprotectors. At the end of storage, the highest numbers of viable cells were obtained in free or encapsulated cells freeze-dried with lyoprotectors, stored at 4°C. Encapsulated and/or lyophilized L. reuteri cells maintained their viability in simulated vaginal fluid as well as the ability to inhibit S. agalactiae NH 17 growth and to form biofilm. Encapsulated and freeze-dried L. reuteri CRL 1324 can be included in a suitable pharmaceutical form for vaginal application to prevent or treat urogenital infections in women.

  4. Augmenting Lagoon Process Using Reactivated Freeze-dried Biogranules.

    Science.gov (United States)

    Pishgar, Roya; Hamza, Rania Ahmed; Tay, Joo Hwa

    2017-02-24

    This study investigated the feasibility of using freeze-dried biogranules in lagoon basins. The effect of different operational conditions on treatment performance and detention time of granule-based lagoons was examined in a series of laboratory-scale batch studies. Optimal granule dosage was 0.1 g/L under anaerobic condition, resulting in 80-94% removal of 1000 mg/L chemical oxygen demand (COD) in 7-10 days. Under aerobic condition, granule dosage of 0.2 g/L achieved the best result for identical COD concentration. However, adequate amount of nutrients (optimal COD/N/P ratio of 100/13/0.8) should be supplied to encourage the growth of aerobic species. At optimal COD/N/P ratio, aerobic treatment interval significantly reduced to 2-3 days with corresponding COD removal efficiency of 88-92%. Inhibition of high concentrations of COD (5000 mg/L) and ammonia (480 mg/L NH4-N) was observed on microbial activity and treatment capacity of the biogranules. Mixing was a crucial measure to overcome mass transfer limitation. Onetime inoculation of lagoon with fresh granules was the best approach to achieve a satisfactory treatment efficiency. This study suggested that utilization of the biogranules is a feasible and sustainable technique for augmenting lagoon plants in terms of improved effluent quality and reduced retention time. Graphical Abstract ᅟ.

  5. Development of freeze-dried miyeokguk, Korean seaweed soup, as space food sterilized by irradiation

    Science.gov (United States)

    Song, Beom-Seok; Park, Jin-Gyu; Kim, Jae-Hun; Choi, Jong-Il; Ahn, Dong-Hyun; Hao, Chen; Lee, Ju-Woon

    2012-08-01

    The purpose of this study was to evaluate microbial populations, Hunter's color values (L*, a*, b*) and the sensory quality of freeze-dried miyeokguk, Korean seaweed soup, in order to use it as space food. Microorganisms were not detected in non-irradiated freeze-dried miyeokguk within the detection limit of 1.00 log CFU/g. However, the microbial population in rehydrated miyeokguk was 7.01 log CFU/g after incubation at 35 °C for 48 h, indicating that freeze-dried miyeokguk was not sterilized by heat treatment during the preparation process. Bacteria in the freeze-dried miyeokguk were tentatively identified as Bacillus cereus, B. subtilis, Enterobacter hormaechei, and Ancinetobacter genomosp. using the 16S rDNA sequencing. In samples that were gamma-irradiated above 10 kGy, it was confirmed that all microorganisms were inactivated. Hunter's color values of the samples irradiated at doses less than 10 kGy were not significantly altered from their baseline appearance (p>0.05). Sensory evaluation showed that preference scores in all sensory properties decreased when freeze-dried miyeokguk was irradiated at doses greater than 10 kGy. Therefore, the results of this study suggest that gamma irradiation at 10 kGy is sufficient to sterilize freeze-dried miyeokguk without significant deterioration in the sensory quality, and thus, the freeze-dried and irradiated miyeokguk at 10 kGy fulfills the microbiological requirements as space food.

  6. Freeze-drying in novel container system: Characterization of heat and mass transfer in glass syringes.

    Science.gov (United States)

    Patel, Sajal M; Pikal, Michael J

    2010-07-01

    This study is aimed at characterizing and understanding different modes of heat and mass transfer in glass syringes to develop a robust freeze-drying process. Two different holder systems were used to freeze-dry in syringes: an aluminum (Al) block and a plexiglass holder. The syringe heat transfer coefficient was characterized by a sublimation test using pure water. Mannitol and sucrose (5% w/v) were also freeze-dried, as model systems, in both the assemblies. Dry layer resistance was determined from manometric temperature measurement (MTM) and product temperature was measured using thermocouples, and was also determined from MTM. Further, freeze-drying process was also designed using Smart freeze-dryer to assess its application for freeze-drying in novel container systems. Heat and mass transfer in syringes were compared against the traditional container system (i.e., glass tubing vial). In the Al block, the heat transfer was via three modes: contact conduction, gas conduction, and radiation with gas conduction being the dominant mode of heat transfer. In the plexiglass holder, the heat transfer was mostly via radiation; convection was not involved. Also, MTM/Smart freeze-drying did work reasonably well for freeze-drying in syringes. When compared to tubing vials, product temperature decreases and hence drying time increases in syringes. (c) 2010 Wiley-Liss, Inc. and the American Pharmacists Association

  7. Caracterização físico-química de ossos liofilizados de origem bovina e humana Physicochemical characterization of bovine and human freeze-dried bones

    Directory of Open Access Journals (Sweden)

    Carlos Roberto Galia

    2009-04-01

    Full Text Available OBJETIVO: Verificar as similaridades físico-químicas por meio de análises orgânicas e minerais de ossos liofilizados humanos e bovinos produzidos a partir de um protocolo de processamento desenvolvido pelos autores. MÉTODOS: Determinaram-se os percentuais de extrato etéreo (gordura bruta, proteína total (nitrogênio total e composição mineral (fósforo total, P2O5 total, cálcio total, sódio total, cinzas e cloretos das amostras de ossos humanos e bovinos liofilizados. RESULTADOS: O percentual de gordura e de proteína bruta foi de 0.14% e 0.06%, e de 27.20% e 27.53%; enquanto que a composição mineral demonstrou 4.3% e 4.3% de nitrogênio; 11.9% e 11.9% de fósforo total; 27.1% e 27.2% de P2O5; 24.6% e 23.7% de cálcio total (relação Ca/P: 2.06 e 1.99; 0.57% e 0.46% de sódio total; 64.8% e 64.3% de cinzas; e 1.3% e 1.3% de cloretos, para as amostras de osso humano e bovino, respectivamente. Nenhuma diferença estatisticamente significativa foi observada entre ossos bovinos e humanos após o processo de liofilização. CONCLUSÃO: Avaliações de características físicas e químicas de ossos liofilizados bovinos e humanos claramente demonstraram que estes ossos mantêm virtualmente todas as características de osso original e de similaridades com os ossos humanos, levando a um produto final com boa biocompatibilidade.OBJECTIVES: To determine the physical and chemical characteristics and similarities between lyophilized bone from bovine and human sources manufactured in a semi-industrial scale, according to a modified protocol developed by the authors. METHODS: The percentages of fat extract (raw fat, total protein (total nitrogen and mineral composition (total phosphorus, total P2O5, total calcium, total sodium, ashes and chlorides was determined on the samples of lyophilized human and bovine bones. RESULTS: The percentage of fat extract and raw protein was of 0.14% and 0.06%; and 27.20% and 27.53%; whereas the mineral composition

  8. Viability of Two Freeze-dried Strains of Bifidobacterium Preparations at Various Temperatures during Prolonged Storage

    Institute of Scientific and Technical Information of China (English)

    DU Peng; DU Li-hui; HUO Gui-cheng

    2005-01-01

    Viability of bifidobacteria in freeze-dried probiotic products at various temperatures during prolonged storage was assessed. Bifidobacterium longum and Bifidobacterium infantis were freeze-dried. The freeze-dried preparations were stored at -18,4, and 20℃. Cell counts were enumerated using BS agar at 37℃ for 48 h under anaerobic conditions at 0, 45 and 120 days. Storage at 20℃ showed the greatest decline in the viability of bifidobacteria, whereas that at -18℃ showed the least decrease.

  9. Freeze-Drying Makes Improved IPN And Semi-IPN Polymers

    Science.gov (United States)

    Pater, Ruth H.; Smith, Ricky E.; Razon, Ruperto T.; Hansen, Marion G.; Hsiung, Hahn J.; Soucek, Mark D.

    1993-01-01

    Novel process developed for production of interpenetrating polymer networks (IPN's) or semi-IPN's with greater fracture toughness and resistance to microcracks. Process controls degree of phase separation in IPN's. In experiment, IPN's and semi-IPN's formed by dissolving constituents in another common solvent in traditional method. Resins and composite materials produced were tested for both traditional and freeze-drying processes. Glass-transition temperatures and data from dynamic mechanical tests of freeze-dried IPN's and semi-IPN's demonstrated freeze-drying process provided much improved IPN's and semi-IPN's.

  10. Mechanisms of deterioration of nutrients. [freeze drying methods for space flight food

    Science.gov (United States)

    Karel, M.; Flink, J. M.

    1974-01-01

    Methods are reported by which freeze dried foods of improved quality will be produced. The applicability of theories of flavor retention has been demonstrated for a number of food polymers, both proteins and polysacchardies. Studies on the formation of structures during freeze drying have been continued for emulsified systems. Deterioration of organoleptic quality of freeze dried foods due to high temperature heating has been evaluated and improved procedures developed. The influence of water activity and high temperature on retention of model flavor materials and browning deterioration has been evaluated for model systems and food materials.

  11. International regulations concerning radiosterilization; Aktualne przepisy miedzynarodowe dotyczace sterylizacji radiacyjnej

    Energy Technology Data Exchange (ETDEWEB)

    Kaluska, I. [Institute of Nuclear Chemistry and Technology, Warsaw (Poland)

    1997-10-01

    European norms (EN 552) and international regulations (ISO 11137) concerning commercial radiosterilization have been described. Licensing of irradiation installation as well as sterilization procedure requirements, and routine control have been discussed in detail. 3 refs.

  12. Sperm preservation by freeze-drying for the conservation of wild animals.

    Directory of Open Access Journals (Sweden)

    Takehito Kaneko

    Full Text Available Sperm preservation is a useful technique for the maintenance of biological resources in experimental and domestic animals, and in wild animals. A new preservation method has been developed that enables sperm to be stored for a long time in a refrigerator at 4 °C. Sperm are freeze-dried in a solution containing 10 mM Tris and 1 mM EDTA. Using this method, liquid nitrogen is not required for the storage and transportation of sperm. We demonstrate that chimpanzee, giraffe, jaguar, weasel and the long-haired rat sperm remain viable after freeze-drying. In all species, pronuclei were formed after the injection of freeze-dried sperm into the mouse oocytes. Although preliminary, these results may be useful for the future establishment of "freeze-drying zoo" to conserve wild animals.

  13. Effect of freeze-drying on the antioxidant compounds and antioxidant activity of selected tropical fruits.

    Science.gov (United States)

    Shofian, Norshahida Mohamad; Hamid, Azizah Abdul; Osman, Azizah; Saari, Nazamid; Anwar, Farooq; Dek, Mohd Sabri Pak; Hairuddin, Muhammad Redzuan

    2011-01-01

    The effects of freeze-drying on antioxidant compounds and antioxidant activity of five tropical fruits, namely starfruit (Averrhoa carambola L.), mango (Mangifera indica L.), papaya (Carica papaya L.), muskmelon (Cucumis melo L.), and watermelon Citruluss lanatus (Thunb.) were investigated. Significant (p 0.05) change, however, observed in the ascorbic acid content of the fresh and freeze-dried fruits. Similarly, freeze-drying did not exert any considerable effect on β-carotene concentration of fruits, except for mango and watermelon, where significantly (p inhibition measurement, a significant (p < 0.05) but random variation was recorded between the fresh and freeze-dried fruits. Overall, in comparison to β-carotene and ascorbic acid, a good correlation was established between the result of TPC and antioxidant assays, indicating that phenolics might have been the dominant compounds contributing towards the antioxidant activity of the fruits tested.

  14. Freeze-drying of ampicillin solid lipid nanoparticles using mannitol as cryoprotectant

    Directory of Open Access Journals (Sweden)

    Faezeh Alihosseini

    2015-12-01

    Full Text Available abstract Solid lipid nanoparticles (SLNs are interesting colloidal drug-delivery systems, since they have all the advantages of the lipid and polymeric nanoparticles. Freeze-drying is a widely used process for improving the stability of SLNs. Cryoprotectants have been used to decrease SLN aggregations during freeze-drying. In this study Ampicillin was chosen to be loaded in a cholesterol carrier with nano size range. To support the stability of SLNs, freeze-drying was done using mannitol. Particle size, drug release profile and antibacterial effects were studied after freeze-drying in comparison with primary SLNs. Preparations with 5% mannitol showed the least particle size enlargement. The average particle size was 150 and 187 nm before and after freeze-drying, respectively. Freeze-drying did not affect the release profile of drug loaded nanopartilces. Also our study showed that lyophilization did not change the antimicrobial effect of ampicillin SLNs. DSC analysis showed probability of chemical interaction between ampicillin and cholesterol.

  15. Spray freeze drying as an alternative technique for lyophilization of polymeric and lipid-based nanoparticles.

    Science.gov (United States)

    Ali, Mohamed Ehab; Lamprecht, Alf

    2017-01-10

    The use of nanoparticles for drug delivery is still restricted by their limited stability when stored in an aqueous medium. Freeze drying is the standard method for long-term storage of colloidal nanoparticles; however the method needs to be elaborated for each formulation. Spray freeze drying (SFD) is proposed here as a promising alternative for lyophilizing colloidal nanoparticles. Different types of polymeric and lipid nanoparticles were prepared and characterized. Afterwards, samples were spray freeze dried by spraying into a column of cold air with a constant concentration of different cryoprotectants, and the frozen spherules were collected for further freeze drying. Similar samples were prepared using the commonly used technique, freeze drying, as controls. Using SFD, fast-dissolving, spherical and porous nanocomposite microparticles with remarkably high flowability (CI≤10) were produced. On the contrary to similar samples prepared using the freeze drying technique, the investigated polymeric and lipid nanoparticles were completely reconstituted (Sf/Si ratio nanoparticles. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Microbial analysis and survey test of gamma-irradiated freeze-dried fruits for patient's food

    Science.gov (United States)

    Park, Jae-Nam; Sung, Nak-Yun; Byun, Eui-Hong; Byun, Eui-Baek; Song, Beom-Seok; Kim, Jae-Hun; Lee, Kyung-A.; Son, Eun-Joo; Lyu, Eun-Soon

    2015-06-01

    This study examined the microbiological and organoleptic qualities of gamma-irradiated freeze-dried apples, pears, strawberries, pineapples, and grapes, and evaluated the organoleptic acceptability of the sterilized freeze-dried fruits for hospitalized patients. The freeze-dried fruits were gamma-irradiated at 0, 1, 2, 3, 4, 5, 10, 12, and 15 kGy, and their quality was evaluated. Microorganisms were not detected in apples after 1 kGy, in strawberries and pears after 4 kGy, in pineapples after 5 kGy, and in grapes after 12 kGy of gamma irradiation. The overall acceptance score, of the irradiated freeze-dried fruits on a 7-point scale at the sterilization doses was 5.5, 4.2, 4.0, 4.1, and 5.1 points for apples, strawberries, pears, pineapples, and grapes, respectively. The sensory survey of the hospitalized cancer patients (N=102) resulted in scores of 3.8, 3.7, 3.9, 3.9, and 3.7 on a 5-point scale for the gamma-irradiated freeze-dried apples, strawberries, pears, pineapples, and grapes, respectively. The results suggest that freeze-dried fruits can be sterilized with a dose of 5 kGy, except for grapes, which require a dose of 12 kGy, and that the organoleptic quality of the fruits is acceptable to immuno-compromised patients. However, to clarify the microbiological quality and safety of freeze-dried fruits should be verified by plating for both aerobic and anaerobic microorganisms.

  17. Bioactivity of freeze-dried platelet-rich plasma in an adsorbed form on a biodegradable polymer material.

    Science.gov (United States)

    Nakajima, Yu; Kawase, Tomoyuki; Kobayashi, Mito; Okuda, Kazuhiro; Wolff, Larry F; Yoshie, Hiromasa

    2012-01-01

    Owing to the necessity for the immediate preparation from patients' blood, autologous platelet-rich plasma (PRP) limits its clinical applicability. To address this concern and respond to emergency care and other unpredictable uses, we have developed a freeze-dried PRP in an adsorbed form on a biodegradable polymer material (Polyglactin 910). On the polymer filaments of PRP mesh, which was prepared by coating the polymer mesh with human fresh PRP and subsequent freeze-drying, platelets were incorporated, and related growth factors were preserved at high levels. This new PRP mesh preparation significantly and reproducibly stimulated the proliferation of human periodontal ligament cells in vitro and neovascularization in a chorioallantoic membrane assay. A full-thickness skin defect model in a diabetic mouse demonstrated the PRP mesh, although prepared from human blood, substantially facilitated angiogenesis, granulation tissue formation, and re-epithelialization without inducing severe inflammation in vivo. These data demonstrate that our new PRP mesh preparation functions as a bioactive material to facilitate tissue repair/regeneration. Therefore, we suggest that this bioactive material, composed of allogeneic PRP, could be clinically used as a promising alternative in emergency care or at times when autologous PRP is not prepared immediately before application.

  18. Freeze drying of red blood cells: the use of directional freezing and a new radio frequency lyophilization device.

    Science.gov (United States)

    Arav, Amir; Natan, Dity

    2012-08-01

    Red blood cell (RBC) units are administered routinely into patients expressing a wide range of acute and chronic conditions (e.g., anemia, traumatic bleeding, chronic diseases, and surgery). The modern blood banking system has been designed to answer this need and assure a continuous, high quality blood supply to patients. However, RBCs units can be stored under hypothermic conditions for only up to 42 days, which leads to periodic shortages. Cryopreservation can solve these shortages, but current freezing methods employ high glycerol concentrations, which need to be removed and the cells washed prior to transfusion, resulting in a long (more than 1 hour) and cumbersome washing step. Thus, frozen RBCs have limited use in acute and trauma situations. In addition, transportation of frozen samples is complicated and costly. Freeze drying (lyophilization) of RBCs has been suggested as a solution for these problems, since it will allow for a low weight sample to be stored at room temperature, but reaching this goal is not a simple task. We studied the effect of different solutions (IMT2 and IMT3) containing trehalose and antioxidants or trehalose and human serum albumin, respectively, on freezing/thawing and freeze drying of RBCs. In addition, we evaluated the effect of cells concentrations and cooling rates on the post thaw and post rehydration recoveries of the RBCs. Finally, we developed a new radio frequency (RF) lyophilization device for a more rapid and homogeneous sublimation process of the frozen RBCs samples. Recovery and free Hb were measured as well as oxygen association/dissociation and cell's deformability. We found that IMT3 (0.3 M trehalose and 10% HSA) solution that was directionally frozen at a rapid interface velocity of 1 mm/sec (resulting in a cooling rate of 150°C/min) yielded the best results (better than IMT2 solution and slow interface velocity). Freeze thawing gave 100% survival, while freeze drying followed by rehydration with 20% dextran-40k

  19. A case study on stress preconditioning of a Lactobacillus strain prior to freeze-drying.

    Science.gov (United States)

    Bergenholtz, Åsa Schoug; Wessman, Per; Wuttke, Anne; Håkansson, Sebastian

    2012-06-01

    Freeze-drying of bacterial cells with retained viability and activity after storage requires appropriate formulation, i.e. mixing of physiologically adapted cell populations with suitable protective agents, and control of the freeze-drying process. Product manufacturing may alter the clinical effects of probiotics and it is essential to identify and understand possible factor co-dependencies during manufacturing. The physical solid-state behavior of the formulation and the freeze-drying parameters are critical for bacterial survival and thus process optimization is important, independent of strain. However, the maximum yield achievable is also strain-specific and strain survival is governed by e.g. medium, cell type, physiological state, excipients used, and process. The use of preferred compatible solutes for cross-protection of Lactobacilli during industrial manufacturing may be a natural step to introduce robustness, but knowledge is lacking on how compatible solutes, such as betaine, influence formulation properties and cell survival. This study characterized betaine formulations, with and without sucrose, and tested these with the model lactic acid bacteria Lactobacillus coryniformis Si3. Betaine alone did not act as a lyo-protectant and thus betaine import prior to freeze-drying should be avoided. Differences in protective agents were analyzed by calorimetry, which proved to be a suitable tool for evaluating the characteristics of the freeze-dried end products.

  20. Adverse effect of cake collapse on the functional integrity of freeze-dried bull spermatozoa.

    Science.gov (United States)

    Hara, Hiromasa; Tagiri, Miho; Hwang, In-Sul; Takahashi, Masato; Hirabayashi, Masumi; Hochi, Shinichi

    2014-06-01

    Under optimal freeze-drying conditions, solutions exhibit a cake-like porous structure. However, if the solution temperature is higher than the glass transition temperature of the maximally freeze-concentrated phase (Tg') during drying phase, the glassy matrix undergoes viscous flow, resulting in cake collapse. The purpose of the present study was to investigate the effect of cake collapse on the integrity of freeze-dried bull spermatozoa. In a preliminary experiment, factors affecting the Tg' of conventional EGTA buffer (consisting of Tris-HCl, EGTA and NaCl) were investigated in order to establish the main experimental protocol because EGTA buffer Tg' was too low (-45.0°C) to suppress collapse. Modification of the EGTA buffer composition by complete removal of NaCl and addition of trehalose (mEGTA buffer) resulted in an increase of Tg' up to -27.7°C. In the main experiment, blastocyst yields after ooplasmic injection of freeze-dried sperm preserved in collapsed cakes (drying temperature: 0 or -15°C) were significantly lower than those of sperm preserved in non-collapsed cake (drying temperature: -30°C). In conclusion, freeze-dried cake collapse may be undesirable for maintaining sperm functions to support embryonic development, and can be inhibited by controlling both Tg' of freeze-drying buffer and temperature during the drying phase.

  1. Effect of Freeze-Drying on the Antioxidant Compounds and Antioxidant Activity of Selected Tropical Fruits

    Directory of Open Access Journals (Sweden)

    Muhammad Redzuan Hairuddin

    2011-07-01

    Full Text Available The effects of freeze-drying on antioxidant compounds and antioxidant activity of five tropical fruits, namely starfruit (Averrhoa carambola L., mango (Mangifera indica L., papaya (Carica papaya L., muskmelon (Cucumis melo L., and watermelon Citruluss lanatus (Thunb. were investigated. Significant (p < 0.05 differences, for the amounts of total phenolic compounds (TPC, were found between the fresh and freeze-dried fruit samples, except muskmelon. There was no significant (p > 0.05 change, however, observed in the ascorbic acid content of the fresh and freeze-dried fruits. Similarly, freeze-drying did not exert any considerable effect on β-carotene concentration of fruits, except for mango and watermelon, where significantly (p < 0.05 higher levels were detected in the fresh samples. The results of DPPH (2,2-diphenyl-1-picrylhydrazyl radical scavenging and reducing power assays revealed that fresh samples of starfruit and mango had relatively higher antioxidant activity. In case of linoleic acid peroxidation inhibition measurement, a significant (p < 0.05 but random variation was recorded between the fresh and freeze-dried fruits. Overall, in comparison to β-carotene and ascorbic acid, a good correlation was established between the result of TPC and antioxidant assays, indicating that phenolics might have been the dominant compounds contributing towards the antioxidant activity of the fruits tested.

  2. Evaluation of Genotoxicity and 28-day Oral Dose Toxicity on Freeze-dried Powder of Tenebrio molitor Larvae (Yellow Mealworm).

    Science.gov (United States)

    Han, So-Ri; Yun, Eun-Young; Kim, Ji-Young; Hwang, Jae Sam; Jeong, Eun Ju; Moon, Kyoung-Sik

    2014-06-01

    The larval form of Tenebrio molitor (T. molitor) has been eaten in many countries and provides benefits as a new food source of protein for humans. However, no information exists regarding its safety for humans. The objective of the present study was to evaluate the genotoxicity and repeated dose oral toxicity of the freeze-dried powder of T. molitor larvae. The genotoxic potential was evaluated by a standard battery testing: bacterial reverse mutation test, in vitro chromosome aberration test, and in vivo micronucleus test. To assess the repeated dose toxicity, the powder was administered once daily by oral gavage to Sprague-Dawley (SD) rats at dose levels of 0, 300, 1000 and 3000 mg/kg/day for 28 days. The parameters which were applied to the study were mortality, clinical signs, body and organ weights, food consumption, ophthalmology, urinalysis, hematology, serum chemistry, gross findings and histopathologic examination. The freezedried powder of T. molitor larvae was not mutagenic or clastogenic based on results of in vitro and in vivo genotoxicity assays. Furthermore, no treatment-related changes or findings were observed in any parameters in rats after 28 days oral administration. In conclusion, the freeze-dried powder of T. molitor larvae was considered to be non-genotoxic and the NOAEL (No Observed Adverse Effect Level) was determined to be 3000 mg/kg/day in both sexes of SD rats under our experimental conditions.

  3. Long-term toxicity of freeze-dried rabies vaccine for human use (Vero cells) for intramuscular injection in machins%食蟹猴肌肉注射冻干人用狂犬病疫苗(Vero细胞)的长期毒性

    Institute of Scientific and Technical Information of China (English)

    苗丽; 丁丽丽; 李春艳; 赵博; 崔文广; 苑志刚; 刘岩; 杨屹

    2014-01-01

    目的 评价食蟹猴反复肌肉注射冻干人用狂犬病疫苗(Vero细胞)的长期毒性.方法 采用区段随机分组法,将24只食蟹猴分为阴性对照组、辅料对照组、冻干人用狂犬病疫苗低(1剂/次)、高(5剂/次)剂量组(分别为临床人用剂量的1和5倍),每组6只,雌雄各半,各组均于第0、3、7、14、28和42 d经肌肉注射各免疫1次,停药后进行一般临床观察及体重、体温、心电图、眼科、血液学指标、血液生化及电解质指标、尿液指标、免疫指标、骨髓涂片、脏器及组织病理学改变观察,连续观察4周.结果 试验期间各组动物一般状况良好,注射部位肉眼观察无异常;体重、体温、心电图、血细胞计数、凝血功能、血生化、眼科检查、尿常规、外周血T淋巴细胞亚群分布、血清细胞因子IL-2和IFNγ水平、骨髓组织、脏器系数等均未见有毒理学意义的规律性改变;疫苗低、高剂量组动物免疫后血清抗狂犬病病毒特异性抗体水平明显升高,均可产生具有保护作用(大于0.5 IU/ml)的中和抗体;辅料对照组和疫苗低、高剂量组部分动物注射局部可见轻微刺激性改变,4周恢复期结束时,局部刺激性反应消退.结论 冻干人用狂犬病疫苗(Vero细胞)5剂/次(临床拟用剂量的5倍)以下为无毒性反应剂量,临床需重点关注注射部位局部刺激性反应.%Objective To evaluate the long-term toxicity of freeze-dried rabies vaccine (Vero cells) for human use in machins after repeat intramuscular injection.Methods Twenty-four machins were randomly divided into negative control,auxiliary material control,as well as low (1 dose / time) and high (5 doses / time) dose groups,six for each,with equal genders.The low and high doses were 1 and 5 times of those for human use in clinic respectively.The machins in each group were injected i.m.on days 0,3,7,14,28 and 42 respectively,and observed for 4 weeks after the last injection

  4. Modelling and simulation of a moving interface problem: freeze drying of black tea extract

    Science.gov (United States)

    Aydin, Ebubekir Sıddık; Yucel, Ozgun; Sadikoglu, Hasan

    2017-01-01

    The moving interface separates the material that is subjected to the freeze drying process as dried and frozen. Therefore, the accurate modeling the moving interface reduces the process time and energy consumption by improving the heat and mass transfer predictions during the process. To describe the dynamic behavior of the drying stages of the freeze-drying, a case study of brewed black tea extract in storage trays including moving interface was modeled that the heat and mass transfer equations were solved using orthogonal collocation method based on Jacobian polynomial approximation. Transport parameters and physical properties describing the freeze drying of black tea extract were evaluated by fitting the experimental data using Levenberg-Marquardt algorithm. Experimental results showed good agreement with the theoretical predictions.

  5. Heat transfer characteristics of current primary packaging systems for pharmaceutical freeze-drying.

    Science.gov (United States)

    Hibler, Susanne; Gieseler, Henning

    2012-11-01

    In the field of freeze-drying, the primary packaging material plays an essential role. Here, the packaging system not only contains and protects the drug product during storage and shipping, but it is also directly involved in the freeze-drying process itself. The heat transfer characteristics of the actual container system influence product temperature and therefore product homogeneity and quality as well as process performance. Consequently, knowledge of the container heat transfer characteristics is of vital importance for process optimization. It is the objective of this review article to provide a summary of research focused on heat transfer characteristics of different container systems for pharmaceutical freeze-drying. Besides the common tubing and molded glass vials and metal trays, more recent packaging solutions like polymer vials, LYOGUARD® trays, syringes, and blister packs are discussed. Recent developments in vial manufacturing are also taken into account.

  6. Modelling and simulation of a moving interface problem: freeze drying of black tea extract

    Science.gov (United States)

    Aydin, Ebubekir Sıddık; Yucel, Ozgun; Sadikoglu, Hasan

    2017-06-01

    The moving interface separates the material that is subjected to the freeze drying process as dried and frozen. Therefore, the accurate modeling the moving interface reduces the process time and energy consumption by improving the heat and mass transfer predictions during the process. To describe the dynamic behavior of the drying stages of the freeze-drying, a case study of brewed black tea extract in storage trays including moving interface was modeled that the heat and mass transfer equations were solved using orthogonal collocation method based on Jacobian polynomial approximation. Transport parameters and physical properties describing the freeze drying of black tea extract were evaluated by fitting the experimental data using Levenberg-Marquardt algorithm. Experimental results showed good agreement with the theoretical predictions.

  7. Comparison of three-dimensional printing and vacuum freeze-dried techniques for fabricating composite scaffolds

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Kai [Tianjin First Center Hospital, No. 24 Fukang Road, Tianjin, TJ 300192 (China); Li, Ruixin [Institute of Medical Equipment, Academy of Military and Medical Sciences, No. 106, Wandong Street, Hedong District, Tianjin 300000 (China); Jiang, Wenxue, E-mail: jiangortholivea@sina.cn [Tianjin First Center Hospital, No. 24 Fukang Road, Tianjin, TJ 300192 (China); Sun, Yufu [Tianjin First Center Hospital, No. 24 Fukang Road, Tianjin, TJ 300192 (China); Li, Hui [Tianjin Medical University General Hospital, No. 154 Anshan Road, Tianjin, TJ 300052 (China)

    2016-09-02

    In this study, the performances of different preparation methods of the scaffolds were analyzed for chondrocyte tissue engineering. Silk fibroin/collagen (SF/C) was fabricated using a vacuum freeze-dried technique and by 3D printing. The porosity, water absorption expansion rates, mechanical properties, and pore sizes of the resulting materials were evaluated. The proliferation and metabolism of the cells was detected at different time points using an MTT assay. Cell morphologies and distributions were observed by histological analysis and scanning electron microscopy (SEM). The porosity, water absorption expansion rate, and Young’s modulus of the material obtained via 3D printing were significantly higher than those obtained by the freeze-dried method, while the pore size did not differ significantly between the two methods. MTT assay results showed that the metabolism of cells seeded on the 3D printed scaffolds was more viable than the metabolism on the freeze-dried material. H&E staining of the scaffolds revealed that the number of cells in the 3D printed scaffold was higher in comparison to a similar measurement on the freeze-dried material. Consequently, stem cells grew well inside the 3D printed scaffolds, as measured by SEM, while the internal structure of the freeze-dried scaffold was disordered. Compared with the freeze-dried technique, the 3D printed scaffold exhibited better overall performance and was more suitable for cartilage tissue engineering. - Highlights: • Silk fibroin/collagen was fabricated using 3D printing. • Physical characterization and Cell compatibility were compared. • 3D printed scaffold exhibited better overall performance.

  8. Novel Foams Based on Freeze-Dried Renewable Vital Wheat Gluten

    DEFF Research Database (Denmark)

    Blomfeldt, Thomas O.J.; Olsson, Richard T.; Menon, Mohan

    2010-01-01

    A new way of producing rigid or semi-rigid foams from vital wheat gluten using a freeze-drying process is reported. Water/gluten-based mixtures were frozen and freeze-dried. Different foam structures were obtained by varying the mixing process and wheat gluten concentration, or by adding glycerol...... or bacterial cellulose nanofibers. MIP revealed that the foams had mainly an open porosity peaking at 93%. The average pore diameter ranged between 20 and 73 µm; the sample with the highest wheat gluten concentration and no plasticizer had the smallest pores. Immersion tests with limonene revealed...

  9. Effect of different disaccharides on the integrity and fertilising ability of freeze-dried boar spermatozoa: a preliminary study.

    Science.gov (United States)

    Garcia, A; Gil, L; Malo, C; Martinez, F; Kershaw-Young, C; de Blas, I

    2014-01-01

    Freeze-drying spermatozoa is a developing technique that facilitates semen storage and transport. However, freeze-dried sperm exhibits impaired DNA integrity, which is associated with reduced fertilizing ability. Boar spermatozoa were freeze-dried in three different freeze-drying EDTA buffers with trehalose (75mM) and lactose (75mM) (EDTA-TL), (2) with sucrose (75mM) and lactose (75mM) (EDTA-SL) or just lactose (150mM) (EDTA-LL) using two freeze-drying protocols. In experiment 1 a one-step protocol was used and in experiment 2 a two-steps protocol was used. Spermatozoa were stored in1.5 mL cryo-tubes and 1.5 mL glass ampules at both 16 degree C and 25 degree C for 1 month. Successfully freeze-dried spermatozoa were stained with acridine-orange to assess chromatin stability. Freeze-drying was most successful when the 2-step protocol was used (experiment 2). Chromatin stability was greater in samples stored in glass ampules compared to cryo tubes. Chromatin stability was also greater in samples freeze-dried in EDTA-LL compared to EDTA-SL or EDTA-TL buffers. Spermatozoa freeze-dried in EDTA-LL and stored for 14 and 28 days at either 16 degree C or 25 degree C were utilized for ICSI. Two pronuclear formation wasgreatest using spermatozoa stored at 25 degree C (69.23%) and for 28 days (50%). Although 16 degree C spermatozoa samples had better stable chromatin, 25 degree C spermatozoa samples offered better two pronuclear formation results. In conclusion, boar spermatozoa freeze-dried using media containing disaccharides exhibit high chromatin stability and are able to fertilise oocytes following ICSI. Disaccharides may therefore advance the development of freeze-drying techniques for spermatozoa enabling ease of sperm storage and transportation.

  10. Microbiological problems in radiosterilization; Zagadnienia mikrobiologiczne w sterylizacji radiacyjnej

    Energy Technology Data Exchange (ETDEWEB)

    Czerniawski, E. [Lodz Univ. (Poland)

    1997-10-01

    Microbiological problems connected with radiosterilization of medical materials, pharmaceuticals and cosmetics have been discussed in detail. Dose-response relationship for different bacteria has been shown. Recommended sterilization and postirradiation control procedures have been described. 24 refs, 6 figs, 5 tabs.

  11. Effect of buffer systems and disaccharides concentration on Podoviridae coliphage stability during freeze drying and storage.

    Science.gov (United States)

    Dini, C; de Urraza, P J

    2013-06-01

    The aims of this study were to determine the stability of Podoviridae coliphage CA933P during lyophilization and storage in different media, and to establish similarities between the results obtained and those expected through mechanisms described for proteins stabilization during freeze-drying. PBS and SM buffer were assayed as lyophilization media. The effect of inorganic salts concentration as well as the addition of disaccharides on phage stability during freeze-drying and storage was also studied. The addition of low sucrose concentration (0.1 mol l⁻¹) to SM buffer stabilized phage during freezing and drying steps of the lyophilization process, but higher sugar concentrations were detrimental to phage stability during freeze-drying. Sucrose stabilized phage during storage for at least 120 days. The lyoprotective effect of low concentrations of disaccharides during the drying step of the lyophilization of proteins as well as the stabilization of the freeze-dried product in time correlated with the results obtained for phage CA933P.

  12. Size and molecular flexibility of sugars determine the storage stability of freeze-dried proteins

    NARCIS (Netherlands)

    Tonnis, W. F.; Mensink, M. A.; de Jager, A.; Maarschalk, K. van der Voort; Frijlink, H. W.; Hinrichs, W. L. J.

    2015-01-01

    Protein-based biopharmaceuticals are generally produced as aqueous solutions and stored refrigerated to obtain sufficient shelf life. Alternatively, proteins may be freeze-dried in the presence of sugars to allow storage stability at ambient conditions for prolonged periods. However, to act as a sta

  13. Freeze-drying of proteins with glass-forming oligosaccharide-derived sugar alcohols.

    Science.gov (United States)

    Kadoya, Saori; Fujii, Kahori; Izutsu, Ken-ichi; Yonemochi, Etsuo; Terada, Katsuhide; Yomota, Chikako; Kawanishi, Toru

    2010-04-15

    Physical properties and protein-stabilizing effects of sugar alcohols in frozen aqueous solutions and freeze-dried solids were studied. Various frozen sugar alcohol solutions showed a glass transition of the maximally freeze-concentrated phase at temperatures (T(g)'s) that depended largely on the solute molecular weights. Some oligosaccharide-derived sugar alcohols (e.g., maltitol, lactitol, maltotriitol) formed glass-state amorphous cake-structure freeze-dried solids. Microscopic observation of frozen maltitol and lactitol solutions under vacuum (FDM) indicated onset of physical collapse at temperatures (T(c)) several degrees higher than their T(g)'s. Freeze-drying of pentitols (e.g., xylitol) and hexitols (e.g., sorbitol, mannitol) resulted in collapsed or crystallized solids. The glass-forming sugar alcohols prevented activity loss of a model protein (LDH: lactate dehydrogenase) during freeze-drying and subsequent storage at 50 degrees C. They also protected bovine serum albumin (BSA) from lyophilization-induced secondary structure perturbation. The glass-forming sugar alcohols showed lower susceptibility to Maillard reaction with co-lyophilized L-lysine compared to reducing and non-reducing disaccharides during storage at elevated temperature. Application of the oligosaccharide-derived sugar alcohols as alternative stabilizers in lyophilized protein formulations was discussed. Copyright 2010 Elsevier B.V. All rights reserved.

  14. Effect of the aerated structure on selected properties of freeze-dried hydrocolloid gels

    Science.gov (United States)

    Ciurzyńska, Agnieszka; Lenart, Andrzej

    2016-01-01

    The ability to create diverse structures and studies on the effect of the aerated structure on selected properties with the use of freeze-dried gels may provide knowledge about the properties of dried foods. Such gels can be a basis for obtaining innovative food products. For the gel preparation, 3 types of hydrocolloids were used: low-methoxyl pectin, a mixture of xanthan gum and locust-bean gum, and a mixture of xanthan gum and guar gum. Gels were aerated for 3 and 7 min, frozen at a temperature of -45°C 2 h-1, and freeze-dried at a temperature of 30°C. For the samples obtained, structure, porosity, shrinkage, rehydration, and colour were investigated. It was shown that the type of the hydrocolloid and aeration time influence the structure of freeze-dried gels, which determines such properties of samples as porosity, shrinkage, density, rehydration, and colour. The bigger pores of low-methoxyl pectin gels undergo rehydration in the highest degree. The delicate and aerated structure of gels with the mixture of xanthan gum and locust-bean gum was damaged during freeze-drying and shrinkage exhibited the highest value. Small pores of samples with the mixture of xanthan gum and guar gum were responsible for the lower rehydration properties, but the highest porosity value contributed to the highest lightness value.

  15. Production of freeze-dried yeast culture for the brewing of traditional sorghum beer, tchapalo.

    Science.gov (United States)

    N'Guessan, Florent K; Coulibaly, Hermann W; Alloue-Boraud, Mireille W A; Cot, Marlène; Djè, Koffi Marcellin

    2016-01-01

    Freeze-drying is a well-known dehydration method widely used to preserve microorganisms. In order to produce freeze-dried yeast starter culture for the brewing purpose of African sorghum beer, we tested protective agents (sucrose, glucose, glycerol) in combination with support materials (millet, maize, sorghum, and cassava flours) at 1:1 ratio (v/v). The yeast strains Saccharomyces cerevisiae F 12-7 and Candida tropicalis C 0-7 previously isolated from sorghum beer were used in a mixed culture at a ratio of 2:1 (C. tropicalis/S. cerevisiae). After the freeze-drying, the residual water contents were between 0.78 -2.27%, 0.55 -4.09%, and 0.40-2.61%, respectively, with sucrose, glucose and glycerol. The dried yeasts viabilities were between 4.0% and 10.6%. Among the protective agents used, sucrose was found to be the best protectant giving cell viabilities of 8.4-10.6%. Considering the support materials, millet flour was the best support after drying. When the freeze-dried yeast powders were stored at 4°C and room temperature (25-28°C) for up to 3 months, the survival rates were the highest with cassava flour as the support material.

  16. Fuzzy Logic-based expert system for evaluating cake quality of freeze-dried formulations

    DEFF Research Database (Denmark)

    Trnka, Hjalte; Wu, Jian-Xiong; van de Weert, Marco

    2013-01-01

    Freeze-drying of peptide and protein-based pharmaceuticals is an increasingly important field of research. The diverse nature of these compounds, limited understanding of excipient functionality, and difficult-to-analyze quality attributes together with the increasing importance of the biosimilar...

  17. Preserving the supersaturation generation capability of amorphous drug-polysaccharide nanoparticle complex after freeze drying.

    Science.gov (United States)

    Kiew, Tie Yi; Cheow, Wean Sin; Hadinoto, Kunn

    2015-04-30

    While the supersaturation generation capability of amorphous nanopharmaceuticals (NPs) in their aqueous suspension form has been well established, their supersaturation generation is adversely affected after drying. Herein we investigated the effects of freeze drying on the supersaturation generation capability of a new class of amorphous NPs referred to as drug nanoplex prepared and stabilized by electrostatic complexation of drug molecules with polysaccharides (dextran sulfate). Using ciprofloxacin as the model drug, two types of freeze-drying adjuvants were investigated, i.e., (1) highly water-soluble excipient (trehalose, mannitol), whose role was to prevent irreversible NPs aggregations upon drying, and (2) crystallization inhibitor (hydroxypropylmethylcellulose (HPMC)), whose role was to suppress crystallization of the dissolved drug and the remaining solid phase. The results showed that dual-adjuvant formulations (i.e. trehalose-HPMC and mannitol-HPMC) were required to preserve the supersaturation generation capability of the drug nanoplex suspension after drying. Freeze drying with only one adjuvant type, or incorporating HPMC as physical mixtures with the freeze-dried nanoplex, were ineffective in preserving the supersaturation. The dual-adjuvant formulations produced prolonged supersaturation levels over 240min at ≈6-8× of the saturation solubility with comparable area under the curve (AUC) in the concentration versus time plot as that exhibited by the suspension form. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. The impact of freeze-drying on microstructure and rehydration properties of carrot

    NARCIS (Netherlands)

    Voda, A.; Homan, N.; Witek, M.; Duijster, A.; Dalen, van G.; Sman, van der R.G.M.; Nijsse, J.; Vliet, van L.J.; As, van H.; Duynhoven, van J.P.M.

    2012-01-01

    The impact of freeze-drying, blanching and freezing rate pre-treatments on the microstructure and on the rehydration properties of winter carrots were studied by µCT, SEM, MRI and NMR techniques. The freezing rate determines the size of ice crystals being formed that leave pores upon drying. Their a

  19. Aerosol delivery of nanoparticles in uniform mannitol carriers formulated by ultrasonic spray freeze drying.

    Science.gov (United States)

    D'Addio, Suzanne M; Chan, John Gar Yan; Kwok, Philip Chi Lip; Benson, Bryan R; Prud'homme, Robert K; Chan, Hak-Kim

    2013-11-01

    While most examples of nanoparticle therapeutics have involved parenteral or IV administration, pulmonary delivery is an attractive alternative, especially to target and treat local infections and diseases of the lungs. We describe a successful dry powder formulation which is capable of delivering nanoparticles to the lungs with good aerosolization properties, high loadings of nanoparticles, and limited irreversible aggregation. Aerosolizable mannitol carrier particles that encapsulate nanoparticles with dense PEG coatings were prepared by a combination of ultrasonic atomization and spray freeze drying. This process was contrasted to particle formation by conventional spray drying. Spray freeze drying a solution of nanoparticles and mannitol (2 wt% solids) resulted in particles with an average diameter of 21 ± 1.7 μm, regardless of the fraction of nanoparticles loaded (0-50% of total solids). Spray freeze dried (SFD) powders with a 50% nanoparticle loading had a fine particle fraction (FPF) of 60%. After formulation in a mannitol matrix, nanoparticles redispersed in water to nanoparticles evident upon rehydration. This study reveals the unique advantages of processing by ultrasonic spray freeze drying to produce aerosol dry powders with controlled properties for the delivery of therapeutic nanoparticles to the lungs.

  20. Optimization of Freeze Drying Conditions for Purified Pectinase from Mango (Mangifera indica cv. Chokanan Peel

    Directory of Open Access Journals (Sweden)

    Abdul Manap Mohd Yazid

    2012-03-01

    Full Text Available Response surface methodology (RSM along with central composite design (CCD was applied to optimize the freeze drying conditions for purified pectinase from mango (Mangifera indica cv. Chokanan peel. The effect of pectinase content (−2.66, 62.66 mg/mL, Arabic gum (−1.21, 10.21%, w/v, and maltodextrin (0.73, 7.26%, w/v as independent variables on activity, yield, and storage stability of freeze-dried enzyme was evaluated. Storage stability of pectinase was investigated after one week at 4 °C and yield percentage of the enzyme after encapsulation was also determined. The independent variables had the most significant (p < 0.05 effect on pectinase activity and yield of the enzyme. It was observed that the interaction effect of Arabic gum and maltodextrin improved the enzymatic properties of freeze-dried pectinase. The optimal conditions for freeze-dried pectinase from mango peel were obtained using 30 mg/mL of pectinase content, 4.5 (%, w/v of Arabic gum, and 4 (%, w/v of maltodextrin. Under these conditions, the maximum activity (11.12 U/mL, yield (86.4% and storage stability (84.2% of encapsulated pectinase were achieved.

  1. Suitability of a Freeze Dried Product as a Vehicle for Vitamin Fortification of Military Ration Packs: A Preliminary Study

    Science.gov (United States)

    2011-01-01

    loaded into the freeze dryer and dried over an eight hour period. The freeze dried product was removed from the freeze dryer and transferred to...plastic bags (one bag per treatment). While in the bag the pieces of freeze dried product were manually broken and tumbled to mix. The bags were placed

  2. Preparation and Characterization of Solid Dispersions of Artemether by Freeze-Dried Method

    Directory of Open Access Journals (Sweden)

    Muhammad Tayyab Ansari

    2015-01-01

    Full Text Available Solid dispersions of artemether and polyethylene glycol 6000 (PEG6000 were prepared in ratio 12 : 88 (group-1. Self-emulsified solid dispersions of artemether were prepared by using polyethylene glycol 6000, Cremophor-A25, olive oil, Transcutol, and hydroxypropyl methylcellulose (HPMC in ratio 12 : 75 : 5 : 4 : 2 : 2, respectively (group-2. In third group, only Cremophor-A25 was replaced with Poloxamer 188 compared to group-2. The solid dispersions and self-emulsified solid dispersions were prepared by physical and freeze dried methods, respectively. All samples were characterized by X-ray diffraction, attenuated total reflectance Fourier transform infrared spectroscopy, differential scanning calorimeter, scanning electron microscopy, and solubility, dissolution, and stability studies. X-ray diffraction pattern revealed artemether complete crystalline, whereas physical mixture and freeze-dried mixture of all three groups showed reduced peak intensities. In attenuated total reflectance Fourier transform infrared spectroscopy spectra, C–H stretching vibrations of artemether were masked in all prepared samples, while C–H stretching vibrations were representative of polyethylene glycol 6000, Cremophor-A25, and Poloxamer 188. Differential scanning calorimetry showed decreased melting endotherm and increased enthalpy change (ΔH in both physical mixture and freeze-dried mixtures of all groups. Scanning electron microscopy of freeze-dried mixtures of all samples showed glassy appearance, size reduction, and embedment, while their physical mixture showed size reduction and embedment of artemether by excipients. In group-1, solubility was improved up to 15 times, whereas group-2 showed up to 121 times increase but, in group-3, when Poloxamer 188 was used instead of Cremophor-A25, solubility of freeze-dried mixtures was increased up to 135 times. In fasted state simulated gastric fluid at pH 1.6, the dissolution of physical

  3. Freeze-dried bone allografts sterilized with gamma radiation and the clinical use in harelip

    Energy Technology Data Exchange (ETDEWEB)

    Luna Z, D.; Reyes F, M. L. [ININ, Carretera Mexico-Toluca s/n, Ocoyoacac 52750, Estado de Mexico (Mexico); Diaz M, I.; Cruz A, L. C. [Centro Estatal de Trasplantes del Estado de Mexico, Pablo Sidar No. 602, Col. Universidad, Toluca 50130, Estado de Mexico (Mexico); Vazquez R, M. A., E-mail: daniel.luna@inin.gob.m [Centro de Especialidades Odontologicas, Instituto Materno Infantil del Estado de Mexico, Paseo Colon esquina Felipe Angeles s/n, Col. Villa Hogar, Toluca 50170, Estado de Mexico (Mexico)

    2010-10-15

    Bone for transplant is part of the musculoskeletal tissue join with fascia lat, tendon, ligament and cartilage. Bone is formed by cells (osteocytes, osteoblasts and osteoclasts) and extracellular matrix formed mainly by collagen and hydroxyapatite, which gives strength and elasticity to the bone. The bone function in the body is to move, support, organs protection, production of blood cells and store minerals. The musculoskeletal tissue is processed in specialized tissue banks using gamma radiation of cobalt-60 for sterilization at 25 kGy doses at very low temperature or at room temperature, getting tissues with high quality for clinical applications in injured patients. The process of the bone for transplants varies depend on the size and the surgeon likes, nevertheless in general the large ones are preserved at low temperature (-80 C), meanwhile the short ones are freeze-dried preserved. The musculoskeletal diseases represent the most common physical incapacity, which affect million of people around the world. Due to the human body has 206 bones, during a bone injury each bone can be replaced or repaired with several devices, in general the surgeon goes to a specialized tissue banks, to get the bone, due to the high bone quantity on the body and the number of bone injuries and diseases, the bone is the most transplanted around the world only behind the blood. The bone can be processed in several sizes and shapes, one of these is bone powder from allograft, which is used over all for bone filling, this can be take advantage for cleft lip and palate defects, which is a birth defect, this can affect the way the child's face looks, it can also lead to problems with eating, talking and ear infections. The description of the bone powder process is presented and the clinical use of this powder in several pediatric patients for cleft lip and palate defects is described. (Author)

  4. Healthy offspring from freeze-dried mouse spermatozoa held on the International Space Station for 9 months.

    Science.gov (United States)

    Wakayama, Sayaka; Kamada, Yuko; Yamanaka, Kaori; Kohda, Takashi; Suzuki, Hiromi; Shimazu, Toru; Tada, Motoki N; Osada, Ikuko; Nagamatsu, Aiko; Kamimura, Satoshi; Nagatomo, Hiroaki; Mizutani, Eiji; Ishino, Fumitoshi; Yano, Sachiko; Wakayama, Teruhiko

    2017-06-06

    If humans ever start to live permanently in space, assisted reproductive technology using preserved spermatozoa will be important for producing offspring; however, radiation on the International Space Station (ISS) is more than 100 times stronger than that on Earth, and irradiation causes DNA damage in cells and gametes. Here we examined the effect of space radiation on freeze-dried mouse spermatozoa held on the ISS for 9 mo at -95 °C, with launch and recovery at room temperature. DNA damage to the spermatozoa and male pronuclei was slightly increased, but the fertilization and birth rates were similar to those of controls. Next-generation sequencing showed only minor genomic differences between offspring derived from space-preserved spermatozoa and controls, and all offspring grew to adulthood and had normal fertility. Thus, we demonstrate that although space radiation can damage sperm DNA, it does not affect the production of viable offspring after at least 9 mo of storage on the ISS.

  5. The Study on Technique of Making Freeze - dried Specimen of Mongolia Horse%The Study on Technique of Making Freeze-dried Specimen of Mongolia Horse

    Institute of Scientific and Technical Information of China (English)

    杨虹; 芒来

    2008-01-01

    冻干标本是在冷态条件下制作的,其方法为:迅速且完全地冷冻所选材料,待其干燥后进行加工.此方法比较简单且能真实的反应组织的位置、形状及它们的关系.以蒙古马为实验材料介绍了冻干标本工艺,以及如何保存维护冻干标本的方法.%The freeze - dried specimen is a kind of specimen made under cold conditions. The method is as follows: freeze the separated materials quickly and completely, then process the specimen after it has been dried. This kind of method is simple and can truly reflect the location and the shape of organs and also reflect their reciprocity. This study takes Mongolian home as the experimental animal to introduce the process. And then introduces the methods about how to preserve and protect freeze - dried specimen

  6. The effect of variety and maturity on the quality of freeze-dried carrots. The effect of microwave blanching on the nutritional and textural quality of freeze-dried spinach

    Science.gov (United States)

    1979-01-01

    Using carrots, the quality of freeze-dried products was studied to determine the optimum varieties and maturation stages for quality attributes such as appearance, flavor, texture, and nutritive value. The quality of freeze-dried carrots is discussed in terms of Gardner color, alcohol insoluble solids, viscosity, and core/cortex ratio. Also, microwave blanching of freeze-dried spinach was studied to determine vitamin interrelationships, anatomical changes, and oxidative deteriorations in terms of preprocessing microwave treatments. Statistical methods were employed in the gathering of data and interpretation of results in both studies.

  7. A Dynamic Design Space for Primary Drying During Batch Freeze-Drying

    DEFF Research Database (Denmark)

    Mortier, Séverine Thérèse F C; Van Bockstal, Pieter Jan; Nopens, Ingmar;

    2016-01-01

    model is used to determine the optimal values for the adaptable variables, hereby accounting for the uncertainty in all involved model parameters. A dynamic Design Space was constructed with a risk of failure acceptance level of 0.01%, i.e. a 'zero-failure' situation. Even for a risk of failure of 0......Biopharmaceutical products are emerging within the pharmaceutical industry. However, biopharmaceuticals are often unstable in aqueous solution. Freeze-drying (lyophilisation) is the preferred method to achieve a stable product with an increased shelf-life. During batch freeze-drying, there are only...... two adaptable process variables, i.e. the shelf temperature and the pressure in the drying chamber. The value of both should be optimized, preferably in a dynamic way, to minimise the primary drying time while respecting process and equipment constraints and ensuring end product quality. A mechanistic...

  8. Characterization of freeze-dried egg melange long stored after irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Bakalivanov, Stefan; Tsvetkova, Eli; Bakalivanova, Todorka; Tsvetkov, Tsvetan [Institute of Cryobiology and Food Technologies, 53 bd. Cherni vrah, 1407 Sofia (Bulgaria); Kaloyanov, Nikolay [University of Chemical Technology and Metallurgy, 8, bd. Kliment Ohridski, 1756 Sofia (Bulgaria)], E-mail: nikolaykaloyanov@yahoo.com; Grigorova, Stoyanka; Alexieva, Vanja [Institute of Cryobiology and Food Technologies, 53 bd. Cherni vrah, 1407 Sofia (Bulgaria)

    2008-01-15

    During the 4-year period of storage at room temperature of the freeze-dried (control group) and the freeze-dried and gamma-irradiated (2.0 and 3.5 kGy) whole hen's egg melange, no significant changes were found into the sensory and functional characteristics till the 28th month. The change in the number of SH groups was not unidirectional up to the 28th month and then it started to decrease in all investigated samples. During the entire period of investigation the amount of malondialdehyde in all three groups of egg melange was considerably below the allowed limit for foodstuffs. The most significant fractions of the protein spectra showed a general tendency of decrease during the storage.

  9. Spray freeze-dried nanofibrillated cellulose aerogels with thermal superinsulating properties.

    Science.gov (United States)

    Jiménez-Saelices, Clara; Seantier, Bastien; Cathala, Bernard; Grohens, Yves

    2017-02-10

    Nanofibrillated cellulose (NFC) aerogels were prepared by spray freeze-drying (SFD). Their structural, mechanical and thermal insulation properties were compared to those of NFC aerogels prepared by conventional freeze-drying (CFD). The purpose of this investigation is to develop superinsulating bioaerogels by reducing their pore size. Severe reduction of the aerogel pore size and skeleton architecture were observed by SEM, aerogels prepared by SFD method show a fibril skeleton morphology, which defines a mesoporous structure. BET analyses confirm the appearance of a new organization structure with pores of nanometric sizes. As a consequence, the thermal insulation properties were significantly improved for SFD materials compared to CFD aerogel, reaching values of thermal conductivity as low as 0.018W/(mK). Moreover, NFC aerogels have a thermal conductivity below that of air in ambient conditions, making them one of the best cellulose based thermal superinsulating material. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Freeze-dried polymer-coated quantum dots for perspective biomedical application

    Science.gov (United States)

    Goftman, Valentina V.; Gaynbuch, Anna V.; Panfilova, Elizaveta V.; Khlebtsov, Boris N.; Goryacheva, Irina Y.

    2015-03-01

    Freeze-drying as known as lyophilization has been considered as a possible technique to improve the long-term stability of colloidal luminescent quantum dots (QDs) for perspective biomedical application. The paper describes synthesis of biocompatible CdSe-based core/shell QDs and discusses their optical and physical properties before and after freezedrying. Importantly, the dried nanoparticles can be stored for a long time under usual conditions and then can easily be redisperse in water at a desired concentration without such hard manipulations as sonication or heating. In this work two PEG-amine derivatives were applied for QDs pegylation: monoamine Jeffamine M1000 and diamine JeffamineED-2003. The use of different Jeffamines allows us to obtain QDs with different length of PEG chains and different ζ-potential. The influence of polymer composition on optical properties of the nanocrystals and on their stability after freeze-drying was studied.

  11. Distribution of Vapor Pressure in the Vacuum Freeze-Drying Equipment

    Directory of Open Access Journals (Sweden)

    Shiwei Zhang

    2012-01-01

    Full Text Available In the big vacuum freeze-drying equipment, the drying rate of materials is uneven at different positions. This phenomenon can be explained by the uneven distribution of vapor pressure in chamber during the freeze-drying process. In this paper, a mathematical model is developed to describe the vapor flow in the passageways either between material plates and in the channel between plate groups. The distribution of vapor pressure along flow passageway is given. Two characteristic factors of passageways are defined to express the effects of structural and process parameters on vapor pressure distribution. The affecting factors and their actions are quantitatively discussed in detail. Two examples are calculated and analyzed. The analysis method and the conclusions are useful to estimate the difference of material drying rate at different parts in equipment and to direct the choice of structural and process parameters.

  12. Density dependent mechanical properties and structures of a freeze dried biopharmaceutical excipient--sucrose.

    Science.gov (United States)

    Devi, Sharmila; Williams, Daryl R

    2014-10-01

    Knowledge of the mechanical behaviour of freeze dried biopharmaceutical products is essential for designing of products with physical robustness that will not to crack, crumble or collapse during processing or transportation. The compressive mechanical deformation behaviour for freeze-dried sucrose cakes has been experimentally studied from a relative density (ρf/ρs) of 0.01-0.30 using a novel in-vial indentation test. Cakes exhibited more open like structures at lower densities and more closed structures at higher densities with some faces being present at all densities, as confirmed by SEM. The reduced elastic modulus Ef/Es=0.0044(ρf/ρs)(1) for all cake densities, indicating that face stretching was the dominant deformation mode assuming Gibson and Ashby's closed cell model. This linear scaling for the reduced elastic modulus is in line with various theoretical treatments based on tetrakaidecahedral cells and other experimental studies. Consistently, the wall thickness to cell diameter ratio scaled ρf/ρs with a power constant of 1.05. The maximum crushing stress was given by σmax=3800(ρf/ρs)(1.48) which agrees with a strut bending failure stress, assuming Gibson and Ashby's open cell model. Overall, the freeze dried cakes behaved as neither classic closed cell nor open cell materials, with their compressive elastic moduli reflecting a closed cell elastic response whilst their failure stresses reflecting an open cell failure mode. It was concluded that the mechanical response of freeze dried cellular materials depends upon their complex cellular structures and morphologies, and they cannot be rationalised using simple limiting case models of open or closed cell solids.

  13. Technological Development of Brewing in Domestic Refrigerator Using Freeze-Dried Raw Materials

    Directory of Open Access Journals (Sweden)

    Angelika-Ioanna Gialleli

    2017-01-01

    Full Text Available Development of a novel directly marketable beer brewed at low temperature in a domestic refrigerator combined with yeast immobilization technology is presented in this study. Separately, freeze-dried wort and immobilized cells of the cryotolerant yeast strain Saccharomyces cerevisiae AXAZ-1 on tubular cellulose were used in low-temperature fermentation (2, 5 and 7 °C. The positive eff ect of tubular cellulose during low-temperature brewing was examined, revealing that freeze-dried immobilized yeast cells on tubular cellulose signifi cantly reduced the fermentation rates in contrast to freeze-dried free cells, although they are recommended for home-made beer production. Immobilization also enhanced the yeast resistance at low-temperature fermentation, reducing the minimum brewing temperature value from 5 to 2 °C. In the case of high-quality beer production, the eff ect of temperature and initial sugar concentration on the fermentation kinetics were assessed. Sensory enrichment of the produced beer was confi rmed by the analysis of the fi nal products, revealing a low diacetyl concentration, together with improved polyphenol content, aroma profi le and clarity. The proposed process for beer production in a domestic refrigerator can easily be commercialized and applied by dissolving the content of two separate packages in tap water; one package containing dried wort and the other dried immobilized cells on tubular cellulose suspended in tap water.

  14. Freeze Drying Improves the Shelf-Life of Conductive Polymer Modified Neural Electrodes

    Directory of Open Access Journals (Sweden)

    Himadri S. Mandal

    2015-08-01

    Full Text Available Coating microelectrodes with conductive polymer is widely recognized to decrease impedance and improve performance of implantable neural devices during recording and stimulation. A concern for wide-spread use of this approach is shelf-life, i.e., the electrochemical stability of the coated microelectrodes prior to use. In this work, we investigated the possibility of using the freeze-drying process in order to retain the native low impedance state and, thereby, improve the shelf-life of conductive polymer poly(3,4-ethylenedioxythiophene (PEDOT-PSS modified neural electrodes. Control PEDOT-PSS coated microelectrodes demonstrated a significant increase in impedance at 1 kHz after 41–50 days of room temperature storage. Based on equivalent circuit modeling derived from electrochemical impedance spectroscopy, this increase in impedance could be largely attributed to a decrease in the interfacial capacitance consistent with a collapse and closing of the porous structure of the polymeric coating. Time-dependent electrochemical impedance measurements revealed higher stability of the freeze-dried coated microelectrodes compared to the controls, such that impedance values after 41–50 days appeared to be indistinguishable from the initial levels. This suggests that freeze drying PEDOT-PSS coated microelectrodes correlates with enhanced electrochemical stability during shelf storage.

  15. Application of plackett-burman design in screening freeze drying cryoprotectants for Lactobacillus bulgaricus

    Directory of Open Access Journals (Sweden)

    Guowei SHU

    2015-08-01

    Full Text Available Lactobacillus bulgaricus is the bacteria commonly used in probiotic dairy product, including yogurt and cheese. The bacteria may be stored for long periods of time if it is freeze-dried. The cryoprotectant mixture for L. bulgaricus was optimized during the process of freeze-drying using a Plackett-Burman design and the steepest ascent test. In our initial tests, the cell survival rate and the number of viable cells were associated with the type of cyroprotectant used. Therefore, our optimization protocol focused on increasing survival rate. Substances that previously had a protective effect during freeze-drying were investigated, for example: sucrose, lactose, skim milk powder, sodium bicarbonate, sodium glutamate, magnesium sulfate, sodium ascorbate, yeast extract, vitamin B2, and phosphate buffer. We determined that the optimum cryoprotectant composition for L. bulgaricus consists of 28.0 g/100 mL skim milk powder, 24.0 g/100 mL lactose and 4.8 g/100 mL sodium ascorbate. The optimized cryoprotectant provides a 63.25% cell survival rate.

  16. Fuzzy Logic-based expert system for evaluating cake quality of freeze-dried formulations.

    Science.gov (United States)

    Trnka, Hjalte; Wu, Jian X; Van De Weert, Marco; Grohganz, Holger; Rantanen, Jukka

    2013-12-01

    Freeze-drying of peptide and protein-based pharmaceuticals is an increasingly important field of research. The diverse nature of these compounds, limited understanding of excipient functionality, and difficult-to-analyze quality attributes together with the increasing importance of the biosimilarity concept complicate the development phase of safe and cost-effective drug products. To streamline the development phase and to make high-throughput formulation screening possible, efficient solutions for analyzing critical quality attributes such as cake quality with minimal material consumption are needed. The aim of this study was to develop a fuzzy logic system based on image analysis (IA) for analyzing cake quality. Freeze-dried samples with different visual quality attributes were prepared in well plates. Imaging solutions together with image analytical routines were developed for extracting critical visual features such as the degree of cake collapse, glassiness, and color uniformity. On the basis of the IA outputs, a fuzzy logic system for analysis of these freeze-dried cakes was constructed. After this development phase, the system was tested with a new screening well plate. The developed fuzzy logic-based system was found to give comparable quality scores with visual evaluation, making high-throughput classification of cake quality possible. © 2013 Wiley Periodicals, Inc. and the American Pharmacists Association.

  17. Effect of Glycerol, as Cryoprotectant in the Encapsulation and Freeze Drying of Microspheres Containing Probiotic Cells

    Directory of Open Access Journals (Sweden)

    Oana Lelia Pop

    2015-05-01

    Full Text Available It is reported that probiotics provide several health benefits as they help in maintaining a good balance and composition of intestinal flora, and increase the resistance against invasion of pathogens. Ensuring adequate dosages of probiotics at the time of consumption is a challenge, because several factors during processing and storage affect the viability of probiotic organisms. Major emphasis has been given to protect the microorganisms with the help of encapsulation technique, by addition of different protectants. In this study, probiotic cells (Bifidobacterium lactis 300B were entrapped in alginate/pullulan microspheres. In the encapsulation formula glycerol was used as cryoprotectant in the freeze drying process for long time storage. It was observed that the survival of Bifidobacterium lactis 300B when encapsulated without cryoprotectant was higher than the formula with glycerol in the fresh obtained microspheres. The addition of glycerol was in order to reduce the deep freezing and freeze drying damages. In the chosen formulations, glycerol did not proved protection for the entrapped probiotic cells in the freeze drying process, for which the use of glycerol as cryoprotectant for alginate/pullulan Bifidobacterium lactis 300B entrapment is not recommended.

  18. Determination of the drying and rehydration kinetics of freeze dried kiwi ( Actinidia deliciosa) slices

    Science.gov (United States)

    Ergün, Kadriye; Çalışkan, Gülşah; Dirim, Safiye Nur

    2016-12-01

    The aim of this study was to determine the drying and rehydration kinetics of freeze dried kiwi slices. Well-known thin layer drying models (Lewis, Page, Modified Page I, Henderson and Pabis, Modified Henderson and Pabis, Logarithmic, Midilli, Modified Midilli, Two-term, Two-term Exponential, Modified Two-term Exponential, and Wang and Singh) were fitted to the experimental data. A nonlinear regression analysis was used to evaluate the parameters of the selected models using statistical software SPSS 16.0. For the freeze drying process of the kiwi slices, the highest R2 value (0.997), and the lowest RMSE (0.018) as well as the χ2 (0.0004) values were obtained from the Two-term Exponential model. The effective moisture diffusivity (Deff) of the freeze dried kiwi slices was calculated with the Fick's diffusion model as 7.302 × 10-10 m2/s. The rehydration behavior was determined using distilled water at different solid-liquid ratios at room temperature (18 ± 1 °C) using Peleg's model. The kinetics of the total soluble solid loss was also determined.

  19. Crystallization and X-ray diffraction of spray-dried and freeze-dried amorphous lactose.

    Science.gov (United States)

    Haque, Md Kamrul; Roos, Yrjö H

    2005-02-07

    Crystallization of spray-dried and freeze-dried amorphous lactose over different relative vapor pressures (RVP) and storage times was studied. Crystallization was observed from increasing peak intensities in X-ray diffraction patterns. Lactose was crystallized in the samples stored at RVP of 44.1% and above in both types of dehydrated powders. The rate of crystallization increased with increasing RVP and storage time. Similar crystallization behavior of both spray-dried and freeze-dried lactose was observed. Lactose crystallized as alpha-lactose monohydrate, anhydrous beta-lactose, and the anhydrous form of alpha- and beta-lactose in a molar ratio of 5:3 and 4:1 in both spray-dried and freeze-dried forms. Peak intensities of X-ray diffraction patterns for anhydrous beta-lactose were decreased, and for alpha-lactose monohydrate increased with increasing storage RVP and time. The crystallization data were successfully modeled using Avrami equation at RVP of 54.5% and above. The crystallization data obtained is helpful in understanding and predicting storage stability of lactose-containing food and pharmaceutical products.

  20. Viability of Bifidobacterium Pseudocatenulatum G4 after Spray-Drying and Freeze-Drying

    Directory of Open Access Journals (Sweden)

    Stephenie Wong

    2010-04-01

    Full Text Available Viability of Bifidobacterium pseudocatenulatum G4 following spray-drying and freeze-drying in skim milk was evaluated. After spray-drying, the strain experienced over 99% loss in viability regardless of the air outlet temperature (75 and 85 °C and the heat-adaptation temperature (45 and 65 °C, 30 min. The use of heat-adaptation treatment to improve the thermotolerance of this strain was ineffective. On the other hand, the strain showed a superior survival at 71.65%–82.07% after freeze-drying. Viable populations of 9.319–9.487 log10 cfu/g were obtained when different combinations of skim milk and sugar were used as cryoprotectant. However, the addition of sugars did not result in increased survival during the freeze-drying process. Hence, 10% (w/v skim milk alone is recommended as a suitable protectant and drying medium for this strain. The residual moisture content obtained was 4.41% ± 0.44%.

  1. Drying of α-amylase by spray drying and freeze-drying - a comparative study

    Directory of Open Access Journals (Sweden)

    S. S. de Jesus

    2014-09-01

    Full Text Available This study is aimed at comparing two traditional methods of drying of enzymes and at verifying the efficiency of each one and their advantages and disadvantages. The experiments were performed with a laboratory spray dryer and freeze-dryer using α-amylase as the model enzyme. An experimental design in star revealed that spray drying is mainly influenced by the inlet air temperature and feed flow rate, which were considered to be the main factors influencing the enzymatic activity and water activity; the long period of material exposure to high temperatures causes a partial activity loss. In the experiments of freeze drying, three methods of freezing were used (freezer, acetone and dry ice, and liquid nitrogen and samples subsequently freeze-dried for times ranging between 0-24 hours. The product obtained from the two techniques showed high enzymatic activity and low water activity. For the drying of heat-resistant enzymes, in which the product to be obtained does not have high added value, spray drying may be more economically viable because, in the freeze drying process, the process time can be considered as a limiting factor when choosing a technique.

  2. Freeze-drying of drug-free and drug-loaded solid lipid nanoparticles (SLN).

    Science.gov (United States)

    Schwarz; Mehnert

    1997-11-28

    Solid lipid nanoparticles (SLN) of a quality acceptable for i.v. administration were freeze-dried. Dynasan 112 and Compritol ATO 888 were used as lipid matrices for the SLN, stabilisers were Lipoid S 75 and poloxamer 188, respectively. To study the protective effect of various types and concentrations of cryoprotectants (e.g. carbohydrates), freeze-thaw cycles were carried out as a pre-test. The sugar trehalose proved to be most effective in preventing particle growth during freezing and thawing and also in the freeze-drying process. Changes in particle size distribution during lyophilisation could be minimised by optimising the parameters of the lyophilisation process, i.e. freezing velocity and redispersion method. Lyophilised drug-free SLN could be reconstituted in a quality considered suitable for i.v. injection with regard to the size distribution. Loading with model drugs (tetracaine, etomidate) impairs the quality of reconstituted SLN. However, the lyophilisate quality is sufficient for formulations less critical to limited particle growth, e.g. freeze-dried SLN for oral administration.

  3. Determination of the drying and rehydration kinetics of freeze dried kiwi (Actinidia deliciosa) slices

    Science.gov (United States)

    Ergün, Kadriye; Çalışkan, Gülşah; Dirim, Safiye Nur

    2016-02-01

    The aim of this study was to determine the drying and rehydration kinetics of freeze dried kiwi slices. Well-known thin layer drying models (Lewis, Page, Modified Page I, Henderson and Pabis, Modified Henderson and Pabis, Logarithmic, Midilli, Modified Midilli, Two-term, Two-term Exponential, Modified Two-term Exponential, and Wang and Singh) were fitted to the experimental data. A nonlinear regression analysis was used to evaluate the parameters of the selected models using statistical software SPSS 16.0. For the freeze drying process of the kiwi slices, the highest R2 value (0.997), and the lowest RMSE (0.018) as well as the χ2 (0.0004) values were obtained from the Two-term Exponential model. The effective moisture diffusivity (Deff) of the freeze dried kiwi slices was calculated with the Fick's diffusion model as 7.302 × 10-10 m2/s. The rehydration behavior was determined using distilled water at different solid-liquid ratios at room temperature (18 ± 1 °C) using Peleg's model. The kinetics of the total soluble solid loss was also determined.

  4. New freeze-drying method for LiFePO 4 synthesis

    Science.gov (United States)

    Palomares, Verónica; Goñi, Aintzane; Muro, Izaskun Gil de; de Meatza, Iratxe; Bengoechea, Miguel; Miguel, Oscar; Rojo, Teófilo

    The freeze-drying method is proposed as an effective synthesis process for the obtaining of LiFePO 4/C composites. The citric acid is used as a complexing agent and carbon source. After the low temperature annealing, the freeze-dried solution leads to a homogeneous carbon covered LiFePO 4 sample. The chemical characterization of the material included ICP and elemental analysis, infrared spectroscopy, X-ray diffraction, magnetic measurements and thermal analysis. SEM and TEM microscopies indicate an aggregate morphology with tiny particles of lithium iron phosphate inside a carbon matrix. Impedance spectroscopy showed a 8.0 × 10 -7 S cm -1 conductivity value. Cyclic voltammetry graphics displayed the two peaks corresponding to the Fe(II)/Fe(III) reaction and demonstrated the good reversibility of the material. The specific capacity value obtained at C/40 rate was 164 mAh g -1, with a slight decrease on greater C-rates reaching 146 mAh g -1 at C/1. The capacity retention study has evidenced good properties, with retention over 97% of the maximum values in the first 50 cycles, which allows an effective performance of the freeze-dried sample as cathodic material in lithium-ion batteries.

  5. FREEZE DRYING OF KIWI (ACTINIDIA DELICIOSA PUREE AND THE POWDER PROPERTIES

    Directory of Open Access Journals (Sweden)

    Gulsah Calıskan

    2015-09-01

    Full Text Available In this study, it was intended to investigate the production of freeze dried kiwi (Actinidia deliciosa puree in the form of powder that can be used as a natural alternative to synthetic additives used in food products such as pudding, instant tea, and sauces for improving their flavour. In order to obtain the powder product, kiwi puree as plain and with maltodextrin (Dextrose Equivalence of 10-12, as 10 % by weight addition were freeze dried. Drying behaviour of plain kiwi puree and kiwi puree with MD were explained by Logarithmic model (R2=0.994, RMSE=0.024, χ2=0.0008 and Wang and Singh model (R2=0.999, RMSE=0.012, χ2=0.0002, respectively. The effective moisture diffusivity (Deff value was calculated as 7.3x10−10 m2/s and it was observed that it was not affected by the addition of MD. The vitamin C content of fresh kiwi fruit was evaluated as 66.3 mg/100 g kiwi and there was a loss of 17.1% for plain and 19.8% for MD containing powders respectively after freeze drying. It was also observed that, the addition of maltodextrin decreased cohesiveness, on the other hand, increased bulk and tapped densities, average time values for wettability and solubility, and glass transition temperature of the powder products.

  6. Physical characterization of pentamidine isethionate during freeze-drying-relevance to development of stable lyophilized product.

    Science.gov (United States)

    Sundaramurthi, Prakash; Burcusa, Michael R; Suryanarayanan, Raj

    2012-05-01

    The purpose of this study was to perform physical characterization of pentamidine isethionate (PI) in frozen and freeze-dried systems and to monitor the phase behavior during all the stages of freeze-drying. Frozen aqueous PI solutions as well as the final lyophiles were characterized by differential scanning calorimetry and X-ray diffractometry. The effect of cosolutes, cosolvents, and processing conditions on the PI crystallization behavior during freeze-drying was evaluated. In frozen aqueous solutions, irrespective of the cooling rate and the initial solute concentration, PI readily crystallized as a trihydrate (C(19) H(24) N(4) O(2) ·3H(2) O). It dehydrated to a poorly crystalline anhydrate upon drying at 100 mTorr. The presence of a readily crystallizing cosolute or an organic cosolvent did not influence the physical form of PI in the final lyophile. On the contrary, even in the absence of cosolutes and cosolvents, the crystalline trihydrate was retained when the chamber pressure was increased to 500 mTorr. By altering the drying conditions, it was possible to obtain either a crystalline trihydrate or a poorly crystalline anhydrate. The stability of PI is dependent on its physical form and only the amorphous PI undergoes discoloration. The PI stability can be enhanced by retaining it in a crystalline state in the lyophile.

  7. Size control in production and freeze-drying of poly-ε-caprolactone nanoparticles.

    Science.gov (United States)

    Zelenková, Tereza; Fissore, Davide; Marchisio, Daniele L; Barresi, Antonello A

    2014-06-01

    This work is focused on the control of poly-ε-caprolactone nanoparticle characteristics, notably size and size distribution, in both the production and preservation (by using freeze-drying) stages. Nanoparticles were obtained by employing the solvent displacement method in a confined impinging jets mixer. The effect of several operating conditions, namely, initial polymer concentration and solvent-to-antisolvent flow rate ratio, and the influence of postprocessing conditions, such as final dilution and solvent evaporation, on nanoparticle characteristics was investigated. Further addition of antisolvent (water) after preparation was demonstrated to be effective in obtaining stable nanoparticles, that is, avoiding aggregation that would result in larger particles. On the contrary, solvent (acetone) evaporation was shown to have a small effect on the final nanoparticle characteristics. Eventually, freeze-drying of the solutions containing nanoparticles, after solvent evaporation, was also investigated. To ensure maximum nanoparticles stability, lyoprotectants (e.g., sucrose and mannitol) and steric stabilizers (e.g., Cremophor EL and Poloxamer 388) had to be added to the suspensions. The efficacy of the selected lyoprotectants, in the presence (or absence) of steric stabilizers, and in various concentrations, to avoid particle aggregation during the freeze-drying process was investigated, thus pointing to the optimal formulation.

  8. Determination of free amino acids and 18 elements in freeze-dried strawberry and blueberry fruit using an Amino Acid Analyzer and ICP-MS with micro-wave digestion.

    Science.gov (United States)

    Zhang, Hua; Wang, Zhen-Yu; Yang, Xin; Zhao, Hai-Tian; Zhang, Ying-Chun; Dong, Ai-Jun; Jing, Jing; Wang, Jing

    2014-03-15

    The objective of this study was to investigate the level of 18 trace elements of two freeze-dried samples from the Blueberry (Vaccinium corymbosum) and the Strawberry (Fragaria × Ananassa). The total free amino acid composition in the blueberry and strawberry was determined by an Amino Acid Analyzer. Eleven free amino acids were found in both berries. The trace elements in each dried fruit sample were determined by ICP-MS with microwave digestion. The linearity range of the standard curves was 0-1250.0 μg L(-1) (Mg, P, K, Ca),while in all cases, except for B, Na, Al, Cr, Mn, Fe, Ni, Cu, Zn, Se, Cd, Pb, Ge and As, which was 125.0 μg mL(-1), all related coefficients were above 0.9999; recovery was in the range of 79.0-106.8%. Minor concentrations of nutritional elements were found in each freeze-dried berry. In sum, the toxic trace element analysis found the content of toxic trace elements in each freeze-dried berry sample was safe for human consumption and that the overall quality of the blueberry surpassed that of the strawberry. The results certify that the two freeze-dried berries have potential for human consumption in value-added products and have a certain theoretical and practical significance.

  9. The influence of freezing rates on bovine pericardium tissue Freeze-drying

    Directory of Open Access Journals (Sweden)

    Camila Figueiredo Borgognoni

    2009-12-01

    Full Text Available The bovine pericardium has been used as biomaterial in developing bioprostheses. Freeze-drying is a drying process that could be used for heart valve's preservation. The maintenance of the characteristics of the biomaterial is important for a good heart valve performance. This paper describes the initial step in the development of a bovine pericardium tissue freeze-drying to be used in heart valves. Freeze-drying involves three steps: freezing, primary drying and secondary drying. The freezing step influences the ice crystal size and, consequently, the primary and secondary drying stages. The aim of this work was to investigate the influence of freezing rates on the bovine pericardium tissue freeze-drying parameters. The glass transition temperature and the structural behaviour of the lyophilized tissues were determined as also primary and secondary drying time. The slow freezing with thermal treatment presented better results than the other freeze-drying protocols.O pericárdio bovino é um material utilizado na fabricação de biopróteses. A liofilização é um método de secagem que vem sendo estudado para a conservação de válvulas cardíacas. A preservação das características do biomaterial é de fundamental importância no bom funcionamento das válvulas. Este artigo é a primeira etapa do desenvolvimento do ciclo de liofilização do pericárdio bovino. Liofilização é o processo de secagem no qual a água é removida do material congelado por sublimação e desorção da água incongelável, sob pressão reduzida. O congelamento influencia o tamanho do cristal de gelo e, consequentemente, a secagem primária e secundária. O objetivo deste estudo foi verificar a influência das taxas de congelamento nos parâmetros de liofilização do pericárdio bovino. Determinou-se a temperatura de transição vítrea e o comportamento estrutural do pericárdio bovino liofilizado. Determinou-se o tempo da secagem primária e secundária. O

  10. Changes in non-volatile taste components of button mushroom (Agaricus bisporus) during different stages of freeze drying and freeze drying combined with microwave vacuum drying.

    Science.gov (United States)

    Pei, Fei; Shi, Ying; Gao, Xingyang; Wu, Fangning; Mariga, Alfred Mugambi; Yang, Wenjian; Zhao, Liyan; An, Xinxin; Xin, Zhihong; Yang, Fangmei; Hu, Qiuhui

    2014-12-15

    Button mushroom slices were dehydrated using freeze drying (FD) or FD combined with microwave vacuum drying (FMVD), and the non-volatile component profiles were studied. The results showed that the level of non-volatile components in button mushroom firstly increased during sublimation of FD/FMVD process and then fell during desorption in FD process and MVD in FMVD process. Compared to FD products, the contents of soluble sugars and polyols in FMVD products were relatively low, whereas the contents of total free amino acids were significantly higher, close to the level of fresh mushroom. However, there was no significant difference in the contents of 5'-nucleotides and organic acids between FD and FMVD products. The equivalent umami concentration (EUC) values for FD and FMVD products did not differ from fresh, indicating that both drying methods could effectively preserve MSG (monosodium glutamate)-like components in button mushroom. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. NaCl stress impact on the key enzymes in glycolysis from Lactobacillus bulgaricus during freeze-drying.

    Science.gov (United States)

    Li, Chun; Sun, Jinwei; Qi, Xiaoxi; Liu, Libo

    2015-01-01

    The viability of Lactobacillus bulgaricus in freeze-drying is of significant commercial interest to dairy industries. In the study, L.bulgaricus demonstrated a significantly improved (p enzymes in glycolysis during 2% NaCl stress were studied. NaCl stress significantly enhanced (p enzymes (phosphofructokinase, pyruvate kinase, and lactate dehydrogenase) decreased during freeze-drying, and NaCl stress were found to improve activities of these enzymes before and after freeze-drying. However, a transcriptional analysis of the corresponding genes suggested that the effect of NaCl stress on the expression of the pfk2 gene was not obvious. The increased survival of freeze-dried cells of L. bulgaricus under NaCl stress might be due to changes in only the activity or translation level of these enzymes in different environmental conditions but have no relation to their mRNA transcription level.

  12. Tertiary combination of freeze-dried urine of Indian breeds of cow with plant products against snail Lymnaea acuminata

    National Research Council Canada - National Science Library

    Kumar, Shiv; Singh, D K; Singh, Vinay Kumar

    2012-01-01

    .... In the present study molluscicidal activity of tertiary combination of freeze-dried urine of different Indian breeds of cow Sahiwal, Geer and Tharparkar with Annona squamosa seed powder, Ferula...

  13. Near-Infrared Imaging for High-Throughput Screening of Moisture-Induced Changes in Freeze-Dried Formulations

    DEFF Research Database (Denmark)

    Trnka, Hjalte; Palou, Anna; Panouillot, Pierre Emanuel

    2014-01-01

    formulations were freeze-dried in well plates. Samples were imaged with a NIR hyperspectral camera after freeze-drying and upon storage. On the basis of Karl Fischer titration reference values, a univariate quantification model was constructed and used to visualize the distribution of water within freeze......Evaluation of freeze-dried biopharmaceutical formulations requires careful analysis of multiple quality attributes. The aim of this study was to evaluate the use of near-infrared (NIR) imaging for fast analysis of water content and related physical properties in freeze-dried formulations. Model...... drying was observed within the samples after 3 days of storage. Further investigations with X-ray powder diffraction confirmed this local drying to be related to crystallization of sucrose. The combination of fast analysis of water content and spatial solid-state information makes NIR imaging a powerful...

  14. Effectiveness of Adjuncts with Demineralized Freeze Dried Bone Allograft in Treatment of Intrabony Defects - A systematic review

    National Research Council Canada - National Science Library

    GB Parthasarathy; ND Jayakumar; M Sankari; SS Varghese; G Karthikayan; S Panda

    2015-01-01

      Abstract Objective: To systematically evaluate the effect of adjuncts with demineralized freeze dried bone in the treatment of intrabony defects in terms of clinical and radiological outcomes. Methods...

  15. A comparative evaluation of freeze dried bone allograft and decalcified freeze dried bone allograft in the treatment of intrabony defects: A clinical and radiographic study

    Directory of Open Access Journals (Sweden)

    Rajat Gothi

    2015-01-01

    Full Text Available Background: Ideal graft material for regenerative procedures is autogenous bone graft but the major disadvantage with this graft is the need for a secondary surgical site to procure donor material and the frequent lack of intraoral donor site to obtain sufficient quantities of autogenous bone for multiple or deep osseous defects. Hence, to overcome these disadvantages, bone allografts were developed as an alternative source of graft material. Materials and Methods: In 10 patients with chronic periodontitis, 20 bilateral infrabony defects were treated with freeze dried bone allograft (FDBA-Group A and decalcified freeze dried bone allograft (DFDBA-Group B. Clinical and radiographic parameters were assessed preoperatively and at 3 months and 6 months postoperatively. Data thus obtained was subjected to statistical analysis. Results: Significant improvement in the reduction in probing depth and relative attachment level (RAL from the baseline to 3 months to baseline to 6 months in group A and group B, which was statistically significant but no statistically significant reduction was seen between 3 months and 6 months. On inter-group comparison, no significant differences were observed at all-time points. In adjunct to the probing depth and RAL, the radiographic area of the defect showed a similar trend in intra-group comparison and no significant difference was seen on inter-group comparison at all-time points. Conclusions: Within the limitations of the current study, it can be concluded that DFDBA did not show any improvement in the clinical and radiographic parameters in the treatment of the intrabony defects as compared to FDBA.

  16. Freeze-drying of HESylated IFNα-2b: Effect of HESylation on storage stability in comparison to PEGylation.

    Science.gov (United States)

    Liebner, Robert; Bergmann, Sarah; Hey, Thomas; Winter, Gerhard; Besheer, Ahmed

    2015-11-10

    A comparison of lyophilized PEGylated and HESylated IFNα was carried out to investigate the influence of protein conjugation, lyoprotectants as well as storage temperature on protein stability. Results show that PEG tends to crystallize during freeze-drying, reducing protein stability upon storage. In contrast, HESylation(®) drastically improved the stability over PEGylation by remaining totally amorphous during lyophilization, with and without lyoprotectants while providing a high glass transition temperature of the freeze-dried cakes.

  17. Optimization of freeze-drying condition of amikacin solid lipid nanoparticles using D-optimal experimental design.

    Science.gov (United States)

    Varshosaz, Jaleh; Ghaffari, Solmaz; Khoshayand, Mohammad Reza; Atyabi, Fatemeh; Dehkordi, Abbas Jafarian; Kobarfard, Farzad

    2012-01-01

    Amikacin as an aminoglycoside antibiotic was chosen to be loaded in a cholesterol carrier with nanoparticle size and sustained release profile to increase the dose interval of amikacin and reduce side-effects. To support the stability of solid lipid nanoparticles (SLNs), freeze-drying was suggested. Factors affecting the freeze-drying process in the present study included the type and concentration of cryoprotectants. Pre-freezing temperature effects were also studied on particle size of SLNs of amikacin. In some preliminary experiments, important factors which influenced the particle size of SLNs after lyophilization were selected and a D-optimal design was applied to optimize the freeze-drying conditions in the production of SLNs with minimum particle size growth after freeze-drying. Zeta potential, DSC thermograms, release profiles and morphology of the optimized particles were studied before and after freeze-drying. Results showed sucrose changed the particle size of SLNs of amikacin from 149 ± 4 nm to 23.9 ± 16.7 nm; in that situation, the absolute value of zeta potential changed from 1 ± 0.7 mV to 13 ± 4 mV. The release profiles showed a sustained release behavior of the loaded drug that did not change significantly before and after freeze-drying, but a burst effect was seen after it in the first 2 h. DSC analysis showed chemical interaction between amikacin and cholesterol.

  18. Stability evaluation of freeze-dried Lactobacillus paracasei subsp. tolerance and Lactobacillus delbrueckii subsp. bulgaricus in oral capsules.

    Science.gov (United States)

    Jalali, M; Abedi, D; Varshosaz, J; Najjarzadeh, M; Mirlohi, M; Tavakoli, N

    2012-01-01

    Freeze-drying is a common preservation technology in the pharmaceutical industry. Various studies have investigated the effect of different cryoprotectants on probiotics during freeze-drying. However, information on the effect of cryoprotectants on the stability of some Lactobacillus strains during freeze-drying seems scarce. Therefore, the aim of the present study was to establish production methods for preparation of oral capsule probiotics containing Lactobacillus paracasei subsp. tolerance and Lactobacillus delbrueckii subsp. Bulgaricus. It was also of interest to examine the effect of various formulations of cryoprotectant media containing skim milk, trehalose and sodium ascorbate on the survival rate of probiotic bacteria during freeze-drying at various storage temperatures. Without any cryoprotectant, few numbers of microorganisms survived. However, microorganisms tested maintained higher viability after freeze-drying in media containing at least one of the cryoprotectants. Use of skim milk in water resulted in an increased viability after lyophilization. Media with a combination of trehalose and skim milk maintained a higher percentage of live microorganisms, up to 82%. In general, bacteria retained a higher number of viable cells in capsules containing freeze-dried bacteria with sodium ascorbate after three months of storage. After this period, a marked decline was observed in all samples stored at 23°C compared to those stored at 4°C. The maximum survival rate (about 72-76%) was observed with media containing 6% skim milk, 8% trehalose and 4% sodium ascorbate.

  19. Optimization of a protective medium for freeze-dried Pichia membranifaciens and application of this biocontrol agent on citrus fruit.

    Science.gov (United States)

    Niu, X; Deng, L; Zhou, Y; Wang, W; Yao, S; Zeng, K

    2016-07-01

    To optimize a protective medium for freeze-dried Pichia membranifaciens and to evaluate biocontrol efficacies of agents against blue and green mould and anthracnose in citrus fruit. Based on the screening assays of saccharides and antioxidants, response surface methodology was used to optimize sucrose, sodium glutamate and skim milk to improve viability of freeze-dried Pi. membranifaciens. Biocontrol assays were conducted between fresh and freeze-dried Pi. membranifaciens against Penicillium italicum, Penicillium digitatum and Colletotrichum gloeosporioides in citrus fruit. Solving the regression equation indicated that the optimal protective medium was 6·06% (w/v) sucrose combined with 3·40% (w/v) sodium glutamate and 5·43% (w/v) skim milk. Pi. membranifaciens freeze-dried in the optimal protective medium showed 76·80% viability, and retained biocontrol efficacy against Pe. italicum, Pe. digitatum and Co. gloeosporioides in citrus fruit. The optimal protective medium showed more effective protective properties than each of the three protectants used alone. The viability of freeze-dried Pi. membranifaciens finally reached 76·80%. Meanwhile, the biocontrol efficacies showed no significant difference between fresh and freeze-dried yeast against Pe. italicum, Pe. digitatum and Co. gloeosporioides in citrus fruit. The results showed the potential value of Pi. membranifaciens CICC 32259 for commercialization. © 2016 The Society for Applied Microbiology.

  20. Investigation of the stabilizing effects of hydroxyethyl cellulose on LDH during freeze drying and freeze thawing cycles.

    Science.gov (United States)

    Al-Hussein, Anas; Gieseler, Henning

    2015-01-01

    The objective of this study was to investigate both the cryoprotective and lyoprotective effects of the polymer hydroxyethyl cellulose (HEC) on the model protein lactate dehydrogenase (LDH) during freeze thawing and freeze drying cycles. The effect of annealing on both protein stability and the physical state of HEC was evaluated. HEC was used as a sole excipient in the protein formulations, and its stabilizing was compared to that of other excipients which are commonly used in freeze dried protein formulations. Furthermore, other quality aspects of the freeze dried samples containing solely HEC were investigated, such as, reconstitution time and product elegance. Protein stability was evaluated functionally by measuring the activity recovery of the model protein LDH. The physical state of HEC after freeze drying was investigated and compared to this of other studied solutes using differential scanning calorimetry and X-ray powder diffractometry. HEC showed superior cryoprotective effects on LDH during freeze thawing, and considerable lyoprotective effects during the freeze drying process. Annealing had limited influence on the stabilizing effect of HEC. The extensive reconstitution times of the HEC lyophilisates could be greatly improved by incorporation of the surfactant Tween 80 into the formulations prior to freeze drying.

  1. A freeze-dried graphene counter electrode enhances the performance of dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Hung, Kai-Hsiang; Wang, Hong-Wen, E-mail: hongwen@cycu.edu.tw

    2014-01-01

    A flexible graphene/polyimide (PI) counter electrode without a fluorine-doped tin oxide (FTO) layer has been fabricated for dye-sensitized solar cell (DSSCs) applications. The flexible counter electrode consists of polyimide double-sided tape as a substrate beneath a graphene film acting as the conductive and catalytic layer. Chemically reduced graphene oxide (rGO) on the PI electrode (rGO-PI) shows comparable catalytic activity to that of the reference sputtered platinum/FTO counter electrodes (Sputter-Pt/FTO). A DSSC with a freeze-dried rGO-PI (FD-rGO-PI) counter electrode shows an overall conversion efficiency (η) of 5.45%, while that of the conventional Sputter-Pt/FTO electrode is 5.52%. The DSSC with a thermally dried rGO-PI (Gel-rGO-PI) counter electrode (not freeze-dried) exhibits a smooth morphology and much poorer performance (η = 1.61%). Field emission scanning electron microscopy, electrochemical impedance spectroscopy, and cyclic voltammetry measurements demonstrate that the FD-rGO-PI electrode possesses a porous structure, numerous edges, minimum charge-transfer resistance and a higher electrocatalytic activity toward the I{sub 3}{sup −}/I{sup −} redox couple than that of the Gel-rGO-PI electrode. The high electrocatalytic activity, facile preparation procedure, absence of FTO, and material flexibility render the FD-rGO-PI electrode an ideal alternative to conventional DSSC counter electrodes. - Highlights: • Highly rough and conductive graphene-based counter electrode is synthesized. • The characteristics of graphene surface by freeze drying are different. • The graphene counter electrode exhibits comparable performance to that of sputtered Pt one.

  2. Analysis of the moisture evaporation process during vacuum freeze-drying of koumiss and shubat

    Science.gov (United States)

    Shingisov, Azret Utebaevich; Alibekov, Ravshanbek Sultanbekovich

    2017-05-01

    The equation for the calculating of a moisture evaporation rate in the vacuum freeze-drying, wherein as a driving force instead of the generally accepted in the drying theory of ∆t temperature difference, ∆p pressure difference, ∆c concentration difference, a difference of water activity in the product and the relative air humidity (a_{{w}} - \\varphi) is suggested. By using the proposed equation, the processes of vacuum freeze-drying of koumiss and shubat were analyzed, and it was found two drying periods: constant and falling. On the first drying period, a moisture evaporation rate of koumiss is j = 2.75 × 10-3 kg/(m2 h) and of shubat is j = 2.37 × 10-3 kg/(m2 h). On the second period, values decrease for koumiss from j = 2.65 × 10-3 kg/(m2 h) to j = 1.60 × 10-3 kg/(m2 h), and for shubat from j = 2.25 × 10-3 kg/(m2 h) to j = 1.62 × 10-3 kg/(m2 h). Specific humidity for koumiss is ueq = 0.61 kg/kg and for shubat is ueq = 0.58 kg/kg. The comparative analyze of the experimental data of the moisture evaporation rate versus the theoretical calculation shows that the approximation reliability is R2 = 0.99. Consequently, the proposed equation is useful for the analyzing a moisture evaporation rate during a vacuum freeze-drying of dairy products, including cultured milk foods.

  3. Optimization of the secondary drying step in freeze drying using TDLAS technology.

    Science.gov (United States)

    Schneid, Stefan C; Gieseler, Henning; Kessler, William J; Luthra, Suman A; Pikal, Michael J

    2011-03-01

    The secondary drying phase in freeze drying is mostly developed on a trial-and-error basis due to the lack of appropriate noninvasive process analyzers. This study describes for the first time the application of Tunable Diode Laser Absorption Spectroscopy, a spectroscopic and noninvasive sensor for monitoring secondary drying in laboratory-scale freeze drying with the overall purpose of targeting intermediate moisture contents in the product. Bovine serum albumin/sucrose mixtures were used as a model system to imitate high concentrated antibody formulations. First, the rate of water desorption during secondary drying at constant product temperatures (-22 °C, -10 °C, and 0 °C) was investigated for three different shelf temperatures. Residual moisture contents of sampled vials were determined by Karl Fischer titration. An equilibration step was implemented to ensure homogeneous distribution of moisture (within 1%) in all vials. The residual moisture revealed a linear relationship to the water desorption rate for different temperatures, allowing the evaluation of an anchor point from noninvasive flow rate measurements without removal of samples from the freeze dryer. The accuracy of mass flow integration from this anchor point was found to be about 0.5%. In a second step, the concept was successfully tested in a confirmation experiment. Here, good agreement was found for the initial moisture content (anchor point) and the subsequent monitoring and targeting of intermediate moisture contents. The present approach for monitoring secondary drying indicated great potential to find wider application in sterile operations on production scale in pharmaceutical freeze drying. © 2011 American Association of Pharmaceutical Scientists

  4. Analysis of the moisture evaporation process during vacuum freeze-drying of koumiss and shubat

    Science.gov (United States)

    Shingisov, Azret Utebaevich; Alibekov, Ravshanbek Sultanbekovich

    2016-10-01

    The equation for the calculating of a moisture evaporation rate in the vacuum freeze-drying, wherein as a driving force instead of the generally accepted in the drying theory of ∆t temperature difference, ∆p pressure difference, ∆c concentration difference, a difference of water activity in the product and the relative air humidity (a_{w} - φ) is suggested. By using the proposed equation, the processes of vacuum freeze-drying of koumiss and shubat were analyzed, and it was found two drying periods: constant and falling. On the first drying period, a moisture evaporation rate of koumiss is j = 2.75 × 10-3 kg/(m2 h) and of shubat is j = 2.37 × 10-3 kg/(m2 h). On the second period, values decrease for koumiss from j = 2.65 × 10-3 kg/(m2 h) to j = 1.60 × 10-3 kg/(m2 h), and for shubat from j = 2.25 × 10-3 kg/(m2 h) to j = 1.62 × 10-3 kg/(m2 h). Specific humidity for koumiss is ueq = 0.61 kg/kg and for shubat is ueq = 0.58 kg/kg. The comparative analyze of the experimental data of the moisture evaporation rate versus the theoretical calculation shows that the approximation reliability is R2 = 0.99. Consequently, the proposed equation is useful for the analyzing a moisture evaporation rate during a vacuum freeze-drying of dairy products, including cultured milk foods.

  5. Large scale synthesis of nanostructured zirconia-based compounds from freeze-dried precursors

    Energy Technology Data Exchange (ETDEWEB)

    Gomez, A.; Villanueva, R.; Vie, D.; Murcia-Mascaros, S.; Martinez, E.; Beltran, A. [Institut de Ciencia dels Materials, Parc Cientific, Universitat de Valencia, PO Box 22085, 46071 Valencia (Spain); Sapina, F., E-mail: fernando.sapina@uv.es [Institut de Ciencia dels Materials, Parc Cientific, Universitat de Valencia, PO Box 22085, 46071 Valencia (Spain); Vicent, M.; Sanchez, E. [Instituto de Tecnologia Ceramica-Asociacion de Investigacion de las Industrias Ceramicas, Universitat Jaume I, 12006 Castellon (Spain)

    2013-01-15

    Nanocrystalline zirconia powders have been obtained at the multigram scale by thermal decomposition of precursors resulting from the freeze-drying of aqueous acetic solutions. This technique has equally made possible to synthesize a variety of nanostructured yttria or scandia doped zirconia compositions. SEM images, as well as the analysis of the XRD patterns, show the nanoparticulated character of those solids obtained at low temperature, with typical particle size in the 10-15 nm range when prepared at 673 K. The presence of the monoclinic, the tetragonal or both phases depends on the temperature of the thermal treatment, the doping concentration and the nature of the dopant. In addition, Rietveld refinement of the XRD profiles of selected samples allows detecting the coexistence of the tetragonal and the cubic phases for high doping concentration and high thermal treatment temperatures. Raman experiments suggest the presence of both phases also at relatively low treatment temperatures. - Graphical abstract: Zr{sub 1-x}A{sub x}O{sub 2-x/2} (A=Y, Sc; 0{<=}x{<=}0.12) solid solutions have been prepared as nanostructured powders by thermal decomposition of precursors obtained by freeze-drying, and this synthetic procedure has been scaled up to the 100 g scale. Highlights: Black-Right-Pointing-Pointer Zr{sub 1-x}A{sub x}O{sub 2-x/2} (A=Y, Sc; 0{<=}x{<=}0.12) solid solutions have been prepared as nanostructured powders. Black-Right-Pointing-Pointer The synthetic method involves the thermal decomposition of precursors obtained by freeze-drying. Black-Right-Pointing-Pointer The temperature of the thermal treatment controls particle sizes. Black-Right-Pointing-Pointer The preparation procedure has been scaled up to the 100 g scale. Black-Right-Pointing-Pointer This method is appropriate for the large-scale industrial preparation of multimetallic systems.

  6. Production of freeze-dried lactic acid bacteria starter culture for cassava fermentation into gari

    CSIR Research Space (South Africa)

    Yao, AA

    2009-10-01

    Full Text Available . One of the most popular foods derived from fermented cassava is gari, consumed by nearly 200 million people in West Africa (Okafor and Ejiofor, 1990). Its cheapness, longer shelf- life, lower bulk (compared with other cassava products) and ease... water in the double jacket of the bioreactor and then concentrated 20 times by centrifugation (3000 ×g, 30 min). The cell suspension was supple- mented with 2% (w/w) and 5% (w/w) maltodextrin as protective compounds. The cells were freeze-dried in a...

  7. Analysis and Application of the Amorphous Properties in Freeze-Dried Foods

    Science.gov (United States)

    Kawai, Kiyoshi

    The dynamic properties of amorphous materials drastically change by the phase transition between glassy state and rubber state. Furthermore, the dynamic properties of amorphous materials in glassy state are affected by the thermal history such as processing and/or storage conditions. In this paper, effect of the glass transition of freeze-dried food systems on the storage stability was summarized. Moreover, analytical approaches of the amorphous properties for glassy products with enthalpy relaxation measurements by using differential scanning calorimetry were presented and its application to food industry was proposed.

  8. Evaluation of Freeze-Dried Kefir Coculture as Starter in Feta-Type Cheese Production

    OpenAIRE

    Kourkoutas, Y.; Kandylis, P.; Panas, P.; Dooley, J. S. G.; P. Nigam; Koutinas, A. A.

    2006-01-01

    The use of freeze-dried kefir coculture as a starter in the production of feta-type cheese was investigated. Maturation of the produced cheese at 4°C was monitored for up to 70 days, and the effects of the starter culture, the salting method, and the ripening process on quality characteristics were studied. The use of kefir coculture as a starter led to increased lactic acid concentrations and decreased pH values in the final product associated with significantly higher conversion rates compa...

  9. Physico-chemical and rheological properties of gelatinized/freeze-dried cereal starches

    Science.gov (United States)

    Krystyjan, Magdalena; Ciesielski, Wojciech; Gumul, Dorota; Buksa, Krzysztof; Ziobro, Rafał; Sikora, Marek

    2017-07-01

    The influence of gelatinization and freeze-drying process on the physico-chemical and rheological properties of cereal starches was evaluated, and it was observed that modified starches revealed an increased water binding capacity and solubility when compared to dry starches, while exhibiting the same amylose and fat contents. The molecular weights of starches decreased after modification which resulted in the lower viscosity of dissolved modified samples in comparison to native starch pastes. As it was observed by scanning electron microscopy modified starches were characterized by an expanded surface, a uniform structure and high porosity.

  10. Study of volatile compounds from the radiosterilization of solid cephalosporins

    Energy Technology Data Exchange (ETDEWEB)

    Barbarin, N.; Crucq, A.S.; Tilquin, B. [Universite Catholique de Louvain (UCL), Louvain-la-Neuve (Belgium)

    1996-12-01

    The use of {gamma}-rays is a promising method to sterilize thermosensitive drugs. Although radiosterilization does not modify drugs activity, this mode of sterilization produces new radiolytic products. This study is devoted to the analysis of volatile compounds which may induce a modification of odour. The volatile compounds produced by radiolysis of cefotaxime, cefuroxime and ceftazidime, three cephalosporins, were analyzed by gas chromatography with a headspace sampling. They were detected and identified by mass and infrared spectrometry. An explanation of their origin is proposed. (Author).

  11. A sustainable freeze-drying route to porous polysaccharides with tailored hierarchical meso- and macroporosity.

    Science.gov (United States)

    Borisova, Aleksandra; De Bruyn, Mario; Budarin, Vitaliy L; Shuttleworth, Peter S; Dodson, Jennifer R; Segatto, Mateus L; Clark, James H

    2015-04-01

    Bio-derived polysaccharide aerogels are of interest for a broad range of applications. To date, these aerogels have been obtained through the time- and solvent-intensive procedure of hydrogel fomation, solvent exchange, and scCO2 drying, which offers little control over meso/macropore distribution. A simpler and more versatile route is developed, using freeze drying to produce highly mesoporous polysaccharide aerogels with various degrees of macroporosity. The hierarchical pore distribution is controlled by addition of different quantities of t-butanol (TBA) to hydrogels before drying. Through a systematic study an interesting relationship between the mesoporosity and t-butanol/water phase diagram is found, linking mesoporosity maxima with eutectic points for all polysaccharides studied (pectin, starch, and alginic acid). Moreover, direct gelation of polysaccharides in aqueous TBA offers additional time savings and the potential for solvent reuse. This finding is a doorway to more accessible polysaccharide aerogels for research and industrial scale production, due to the widespread accessibility of the freeze drying technology and the simplicity of the method.

  12. Development of freeze-dried DOTMP kits for labeling with {sup 68} Ga

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Jae Cheong; Choi, Sang Mu; Cho, Eun Ha; Lee, So Young; Dho, So Hee; Kim, Soo Yong [Radioisotope Research Division, Dept. of Research Reactor Utilization, Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-05-15

    Lyophilized dotMP kits were prepared using dotMP, ammonium acetate, and ascorbic acid. the {sup 68}Ga-dotMP was prepared by incubating the kit dissolved in 0.5 ml of concentrated {sup 68}Ga using nacl method and 0.5 ml of ddW, at 100 degrees C for 7 min. the labeling yield was evaluated by two solvent systems of tLc. 1 MBq of concentrated {sup 68}Ga was labeled with 0.8 μg of DOTMP by high radiolabeling yield (>98%), which was determined by two tLc methods. the composition of the prepared freeze-dried vial is 400 μg of DOTMP, 19.27 mg of ammonium acetate and 17.62 mg of ascorbic acid. ⁓555 MBq of {sup 68}Ga-dotMP was prepared with excellent radiochemical purity (>98%) and it was stable for 4 hr at room temperature. In conclusion, Freeze-dried dotMP kits for the convenient preparation of {sup 68}Ga-dotMP have been developed. Availability of this kit is expected to stimulate the widespread use of {sup 68}Ga-DOTMP in the fields of nuclear medicine.

  13. Optimization of the bioactive compounds content in raspberry during freeze-drying using response surface method

    Directory of Open Access Journals (Sweden)

    Tumbas-Šaponjac Vesna T.

    2015-01-01

    Full Text Available The production of high-quality freeze-dried raspberry was studied by response surface method. Two independent variables, temperature (X1 and time (X2 were determined as the most important factors affecting the final product quality estimated by the responses: total phenol (Y1, total anthocyanin (Y2, vitamin C (Y3 and total bioactive compounds (Y4 content. A two-factor central composite design was used for freeze-drying experiments. The second order polynomial models obtained were found to be significant (p<0.05 for all responses. The statistical analysis of experimental data indicated that only quadratic time variable (X22 had significant (p<0.05 effect on all responses. The optimal conditions for all responses combined were found to be: -31 ºC and 35 h. The experimental values of all responses obtained under optimal conditions were in good agreement with predicted values which enables the use of the proposed mathematical models for optimization of investigated process. [Projekat Ministarstav nauke Republike Srbije, br. TR31044

  14. Development of a freeze-dried fungal wettable powder preparation able to biodegrade chlorpyrifos on vegetables.

    Directory of Open Access Journals (Sweden)

    Jie Liu

    Full Text Available Continuous use of the pesticide chlorpyrifos has resulted in harmful contaminations in environment and species. Based on a chlorpyrifos-degrading fungus Cladosporium cladosporioides strain Hu-01 (collection number: CCTCC M 20711, a fungal wettable powder preparation was developed aiming to efficiently remove chlorpyrifos residues from vegetables. The formula was determined to be 11.0% of carboxymethyl cellulose-Na, 9.0% of polyethylene glycol 6000, 5.0% of primary alcohol ethoxylate, 2.5% of glycine, 5.0% of fucose, 27.5% of kaolin and 40% of freeze dried fungi by response surface methodology (RSM. The results of quality inspection indicated that the fungal preparation could reach manufacturing standards. Finally, the degradation of chlorpyrifos by this fungal preparation was determined on pre-harvest cabbage. Compared to the controls without fungal preparation, the degradation of chlorpyrifos on cabbages, which was sprayed with the fungal preparation, was up to 91% after 7 d. These results suggested this freeze-dried fungal wettable powder may possess potential for biodegradation of chlorpyrifos residues on vegetables and provide a potential strategy for food and environment safety against pesticide residues.

  15. Optimization of freeze drying conditions for purified pectinase from mango (Mangifera indica cv. Chokanan) peel.

    Science.gov (United States)

    Mehrnoush, Amid; Mustafa, Shuhaimi; Yazid, Abdul Manap Mohd

    2012-01-01

    Response surface methodology (RSM) along with central composite design (CCD) was applied to optimize the freeze drying conditions for purified pectinase from mango (Mangifera indica cv. Chokanan) peel. The effect of pectinase content (-2.66, 62.66 mg/mL), Arabic gum (-1.21, 10.21%, w/v), and maltodextrin (0.73, 7.26%, w/v) as independent variables on activity, yield, and storage stability of freeze-dried enzyme was evaluated. Storage stability of pectinase was investigated after one week at 4 °C and yield percentage of the enzyme after encapsulation was also determined. The independent variables had the most significant (p mango peel were obtained using 30 mg/mL of pectinase content, 4.5 (%, w/v) of Arabic gum, and 4 (%, w/v) of maltodextrin. Under these conditions, the maximum activity (11.12 U/mL), yield (86.4%) and storage stability (84.2%) of encapsulated pectinase were achieved.

  16. Sugars as bulking agents to prevent nano-crystal aggregation during spray or freeze-drying.

    Science.gov (United States)

    Kumar, Sumit; Gokhale, Rajeev; Burgess, Diane J

    2014-08-25

    In this study, the effect of low and high molecular weight sugars on indomethacin nano-crystalline suspension powders prepared by spray or freeze-drying was evaluated. Dowfax 2A1 (negatively charged surfactant) was utilized as indomethacin nanosuspensions stabilizer. Dried crystalline powders with or without sugars were characterized for crystallinity, particle size and powder yield. Interactions between the nanosuspension stabilizer (i.e. Dowfax 2A1) and sugars were investigated by utilizing IR spectroscopy and contact angle measurements. The nanosuspension formulations containing small molecular weight sugars were non-aggregating compared to those containing polysaccharides. Additionally, higher powder yields were observed with formulations containing sugars with higher glass transition temperature during spray drying. The formulations containing low glass transition temperature sugars were sticking to the spray drier glass walls and thus resulted in lower yields. The small molecular weight sugars showed favorable interactions with Dowfax 2A1, as evident by the IR and contact angle data, possibly resulting in minimal nano-crystal aggregation during spray or freeze-drying. A combination of sugars (i.e. small molecular weight and polysaccharides) may be utilized to achieve higher spray-drying yields and non-aggregating nano-crystalline powders.

  17. Preparation of freeze-dried coffee tablets%冻干咖啡片的研制

    Institute of Scientific and Technical Information of China (English)

    陈三宝

    2012-01-01

    The freeze-dried coffee tablets were prepared by hot water extraction and freeze drying with coffee extract as the raw material.The optimal process was that the temperature of the extract of coffee was 90℃,extract time 12 min,the ratio of coffee to water%以咖啡粉为原料,采用热水提取、冷冻干燥的方法,制备了冻干咖啡片。通过实验确定最佳制片方案为:咖啡粉浸提温度90℃,浸提时间12min,料液比为1:15,提取液浓缩至65%浓度,于共熔点温度-36℃以下冷冻干燥。按优选工艺制得的冻干咖啡片硬度适当,片型完整,溶解迅速,具有较速溶咖啡更好的风味、复水性和感官品质。

  18. Freeze-dried platelet-rich plasma shows beneficial healing properties in chronic wounds.

    Science.gov (United States)

    Pietramaggiori, Giorgio; Kaipainen, Arja; Czeczuga, Joshua M; Wagner, Christopher T; Orgill, Dennis P

    2006-01-01

    Fresh platelet concentrates are used in many centers to treat recalcitrant wounds. To extend the therapeutic shelf-life of platelets, we analyzed the wound-healing effects of fresh-frozen and freeze-dried (FD) platelet-rich plasma (PRP) using a diabetic mouse model. Db/db mice with 1.0 cm2 dorsal excisional wounds (n = 15/group) were treated with a single application of FD PRP (1.2 x 10(6) platelets/microL) with or without a stabilization solution, and compared with wounds treated with fresh-frozen, sonicated PRP, and untreated wounds. Granulation tissue area, thickness, and wound size were analyzed 9 days posttreatment. Immunostained sections were quantified for vascularity and proliferation using antiplatelet endothelial cell adhesion molecule I and antiproliferating cell nuclear antigen antibodies. The results showed that all PRP preparations increased granulation tissue formation as assessed by surface coverage, thickness, and angiogenic response, when compared with untreated wounds. In addition, wounds treated with FD PRP, and biochemically stabilized FD PRP, exhibited higher proliferative levels. The possibility to deliver growth factors using platelets, and the potential to extend the shelf-life of platelet concentrates makes freeze-drying methods particularly suitable for enhanced wound care.

  19. Production of grape juice powder obtained by freeze-drying after concentration by reverse osmosis

    Directory of Open Access Journals (Sweden)

    Poliana Deyse Gurak

    2013-12-01

    Full Text Available This study aimed to evaluate the freeze-drying process for obtaining grape juice powder by reverse osmosis using 50% grape juice pre-concentrated (28.5 °Brix and 50% hydrocolloids (37.5% maltodextrin and 12.5% arabic gum. The morphology of the glassy food showed the absence of crystalline structure, which was the amorphous wall that protected the contents of the powder. The samples were stored in clear and dark containers at room temperature, evaluated for their physical (X-ray diffraction for 65 days and chemical (polyphenol content stability for 120 days. During the storage time in plastic vessels, samples remained physically stable (amorphous and the phenolic concentration was constant, indicating the potentiality of this technique to obtain a stable product with a high concentration of phenolic compounds. Therefore, the freeze-drying process promoted the encapsulation of concentrated grape juice increasing its stability and shelf life, as well as proving to be an applicable process to food industry

  20. Experimental determination of the key heat transfer mechanisms in pharmaceutical freeze-drying.

    Science.gov (United States)

    Ganguly, Arnab; Nail, Steven L; Alexeenko, Alina

    2013-05-01

    The study is aimed at quantifying the relative contribution of key heat transfer modes in lyophilization. Measurements of vial heat transfer rates in a laboratory-scale freeze-dryer were performed using pure water, which was partially sublimed under various conditions. The separation distance between the shelf and the vial was systematically varied, and sublimation rates were determined gravimetrically. The heat transfer rates were observed to be independent of separation distance between the vial and the shelf and linearly dependent on pressure in the free molecular flow limit, realized at low pressures (120 mTorr), heat transfer rates were independent of pressure and inversely proportional to separation distance. Previous heat transfer studies in conventional freeze-drying cycles have attributed a dominant portion of the total heat transfer to radiation, the rest to conduction, whereas convection has been found to be insignificant. Although the measurements reported here confirm the significance of the radiative and gas conduction components, the convective component has been found to be comparable to the gas conduction contribution at pressures greater than 100 mTorr. The current investigation supports the conclusion that the convective component of the heat transfer cannot be ignored in typical laboratory-scale freeze-drying conditions. Copyright © 2013 Wiley Periodicals, Inc.

  1. Tert-butyl alcohol used to fabricate nano-cellulose aerogels via freeze-drying technology

    Science.gov (United States)

    Wang, Xiaoyu; Zhang, Yang; Jiang, Hua; Song, Yuxuan; Zhou, Zhaobing; Zhao, Hua

    2017-06-01

    Aerogel, a highly porous material, is attracting increasing attention owing to low thermal conductivity and high specific surface area. Freeze-drying technology has been employed to produce nano-cellulose aerogels; however, the resultant product has low specific surface areas. Here, a modified approach to prepare nano-cellulose aerogels was reported, which involves tert-butyl alcohol as a solvent. Nano-cellulose aerogels were prepared via a spontaneous gelation fashion using calcium chloride solution, followed by tert-butyl alcohol solvent displacement and freeze drying. Addition of calcium chloride (0.25%) accelerated the physical gelation process. The application of tert-butyl alcohol as a solvent contributed to preservation of gel network. The obtained spherical nano-cellulose aerogels had a shrinkage rate of 5.89%. The specific surface area and average pore size was 164. 9666 m2 g-1 and 10.01 nm, respectively. Additionally, nano-cellulose aerogels had a comparable thermal degradation property when compared to microcrystalline cellulose. These biophysical properties make nano-cellulose aerogels as a promising absorption material.

  2. Microencapsulation of saffron petal anthocyanins with cress seed gum compared with Arabic gum through freeze drying.

    Science.gov (United States)

    Jafari, Seid-Mahdi; Mahdavi-Khazaei, Katayoun; Hemmati-Kakhki, Abbas

    2016-04-20

    In this research, encapsulation efficiency of cress seed gum (CSG) as a native hydrocolloid was compared with Arabic gum (AG) and maltodextrin (dextrose equivalent of 20 (M20), and 7 (M7)) for saffron (Crocus sativus) petal's extract by freeze drying method. Combinations of CSG-M20, AG-M20, and M7-M20 with ratios of 50:50 and M20 alone (100%) were used as wall materials. A mixture of 1:5 (based on dry matter) between core (concentrated anthocyanin extract of saffron petal) and wall materials were freeze dried and stability of encapsulated anthocyanins along with color parameters (a*, b*, L*, C, H° and TCD) of final powders were measured during 10 weeks of storage (at 35°C as an accelerated method). Total anthocyanins were determined through pH differential method every week. Four prepared formulations of encapsulated powders didn't show any significant differences (P>0.01) in terms of total anthocyanin content measured immediately after production and after 10 weeks storage. AG-M20 mixture and M20 alone showed the highest and lowest TCD, respectively. The mixture of CSG-M20 in comparison with AG-M20 and M20 had the same protecting effect (P<0.01) but showed a relatively high TCD (9.33).

  3. Demineralized Freeze-Dried Bovine Cortical Bone: Its Potential for Guided Bone Regeneration Membrane

    Directory of Open Access Journals (Sweden)

    David B. Kamadjaja

    2017-01-01

    Full Text Available Background. Bovine pericardium collagen membrane (BPCM had been widely used in guided bone regeneration (GBR whose manufacturing process usually required chemical cross-linking to prolong its biodegradation. However, cross-linking of collagen fibrils was associated with poorer tissue integration and delayed vascular invasion. Objective. This study evaluated the potential of bovine cortical bone collagen membrane for GBR by evaluating its antigenicity potential, cytotoxicity, immune and tissue response, and biodegradation behaviors. Material and Methods. Antigenicity potential of demineralized freeze-dried bovine cortical bone membrane (DFDBCBM was done with histology-based anticellularity evaluation, while cytotoxicity was analyzed using MTT Assay. Evaluation of immune response, tissue response, and biodegradation was done by randomly implanting DFDBCBM and BPCM in rat’s subcutaneous dorsum. Samples were collected at 2, 5, and 7 days and 7, 14, 21, and 28 days for biocompatibility and tissue response-biodegradation study, respectively. Result. DFDBCBM, histologically, showed no retained cells; however, it showed some level of in vitro cytotoxicity. In vivo study exhibited increased immune response to DFDBCBM in early healing phase; however, normal tissue response and degradation rate were observed up to 4 weeks after DFDBCBM implantation. Conclusion. Demineralized freeze-dried bovine cortical bone membrane showed potential for clinical application; however, it needs to be optimized in its biocompatibility to fulfill all requirements for GBR membrane.

  4. Preparation of 3-D porous fibroin scaffolds by freeze drying with treatment of methanol solutions

    Institute of Scientific and Technical Information of China (English)

    ZHAN JingLin; SUN XiaoDan; CUI FuZhai; KONG XiangDong

    2007-01-01

    In this study,silk scaffolds with appropriate porous structures were prepared by adjusting solution concentrations and providing treatment with methanol solutions in the way of freeze drying. The effects of the preparation conditions on the microstructures and properties of the scaffolds were discussed. Fibroin solutions with different concentrations of 4,6,8,10 wt% were used respectively to prepare the scaffolds. The effects of the addition of 20 vol% methanol before or after freeze drying to the 4 wt% fibroin solution were investigated. As demonstrated by Scanning Electron Microscope (SEM),the fibroin scaffolds prepared without methanol had porous microstructures composed of thin sheets,and the sizes of the pores decreased with the increase of the fibroin solution concentrations,while the scaffolds prepared in the presence of methanol showed porous microstructures formed by fine-particle aggregates. The porosities and mechanical properties of the prepared fibroin scaffolds under different conditions were tested. The crystalline structures and conformations of the fibroin scaffolds were detected by Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD).

  5. Constant size, variable density aerosol particles by ultrasonic spray freeze drying.

    Science.gov (United States)

    D'Addio, Suzanne M; Chan, John Gar Yan; Kwok, Philip Chi Lip; Prud'homme, Robert K; Chan, Hak-Kim

    2012-05-10

    This work provides a new understanding of critical process parameters involved in the production of inhalation aerosol particles by ultrasonic spray freeze drying to enable precise control over particle size and aerodynamic properties. A series of highly porous mannitol, lysozyme, and bovine serum albumin (BSA) particles were produced, varying only the solute concentration in the liquid feed, c(s), from 1 to 5 wt%. The particle sizes of mannitol, BSA, and lysozyme powders were independent of solute concentration, and depend only on the drop size produced by atomization. Both mannitol and lysozyme formulations showed a linear relationship between the computed Fine Particle Fraction (FPF) and the square root of c(s), which is proportional to the particle density, ρ, given a constant particle size d(g). The FPF decreased with increasing c(s) from 57.0% to 16.6% for mannitol and 44.5% to 17.2% for lysozyme. Due to cohesion, the BSA powder FPF measured by cascade impaction was less than 10% and independent of c(s). Ultrasonic spray freeze drying enables separate control over particle size, d(g), and aerodynamic size, d(a) which has allowed us to make the first experimental demonstration of the widely accepted rule d(a)=d(g)(ρ/ρ(o))(1/2) with particles of constant d(g), but variable density, ρ (ρ(o) is unit density).

  6. Sol Freeze Dry Nd:YAG Nanopowder Synthesis and Sinterability Studies

    Directory of Open Access Journals (Sweden)

    Rekha Mann

    2015-09-01

    Full Text Available Citrate nitrate sol freeze dry synthesis of 2 atomic % neodymium ion doped Yttrium Aluminium Oxide (Nd:YAG nanopowders was explored for the first time. Sol was prepared by dissolving nitrates of Al3+, Y3+ and Nd3+ keeping molar ratio to be 5: 2.94: 0.06. Total metal ion to citric acid ratio was optimised at 1 is to 0.25. Sol was freeze dried at -80 °C for 48 h. Dried mass thus obtained was calcined at 1000 °C for 2 h to give phase pure Nd:YAG as characterised by FTIR and XRD. Particles were in the size range of 35 nm - 50 nm with close to spherical morphology as observed by TEM. Nanopowder was compacted and sintered at 1700 °C for 5 h under 10-6 mbar followed by hot isostatic press at 1750 °C for 4 h under 200 MPa, to give 71 per cent transmission at 1064 nm indicating synthesis of well sinterable Nd:YAG nanopowders.

  7. Effects of ultrasonic pretreatments on quality, energy consumption and sterilization of barley grass in freeze drying.

    Science.gov (United States)

    Cao, Xiaohuang; Zhang, Min; Mujumdar, Arun S; Zhong, Qifeng; Wang, Zhushang

    2018-01-01

    Barley grass is a plant resource for rehabilitation therapy. Its processing requires retaining nutrition well for rehabilitation cure of consumers. To meet the aim as well as low energy consumption and microbiological safety of products, ultrasonic treatments (UT) were applied to bathing materials at different power levels (10, 30, 45, 60W/L) for 10mins. After treatments, the bathed barley grass (100g) was freeze-dried under vacuum -0.09MPa with fixed power of 2W/g. Parameters of color, microbial colony, energy consumption, glass transition temperature, moisture content, water activity, taste substances, contents of flavonoid and chlorophyll were determined after drying. In contrast with no treatment case, UT (45W/L) decreased drying time by 14% and decreased energy consumption by 19%; UT (60W/L) decreased total microbial colonies by 33%. Also, UT (30W/L) yielded contents of flavonoid (9.2/kg) and chlorophyll (10.5g/kg) of dried sample; UT power (10W/L) yielded the highest L(∗)(51.5) and the lowest a(∗)(-9.3) value. Simultaneously, UT leads to a higher glass transition temperature (Tg), lower water activity and produces less sourness and bitterness of dried products. Ultra-sonication is an alternative to improve quality, flavor and energy consumption of barley grass in freeze drying. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Factors influencing the stability of freeze-dried stress-resilient and stress-sensitive strains of bifidobacteria.

    Science.gov (United States)

    Celik, O F; O'Sullivan, D J

    2013-06-01

    Freeze-drying is a common method for preservation of probiotics, including bifidobacteria, for further industrial applications. However, the stability of freeze-dried bifidobacteria varies depending on the freeze-drying method and subsequent storage conditions. The primary goals of this study were to develop an optimized freeze-drying procedure and to determine the effects of temperature, water activity, and atmosphere on survival of freeze-dried bifidobacteria. To address these goals, a commercially used bifidobacteria strain that is resilient to stress, Bifidobacterium animalis ssp. lactis Bb-12, and a characterized intestinal strain that is more sensitive to stress conditions, Bifidobacterium longum DJO10A, were used. A freeze-drying protocol was developed using trehalose as the cryoprotectant, which resulted in almost no loss of viability during freeze-drying. Resuscitation medium, temperature, and time did not significantly influence recovery rates when this cryoprotectant was used. The effects of temperature (-80 to 45°C), water activity (0.02 to 0.92), and atmosphere (air, vacuum, and nitrogen) were evaluated for the stability of the freeze-dried powders during storage. Freeze-dried B. animalis ssp. lactis Bb-12 was found to survive under all conditions tested, with optimum survival at temperatures up to 21°C, water activities up to 0.44, and all 3 atmospheres tested. The intestinal-adapted strain B. longum DJO10A was much more sensitive to the different storage conditions, but could be adequately maintained using optimum conditions. These optimum storage conditions included frozen storage, replacement of oxygen with nitrogen, and water activities between 0.11 and 0.22. These results indicated that an optimized storage environment is required to maintain viability of stress-sensitive bifidobacteria strains, whereas stress-resilient bifidobacteria strains can maintain viability over a wide range of storage conditions, which is practical in countries where

  9. Freeze-dried snake antivenoms formulated with sorbitol, sucrose or mannitol: comparison of their stability in an accelerated test.

    Science.gov (United States)

    Herrera, María; Tattini, Virgilio; Pitombo, Ronaldo N M; Gutiérrez, José María; Borgognoni, Camila; Vega-Baudrit, José; Solera, Federico; Cerdas, Maykel; Segura, Alvaro; Villalta, Mauren; Vargas, Mariángela; León, Guillermo

    2014-11-01

    Freeze-drying is used to improve the long term stability of pharmaceutical proteins. Sugars and polyols have been successfully used in the stabilization of proteins. However, their use in the development of freeze-dried antivenoms has not been documented. In this work, whole IgG snake antivenom, purified from equine plasma, was formulated with different concentrations of sorbitol, sucrose or mannitol. The glass transition temperatures of frozen formulations, determined by Differential Scanning Calorimetry (DSC), ranged between -13.5 °C and -41 °C. In order to evaluate the effectiveness of the different stabilizers, the freeze-dried samples were subjected to an accelerated stability test at 40 ± 2 °C and 75 ± 5% relative humidity. After six months of storage at 40 °C, all the formulations presented the same residual humidity, but significant differences were observed in turbidity, reconstitution time and electrophoretic pattern. Moreover, all formulations, except antivenoms freeze-dried with mannitol, exhibited the same potency for the neutralization of lethal effect of Bothrops asper venom. The 5% (w:v) sucrose formulation exhibited the best stability among the samples tested, while mannitol and sorbitol formulations turned brown. These results suggest that sucrose is a better stabilizer than mannitol and sorbitol in the formulation of freeze-dried antivenoms under the studied conditions.

  10. NaCl stress impact on the key enzymes in glycolysis from Lactobacillus bulgaricus during freeze-drying

    Science.gov (United States)

    Li, Chun; Sun, Jinwei; Qi, Xiaoxi; Liu, Libo

    2015-01-01

    Abstract The viability of Lactobacillus bulgaricus in freeze-drying is of significant commercial interest to dairy industries. In the study, L.bulgaricus demonstrated a significantly improved (p < 0.05) survival rate during freeze-drying when subjected to a pre-stressed period under the conditions of 2% (w/v) NaCl for 2 h in the late growth phase. The main energy source for the life activity of lactic acid bacteria is related to the glycolytic pathway. To investigate the phenomenon of this stress-related viability improvement in L. bulgaricus, the activities and corresponding genes of key enzymes in glycolysis during 2% NaCl stress were studied. NaCl stress significantly enhanced (p < 0.05) glucose utilization. The activities of glycolytic enzymes (phosphofructokinase, pyruvate kinase, and lactate dehydrogenase) decreased during freeze-drying, and NaCl stress were found to improve activities of these enzymes before and after freeze-drying. However, a transcriptional analysis of the corresponding genes suggested that the effect of NaCl stress on the expression of the pfk2 gene was not obvious. The increased survival of freeze-dried cells of L. bulgaricus under NaCl stress might be due to changes in only the activity or translation level of these enzymes in different environmental conditions but have no relation to their mRNA transcription level. PMID:26691481

  11. Effects of physical parameters on the heat and mass transfer characteristics in freeze-drying processes of fruits and vegetables

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Yuming; Liu, Lijuan; Liang, Li [Shanxi Agricultural Univ. (China). Coll. of Engineering and Technology], E-mail: guoyuming99@sina.com

    2008-07-01

    Studying the effects mechanism of material physical parameters on the heat and mass transfer characteristics, the process parameters and energy consumption during freeze-drying process is of importance in improving the vacuum freeze-drying process with low energy consumption. In this paper, the sliced and mashed carrots of one variety were selected to perform the vacuum freeze-drying experiments. First, the variation laws of surface temperatures and sublimation front temperatures of the two shapes samples during the freeze-drying processes were analyzed, and it was verified that the process of sliced carrots is controlled by mass transfer, while that of the mashed ones is heat-transfer control. Second, the variations of water loss rate, energy consumption and temperature of the two shapes samples under the appropriate heating plate temperature and the different drying chamber pressure were analyzed. In addition, the effects of thermal conductivity and thermal diffusivity on freeze-drying time and process parameters were discussed by utilizing the theory of heat and mass transfer. In conclusion, under the heat transfer condition, the temperature of the heating plate should be as high as possible within the permitted range, and the drying chamber pressure should be set at optimal level. While under the mass transport-limited condition, the pressure level need to be altered in short time. (author)

  12. Breads Fortified with Freeze-Dried Vegetables: Quality and Nutritional Attributes. Part 1: Breads Containing Oil as an Ingredient

    Directory of Open Access Journals (Sweden)

    Viren Ranawana

    2016-03-01

    Full Text Available There is increasing emphasis on reformulating processed foods to make them healthier. This study for the first time comprehensively investigated the effects of fortifying bread (containing oil as an ingredient with freeze-dried vegetables on its nutritional and physico-chemical attributes. Breads fortified with carrot, tomato, beetroot or broccoli were assessed for nutrition, antioxidant potential, storage life, shelf stability, textural changes and macronutrient oxidation. Furthermore, using an in vitro model the study for the first time examined the impact of vegetable addition on the oxidative stability of macronutrients during human gastro-intestinal digestion. As expected, adding vegetables improved the nutritional and antioxidant properties of bread. Beetroot and broccoli significantly improved bread storage life. None of the vegetables significantly affected bread textural changes during storage compared to the control. Lipid oxidation in fresh bread was significantly reduced by all four types of vegetables whilst protein oxidation was lowered by beetroot, carrot and broccoli. The vegetables demonstrated varying effects on macronutrient oxidation during gastro-intestinal digestion. Beetroot consistently showed positive effects suggesting its addition to bread could be particularly beneficial.

  13. Effects of Freeze-Dried Vegetable Products on the Technological Process and the Quality of Dry Fermented Sausages.

    Science.gov (United States)

    Eisinaite, Viktorija; Vinauskiene, Rimante; Viskelis, Pranas; Leskauskaite, Daiva

    2016-09-01

    The aim of this study was to compare the chemical composition of freeze-dried vegetable powders: celery, celery juice, parsnip and leek. The effect of different freeze-dried vegetables onto the ripening process and the properties of dry fermented sausages was also evaluated. Vegetable products significantly (p fermentation and ripening process of dry fermented sausages. In addition, the color parameters for sausages with the added lyophilised celery products were considerable (p sausages made with lyophilised celery juice were characterised by higher lightness and lower hardness than those made with the addition of other vegetable products and control. Freeze-dried celery, celery juice, parsnip and leek have some potential for the usage as a functional ingredient or as a source for indirect addition of nitrate in the production of fermented sausages.

  14. Effects of Food Additives on Drying Rate, Rehydration Ratio and Sense Value of Freeze-dried Dumplings

    Directory of Open Access Journals (Sweden)

    Xingli Jiao

    2015-07-01

    Full Text Available Dumpling has always been a traditional and delicious food in China. Nevertheless, the rehydration effects, especially the nip of dumplings, are far from people’s satisfaction. To solve this problem, in this study, aimed at the improving the rehydration properties of freeze-dried dumplings, three kinds of food additives, including compound phosphate, soybean lecithin and guar gum, were added into dumplings wrappers. Results showed that, the drying rate, rehydration ratio and sense value were the highest with respective addition of 0.1% compound phosphate, 0.6% soybean lecithin and 0.35% guar gum. The interactions between freeze-dried dumplings and food additives were discussed, which provided the theory foundation for preparation of freeze-dried food.

  15. The Production of a Stable Infliximab Powder: The Evaluation of Spray and Freeze-Drying for Production

    Science.gov (United States)

    Kanojia, Gaurav; Have, Rimko ten; Bakker, Arjen; Wagner, Koen; Frijlink, Henderik W.; Kersten, Gideon F. A.; Amorij, Jean-Pierre

    2016-01-01

    In prospect of developing an oral dosage form of Infliximab, for treatment of Crohn’s disease and rheumatoid arthritis, freeze-drying (vial vs Lyoguard trays) and spray-drying were investigated as production method for stable powders. Dextran and inulin were used in combination with sucrose as stabilizing excipients. The drying processes did not affect Infliximab in these formulations, i.e. both the physical integrity and biological activity (TNF binding) were retained. Accelerated stability studies (1 month at 60°C) showed that the TNF binding ability of Infliximab was conserved in the freeze-dried formulations, whereas the liquid counterpart lost all TNF binding. After thermal treatment, the dried formulations showed some chemical modification of the IgG in the dextran-sucrose formulation, probably due to Maillard reaction products. This study indicates that, with the appropriate formulation, both spray-drying and freeze-drying may be useful for (bulk) powder production of Infliximab. PMID:27706175

  16. Freeze-dried nifedipine-lipid nanoparticles with long-term nano-dispersion stability after reconstitution.

    Science.gov (United States)

    Ohshima, Hiroyuki; Miyagishima, Atsuo; Kurita, Takurou; Makino, Yuji; Iwao, Yasunori; Sonobe, Takashi; Itai, Shigeru

    2009-07-30

    Nifedipine (NI) is a poorly water-soluble drug and its oral bioavailability is very low. To improve the water solubility, NI-lipid nanoparticle suspensions were prepared by a combination of co-grinding by a roll mill and high-pressure homogenization without any organic solvent. The mean particle size and zeta potential of the NI-lipid nanoparticle suspensions were about 52.6 nm and -61.8 mV, respectively, and each parameter remained extremely constant during a period of 4 months under 6 degrees C and dark conditions, suggesting that the negative charge of the phospholipid, dipalmitoyl phosphatidylglycerol, is very effective in preventing coagulation of the particles. In order to assure the nano-order particle size of the suspensions in view of long-term stability, a freeze-drying technique was applied to the NI-lipid nanoparticle suspensions. The mean particle size of freeze-dried NI-lipid nanoparticles after reconstitution was significantly increased in comparison to that of the preparations before freeze-drying. It was found, however, that the addition of sugars (glucose, fructose, maltose or sucrose) to the suspensions before freeze-drying inhibited the aggregation of nanoparticles, suggesting that the long-term stability storage of freeze-dried NI-lipid nanoparticles after reconstitution would be overcome. In addition, freeze-dried nanoparticles with 100mg sugar (glucose, fructose, maltose or sucrose) showed excellent solubility (>80%), whereas without sugar, as a control, showed low solubility (coagulation of NI nanoparticle suspensions, and reproduce the nanoparticle dispersion after reconstitution; and remarkably increase the apparent solubility of nifedipine.

  17. The role of protein modifications in senescence of freeze-dried Acetobacter senegalensis during storage

    Science.gov (United States)

    2014-01-01

    Background Loss of viability is one of the most important problems during starter culture production. Previous research has mostly focused on the production process of bacterial starters, but there are few studies about cellular protein deterioration causing cell defectiveness during storage. In the present study, we investigated the influence of storage temperature (−21, 4, 35°C) on the cellular protein modifications which may contribute to the senescence of freeze-dried Acetobacter senegalensis. Results Heterogeneous populations composed of culturable cells, viable but non-culturable cells (VBNC) and dead cells were generated when freeze-dried cells were kept at −21 and 4°C for 12 months whereas higher storage temperature (35°C) mainly caused death of the cells. The analysis of stored cell proteome by 2D-DiGE demonstrated a modified pattern of protein profile for cell kept at 4 and 35°C due to the formation of protein spot trains and shift of Isoelectric point (pI). Quantification of carbonylated protein by ELISA showed that the cells stored at 4 and 35°C had higher carbonylated protein contents than fresh cells. 2D-DiGE followed by Western blotting also confirmed the carbonylation of cellular proteins involved in translation process and energy generation. The auto-fluorescent feature of cells kept at 35°C increased significantly which may be an indication of protein glycation during storage. In addition, the percentage of cellular unsaturated fatty acid and the solubility of cellular proteins decreased upon storage of cells at higher temperature suggesting that peroxidation of fatty acids and possibly protein lipidation and oxidation occurred. Conclusions High storage temperature induces some deteriorative reactions such as protein oxidation, lipidation and glycation which may cause further protein modifications like pI-shift, and protein insolubility. These modifications can partly account for the changes in cell viability. It can also be deduced

  18. Structural determinants of hydration, mechanics and fluid flow in freeze-dried collagen scaffolds.

    Science.gov (United States)

    Offeddu, G S; Ashworth, J C; Cameron, R E; Oyen, M L

    2016-09-01

    Freeze-dried scaffolds provide regeneration templates for a wide range of tissues, due to their flexibility in physical and biological properties. Control of structure is crucial for tuning such properties, and therefore scaffold functionality. However, the common approach of modeling these scaffolds as open-cell foams does not fully account for their structural complexity. Here, the validity of the open-cell model is examined across a range of physical characteristics, rigorously linking morphology to hydration and mechanical properties. Collagen scaffolds with systematic changes in relative density were characterized using Scanning Electron Microscopy, X-ray Micro-Computed Tomography and spherical indentation analyzed in a time-dependent poroelastic framework. Morphologically, all scaffolds were mid-way between the open- and closed-cell models, approaching the closed-cell model as relative density increased. Although pore size remained constant, transport pathway diameter decreased. Larger collagen fractions also produced greater volume swelling on hydration, although the change in pore diameter was constant, and relatively small at ∼6%. Mechanically, the dry and hydrated scaffold moduli varied quadratically with relative density, as expected of open-cell materials. However, the increasing pore wall closure was found to determine the time-dependent nature of the hydrated scaffold response, with a decrease in permeability producing increasingly elastic rather than viscoelastic behavior. These results demonstrate that characterizing the deviation from the open-cell model is vital to gain a full understanding of scaffold biophysical properties, and provide a template for structural studies of other freeze-dried biomaterials. Freeze-dried collagen sponges are three-dimensional microporous scaffolds that have been used for a number of exploratory tissue engineering applications. The characterization of the structure-properties relationships of these scaffolds is

  19. Influence of crystallizing and non-crystallizing cosolutes on trehalose crystallization during freeze-drying.

    Science.gov (United States)

    Sundaramurthi, Prakash; Suryanarayanan, Raj

    2010-11-01

    To study the influence of crystallizing and non-crystallizing cosolutes on the crystallization behavior of trehalose in frozen solutions and to monitor the phase behavior of trehalose dihydrate and mannitol hemihydrate during drying. Trehalose (a lyoprotectant) and mannitol (a bulking agent) are widely used as excipients in freeze-dried formulations. Using differential scanning calorimetry (DSC) and X-ray diffractometry (XRD), the crystallization behavior of trehalose in the presence of (i) a crystallizing (mannitol), (ii) a non-crystallizing (sucrose) solute and (iii) a combination of mannitol and a model protein (lactose dehydrogenase, catalase, or lysozyme) was evaluated. By performing the entire freeze-drying cycle in the sample chamber of the XRD, the phase behavior of trehalose and mannitol were simultaneously monitored. When an aqueous solution containing trehalose (4% w/v) and mannitol (2% w/v) was cooled to -40°C at 0.5°C/min, hexagonal ice was the only crystalline phase. However, upon warming the sample to the annealing temperature (-18°C), crystallization of mannitol hemihydrate was readily evident. After 3 h of annealing, the characteristic XRD peaks of trehalose dihydrate were also observed. The DSC heating curve of frozen and annealed solution showed two overlapping endotherms, attributed by XRD to the sequential melting of trehalose dihydrate-ice and mannitol hemihydrate-ice eutectics, followed by ice melting. While mannitol facilitated trehalose dihydrate crystallization, sucrose completely inhibited it. In the presence of protein (2 mg/ml), trehalose crystallization required a longer annealing time. When the freeze-drying was performed in the sample chamber of the diffractometer, drying induced the dehydration of trehalose dihydrate to amorphous anhydrate. However, the final lyophiles prepared in the laboratory lyophilizer contained trehalose dihydrate and mannitol hemihydrate. Using XRD and DSC, the sequential crystallization of ice, mannitol

  20. Requirements concerning radiosterilization process organization; Wymagania dotyczace organizacji procesu sterylizacji radiacyjnej

    Energy Technology Data Exchange (ETDEWEB)

    Kaluska, I. [Institute of Nuclear Chemistry and Technology, Warsaw (Poland)

    1997-10-01

    Administrative procedure connecting for licensing new materials or consumer products appropriated to radiosterilization have been performed and explained. Also the organization of irradiation process for attaining the proper result have been described in detail. 4 refs, 1 tab.

  1. Effect of ultrasound and blanching pretreatments on polyacetylene and carotenoid content of hot air and freeze dried carrot discs.

    Science.gov (United States)

    Rawson, A; Tiwari, B K; Tuohy, M G; O'Donnell, C P; Brunton, N

    2011-09-01

    The effect of ultrasound and blanching pretreatments on polyacetylene (falcarinol, falcarindiol and falcarindiol-3-acetate) and carotenoid compounds of hot air and freeze dried carrot discs was investigated. Ultrasound pretreatment followed by hot air drying (UPHD) at the highest amplitude and treatment time investigated resulted in higher retention of polyacetylenes and carotenoids in dried carrot discs than blanching followed by hot air drying. Freeze dried samples had a higher retention of polyacetylene and carotenoid compounds compared to hot air dried samples. Color parameters were strongly correlated with carotenoids (p<0.05). This study shows that ultrasound pretreatment is a potential alternative to conventional blanching treatment in the drying of carrots.

  2. The use of a freeze-dried extract of Ligusticum mutellina in a cosmetic cream with potential antioxidant properties

    Directory of Open Access Journals (Sweden)

    Tomasz Baj

    2016-12-01

    Full Text Available The aim of this work was to develop a cream formulation with potential antioxidant properties. Herein, a freeze-dried extract of Ligusticum mutellina was used as a source of active compounds. The proposed qualitative composition of the cream was characterized by a good polyphenolic compounds release profile. Of note, the highest R2adj values were obtained for the Korsmeyer-Peppas and Higuchi models (0.9159 and 0.9226, respectively. These results indicate that a freeze-dried extract of L. mutellina, due to its retained high phenolic acids content, could become a key component in antioxidant creams.

  3. Characteristics of Vacuum Freeze Drying with Utilization of Internal Cooling and Condenser Waste Heat for Sublimation

    Directory of Open Access Journals (Sweden)

    Muhammad Alhamid

    2013-09-01

    Full Text Available Vacuum freeze drying is an excellent drying method, but it is very energy-intensive because a relatively long drying time is required. This research investigates the utilization of condenser waste heat for sublimation as a way of accelerating the drying rate. In addition, it also investigates the effect of internal cooling combined with vacuum cooling in the pressure reduction process. Jelly fish tentacles were used as the specimen, with different configurations for condenser heat waste and internal cooling valve opening. The results show that heating with condenser heat waste can accelerate the drying rate up to 0.0035 kg/m2.s. In addition, pre-freezing by internal cooling prevents evaporation until the mass of the specimen is 0.47 g and promotes transition of the specimen into the solid phase.

  4. Depositing nanoparticles on a silicon substrate using a freeze drying technique

    Science.gov (United States)

    Sigehuzi, Tomoo

    2017-08-01

    For the microscopic observation of nanoparticles, an adequate sample preparation is an essential part of this task. Much research has been performed for usable preparation methods that will yield aggregate-free samples. A freeze drying technique, which only requires a -80 °C freezer and a freeze dryer, is shown to provide an on-substrate dispersion of mostly isolated nanoparticles. The particle density could be made sufficiently high for efficient observations using atomic force microscopy. Since this sandwich method is purely physical, it could be applied to deposit various nanoparticles independent of their surface chemical properties. Suspension film thickness, or the dimensionality of the suspension film, was shown to be crucial for the isolation of the particles. Silica nanoparticles were dispersed on a silicon substrate using this method and the sample properties were examined using atomic force microscopy.

  5. Physical characteristics of phycocyanin from spirulina microcapsules using different coating materials with freeze drying method

    Science.gov (United States)

    Dewi, E. N.; Purnamayati, L.; Kurniasih, R. A.

    2017-02-01

    The aim of this study was to compare the physical characteristics of phycocyanin microcapsules (F) from Spirulina sp. with different coating materials, such as κ-Carrageenan (C) and Na-alginate (A) in combination with maltodextrin (M) by freeze drying method. Microcapsules were prepared in three variations of coating materials i.e. maltodextrin (FM); maltodextrin and Na-alginate (FMA); and maltodextrin and carrageenan (FMC) with concentration of each materials were 10%; 9%:1.0%; and 9%:1% (w/w), respectively. The results showed that FMA with Na-alginate 1.0% produced the highest bulk density and total soluble solid, there were 0,334 g/ml and 9,067%, respectively. Color analysis by chromameter showed that FMC produced the bluest color compared to other samples. The glass transition temperature (Tg) investigated with Differential scanning calorimeter (DSC) in all of the samples.

  6. Study on the Effect of Pickled Cabbage using Freeze-drying Protective Agent

    Directory of Open Access Journals (Sweden)

    Xing Long

    2013-10-01

    Full Text Available The protective effect of pickled cabbage using biological material was researched in the study. Firstly, the research determined the centrifugal condition of bacterial sludge and then detected the influence of various protective agents on the survival rate of lactobacillus. The final test result can show the influence degree of various protective agents on the survival rate of the freeze-drying lactobacillus was sodium glutamate>skim milk>mannitol>sucrose>glycerol>maltose. The best formula of the protective agent was: the skim milk, sucrose, glycerol, maltose and sodium glutamate shall be 6% and the mannitol shall be 4%. The survival rate of the lactobacillus after using the sodium glutamate with the best protection effect can reach 65.5%. The experience proved that these protective agents and ratio can guarantee the nutrients in the pickled cabbage not destroyed.

  7. Versatile Aerogel Fabrication by Freezing and Subsequent Freeze-Drying of Colloidal Nanoparticle Solutions.

    Science.gov (United States)

    Freytag, Axel; Sánchez-Paradinas, Sara; Naskar, Suraj; Wendt, Natalja; Colombo, Massimo; Pugliese, Giammarino; Poppe, Jan; Demirci, Cansunur; Kretschmer, Imme; Bahnemann, Detlef W; Behrens, Peter; Bigall, Nadja C

    2016-01-18

    A versatile method to fabricate self-supported aerogels of nanoparticle (NP) building blocks is presented. This approach is based on freezing colloidal NPs and subsequent freeze drying. This means that the colloidal NPs are directly transferred into dry aerogel-like monolithic superstructures without previous lyogelation as would be the case for conventional aerogel and cryogel fabrication methods. The assembly process, based on a physical concept, is highly versatile: cryogelation is applicable for noble metal, metal oxide, and semiconductor NPs, and no impact of the surface chemistry or NP shape on the resulting morphology is observed. Under optimized conditions the shape and volume of the liquid equal those of the resulting aerogels. Also, we show that thin and homogeneous films of the material can be obtained. Furthermore, the physical properties of the aerogels are discussed.

  8. Thermal, Structural, and Physical Properties of Freeze Dried Tropical Fruit Powder

    Directory of Open Access Journals (Sweden)

    K. A. Athmaselvi

    2014-01-01

    Full Text Available This study evaluates the physical properties of freeze dried tropical (guava, sapota, and papaya fruit powders. Thermal stability and weight loss were evaluated using TGA-DSC and IR, which showed pectin as the main solid constituent. LCR meter measured electrical conductivity, dielectric constant, and dielectric loss factor. Functional groups assessed by FTIR showed presence of chlorides, and O–H and N–H bonds in guava, chloride and C–H bond in papaya, and chlorides, and C=O and C–H bonds in sapota. Particle size and type of starch were evaluated by X-ray diffraction and microstructure through scanning electronic microscopy. A semicrystalline profile and average particle size of the fruit powders were evidenced by X-ray diffraction and lamellar/spherical morphologies by SEM. Presence of A-type starch was observed in all three fruits. Dependence of electric and dielectric properties on frequency and temperature was observed.

  9. Spectroscopic evaluation of a freeze-dried vaccine during an accelerated stability study.

    Science.gov (United States)

    Hansen, Laurent; Van Renterghem, Jeroen; Daoussi, Rim; Vervaet, Chris; Remon, Jean Paul; De Beer, Thomas

    2016-07-01

    This research evaluates a freeze-dried live, attenuated virus vaccine during an accelerated stability study using Near Infrared (NIR) and Fourier Transform Infrared (FTIR) spectroscopy in addition to the traditional quality tests (i.e., potency assay and residual moisture analysis) and Modulated Differential Scanning Calorimetry (MDSC). Therefore, freeze-dried live, attenuated virus vaccines were stored during four weeks at 4°C (i.e., recommended storage condition) and at 37°C (i.e., accelerated storage condition) and weekly analyzed using these techniques. The potency assay showed that the virus titer decreased in two phases when the samples were stored at 37°C. The highest titer loss occurred during the first week storage at 37°C after which the degradation rate decreased. Both the residual moisture content and the relaxation enthalpy also increased according to this two-phase pattern during storage at 37°C. In order to evaluate the virus and its interaction with the amorphous stabilizer in the formulation (trehalose), the NIR spectra were analyzed via principal component analysis (PCA) using the amide A/II band (5029-4690cm(-1)). The FTIR spectra were also analyzed via PCA using the amide III spectral range (1350-1200cm(-1)). Analysis of the amide A/II band in the NIR spectra revealed that the titer decrease during storage was probably linked to a change of the hydrogen bonds (i.e., interaction) between the virus proteins and the amorphous trehalose. Analyzing the amide III band (FTIR spectra) showed that the virus destabilization was coupled to a decrease of the coated proteins β turn and an increase of α helix. During storage at 4°C, the titer remained constant, no enthalpic relaxation was observed and neither the Amide A/II band (NIR spectra) nor the Amide III band (FTIR spectra) varied.

  10. Freeze-dried Xanthan/Guar Gum Nasal Inserts for the Delivery of Metoclopramide Hydrochloride.

    Science.gov (United States)

    Dehghan, Mohamed Hassan; Girase, Mohan

    2012-01-01

    Prolonged residence of drug formulation in the nasal cavity is important for the enhancing intranasal drug delivery. The objective of the present study was to develop a mucoadhesive in-situ gelling nasal insert which would enable the reduced nasal mucociliary clearance in order to improve the bioavailability of metoclopramide hydrochloride. Metoclopramide hydrochloride is a potent antiemetic and effective for preventing emesis induced by cancer chemotherapy, migraine, pregnancy and gastroparesis. It undergoes hepatic first pass metabolism and both the absolute bioavailability and the plasma concentrations are subjected to wide inter-individual variation showing values between 32% and 98%. Oral antiemetic often gets vomited out before the systemic absorption compelling parenteral administration which results in low patient compliance. Adverse effect of metoclopramide HCL on CNS caused by high plasma peaks can be avoided through sustained formulation. A novel combination of xanthan gum and guar gum was used to prepare the nasal inserts and the effect of blend ratio of xanthan gum and guar gum on drug release from in-situ gelling nasal inserts and on other insert properties such as bioadhesion potential and water uptake was studied. PXRD was used to determine the effect of freeze-drying on crystalline nature of formulation. The viscosities of xanthan gum in combination with guar gum were observed to be higher than that of single polymer solutions. This is because of the synergistic rheological interaction between xanthan and guar gum. There is a substantial loss in crystalline nature of the formulation after freeze-drying. The best nasal inserts formulation containing xanthan gum and guar gum ratio 1:5, showed good release (91.83%) as well as bioadhesion which may result in an increase in the nasal residence time.

  11. The Effect of Non Freeze-dried Hydrogel-CHA on Fibroblast Proliferation

    Directory of Open Access Journals (Sweden)

    Ivan Arie Wahyudi

    2015-05-01

    Full Text Available Bone damage can be caused by variety of surgical procedures. Bone reconstruction has been developed lately is tissue engineering techniques. One of materials that proved to be effective as a scaffold in tissue engineering is a hydrogel. The addition of carbonate apatite (CHA will produce a hydrogel-CHA material which is believed to improve the mechanical properties and biological similarities with the original bone. Scaffold is considered an important aspect in the field of tissue engineering, because it’s ability to mimic extracellular matrix of the damaged tissue. Fibroblasts are mesenchymal cells that can be readily cultured in the laboratory and play a significant role in epithelial-mesenchymal interactions, secreting various growth factors and cytokines. On certain condition, Fibroblast will differentiate into bone-forming cells, osteoblasts. Objective: to determine the effect of non freezedried hydrogels - CHA on the number of fibroblasts. Methods: In the treatment groups (hydrogel and hydrogel-CHA group, the static seeding, where cells and scaffolds were simply brought into contact, was performed. The other group contained only cells and growth media. Cells were seeded at a density of 2x104 cells/ml in a 96-well plate. Number of fibroblasts cell in each group was observed by light microscopy and quantitified by MTT assay on days 1, 2 and 3 post-application. Results: Proliferation of fibroblasts increased significantly on day 3rd after application of non freeze-dried hydrogel - CHA (p< 0.05. Conclusion: Application of non freeze-dried hydrogel - CHA may induce fibroblasts proliferation.

  12. Jet-vortex spray freeze drying for the production of inhalable lyophilisate powders.

    Science.gov (United States)

    Wanning, Stefan; Süverkrüp, Richard; Lamprecht, Alf

    2017-01-01

    Spray-freeze-dried powders were suggested for nasal, epidermal (needle-free injection) or pulmonary application of proteins, peptides or nucleic acids. In spray-freeze-drying processes an aqueous solution is atomized into a refrigerant medium and subsequently dried by sublimation. Droplet-stream generators produce a fast stream of monodisperse droplets, where droplets are subject to collisions and therefore the initial monodispersity is lost and droplets increase in diameter, which reduces their suitability for pulmonary application. In jet-vortex-freezing, a droplet-stream is injected into a vortex of cold process gas to prevent droplet collisions. Both the injection position of the droplet-stream and the velocity of the cold gas vortex have an impact on the size distributions of the resulting powders. A model solution containing mannitol (1.5%m/V) and maltodextrin (1.5%m/V) was sprayed at 5 droplet-stream positions at distances between 1mm and 30mm from the gas jet nozzle and 5 gas velocities (0.8-6.8m/s) at a process temperature of -100°C. Mean geometric diameters of the highly porous particles (bulk density: 0.012±0.007g/cm3) ranged between 55±4 and 98±4μm. Evaluation of the aerodynamic properties by Next-Generation-Impactor (NGI) analysis showed that all powders had high emitted doses (98±1%) and fine-particle fractions ranged between 4±1% and 21±2%. It was shown that jet-vortex freezing is a suitable method for the reproducible production of lyophilized powders with excellent dispersibility in air, which has a high potential for nasal and pulmonary drug delivery. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Quality of freeze-dried (lyophilized) quarantined single-donor plasma.

    Science.gov (United States)

    Bux, Jürgen; Dickhörner, Dieter; Scheel, Edgar

    2013-12-01

    Transfusion of plasma is a basic treatment for complex coagulopathies as well as in major blood loss. Early transfusion of plasma after trauma with major hemorrhage has been recommended by retrospective studies. However, the use of plasma is often hampered by the need to maintain a cold chain and the time needed for thawing fresh-frozen plasma (FFP). With freeze-dried (lyophilized) plasma (FDP) both difficulties can be avoided. Here, we describe the production, quality characteristics, and our experiences with FDP. Quarantine plasma samples were freeze-dried. The clotting factors fibrinogen, Factor (F)V, FVIII, FXI, von Willebrand factor (vWF), protein S, antithrombin, plasminogen, and plasmin inhibitor were determined after manufacturing and after storage at room temperature and refrigeration. Reported adverse transfusion events were evaluated and compared to that of FFP. Clinical effectiveness was estimated by inquiry among experienced users. Lyophilization resulted in a loss of coagulation factor activity between 0% and up to 20% to 25% (FVIII, vWF). When stored refrigerated, coagulation factors did not lose more than 10% of their activities. Storage at room temperature for 24 months mainly affected vWF/ristocetin cofactor activity and fibrinogen activity. From 2007 to 2011 more than 230,000 units of FDP were delivered. There were no reports about clinical ineffectiveness. The frequency of transfusion reactions was not different from that of FFP. Lyophilized plasma showed characteristics similar to FFP. Since FDP requires neither complex logistics nor time-consuming thawing, it allows rapid treatment of coagulopathies. © 2013 American Association of Blood Banks.

  14. Formation of highly porous aerosol particles by atmospheric freeze-drying in ice clouds.

    Science.gov (United States)

    Adler, Gabriela; Koop, Thomas; Haspel, Carynelisa; Taraniuk, Ilya; Moise, Tamar; Koren, Ilan; Heiblum, Reuven H; Rudich, Yinon

    2013-12-17

    The cycling of atmospheric aerosols through clouds can change their chemical and physical properties and thus modify how aerosols affect cloud microphysics and, subsequently, precipitation and climate. Current knowledge about aerosol processing by clouds is rather limited to chemical reactions within water droplets in warm low-altitude clouds. However, in cold high-altitude cirrus clouds and anvils of high convective clouds in the tropics and midlatitudes, humidified aerosols freeze to form ice, which upon exposure to subsaturation conditions with respect to ice can sublimate, leaving behind residual modified aerosols. This freeze-drying process can occur in various types of clouds. Here we simulate an atmospheric freeze-drying cycle of aerosols in laboratory experiments using proxies for atmospheric aerosols. We find that aerosols that contain organic material that undergo such a process can form highly porous aerosol particles with a larger diameter and a lower density than the initial homogeneous aerosol. We attribute this morphology change to phase separation upon freezing followed by a glass transition of the organic material that can preserve a porous structure after ice sublimation. A porous structure may explain the previously observed enhancement in ice nucleation efficiency of glassy organic particles. We find that highly porous aerosol particles scatter solar light less efficiently than nonporous aerosol particles. Using a combination of satellite and radiosonde data, we show that highly porous aerosol formation can readily occur in highly convective clouds, which are widespread in the tropics and midlatitudes. These observations may have implications for subsequent cloud formation cycles and aerosol albedo near cloud edges.

  15. Effect of allogenic freeze-dried demineralized bone matrix on guided tissue regeneration in dogs.

    Science.gov (United States)

    Caplanis, N; Lee, M B; Zimmerman, G J; Selvig, K A; Wikesjö, U M

    1998-08-01

    This randomized, split-mouth study was designed to evaluate the adjunctive effect of allogenic, freeze-dried, demineralized bone matrix (DBM) to guided tissue regeneration (GTR). Contralateral fenestration defects (6 x 4 mm) were created 6 mm apical to the buccal alveolar crest on maxillary canine teeth in 6 beagle dogs. DBM was implanted into one randomly selected fenestration defect. Expanded polytetrafluoroethylene (ePTFE) membranes were used to provide bilateral GTR. Tissue blocks including defects with overlying membranes and soft tissues were harvested following a four-week healing interval and prepared for histometric analysis. Differences between GTR+DBM and GTR defects were evaluated using a paired t-test (N = 6). DBM was discernible in all GTR+DBM defects with limited, if any, evidence of bone metabolic activity. Rather, the DBM particles appeared solidified within a dense connective tissue matrix, often in close contact to the instrumented root. There were no statistically significant differences between the GTR+DBM versus the GTR condition for any histometric parameter examined. Fenestration defect height averaged 3.7+/-0.3 and 3.9+/-0.3 mm, total bone regeneration 0.8+/-0.6 and 1.5+/-0.8 mm, and total cementum regeneration 2.0+/-1.3 and 1.6+/-1.7 mm for GTR+DBM and GTR defects, respectively. The histologic and histometric observations, in concert, suggest that allogenic freeze-dried DBM has no adjunctive effect to GTR in periodontal fenestration defects over a four-week healing interval. The critical findings were 1) the DBM particles remained, embedded in dense connective tissue without evidence of bone metabolic activity; and 2) limited and similar amounts of bone and cementum regeneration were observed for both the GTR+DBM and GTR defects.

  16. Fabrication of Li{sub 2}TiO{sub 3} pebbles by a freeze drying process

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sang-Jin, E-mail: lee@mokpo.ac.kr [Department of Advanced Materials Science and Engineering, Mokpo National University, Muan 534-729 (Korea, Republic of); Park, Yi-Hyun [National Fusion Research Institute, Daejeon 305-806 (Korea, Republic of); Yu, Min-Woo [Department of Advanced Materials Science and Engineering, Mokpo National University, Muan 534-729 (Korea, Republic of)

    2013-11-15

    Li{sub 2}TiO{sub 3} pebbles were successfully fabricated by using a freeze drying process. The Li{sub 2}TiO{sub 3} slurry was prepared using a commercial powder of particle size 0.5–1.5 μm and the pebble pre-form was prepared by dropping the slurry into liquid nitrogen through a syringe needle. The droplets were rapidly frozen, changing their morphology to spherical pebbles. The frozen pebbles were dried at −10 °C in vacuum. To make crack-free pebbles, some glycerin was employed in the slurry, and long drying time and a low vacuum condition were applied in the freeze drying process. In the process, the solid content in the slurry influenced the spheroidicity of the pebble green body. The dried pebbles were sintered at 1200 °C in an air atmosphere. The sintered pebbles showed almost 40% shrinkage. The sintered pebbles revealed a porous microstructure with a uniform pore distribution and the sintered pebbles were crushed under an average load of 50 N in a compressive strength test. In the present study, a freeze drying process for fabrication of spherical Li{sub 2}TiO{sub 3} pebbles is introduced. The processing parameters, such as solid content in the slurry and the conditions of freeze drying and sintering, are also examined.

  17. Inulin sugar glasses preserve the structural integrity and biological activity of influenza virosomes during freeze-drying and storage

    NARCIS (Netherlands)

    de Jonge, Jørgen; Amorij, Jean-Pierre; Hinrichs, Wouter L.J.; Wilschut, Jan; Huckriede, Anke; Frijlink, Henderik W.

    2007-01-01

    Influenza virosomes are reconstituted influenza virus envelopes that may be used as vaccines or as carrier systems for cellular delivery of therapeutic molecules. Here we present a procedure to generate influenza virosomes as a stable dry-powder formulation by freeze-drying (lyophilization) using an

  18. Optimization of a cryoprotective medium to increase the viability of freeze-dried Streptococcus thermophilus by response surface methodology

    Science.gov (United States)

    Streptococcus thermophilus normally exhibits different survival rates in different bacteria medium during freeze-drying. In this study, response surface methodology (RSM) was applied on the design of experiments for optimizing the cryoprotective medium. Results showed that the most significant facto...

  19. A batch modelling approach to monitor a freeze-drying process using in-line Raman spectroscopy.

    Science.gov (United States)

    Sarraguça, Mafalda Cruz; De Beer, Thomas; Vervaet, Chris; Remon, Jean-Paul; Lopes, João Almeida

    2010-11-15

    Freeze-drying or lyophilisation is a batch wise industrial process used to remove water from solutions, hence stabilizing the solutes for distribution and storage. The objective of the present work was to outline a batch modelling approach to monitor a freeze-drying process in-line and in real-time using Raman spectroscopy. A 5% (w/v) D-mannitol solution was freeze-dried in this study as model. The monitoring of a freeze-drying process using Raman spectroscopy allows following the product behaviour and some process evolution aspects by detecting the changes of the solutes and solvent occurring during the process. Herewith, real-time solid-state characterization of the final product is also possible. The timely spectroscopic measurements allowed the differentiation between batches operated in normal process conditions and batches having deviations from the normal trajectory. Two strategies were employed to develop batch models: partial least squares (PLS) using the unfolded data and parallel factor analysis (PARAFAC). It was shown that both strategies were able to developed batch models using in-line Raman spectroscopy, allowing to monitor the evolution in real-time of new batches. However, the computational effort required to develop the PLS model and to evaluate new batches using this model is significant lower compared to the PARAFAC model. Moreover, PLS scores in the time mode can be computed for new batches, while using PARAFAC only the batch mode scores can be determined for new batches.

  20. Impact of Microscale and Pilot-Scale Freeze-Drying on Protein Secondary Structures: Sucrose Formulations of Lysozyme and Catalase.

    Science.gov (United States)

    Peters, Björn-Hendrik; Leskinen, Jari T T; Molnár, Ferdinand; Ketolainen, Jarkko

    2015-11-01

    Microscale (MS) freeze-drying offers rapid process cycles for early-stage formulation development. The effects of the MS approach on the secondary structures of two model proteins, lysozyme and catalase, were compared with pilot-scale (PS) vial freeze-drying. The secondary structures were assessed by attenuated total reflection Fourier transformed infrared spectroscopy. Formulations were made with increasing sucrose-protein ratios. Freeze-drying protocols involved regular cooling without thermal treatment and annealing with MS and PS equipment, and cooling rate variations with the MS. Principal component analysis of smoothed second-derivative amide I spectra revealed sucrose-protein ratio-dependent shifts toward α-helical structures. Transferability of sucrose-protein formulations from MS to PS vial freeze-drying was evidenced at regular cooling rates. Local differences in protein secondary structures between the bottom and top of sucrose-catalase samples could be detected at the sucrose-catalase ratios of 1 and 2, this being related to the initial filling height and ice crystal morphology. Annealing revealed temperature, protein, formulation, and sample location-dependent effects influencing surface morphology at the top, or causing protein secondary structure perturbation at the bottom. With the MS approach, protein secondary structure differences at different cooling rates could be detected for sucrose-lysozyme samples at the sucrose-lysozyme ratio of 1.

  1. Cell viability of microencapsulated Bifidobacterium animalis subsp. lactis under freeze-drying, storage and gastrointestinal tract simulation conditions.

    Science.gov (United States)

    Shamekhi, Fatemeh; Shuhaimi, Mustafa; Ariff, Arbakariya; Manap, Yazid A

    2013-03-01

    The purpose of this study was to improve the survival of Bifidobacterium animalis subsp. lactis 10140 during freeze-drying process by microencapsulation, using a special pediatric prebiotics mixture (galactooligosaccharides and fructooligosaccharides). Probiotic microorganisms were encapsulated with a coat combination of prebiotics-calcium-alginate prior to freeze-drying. Both encapsulated and free cells were then freeze-dried in their optimized combinations of skim milk and prebiotics. Response surface methodology (RSM) was used to produce a coating combination as well as drying medium with the highest cell viability during freeze-drying. The optimum encapsulation composition was found to be 2.1 % Na-alginate, 2.9 % prebiotic, and 21.7 % glycerol. Maximum survival predicted by the model was 81.2 %. No significant (p > 0.05) difference between the predicted and experimental values verified the adequacy of final reduced models. The protection ability of encapsulation was then examined over 120 days of storage at 4 and 25 °C and exposure to a sequential model of infantile GIT conditions including both gastric conditions (pH 3.0 and 4.0, 90 min, 37 °C) and intestinal conditions (pH 7.5, 5 h, 37 °C). Significantly improved cell viability showed that microencapsulation of B. lactis 10140 with the prebiotics was successful in producing a stable symbiotic powdery nutraceutical.

  2. Evaluation of 3D-Printed Polycaprolactone Scaffolds Coated with Freeze-Dried Platelet-Rich Plasma for Bone Regeneration

    Directory of Open Access Journals (Sweden)

    Junda Li

    2017-07-01

    Full Text Available Three-dimensional printing is one of the most promising techniques for the manufacturing of scaffolds for bone tissue engineering. However, a pure scaffold is limited by its biological properties. Platelet-rich plasma (PRP has been shown to have the potential to improve the osteogenic effect. In this study, we improved the biological properties of scaffolds by coating 3D-printed polycaprolactone (PCL scaffolds with freeze-dried and traditionally prepared PRP, and we evaluated these scaffolds through in vitro and in vivo experiments. In vitro, we evaluated the interaction between dental pulp stem cells (DPSCs and the scaffolds by measuring cell proliferation, alkaline phosphatase (ALP activity, and osteogenic differentiation. The results showed that freeze-dried PRP significantly enhanced ALP activity and the mRNA expression levels of osteogenic genes (ALP, RUNX2 (runt-related gene-2, OCN (osteocalcin, OPN (osteopontin of DPSCs (p < 0.05. In vivo, 5 mm calvarial defects were created, and the PRP-PCL scaffolds were implanted. The data showed that compared with traditional PRP-PCL scaffolds or bare PCL scaffolds, the freeze-dried PRP-PCL scaffolds induced significantly greater bone formation (p < 0.05. All these data suggest that coating 3D-printed PCL scaffolds with freeze-dried PRP can promote greater osteogenic differentiation of DPSCs and induce more bone formation, which may have great potential in future clinical applications.

  3. Effects of formulation and process factors on the crystal structure of freeze-dried Myo-inositol.

    Science.gov (United States)

    Izutsu, Ken-Ichi; Yomota, Chikako; Okuda, Haruhiro; Kawanishi, Toru; Yamaki, Takuya; Ohdate, Ryohei; Yu, Zhaokun; Yonemochi, Etsuo; Terada, Katsuhide

    2014-08-01

    The objective of this study was to elucidate effects of formulation and process variables on the physical forms of freeze-dried myo-inositol. Physical properties of myo-inositol in frozen solutions, freeze-dried solids, and cooled heat-melt solids were characterized by powder X-ray diffraction (PXRD), thermal analysis (differential scanning calorimetry [DSC] and thermogravimetric), and simultaneous PXRD-DSC analysis. Cooling of heat-melt myo-inositol produced two forms of metastable anhydrate crystals that change to stable form (melting point 225 °C-228 °C) with transition exotherms at around 123 °C and 181 °C, respectively. Freeze-drying of single-solute aqueous myo-inositol solutions after rapid cooling induced crystallization of myo-inositol as metastable anhydrate (transition at 80 °C-125 °C) during secondary drying segment. Contrarily, postfreeze heat treatment (i.e., annealing) induced crystallization of myo-inositol dihydrate. Removal of the crystallization water during the secondary drying produced the stable-form myo-inositol anhydrate crystal. Shelf-ramp slow cooling of myo-inositol solutions resulted in the stable and metastable anhydrous crystal solids depending on the solute concentrations and the solution volumes. Colyophilization with phosphate buffer retained myo-inositol in the amorphous state. Crystallization in different process segments varies crystal form of freeze-dried myo-inositol solids.

  4. Freeze-drying for controlled nanoparticle distribution in Co/SiO 2 Fischer–Tropsch catalysts

    NARCIS (Netherlands)

    Eggenhuisen, T.M.; Munnik, P.; Talsma, H.; de Jongh, P.E.; de Jong, K.P.

    2013-01-01

    Controlling the nanoparticle distribution over a support is considered essential to arrive at more stable catalysts. By developing a novel freeze drying method, the nanoparticle distribution was successfully manipulated for the preparation of Co/SiO2 Fischer-Tropsch catalysts using a commercial sili

  5. IR STUDY ON MONOMOLECULAR PARTICLE AGGLOMERATES OF POLYSTYRENE OBTAINED BY FREEZE-DRYING OF ITS DILUTE SOLUTION

    Institute of Scientific and Technical Information of China (English)

    Song Wang; Qing-hua Wang; Rong-shi Cheng

    2002-01-01

    The monomolecular particle agglomerates of polystyrenes were obtained by freeze-drying of its very dilutesolutions of 1.3 x 10-5-2.0 x 10-s g/mL in benzene:cylcohexane (100:1) solvents, and they were annealed at roomtemperature for hundred days before use. According to 13C-NMR measurement the polystyrenes should be practically atactic.The number average molecular weights of the samples are 2.80 x 103, 2.00 x 104, and 1.55 x 106, respectively. The freeze-dried aPS with a molecular weight higher than 104 show two new IR absorption bands at 1098 and 1261 cm-1, which areabsent in the normal aPS and freeze-dried styrene oligomer. it was also found that the low molecular weight samples canonly form powders, whereas the freeze-dried aPS with higher molecular weight form a mixture of powders and fibrils, ofwhich the longer fibrils show a much stronger 1261 cm-1 band than the shorter fibrils and the powder. It seems that the1261 cm-1 band corresponds to the stacking behavior of monomolecular particles.

  6. A comparison between spray drying and spray freeze drying to produce an influenza subunit vaccine powder for inhalation

    NARCIS (Netherlands)

    Saluja, V.; Amorij, J-P.; Kapteyn, J. C.; de Boer, A. H.; Frijlink, H. W.; Hinrichs, W. L. J.

    2010-01-01

    The aim of this study was to investigate two different processes to produce a stable influenza subunit vaccine powder for pulmonary immunization i.e. spray drying (SD) and spray freeze drying (SFD). The formulations were analyzed by proteolytic assay, single radial immunodiffusion assay (SRID), casc

  7. Research Article: Effects of long-term simulated Martian conditions on a freeze-dried and homogenized bacterial permafrost community

    DEFF Research Database (Denmark)

    Hansen, Aviaja Anna; Jensen, Lars Liengård; Kristoffersen, Tommy

    2009-01-01

    Indigenous bacteria and biomolecules (DNA and proteins) in a freeze-dried and homogenized Arctic permafrost were exposed to simulated martian conditions that correspond to about 80 days on the surface of Mars with respect to the accumulated UV dose. The simulation conditions included UV radiation...... and polynucleotides are more resistant to destruction than living biota. Astrobiology 9, 229-240....

  8. A comparison between spray drying and spray freeze drying to produce an influenza subunit vaccine powder for inhalation

    NARCIS (Netherlands)

    Saluja, V.; Amorij, J-P.; Kapteyn, J. C.; de Boer, A. H.; Frijlink, H. W.; Hinrichs, W. L. J.

    2010-01-01

    The aim of this study was to investigate two different processes to produce a stable influenza subunit vaccine powder for pulmonary immunization i.e. spray drying (SD) and spray freeze drying (SFD). The formulations were analyzed by proteolytic assay, single radial immunodiffusion assay (SRID),

  9. Study of nonvolatile degradation compounds produced by radiosterilization of cefotaxime

    Science.gov (United States)

    Barbarin, N.; Tilquin, B.

    2001-01-01

    The effects of radiosterilization on the purity profile of cefotaxime were evaluated by a liquid chromatography-diode array method. Numerous new radiolytic compounds were detected in very small amount. They were quantified and it appeared that none was present above the level of 0.1% of the main compound and the total amount was only of 0.72%. Despite the low quantities present, some radiolytic compounds had UV spectra which could justify the apparition of a yellow coloration detected after irradiation. Others had UV spectra similar to that of cefotaxime, suggesting similarity in the molecular structures. Finally, some mechanisms of formation were proposed for four radiolytic compounds which were identified by mass spectrometry in a former study.

  10. Study of nonvolatile degradation compounds produced by radiosterilization of cefotaxime

    Energy Technology Data Exchange (ETDEWEB)

    Barbarin, N.; Tilquin, B. E-mail: tilquin@cham.ucl.ac.be

    2001-07-01

    The effects of radiosterilization on the purity profile of cefotaxime were evaluated by a liquid chromatography-diode array method. Numerous new radiolytic compounds were detected in very small amount. They were quantified and it appeared that none was present above the level of 0.1% of the main compound and the total amount was only of 0.72%. Despite the low quantities present, some radiolytic compounds had UV spectra which could justify the apparition of a yellow coloration detected after irradiation. Others had UV spectra similar to that of cefotaxime, suggesting similarity in the molecular structures. Finally, some mechanisms of formation were proposed for four radiolytic compounds which were identified by mass spectrometry in a former study. (author)

  11. First steps towards tissue engineering of small-diameter blood vessels: preparation of flat scaffolds of collagen and elastin by means of freeze drying

    NARCIS (Netherlands)

    Buttafoco, L.; Engbers-Buijtenhuijs, P.; Poot, Andreas A.; Dijkstra, Pieter J.; Daamen, W.F.; van Kuppevelt, T.H.; Vermes, I.; Feijen, Jan

    2006-01-01

    Porous scaffolds composed of collagen or collagen and elastin were prepared by freeze drying at temperatures between -18 and -196°C. All scaffolds had a porosity of 90-98% and a homogeneous distribution of pores. Freeze drying at -18°C afforded collagen and collagen/elastin matrices with average

  12. Stability of buffer-free freeze-dried formulations: A feasibility study of a monoclonal antibody at high protein concentrations.

    Science.gov (United States)

    Garidel, Patrick; Pevestorf, Benjamin; Bahrenburg, Sven

    2015-11-01

    We studied the stability of freeze-dried therapeutic protein formulations over a range of initial concentrations (from 40 to 160 mg/mL) and employed a variety of formulation strategies (including buffer-free freeze dried formulations, or BF-FDF). Highly concentrated, buffer-free liquid formulations of therapeutic monoclonal antibodies (mAbs) have been shown to be a viable alternative to conventionally buffered preparations. We considered whether it is feasible to use the buffer-free strategy in freeze-dried formulations, as an answer to some of the known drawbacks of conventional buffers. We therefore conducted an accelerated stability study (24 weeks at 40 °C) to assess the feasibility of stabilizing freeze-dried formulations without "classical" buffer components. Factors monitored included pH stability, protein integrity, and protein aggregation. Because the protein solutions are inherently self-buffering, and the system's buffer capacity scales with protein concentration, we included highly concentrated buffer-free freeze-dried formulations in the study. The tested formulations ranged from "fully formulated" (containing both conventional buffer and disaccharide stabilizers) to "buffer-free" (including formulations with only disaccharide lyoprotectant stabilizers) to "excipient-free" (with neither added buffers nor stabilizers). We evaluated the impacts of varying concentrations, buffering schemes, pHs, and lyoprotectant additives. At the end of 24 weeks, no change in pH was observed in any of the buffer-free formulations. Unbuffered formulations were found to have shorter reconstitution times and lower opalescence than buffered formulations. Protein stability was assessed by visual inspection, sub-visible particle analysis, protein monomer content, charge variants analysis, and hydrophobic interaction chromatography. All of these measures found the stability of buffer-free formulations that included a disaccharide stabilizer comparable to buffer

  13. Effect of protective agents and previous acclimation on ethanol resistance of frozen and freeze-dried Lactobacillus plantarum strains.

    Science.gov (United States)

    Bravo-Ferrada, Bárbara Mercedes; Brizuela, Natalia; Gerbino, Esteban; Gómez-Zavaglia, Andrea; Semorile, Liliana; Tymczyszyn, E Elizabeth

    2015-12-01

    The aim of this work was to study the protective effect of sucrose, trehalose and glutamate during freezing and freeze-drying of three oenological Lactobacillus plantarum strains previously acclimated in the presence of ethanol. The efficiency of protective agents was assessed by analyses of membrane integrity and bacterial cultivability in a synthetic wine after the preservation processes. No significant differences in the cultivability, with respect to the controls cells, were observed after freezing at -80 °C and -20 °C, and pre-acclimated cells were more resistant to freeze-drying than non-acclimated ones. The results of multiparametric flow cytometry showed a significant level of membrane damage after freeze-drying in two of the three strains. The cultivability was determined after incubation in wine-like medium containing 13 or 14% v/v ethanol at 21 °C for 24 h and the results were interpreted using principal component analysis (PCA). Acclimation was the most important factor for preservation, increasing the bacterial resistance to ethanol after freezing and freeze-drying. Freeze-drying was the most drastic method of preservation, followed by freezing at -20 °C. The increase of ethanol concentration from 6 to 10% v/v in the acclimation medium improved the recovery of two of the three strains. In turn, the increase of ethanol content in the synthetic wine led to a dramatic decrease of viable cells in the three strains investigated. The results of this study indicate that a successful inoculation of dehydrated L. plantarum in wine depends not only on the use of protective agents, but also on the cell acclimation process prior to preservation, and on the ethanol content of wine.

  14. Development of Freeze-Dried Bacteriocin-Containing Preparations from Lactic Acid Bacteria to Inhibit Listeria monocytogenes and Staphylococcus aureus.

    Science.gov (United States)

    Dimitrieva-Moats, Galina Yu; Ünlü, Gülhan

    2012-03-01

    There has been a recent movement to produce and consume "minimally processed" and more "natural" foods through the use of fewer chemical preservatives. The shift to more "natural" foods has resulted in a great interest in the use of bacteriocins from lactic acid bacteria as natural biopreservatives. The objective of this comparative study was to identify bacteriocins that can be produced in low-cost or no-cost dairy-based media (DBM), concentrated using freeze-drying, and applied to Cheddar cheese samples to concurrently inhibit Listeria monocytogenes and Staphylococcus aureus. Select bacteriocin producers were grown in DBM, their cell-free supernatants (CFS) were frozen, and the frozen CFS samples were freeze-dried to produce bacteriocin-containing powders. Cheddar cheese samples were challenged with L. monocytogenes or Staph. aureus cells. The challenged samples were exposed to buffered solutions of freeze-dried powders containing bacteriocins, incubated at 4 °C for 24-72 h, and plated onto appropriate selective media. All freeze-dried bacteriocin-containing powders tested were active against L. monocytogenes and Staph. aureus. Our research findings indicated that low-cost or no-cost DBM could successfully be used for production of bacteriocin-containing preparations. In addition, freeze-drying was determined to be a feasible approach to prepare concentrated and stable bacteriocin-containing powders for prospective food applications. The prevention of even a very small percentage of foodborne illnesses via the use of bacteriocins as natural biopreservatives would help reduce the number of foodborne illness-related hospitalizations, deaths, and financial loss due to medical expenses, lost income/productivity, cost of litigation/penalties, and loss of trade.

  15. Enhancing the aqueous solubility and dissolution of olanzapine using freeze-drying

    Directory of Open Access Journals (Sweden)

    Mudit Dixit

    2011-12-01

    Full Text Available The aim of the present study was to develop an olanzapine freeze-dried tablet (FDT. The solubility and dissolution rate of poorly water-soluble olanzapine was improved by preparing a freeze-dried tablet of olanzapine using the freeze-drying technique . The FDT was prepared by dispersing the drug in an aqueous solution of highly water-soluble carrier materials consisting of gelatin, glycine, and sorbitol. The mixture was poured in to the pockets of blister packs and then was subjected to freezing and lyophilisation. The FDT was characterised by DSC, XRD and SEM and was evaluated for saturation solubility and dissolution. The samples were stored in a stability chamber to investigate their physical stability. Results obtained by DSC and X-ray were analysed and showed the crystalline state of olanzapine in FDT transformation to the amorphous state during the formation of FDT. Scanning electron microscope (SEM results suggest reduction in olanzapine particle size. The solubility of olanzapine from the FDT was observed to be nearly four and a half times greater than the pure drug. Results obtained from dissolution studies showed that olanzapine FDT significantly improved the dissolution rate of the drug compared with the physical mixture (PM and the pure drug. More than 90% of olanzapine in FDT dissolved within 5 minutes, compared to only 19.78% of olanzapine pure drug dissolved over the course of 60 minutes. In a stability test, the release profile of the FDT was unchanged, as compared to the freshly prepared FDT after 90 days of storing.O objetivo do presente estudo foi desenvolver comprimidos liofilizados de olanzapina (FDT. A solubilidade e a taxa de dissolução da olanzapina, fracamente solúvel em água, foram melhoradas com a preparação de comprimidos liofilizados de olanzapina usando a técnica de liofilização. O FDT foi preparado por dispersão do fármaco em solução aquosa de materiais altamente solúveis em água, como gelatina

  16. Inhibitory effects of freeze-dried milk fermented by selected Lactobacillus bulgaricus strains on carcinogenesis induced by 1,2-dimethylhydrazine in rats and by diethylnitrosamine in hamsters.

    Science.gov (United States)

    Balansky, R; Gyosheva, B; Ganchev, G; Mircheva, Z; Minkova, S; Georgiev, G

    1999-12-01

    Fermented milk products might be used for cancer chemoprevention due to their putative anticarcinogenic and antitumor activities. The diet was supplemented with freeze-dried milk fermented by Lactobacillus bulgaricus strain LBB.B 144 (product FFM.B 144) added throughout the experiment at doses of 1.3 g and 2.5 g per rat, 5 times a week starting 3 weeks before the first carcinogen injection. This treatment significantly inhibited, by 26.2-28.6% and by 34.2%, the total intestinal carcinogenesis induced by 1,2-dimethylhydrazine (DMH, 21 mg/kg, s.c., once per week for 20 weeks) in male and female BD6 rats, respectively. FFM.B144 decreased the tumor incidence and multiplicity in large bowel, caecum, and duodenum. Protective effects were better expressed in female animals, with exception of that observed in duodenum. Supplementation of diet with freeze-dried milk fermented by Lactobacillus bulgaricus strain LBB.B5 (product FFM.B5) inhibited DMH-induced carcinogenesis only in the large bowel, but had no significant protective effect when all intestinal tumors were taken into account. However, both freeze-dried products favorably shifted the differentiation of large bowel tumors by increasing the proportion of benign and highly differentiated malignant tumors and decreasing in parallel the number of poorly differentiated carcinomas without influencing the tumor size. A lower number of cases with visible mesenterial metastasis was also observed in FFM-treated rats. In addition, both FFM.B 144 and FFM.B5 significantly inhibited, by 26-33%, the induction in the same rats of ear-duct tumors. FFM.B144 but not FFM.B5 was also effective in inhibiting the tracheal carcinogenesis induced in Syrian golden hamsters by diethylnitrosamine (DEN, 100 mg/kg, two s.c. injections), the protective effect being better expressed in female animals. The anticarcinogenic potential of some fermented milk products might be exploited in chemoprevention of cancer in humans.

  17. Biomaterials in periodontal regenerative surgery: effects of cryopreserved bone, commercially available coral, demineralized freeze-dried dentin, and cementum on periodontal ligament fibroblasts and osteoblasts.

    Science.gov (United States)

    Devecioğlu, Didem; Tözüm, Tolga F; Sengün, Dilek; Nohutcu, Rahime M

    2004-10-01

    The ultimate goal of periodontal therapy is to achieve successful periodontal regeneration. The effects of different biomaterials, allogenic and alloplastic, used in periodontal surgeries to achieve regeneration have been studied in vitro on periodontal ligament (PDL) cells and MC3T3-E1 cells. The materials tested included cryopreserved bone allograft (CBA), coralline hydroxyapatite (CH), demineralized freeze-dried dentin (DFDD), and cementum. CBA and CH revealed an increase in initial PDL cell attachment, whereas CH resulted in an increase in long-term PDL cell attachment. Mineral-like nodule formation was observed significantly higher in DFDD compared to other materials tested for osteoblasts. Based on the results of this in vitro study, we conclude that the materials used are all biocompatible with human PDL cells and osteoblasts, which have pivotal importance in periodontal regeneration.

  18. Criteria for permission of radiosterilized products to application in medicine; Zasady dopuszczania wyrobow sterylizowanych radiacyjnie do stosowania w medycynie

    Energy Technology Data Exchange (ETDEWEB)

    Achmatowicz, T. [Instytut Lekow, Warsaw (Poland)

    1997-10-01

    The criteria being used in Poland for permission of radiosterilized medical materials to commercial application result from regulations being in force. The international regulations are also taken into account. The all criteria and procedure needed for any product become accepted for radiosterilization and commercial medical use have been presented and discussed. 1 tab.

  19. Solidification drug nanosuspensions into nanocrystals by freeze-drying: a case study with ursodeoxycholic acid.

    Science.gov (United States)

    Ma, Yue-Qin; Zhang, Zeng-Zhu; Li, Gang; Zhang, Jing; Xiao, Han-Yang; Li, Xian-Fei

    2016-03-01

    To elucidate the effect of solidification processes on the redispersibility of drug nanocrystals (NC) during freeze-drying, ursodeoxycholic acid (UDCA) nanosuspensions were transformed into UDCA-NC via different solidification process included freezing and lyophilization. The effect of different concentrations of stabilizers and cryoprotectants on redispersibility of UDCA-NC was investigated, respectively. The results showed that the redispersibility of UDCA-NC was RDI-20 °C lyophilization. The hydroxypropylmethylcellulose and PVPK30 were effective to protect UDCA-NC from damage during lyophilization, which could homogeneously adsorb into the surface of NC to prevent from agglomerates. The sucrose and glucose achieved excellent performance that protected UDCA-NC from crystal growth during lyophilization, respectively. It was concluded that UDCA-NC was subjected to agglomeration during solidification transformation, and the degree of agglomeration suffered varied with the type and the amounts of stabilizers used, as well as different solidification conditions. The PVPK30-sucrose system was more effective to protect UDCA-NC from the damage during solidification process.

  20. Spray Freeze-drying - The Process of Choice for Low Water Soluble Drugs?

    Energy Technology Data Exchange (ETDEWEB)

    Leuenberger, H. [University of Basel, Pharmacenter, Institute of Pharmaceutical Technology (Switzerland)], E-mail: hans.leuenberger@unibas.ch

    2002-04-15

    Most of the novel highly potent drugs, developed on the basis of modern molecular medicine, taking into account cell surface recognition techniques, show poor water solubility. A chemical modification of the drug substance enhancing the solubility often decreases the pharmacological activity. Thus, as an alternative an increase of the solubility can be obtained by the reduction of the size of the drug particles. Unfortunately, it is often difficult to obtain micro or nanosized drug particles by classical or more advanced crystallization using supercritical gases or by milling techniques. In addition, nanosized particles are often not physically stable and need to be stabilized in an appropriate matrix. Thus, it may be of interest to manufacture directly nanosized drug particles stabilized in an inert hydrophilic matrix, i.e. nanostructured and nanocomposite systems. Solid solutions and solid dispersions represent nanostructured and nanocomposite systems. In this context, the use of the vacuum-fluidized-bed technique for the spray-drying of a low water soluble drug cosolubilized with a hydrophilic excipient in a polar organic solvent is discussed. In order to avoid the use of organic solvents, a special spray-freeze-drying technique working at atmospheric pressure is presented. This process is very suitable for temperature and otherwise sensitive drugs such as pharmaproteins.

  1. Development of a nanosuspension for iv administration: From miniscale screening to a freeze dried formulation.

    Science.gov (United States)

    Frank, Kerstin J; Boeck, Georg

    2016-05-25

    The aim was to develop a nanosuspension of the poorly soluble BI XX. The nanosuspension is intended for intravenous (iv) administration in preclinical studies and should not cause any unwanted side effects. Thus, only stabilizers that are accepted for iv application should be used and isotonicity, euhydria and the absence of living microorganisms were targeted. Suspensions were prepared in a ball-mill (mixing mill MM 400 from Retsch). There were various vials used as containers; HPLC-vials were used for the small scale screening of stabilizers and injection vials for preparation of larger quantities of the nanosuspensions. Particle size distribution was analyzed by laser diffraction measurement (Mastersizer 2000). Lyophilization was used for processing of the suspensions (Christ freeze dryer). Stable nanosuspensions (d90 remained nanosuspension. Various FDA accepted excipients were identified which resulted in stable nanosuspensions of BI XX. The most stable formulation was successfully freeze dried. It was proven that milling in the ball-mill decreases the presence of living microorganisms.

  2. Spray-freeze-dried dry powder inhalation of insulin-loaded liposomes for enhanced pulmonary delivery.

    Science.gov (United States)

    Bi, Ru; Shao, Wei; Wang, Qun; Zhang, Na

    2008-11-01

    Nowadays, growing attention has been paid to the pulmonary region as a target for the delivery of peptide and protein drugs, especially macromolecules with systemic effect like insulin, since the pulmonary route exhibits numerous benefits to be an alternative for repeated injection. Furthermore, encapsulation of insulin into liposomal carriers is an attractive way to increase drug retention time and control the drug release in the lung; however, its long-term stability during storage in the reservoir and the process of aerosolization might be suspected when practically applied. Thus, the aim of this study was to design and characterize dry powder inhalation of insulin-loaded liposomes prepared by novel spray-freeze-drying method for enhanced pulmonary delivery. Process variables such as compressed air pressure, pump speed, and concentration were optimized for parameters such as mean particle diameter, moisture content, and fine particle fraction of the produced powders. Influence of different kinds and amounts of lyoprotectants was also evaluated for the best preservation of the drug entrapped in the liposome bilayers after the dehydration-rehydration cycle. The in vivo study of intratracheal instillation of insulin-loaded liposomes to diabetic rats showed successful hypoglycemic effect with low blood glucose level and long-lasting period and a relative pharmacological bioavailability as high as 38.38% in the group of 8 IU/kg dosage.

  3. Effect of microencapsulation methods on the survival of freeze-dried Bifidobacterium bifidum.

    Science.gov (United States)

    Zhang, Fan; Li, Xiao Yan; Park, Hyun Jin; Zhao, Min

    2013-01-01

    Six kinds of Bifidobacterium bifidum microcapsules were prepared by extrusion methods, emulsion methods and coacervation methods. Effects of preparation methods on the survival of encapsulated B. bifidum were examined. Results showed that microcapsules prepared by emulsion method with alginate and chitosan exhibited the best protection for B. bifidum. The diameter was 10-20 µm, encapsulation efficiency was 90.36% and the live cell amount was 3.01 × 10₉ cfu/g after freeze-drying. Encapsulated cells exhibited significantly higher resistance to artificial gastrointestinal juice and the cell numbers were above 10₉ cfu/g after exposure to simulated gastric (pH 1.2) and bile salt (1%, w/v). Cell numbers of microencapsulated B. bifidum was 8.61 × 10₈ cfu/g after storage at 37°C, relative humidity 60%-65% for 3 months. Results indicated microcapsules prepared with alginate and chitosan by emulsion method could successfully protect B. bifidum against adverse conditions and it might be useful in the delivery of probiotic cultures as a functional food.

  4. Multi-scale mechanical response of freeze-dried collagen scaffolds for tissue engineering applications.

    Science.gov (United States)

    Offeddu, Giovanni S; Ashworth, Jennifer C; Cameron, Ruth E; Oyen, Michelle L

    2015-02-01

    Tissue engineering has grown in the past two decades as a promising solution to unresolved clinical problems such as osteoarthritis. The mechanical response of tissue engineering scaffolds is one of the factors determining their use in applications such as cartilage and bone repair. The relationship between the structural and intrinsic mechanical properties of the scaffolds was the object of this study, with the ultimate aim of understanding the stiffness of the substrate that adhered cells experience, and its link to the bulk mechanical properties. Freeze-dried type I collagen porous scaffolds made with varying slurry concentrations and pore sizes were tested in a viscoelastic framework by macroindentation. Membranes made up of stacks of pore walls were indented using colloidal probe atomic force microscopy. It was found that the bulk scaffold mechanical response varied with collagen concentration in the slurry consistent with previous studies on these materials. Hydration of the scaffolds resulted in a more compliant response, yet lesser viscoelastic relaxation. Indentation of the membranes suggested that the material making up the pore walls remains unchanged between conditions, so that the stiffness of the scaffolds at the scale of seeded cells is unchanged; rather, it is suggested that thicker pore walls or more of these result in the increased moduli for the greater slurry concentration conditions.

  5. Model-Based PAT for Quality Management in Pharmaceuticals Freeze-Drying: State of the Art

    Science.gov (United States)

    Fissore, Davide

    2017-01-01

    Model-based process analytical technologies can be used for the in-line control and optimization of a pharmaceuticals freeze-drying process, as well as for the off-line design of the process, i.e., the identification of the optimal operating conditions. This paper aims at presenting the state of the art in this field, focusing, particularly, on three groups of systems, namely, those based on the temperature measurement (i.e., the soft sensor), on the chamber pressure measurement (i.e., the systems based on the test of pressure rise and of pressure decrease), and on the sublimation flux estimate (i.e., the tunable diode laser absorption spectroscopy and the valveless monitoring system). The application of these systems for in-line process optimization (e.g., using a model predictive control algorithm) and to get a true quality by design (e.g., through the off-line calculation of the design space of the process) is presented and discussed. PMID:28224123

  6. PREPARATION OF POROUS NANOCOMPOSITE SCAFFOLDS WITH HONEYCOMB MONOLITH STRUCTURE BY ONE PHASE SOLUTION FREEZE DRYING METHOD

    Institute of Scientific and Technical Information of China (English)

    Yang Xu; Duo Zhang; Zong-liang Wang; Zhan-tuan Gao; Pei-biao Zhang; Xue-si Chen

    2011-01-01

    Biodegradable porous nanocomposite scaffolds of poly(lactide-co-glycolide) (PLGA) and L-lactic acid (LAc) oligomer surface-grafted hydroxyapatite nanoparticles (op-HA) with a honeycomb monolith structure were fabricated with the single-phase solution freeze-drying method. The effects of different freezing temperatures on the properties of the scaffolds, such as microstructures, compressive strength, cell penetration and cell proliferation were studied. The highly porous and well interconnected scaffolds with a tunable pore structure were obtained. The effect of different freezing temperature (4℃, -20℃, -80℃ and -196℃) was investigated in relation to the scaffold morphology, the porosity varied from 91.2% to 83.0% and the average pore diameter varied from (167.2 ± 62.6) pm to (11.9 ± 4.2) μm while the σ10 increased significantly. The cell proliferation were decreased and associated with the above-mentioned properties. Uniform distribution of op-HA particles and homogeneous roughness of pore wall surfaces were found in the 4℃ frozen scaffold. The 4℃ frozen scaffold exhibited better cell penetration and increased cell proliferation because of its larger pore size, higher porosity and interconnection. The microstmctures described here provide a new approach for the design and fabrication of op-HA/PLGA based scaffold materials with potentially broad applicability for replacement of bone defects.

  7. Effects of freezing, freeze drying and convective drying on in vitro gastric digestion of apples.

    Science.gov (United States)

    Dalmau, Maria Esperanza; Bornhorst, Gail M; Eim, Valeria; Rosselló, Carmen; Simal, Susana

    2017-01-15

    The influence of processing (freezing at -196°C in liquid N2, FN sample; freeze-drying at -50°C and 30Pa, FD sample; and convective drying at 60°C and 2m/s, CD sample) on apple (var. Granny Smith) behavior during in vitro gastric digestion was investigated. Dried apples (FD and CD samples) were rehydrated prior to digestion. Changes in carbohydrate composition, moisture, soluble solids, acidity, total polyphenol content (TPC), and antioxidant activity (AA) of apple samples were measured at different times during digestion. Processing resulted in disruption of the cellular structure during digestion, as observed by scanning electron microscopy, light microscopy, and changes in carbohydrate composition. Moisture content increased (6-11% dmo), while soluble solids (55-78% dmo), acidity (44-72% dmo), total polyphenol content (30-61% dmo), and antioxidant activity (41-87%) decreased in all samples after digestion. Mathematical models (Weibull and exponential models) were used to better evaluate the influence of processing on apple behavior during gastric digestion.

  8. Noncontact Infrared-Mediated Heat Transfer During Continuous Freeze-Drying of Unit Doses.

    Science.gov (United States)

    Van Bockstal, Pieter-Jan; De Meyer, Laurens; Corver, Jos; Vervaet, Chris; De Beer, Thomas

    2017-01-01

    Recently, an innovative continuous freeze-drying concept for unit doses was proposed, based on spinning the vials during freezing. An efficient heat transfer during drying is essential to continuously process these spin frozen vials. Therefore, the applicability of noncontact infrared (IR) radiation was examined. The impact of several process and formulation variables on the mass of sublimed ice after 15 min of primary drying (i.e., sublimation rate) and the total drying time was examined. Two experimental designs were performed in which electrical power to the IR heaters, distance between the IR heaters and the spin frozen vial, chamber pressure, product layer thickness, and 5 model formulations were included as factors. A near-infrared spectroscopy method was developed to determine the end point of primary and secondary drying. The sublimation rate was mainly influenced by the electrical power to the IR heaters and the distance between the IR heaters and the vial. The layer thickness had the largest effect on total drying time. The chamber pressure and the 5 model formulations had no significant impact on sublimation rate and total drying time, respectively. This study shows that IR radiation is suitable to provide the energy during the continuous processing of spin frozen vials.

  9. Ice crystal damage in freeze-dried articular cartilage studied by scanning electron microscopy.

    Science.gov (United States)

    Draenert, Y; Draenert, K

    1982-01-01

    The aim of preparing specimens at very low temperatures is to maintain biological tissue in its natural state. The problems which arise are: 1) obtaining the highest possible cooling rate when freezing the tissue; 2) preventing melting with recrystallization during the drying process; and 3) preventing the dried specimens from water vapor contamination. Biological tissue is prepared in a cooling chain by freezing the samples in a supercooled nitrogen bath, breaking the specimens in the frozen state, sputtering the fracture surfaces in a vacuum on the cooling stage of a special device and then transferring the specimens under vacuum to the SEM where they are studied on a cooling stage. They have smooth surfaces, with the liquid and solid phases present simultaneously, and no artefacts. Any shifts or deformations which may occur within the structure cannot yet be determined. Freeze-drying quenched specimens at various temperatures (-140 degrees to -60 degrees C) taking the dynamics of vapor pressure into consideration shows that sublimation, the melting processes with recrystallization and the resulting damage to the structures occur simultaneously during the drying process. The destruction of the tissue is inversely proportional to the ratio of sublimation to melting.

  10. Effect of mixing time, freeze-drying and baking on phenolics, anthocyanins and antioxidant capacity of raspberry juice during processing of muffins.

    Science.gov (United States)

    Rosales-Soto, Maria U; Powers, Joseph R; Alldredge, J Richard

    2012-05-01

    Consumption of baked products constitutes an important part of a daily breakfast considering that people are continually grabbing meals on the go. Among baked products, muffins rank third in breakfast products and attract a broad range of consumers. Incorporation of red raspberry juice into muffins can add value to the product while preserving health benefits to the consumer. The purpose of this study was to evaluate the effect of mixing time, freeze-drying and baking on the phenolic and anthocyanin contents and antioxidant capacity of raspberry juice during the preparation of muffins. Freeze-drying of raspberry batters reduced their phenolic content and antioxidant capacity regardless of mixing time. Non-freeze-dried raspberry batter mixed for 5 min had the highest phenolic content (0.88 mg gallic acid equivalent g(-1) dry matter (DM)). Non-freeze-dried raspberry muffins had the highest antioxidant capacity (0.041 µmol Trolox equivalent g(-1) DM). Freeze-dried raspberry batters mixed for 5 and 10 min had the highest anthocyanin content (0.065 mg cyanidin-3-glucoside g(-1) DM). Baking reduced the anthocyanin content of both non-freeze-dried and freeze-dried raspberry muffins. Despite the reduction in valuable compounds, muffin is a vehicle for the delivery of these compounds. Copyright © 2012 Society of Chemical Industry.

  11. Freeze-Drying of L-Arginine/Sucrose-Based Protein Formulations, Part 2: Optimization of Formulation Design and Freeze-Drying Process Conditions for an L-Arginine Chloride-Based Protein Formulation System.

    Science.gov (United States)

    Stärtzel, Peter; Gieseler, Henning; Gieseler, Margit; Abdul-Fattah, Ahmad M; Adler, Michael; Mahler, Hanns-Christian; Goldbach, Pierre

    2015-12-01

    We recently reported that the presence of chloride counter ions in freeze-dried l-arginine/sucrose formulations provided the greatest protein stability, but led to low collapse temperatures and glass transition temperatures of the freeze concentrates. The objectives of this study were to identify l-arginine chloride-based formulations and optimize freeze-drying process conditions to deliver a freeze-dried product with good physical quality attributes (including cake appearance, residual moisture, and reconstitution time). Additional properties were tested such as thermal properties, cake microstructure, and protein physical stability. Excipient concentrations were varied with and without a model protein (bovine serum albumin, BSA). Formulations were frozen with and without annealing or with and without controlled nucleation. Primary drying was conducted at high and low shelf temperature. Cakes with least defects and optimum physical attributes were achieved when protein to excipient ratios were high. Controlled nucleation led to elegant cakes for most systems at a low shelf temperature. Replacing BSA by a monoclonal antibody showed that protein (physical) stability was slightly improved under stress storage temperature (i.e., 40°C) in the presence of a low concentration of l-arginine in a sucrose-based formulation. At higher l-arginine concentrations, cake defects increased. Using optimized formulation design, addition of l-arginine chloride to a sucrose-based formulation provided elegant cakes and benefits for protein stability.

  12. Influence of Freeze-Drying and Oven-Drying Post Blanching on the Nutrient Composition of the Edible Insect Ruspolia differens

    Directory of Open Access Journals (Sweden)

    Forkwa Tengweh Fombong

    2017-09-01

    Full Text Available The longhorn grasshopper, Ruspolia differens (Serville, plays an important role as a food source across Sub-Saharan Africa, where it is consumed as a delicacy in both rural and urban areas. The effect of two drying methods (freeze-drying and oven-drying, employed after blanching, on the proximate, fatty acid and mineral composition of the two most common morphs was determined. Ruspolia differens grasshoppers were harvested in Uganda and Kenya from wild swarms during the rainy periods of November–December 2016. Based on cuticular coloration, we identified three morphs, green, brown and purple, which occurred at a ratio of 65:33:2, respectively. Results indicated that these insects have a high lipid content of 36%, as well as significant protein levels ranging between 33% and 46% dry matter. Oleic acid (44% and palmitic acid (28% were the two most abundant fatty acids; while the presence of arachidonic acid (0.6% and docosahexaenoic acid (0.21% suggests that Ruspolia differens is also a source of polyunsaturated fatty acids. The observed amino acid profile showed similar trends in all morphs, and all essential amino acids were present. Calcium (896–1035 mg/100 g, potassium (779–816 mg/100 g and phosphorus (652–685 mg/100 g were quite high among the minerals. The presence of the trace elements iron (217–220 mg/100 g, zinc (14.2–14.6 mg/100 g, manganese (7.4–8.3 mg/100 g and copper (1.66 mg/100 g suggests that inclusion of these grasshoppers in human diets may aid in combatting micronutrient deficiencies. Oven-drying Ruspolia differens delivered the same nutritional quality as freeze-drying. Hence, both drying approaches can be adequately used to formulate insect-based food products without noticeable nutritional changes.

  13. Influence of Freeze-Drying and Oven-Drying Post Blanching on the Nutrient Composition of the Edible Insect Ruspolia differens

    Science.gov (United States)

    Fombong, Forkwa Tengweh; Van Der Borght, Mik; Vanden Broeck, Jozef

    2017-01-01

    The longhorn grasshopper, Ruspolia differens (Serville), plays an important role as a food source across Sub-Saharan Africa, where it is consumed as a delicacy in both rural and urban areas. The effect of two drying methods (freeze-drying and oven-drying), employed after blanching, on the proximate, fatty acid and mineral composition of the two most common morphs was determined. Ruspolia differens grasshoppers were harvested in Uganda and Kenya from wild swarms during the rainy periods of November–December 2016. Based on cuticular coloration, we identified three morphs, green, brown and purple, which occurred at a ratio of 65:33:2, respectively. Results indicated that these insects have a high lipid content of 36%, as well as significant protein levels ranging between 33% and 46% dry matter. Oleic acid (44%) and palmitic acid (28%) were the two most abundant fatty acids; while the presence of arachidonic acid (0.6%) and docosahexaenoic acid (0.21%) suggests that Ruspolia differens is also a source of polyunsaturated fatty acids. The observed amino acid profile showed similar trends in all morphs, and all essential amino acids were present. Calcium (896–1035 mg/100 g), potassium (779–816 mg/100 g) and phosphorus (652–685 mg/100 g) were quite high among the minerals. The presence of the trace elements iron (217–220 mg/100 g), zinc (14.2–14.6 mg/100 g), manganese (7.4–8.3 mg/100 g) and copper (1.66 mg/100 g) suggests that inclusion of these grasshoppers in human diets may aid in combatting micronutrient deficiencies. Oven-drying Ruspolia differens delivered the same nutritional quality as freeze-drying. Hence, both drying approaches can be adequately used to formulate insect-based food products without noticeable nutritional changes. PMID:28926949

  14. In-line near infrared spectroscopy during freeze-drying as a tool to measure efficiency of hydrogen bond formation between protein and sugar, predictive of protein storage stability

    NARCIS (Netherlands)

    Mensink, Maarten A; Van Bockstal, Pieter-Jan; Pieters, Sigrid; De Meyer, Laurens; Frijlink, Henderik W; van der Voort Maarschalk, Kees; Hinrichs, Wouter L J; De Beer, Thomas

    2015-01-01

    Sugars are often used as stabilizers of protein formulations during freeze-drying. However, not all sugars are equally suitable for this purpose. Using in-line near-infrared spectroscopy during freeze-drying, it is shown here that hydrogen bond formation during freeze-drying, under secondary drying

  15. Freeze-Drying Above the Glass Transition Temperature in Amorphous Protein Formulations While Maintaining Product Quality and Improving Process Efficiency.

    Science.gov (United States)

    Depaz, Roberto A; Pansare, Swapnil; Patel, Sajal Manubhai

    2016-01-01

    This study explored the ability to conduct primary drying during lyophilization at product temperatures above the glass transition temperature of the maximally freeze-concentrated solution (Tg′) in amorphous formulations for four proteins from three different classes. Drying above Tg′ resulted in significant reductions in lyophilization cycle time. At higher protein concentrations, formulations freeze dried above Tg′ but below the collapse temperature yielded pharmaceutically acceptable cakes. However, using an immunoglobulin G type 4 monoclonal antibody as an example, we found that as protein concentration decreased, minor extents of collapse were observed in formulations dried at higher temperatures. No other impacts to product quality, physical stability, or chemical stability were observed in this study among the different drying conditions for the different proteins. Drying amorphous formulations above Tg′, particularly high protein concentration formulations, is a viable means to achieve significant time and cost savings in freeze-drying processes.

  16. Freeze-drying of “pearl milk tea”: A general strategy for controllable synthesis of porous materials

    Science.gov (United States)

    Zhou, Yingke; Tian, Xiaohui; Wang, Pengcheng; Hu, Min; Du, Guodong

    2016-05-01

    Porous materials have been widely used in many fields, but the large-scale synthesis of materials with controlled pore sizes, pore volumes, and wall thicknesses remains a considerable challenge. Thus, the controllable synthesis of porous materials is of key general importance. Herein, we demonstrate the “pearl milk tea” freeze-drying method to form porous materials with controllable pore characteristics, which is realized by rapidly freezing the uniformly distributed template-containing precursor solution, followed by freeze-drying and suitable calcination. This general and convenient method has been successfully applied to synthesize various porous phosphate and oxide materials using different templates. The method is promising for the development of tunable porous materials for numerous applications of energy, environment, and catalysis, etc.

  17. Anti- and pro-oxidative effect of fresh and freeze-dried vegetables during storage of mayonnaise.

    Science.gov (United States)

    Raikos, Vassilios; Neacsu, Madalina; Morrice, Philip; Duthie, Garry

    2015-12-01

    Mayonnaise was supplemented with vegetables (5 % w/w) and the effect of storage time at 4 °C on the oxidative stability of the dispersed phase was investigated. Results indicated that mayonnaise is prone to lipid oxidation during storage under refrigerator conditions. The type of vegetable used for mayonnaise reformulation was critical in inhibiting oxidation and followed the order beetroot > carrot ≈ onion with respect to antioxidant capacity. Broccoli induced a pro-oxidant effect and the rate of oxidation by the end of the storage period was 42 times higher compared with the control. The addition of beetroot, either fresh or freeze-dried, improved the oxidative stability of mayonnaise significantly. The process of freeze-drying affected adversely the ability of vegetables to decrease oil oxidation of the emulsions. This may reflect loss of important natural antioxidants during the drying procedure.

  18. Preservation of functionality of Bifidobacterium animalis subsp. lactis INL1 after incorporation of freeze-dried cells into different food matrices.

    Science.gov (United States)

    Vinderola, G; Zacarías, M F; Bockelmann, W; Neve, H; Reinheimer, J; Heller, K J

    2012-05-01

    The aim of this work was to investigate how production and freeze-drying conditions of Bifidobacterium animalis subsp. lactis INL1, a probiotic strain isolated from breast milk, affected its survival and resistance to simulated gastric digestion during storage in food matrices. The determination of the resistance of bifidobacteria to simulated gastric digestion was useful for unveiling differences in cell sensitivity to varying conditions during biomass production, freeze-drying and incorporation of the strain into food products. These findings show that bifidobacteria can become sensitive to technological variables (biomass production, freeze-drying and the food matrix) without this fact being evidenced by plate counts.

  19. Identification of Components or Fractions Associated with Adverse Changes in Freeze Dried Chicken and Pork during Storage

    Science.gov (United States)

    1978-06-01

    of glucose by yeast fermentation . Food Techmol. 9: 290 (1955). 12 Fleming, I. E. and H. F. Pegler. The determination of glucose in the pre.- ence of...Amerine et al., 1965). 17 Osman, 0. A. H. and R. E. Morse. Preparation and storage characteristics of freeze dried sausages . I. Formulation and...processing of comminuted sausages (frankfurters). Food Technol. 14: 37 (Abstract) (1960). 1Amerine, M. A., R. M. Pangborn, and E. P. Roessler. Principles of

  20. Effect of freeze-dried leek powder (FDLP) and nitrite level on processing and quality characteristics of fermented sausages.

    Science.gov (United States)

    Tsoukalas, D S; Katsanidis, E; Marantidou, S; Bloukas, J G

    2011-02-01

    Fermented sausages were produced with 0.84% and 1.68% freeze-dried leek powder (FDLP), providing 75 and 150 mg/kg NaNO(3), respectively, and three levels of added nitrite (0, 75, and 150 mg/kg NaNO(2). A control treatment was also produced with 150 mg/kg NaNO(2). Sausages with FDLP were darker and yellower (psausages (pfermented sausages, as it results in a 50% reduction in added nitrite.

  1. Validation of a multipoint near-infrared spectroscopy method for in-line moisture content analysis during freeze-drying.

    Science.gov (United States)

    Kauppinen, Ari; Toiviainen, Maunu; Lehtonen, Marko; Järvinen, Kristiina; Paaso, Janne; Juuti, Mikko; Ketolainen, Jarkko

    2014-07-01

    This study assessed the validity of a multipoint near-infrared (NIR) spectroscopy method for in-line moisture content analysis during a freeze-drying process. It is known that the moisture content affects the stability of a freeze-dried product and hence it is a major critical quality attribute. Therefore assessment of the validity of an analytical method for moisture content determination is vital to ensure the quality of the final product. An aqueous sucrose solution was used as the model formulation of the study. The NIR spectra were calibrated to the moisture content using partial least squares (PLS) regression with coulometric Karl Fischer (KF) titration as the reference method. Different spectral preprocessing methods were compared for the PLS models. A calibration model transfer protocol was established to enable the use of the method in the multipoint mode. The accuracy profile was used as a decision tool to determine the validity of the method. The final PLS model, in which NIR spectra were preprocessed with standard normal variate transformation (SNV), resulted in low root mean square error of prediction value of 0.04%-m/v, i.e. evidence of sufficient overall accuracy of the model. The validation results revealed that the accuracy of the model was acceptable within the moisture content range 0.16-0.70%-m/v that is specific for the latter stages of the freeze-drying process. In addition, the results demonstrated the method's reliable in-process performance and robustness. Thus, the multipoint NIR spectroscopy method was proved capable of providing in-line evaluation of moisture content and it is readily available for use in laboratory scale freeze-drying research and development. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Effect of chemical stabilizers on the thermostability and infectivity of a representative panel of freeze dried viruses.

    Directory of Open Access Journals (Sweden)

    Boris Pastorino

    Full Text Available As a partner of the European Virus Archive (EVA FP7 project, our laboratory maintains a large collection of freeze-dried viruses. The distribution of these viruses to academic researchers, public health organizations and industry is one major aim of the EVA consortium. It is known that lyophilization requires appropriate stabilizers to prevent inactivation of the virus. However, few studies have investigated the influence of different stabilizers and lyophilization protocols on the thermostability of different viruses. In order to identify optimal lyophilization conditions that will deliver maximum retention of viral infectivity titre, different stabilizer formulations containing trehalose, sorbitol, sucrose or foetal bovine serum were evaluated for their efficacy in stabilizing a representative panel of freeze dried viruses at different storage temperatures (-20°C, +4°C and +20°C for one week, the two latter mimicking suboptimal shipping conditions. The Tissue Culture Infectious Dose 50% (TCID50 assay was used to compare the titres of infectious virus. The results obtained using four relevant and model viruses (enveloped/non enveloped RNA/DNA viruses still serve to improve the freeze drying conditions needed for the development and the distribution of a large virus collection.

  3. Solidification of liposomes by freeze-drying: the importance of incorporating gelatin as interior support on enhanced physical stability.

    Science.gov (United States)

    Guan, Peipei; Lu, Yi; Qi, Jianping; Niu, Mengmeng; Lian, Ruyue; Wu, Wei

    2015-01-30

    The main purpose of this study was to investigate the effect of gelatin as interior support on the physical stability of freeze-dried liposomes. Anticancer agent paclitaxel (PTX) was selected as a model drug. Freeze-dried liposomes containing interior gelatin support (GLs) were prepared by thin-film dispersion/freeze-drying method. Several properties of the GLs, including entrapment efficiency, particle size and gelation temperature, were extensively characterized. Encapsulation efficiency of conventional liposomes (CLs) and liposomes containing lyoprotectants as interior support dropped to lower than 20% after reconstitution, while GLs still maintained an entrapment efficiency of over 84%. Scanning electron microscopy revealed well preserved liposomal structure of GLs after reconstitution. Meanwhile, the particle size and entrapment efficiency of GLs were also well preserved after reconstitution. In contrary, deformation of CLs and recrystallization of PTX were observed, as well as significant changes in particle size and entrapment efficiency. Taken together, interior gelatin support obviously enhanced the physical stability of liposomes against the lyophilization stress.

  4. Effects of sugar alcohol and proteins on the survival of Lactobacillus bulgaricus LB6 during freeze drying

    Directory of Open Access Journals (Sweden)

    He Chen

    2015-06-01

    Full Text Available Background. Lactobacillus bulgaricus LB6 is a bacterium which was selected in the commercial yoghurt with high angiotensin converting enzyme (ACE inhibitory activity. Preparation of concentrated starter cultures via freeze drying is of practical importance to dairy and food industries. Material and methods. We optimized the optimal sugar alcohol and proteins for Lactobacillus bulgaricus LB6 during the process of freeze drying using a Plackett-Burman design. In our initial tests survival rate and the number of viable cells were associated with the type of lyoprotectant used and so our optimization protocol focused on increasing survival rate. Substances that had previously had a protective effect during freeze drying were investigated, for example: mannitol, sorbitol, xylitol, meso-erythritol, lactitol, whey protein isolate 90, bovine serum albumin, and whey protein concentrate 80 and soy protein isolate 70. Results. We found that the optimum sugar alcohol and proteins for survival of Lactobacillus bulgaricus LB6 were whey protein concentrate (p = 0.0040 for survival rate, xylitol (p = 0.0067 for survival rate and sorbitol (p = 0.0073 for survival rate, they showed positive effect (whey protein concentrate and sorbitol or negative effect (xylitol. Discussion. The effectiveness of three chosen sugar alcohols and protein implied that they could be used as lyoprotectant for Lactobacillus bulgaricus LB6 in the further research, the optimal composition of sugar alcohol and protein for the lyoprotectant use must be established.

  5. Thermal, Structural and Morphological Characterisation of Freeze-dried Copper(II Acetate Monohydrate and its Solid Decomposition Products

    Directory of Open Access Journals (Sweden)

    Bellini J.V.

    2002-01-01

    Full Text Available In the present study the thermal decomposition of a freeze-dried copper(II acetate monohydrate powder, (CH3COO2Cu.H2O, (FDCuAcH2O, was analysed by a combination of high-temperature X-ray diffractometry; differential scanning calorimetry and thermogravimetry, up to 700 degreesC. The structure and morphology of the calcined freeze-dried powders were analysed by scanning electron microscopy and X-ray diffractometry. The results showed that FDAcCuH2O decomposes during heating in two stages: I (25-225 degreesC FDCuAcH2O dehydrates giving rise to copper(II acetate, (CH3COO2Cu, (AcCu, and II (225-525 degreesC AcCu decomposes to CuO through complex oxidation reactions of Cu and Cu2O, simultaneously. SEM showed that FDCuAcH2O powder has a scale-like morphology, which is created in the freezing stage and retained after freeze-drying. After calcination at 125 and 225 degreesC, clusters of elongated tubes (or filaments compose the resulting powder (AcCu. Subsequent calcination at temperatures above 325 degreesC resulted in hard clusters of spheroid-like CuO particles.

  6. Evaluation of three methods for preservation of Azotobacter: freeze-drying, cryopreservation, and immobilization in dry polymers

    Directory of Open Access Journals (Sweden)

    Daniel Fernando Rojas Tapias

    2013-04-01

    Full Text Available Because the use of bacteria for biotechnological processes requires maintaining their viability and geneticstability, preserving them becomes essential. Here, we evaluated three preservation methods for A.chroococcum C26 and A. vinelandii C27; preservation methods: cryopreservation and immobilization in drypolymers for 60 days, and freeze-drying for 30. We evaluated their efficiency by counting viable cells andmeasuring nitrogen fixation activity. Additionally, we assessed the effect of three protective agents forfreeze-drying, three for cryopreservation, and four polymers. Freeze-drying proved the best technique tomaintain viability and activity, followed by immobilization and cryopreservation. Bacterial nitrogen fixingability remained unchanged using the freeze-drying method, and bacterial survival exceeded 80%; S/BSAwas the best protective agent. Immobilization maintained bacterial survival over 80%, but nitrogen fixationwas decreased by 20%. Lastly, cryopreservation resulted in a dramatic loss of viability for C26 (BSRapprox. 70%, whereas C27 was well preserved. Nitrogen fixation for both strains decreased regardless ofthe cryoprotective agent used (P < 0.05. In conclusion, the success of Azotobacter preservation methodsdepend on the technique, the protective agent, and the strain used. Our results also indicated that freezedryingusing S/BSA is the best technique to preserve bacteria of this genus.

  7. Microencapsulation of Purified Amylase Enzyme from Pitaya (Hylocereus polyrhizus Peel in Arabic Gum-Chitosan using Freeze Drying

    Directory of Open Access Journals (Sweden)

    Mehrnoush Amid

    2014-03-01

    Full Text Available Amylase is one of the most important enzymes in the world due to its wide application in various industries and biotechnological processes. In this study, amylase enzyme from Hylocereus polyrhizus was encapsulated for the first time in an Arabic gum-chitosan matrix using freeze drying. The encapsulated amylase retained complete biocatalytic activity and exhibited a shift in the optimum temperature and considerable increase in the pH and temperature stabilities compared to the free enzyme. Encapsulation of the enzyme protected the activity in the presence of ionic and non-ionic surfactants and oxidizing agents (H2O2 and enhanced the shelf life. The storage stability of amylase is found to markedly increase after immobilization and the freeze dried amylase exhibited maximum encapsulation efficiency value (96.2% after the encapsulation process. Therefore, the present study demonstrated that the encapsulation of the enzyme in a coating agent using freeze drying is an efficient method to keep the enzyme active and stable until required in industry.

  8. Mimicking the quasi-random assembly of protein fibers in the dermis by freeze-drying method.

    Science.gov (United States)

    Ghaleh, Hakimeh; Abbasi, Farhang; Alizadeh, Mina; Khoshfetrat, Ali Baradar

    2015-04-01

    Freeze-drying is extensively used for fabrication of porous materials in tissue engineering and biomedical applications, due to its versatility and use of no toxic solvent. However, it has some significant drawbacks. Conventional freeze-drying technique leads to the production of heterogeneous porous structures with side orientated columnar pores. As the top and bottom surfaces of the sample are not in contact with similar environments, different rates of heat transfer in the surfaces and the temperature gradient across the sample establish the preferential direction of heat transfer. To achieve a scaffold with a desirable microstructure for skin tissue engineering, freeze-drying method was modified by controlling the rate of cooling and regulation of heat transfer across the sample during the freezing step. It could create a homogeneous porous structure with more equiaxed non-oriented pores. Freezing the polymeric solution in the aluminum mold enhanced pore interconnectivity relative to the polystyrene mold. Recrystallization process was discussed how to influence the mean pore size of the scaffold when the final freezing temperature varied. Higher final freezing temperature can easily provide the energy required for the recrystallization process, which lead to enlarged ice crystals and resulting pores.

  9. Freeze-dried stallion spermatozoa: evaluation of two chelating agents and comparative analysis of three sperm DNA damage assays.

    Science.gov (United States)

    Olaciregui, M; Luño, V; Martí, J I; Aramayona, J; Gil, L

    2016-11-01

    During the freeze-drying procedure, sperm DNA might become damaged by both freezing and drying stresses. Sperm DNA status can be detected using well-established assays; however, most techniques are expensive and involve elaborate protocols and equipment. Indirect assessments can provide alternative strategies. The objective of this study was to compare a simple test of DNA status using Diff-Quik (DQ) with two established procedures: acridine orange test (AOT) and sperm chromatin dispersion (SCD) on freeze-dried (FD) stallion spermatozoa. Ejaculated spermatozoa from three stallions were freeze-dried in basic medium supplemented with two different chelating agents: EGTA or EDTA. After rehydration, the spermatozoa were subjected to DNA damage detection using a SCDt, AOT and DQ stain simultaneously. The results showed that the DNA damage levels in the EGTA group were significantly lower than those in the EDTA group. AOT detected a significantly higher proportion of spermatozoa with fragmented DNA than DQ and SCD. The results of the SCD test and DQ stain exhibited a significant positive correlation for DNA fragmentation (r = 0.528), whereas a negative correlation was observed between SCD, DQ and AOT (r = -0.134 and r = -0.332 respectively). The present study shows that both the SCD test and DQ assay are effective methods for detecting FD stallion sperm DNA fragmentation, whereas using of AOT is questionable.

  10. Microencapsulation of purified amylase enzyme from pitaya (Hylocereus polyrhizus) peel in Arabic gum-chitosan using freeze drying.

    Science.gov (United States)

    Amid, Mehrnoush; Manap, Yazid; Zohdi, Nor Khanani

    2014-03-24

    Amylase is one of the most important enzymes in the world due to its wide application in various industries and biotechnological processes. In this study, amylase enzyme from Hylocereus polyrhizus was encapsulated for the first time in an Arabic gum-chitosan matrix using freeze drying. The encapsulated amylase retained complete biocatalytic activity and exhibited a shift in the optimum temperature and considerable increase in the pH and temperature stabilities compared to the free enzyme. Encapsulation of the enzyme protected the activity in the presence of ionic and non-ionic surfactants and oxidizing agents (H₂O₂) and enhanced the shelf life. The storage stability of amylase is found to markedly increase after immobilization and the freeze dried amylase exhibited maximum encapsulation efficiency value (96.2%) after the encapsulation process. Therefore, the present study demonstrated that the encapsulation of the enzyme in a coating agent using freeze drying is an efficient method to keep the enzyme active and stable until required in industry.

  11. Optimisation of freeze drying conditions for purified serine protease from mango (Mangifera indicaCv. Chokanan) peel.

    Science.gov (United States)

    Mehrnoush, Amid; Tan, Chin Ping; Hamed, Mirhosseini; Aziz, Norashikin Ab; Ling, Tau Chuan

    2011-09-01

    This study investigated the possible relationship between the encapsulation variables, namely serine protease content (9-50mg/ml, X1), Arabic gum (0.2-10%(w/w), X2), maltodextrin (2-5%(w/w), X3) and calcium chloride (1.3-5.5%(w/w), X4) on the enzymatic properties of encapsulated serine protease. The study demonstrated that Arabic gum, maltodextrin and calcium chloride, as coating agents, protected serine protease from activity loss during freeze-drying. The overall optimum region resulted in a suitable freeze drying condition with a yield of 92% for the encapsulated serine protease, were obtained using 29.5mg/ml serine protease content, 5.1%(w/w) Arabic gum, 3.5%(w/w) maltodextrin and 3.4%(w/w) calcium chloride. It was found that the interaction effect of Arabic gum and calcium chloride improved the serine protease activity, and Arabic gum was the most effective amongst the examined coating agents. Thus, Arabic gum should be considered as potential protection in freeze drying of serine protease.

  12. Freeze-drying as suitable method to achieve ready-to-use yeast biosensors for androgenic and estrogenic compounds.

    Science.gov (United States)

    Jarque, Sergio; Bittner, Michal; Hilscherová, Klára

    2016-04-01

    Recombinant yeast assays (RYAs) have been proved to be a suitable tool for the fast screening of compounds with endocrine disrupting activities. However, ready-to-use versions more accessible to less equipped laboratories and field studies are scarce and far from optimal throughputs. Here, we have applied freeze-drying technology to optimize RYA for the fast assessment of environmental compounds with estrogenic and androgenic potencies. The effects of different cryoprotectants, initial optical density and long-term storage were evaluated. The study included detailed characterization of sensitivity, robustness and reproducibility of the new ready-to-use versions, as well as comparison with the standard assays. Freeze-dried RYAs showed similar dose-responses curves to their homolog standard assays, with Lowest Observed Effect Concentration (LOEC) and Median effective Concentration (EC50) of 1 nM and 7.5 nM for testosterone, and 0.05 nM and 0.5 nM for 17β-estradiol, respectively. Freeze-dried cells stored at 4 °C retained maximum sensitivity up to 2 months, while cells stored at -18 °C showed no decrease in sensitivity throughout the study (10 months). This ready-to-use RYA is easily accessible and may be potentially used for on-site applications.

  13. Preparation of Chitosan Nanocompositeswith a Macroporous Structure by Unidirectional Freezing and Subsequent Freeze-Drying

    Directory of Open Access Journals (Sweden)

    Inmaculada Aranaz

    2014-11-01

    Full Text Available Chitosan is the N-deacetylated derivative of chitin, a naturally abundant mucopolysaccharide that consists of 2-acetamido-2-deoxy-β-d-glucose through a β (1→4 linkage and is found in nature as the supporting material of crustaceans, insects, etc. Chitosan has been strongly recommended as a suitable functional material because of its excellent biocompatibility, biodegradability, non-toxicity, and adsorption properties. Boosting all these excellent properties to obtain unprecedented performances requires the core competences of materials chemists to design and develop novel processing strategies that ultimately allow tailoring the structure and/or the composition of the resulting chitosan-based materials. For instance, the preparation of macroporous materials is challenging in catalysis, biocatalysis and biomedicine, because the resulting materials will offer a desirable combination of high internal reactive surface area and straightforward molecular transport through broad “highways” leading to such a surface. Moreover, chitosan-based composites made of two or more distinct components will produce structural or functional properties not present in materials composed of one single component. Our group has been working lately on cryogenic processes based on the unidirectional freezing of water slurries and/or hydrogels, the subsequent freeze-drying of which produce macroporous materials with a well-patterned structure. We have applied this process to different gels and colloidal suspensions of inorganic, organic, and hybrid materials. In this review, we will describe the application of the process to chitosan solutions and gels typically containing a second component (e.g., metal and ceramic nanoparticles, or carbon nanotubes for the formation of chitosan nanocomposites with a macroporous structure. We will also discuss the role played by this tailored composition and structure in the ultimate performance of these materials.

  14. Preparation and characterization of solid dispersion freeze-dried efavirenz – polyvinylpyrrolidone K-30

    Science.gov (United States)

    Fitriani, Lili; Haqi, Alianshar; Zaini, Erizal

    2016-01-01

    The aim of this research is to prepare and characterize solid dispersion of efavirenz – polyvinylpyrrolidone (PVP) K-30 by freeze drying to increase its solubility. Solid dispersion of efavirenz – PVP K-30 was prepared by solvent evaporation method with ratio 2:1, 1:1, and 1:2 and dried using a freeze dryer. Characterizations were done by scanning electron microscopy (SEM), powder X-ray diffraction analysis, differential thermal analysis (DTA), and Fourier transform infrared (FT-IR) spectroscopy. Solubility test was carried out in CO2-free distilled water, and efavirenz assay was conducted using high-performance liquid chromatography with acetonitrile:acetic acid (80:20) as the mobile phases. Powder X-ray diffractogram showed a decrease in the peak intensity, which indicated the crystalline altered to amorphous phase. DTA thermal analysis showed a decrease in the melting point of the solid dispersion compared to intact efavirenz. SEM results indicated the changes in the morphology of the crystal into an amorphous form compared to pure components. FT-IR spectroscopy analysis showed a shift wavenumber of the spectrum efavirenz and PVP K-30. The solubility of solid dispersion at ratio 2:1, 1:1, and 1:2 was 6.777 μg/mL, 6.936 μg/mL, and 14,672 μg/mL, respectively, whereas the solubility of intact efavirenz was 0.250 μg/mL. In conclusion, the solubility of solid dispersion increased significantly (P < 0.05). PMID:27429930

  15. Sterilization of freeze dried manila clam (Ruditapea philippinarum) porridge for immuno-compromised patients

    Energy Technology Data Exchange (ETDEWEB)

    Song, Beom Seok; Park, Jae Nam [Team for Radiation Food Science and Biotechnology, Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of)

    2017-02-15

    This study was conducted to evaluate the combined effect of gamma irradiation and different conditions (vacuum packaging, antioxidant and freezing) on the microbiological and sensory characteristics of freeze dried Manila clam porridge (MCP) for immuno-compromised patient food. McP can be sterilized at 1 kGy to 10 kGy. the initial counts of total aerobic bacteria and yeast molds in the non-irradiated MCP were 2.4±0.5 and 1.2±0.3 log CFU g{sup -}'1, respectively, but gamma irradiation significantly decreased the total aerobic bacteria to below the detection limit (1 log CFU g{sup -1}) (5 kGy). Moreover, gamma irradiation effectively eliminated yeasts/molds at dose below than 1 kGy. However, gamma irradiation accelerated the increase of lipid oxidation and therefore, decreased the sensory characteristics of MCP as irradiation dose increased. to improve the sensory qualities of gamma irradiated MCP, combination treatment (vacuum packaging, 0.1% vitamin c) were applied. there was no significant difference in the overall acceptance scores between the combined-treatment sample (5.6 points) and the non-irradiated samples (6.0). the results indicate that combination treatment (vacuum packaging, 0.1% vitamin c) may help to maintain the quality of MCP. therefore, it considered that irradiation of MCP with combined treatment and this is an effective method for the consumption as a special purpose food such as for space travel or immuno-compromised patients.

  16. Dynamic culture improves MSC adhesion on freeze-dried bone as a scaffold for bone engineering.

    Science.gov (United States)

    Gonçalves, Fabiany da Costa; Paz, Ana Helena da Rosa; Lora, Priscila Schmidt; Passos, Eduardo Pandolfi; Cirne-Lima, Elizabeth Obino

    2012-02-26

    To investigate the interaction between mesenchymal stem cells (MSCs) and bone grafts using two different cultivation methods: static and dynamic. MSCs were isolated from rat bone marrow. MSC culture was analyzed according to the morphology, cell differentiation potential, and surface molecular markers. Before cell culture, freeze-dried bone (FDB) was maintained in culture for 3 d in order to verify culture medium pH. MSCs were co-cultured with FDB using two different cultivation methods: static co-culture (two-dimensional) and dynamic co-culture (three-dimensional). After 24 h of cultivation by dynamic or static methods, histological analysis of Cell adhesion on FDB was performed. Cell viability was assessed by the Trypan Blue exclusion method on days 0, 3 and 6 after dynamic or static culture. Adherent cells were detached from FDB surface, stained with Trypan Blue, and quantified to determine whether the cells remained on the graft surface in prolonged non-dynamic culture. Statistical analyses were performed with SPSS and a P cultures. Rat MSCs were positive for CD44, CD90 and CD29 and negative for CD34, CD45 and CD11bc. FDBs were maintained in culture for 3 d and the results showed there was no significant variation in the culture medium pH with FDB compared to pure medium pH (P > 0.05). In histological analysis, there was a significant difference in the amount of adhered cells on FDB between the two cultivation methods (P culture method demonstrated greater adhesion on the bone surface than in static co-culture method. On day 0, the cell viability in the dynamic system was significantly higher than in the static system (P statistical difference in cell viability between days 0, 3 and 6 after dynamic culture (P culture, cell viability on day 6 was significantly lower than on day 3 and 0 (P culture provides a superior environment over static conditions.

  17. Evaluation of Freeze-Dried Kefir Coculture as Starter in Feta-Type Cheese Production

    Science.gov (United States)

    Kourkoutas, Y.; Kandylis, P.; Panas, P.; Dooley, J. S. G.; Nigam, P.; Koutinas, A. A.

    2006-01-01

    The use of freeze-dried kefir coculture as a starter in the production of feta-type cheese was investigated. Maturation of the produced cheese at 4°C was monitored for up to 70 days, and the effects of the starter culture, the salting method, and the ripening process on quality characteristics were studied. The use of kefir coculture as a starter led to increased lactic acid concentrations and decreased pH values in the final product associated with significantly higher conversion rates compared to salted rennet cheese. Determination of bacterial diversity at the end of the ripening process in salted kefir and rennet cheeses by denaturing gradient gel electrophoresis technology, based on both DNA and RNA analyses, suggested a potential species-specific inhibition of members of the genera Staphylococcus and Psychrobacter by kefir coculture. The main active microbial associations in salted kefir cheese appeared to be members of the genera Pseudomonas and Lactococcus, while in salted rennet cheese, Oxalobacteraceae, Janthinobacterium, Psychrobacter, and Pseudomonas species were noted. The effect of the starter culture on the production of aroma-related compounds responsible for cheese flavor was also studied by the solid-phase microextraction-gas chromatography-mass spectrometry technique. Kefir coculture also appeared to extend the shelf life of unsalted cheese. Spoilage of kefir cheese was observed on the 9th and 20th days of preservation at 10 and 5°C, respectively, while spoilage in the corresponding rennet cheese was detected on the 7th and 16th days. Microbial counts during preservation of both types of unsalted cheese increased steadily and reached similar levels, with the exception of staphylococci, which were significantly lower in unsalted kefir cheese. All types of cheese produced with kefir as a starter were approved and accepted by the panel during the preliminary sensory evaluation compared to commercial feta-type cheese. PMID:16957238

  18. Stability study perspective of the effect of freeze-drying using cryoprotectants on the structure of insulin loaded into PLGA nanoparticles.

    Science.gov (United States)

    Fonte, Pedro; Soares, Sandra; Sousa, Flávia; Costa, Ana; Seabra, Vítor; Reis, Salette; Sarmento, Bruno

    2014-10-13

    This work aimed to evaluate the influence of a freeze-drying process using different cryoprotectants on the structure of insulin loaded into poly(lactic-co-glycolic acid) (PLGA) nanoparticles and to assess the stability of these nanoparticles upon 6 months of storage following ICH guidelines. Insulin-loaded PLGA nanoparticles with a size around 450 nm were dehydrated using a standard freeze-drying cycle, using trehalose, glucose, sucrose, fructose, and sorbitol at 10% (w/v) as cryoprotectants. All formulations, except those nonadded of cryoprotectant and added with trehalose, collapsed after freeze-drying. The addition of cryoprotectants increased the nanoparticles stability upon storage. FTIR results showed that insulin maintained its structure after encapsulation in about 88%, decreasing to 71% after freeze-drying. The addition of cryoprotectants prior to freeze-drying increased insulin structural stability an average of up to 79%. Formulations collapsed after freeze-drying showed better protein stabilization upon storage, in special sorbitol added formulation, preserving 76, 80, and 78% of insulin structure at 4 °C, 25 °C/60% RH, and 40 °C/75% RH, respectively. Principal component analysis also showed that the sorbitol-added formulation showed the most similar insulin structural modifications among the tested storage conditions. These findings suggested that regarding nanoparticles stability, cryoprotectants are versatile to be used in a standard freeze-drying, however they present different performances on the stabilization of the loaded protein. Thus, on the freeze-drying of the nanoparticles field, this work gives rise to the importance of the process of optimization, searching for a balance between a good obtainable cake with an optimal structural stabilization of the loaded protein.

  19. Clinical and Histomorphometric Assessment of Lateral Alveolar Ridge Augmentation Using a Corticocancellous Freeze-Dried Allograft Bone Block.

    Science.gov (United States)

    Ahmadi, Roya Shariatmadar; Sayar, Ferena; Rakhshan, Vahid; Iranpour, Babak; Jahanbani, Jahanfar; Toumaj, Ahmad; Akhoondi, Nasrin

    2017-06-01

    Horizontal ridge augmentation with allografts has attracted notable attention because of its proper success rate and the lack of disadvantages of autografts. Corticocancellous block allografts have not been adequately studied in humans. Therefore, this study clinically and histomorphometrically evaluated the increase in ridge width after horizontal ridge augmentation using corticocancellous block allografts as well as implant success after 12 to 18 months after implantation. In 10 patients receiving implants (3 women, 7 men; mean age = 45 years), defective maxillary alveolar ridges were horizontally augmented using freeze-dried bone allograft blocks. Ridge widths were measured before augmentation, immediately after augmentation, and ∼6 months later in the reentry surgery for implantation. This was done at points 2 mm (A) and 5 mm (B) apically to the crest. Biopsy cores were acquired from the implantation site. Implant success was assessed 15.1 ± 2.7 months after implantation (range = 12-18 months). Data were analyzed using Friedman and Dunn tests (α = 0.05). At point A, ridge widths were 2.77 ± 0.37, 8.02 ± 0.87, and 6.40 ± 0.66 mm, respectively, before surgery, immediately after surgery, and before implantation. At point B, ridge widths were 3.40 ± 0.39, 9.35 ± 1.16, and 7.40 ± 1.10 mm, respectively, before surgery, immediately after surgery, and before implantation. The Friedman test showed significant increases in ridge widths, both at point A and point B (both P = .0000). Postaugmentation resorption was about 1.5-2 mm and was statistically significant at points A and B (P < .05, Dunn). The percentage of newly formed bone, residual graft material, and soft tissue were 33.0% ± 11.35% (95% confidence interval [CI] = 24.88%-41.12%), 37.50% ± 19.04% (95% CI = 23.88%-51.12%), and 29.5%, respectively. The inflammation was limited to grades 1 or zero. Twelve to 18 months after implantation, no implants caused pain or showed exudates or pockets. Radiographic

  20. Immunisation of Sheep with Bovine Viral Diarrhoea Virus, E2 Protein Using a Freeze-Dried Hollow Silica Mesoporous Nanoparticle Formulation.

    Directory of Open Access Journals (Sweden)

    Donna Mahony

    Full Text Available Bovine viral diarrhoea virus 1 (BVDV-1 is arguably the most important viral disease of cattle. It is associated with reproductive, respiratory and chronic diseases in cattle across the world. In this study we have investigated the capacity of the major immunological determinant of BVDV-1, the E2 protein combined with hollow type mesoporous silica nanoparticles with surface amino functionalisation (HMSA, to stimulate immune responses in sheep. The current work also investigated the immunogenicity of the E2 nanoformulation before and after freeze-drying processes. The optimal excipient formulation for freeze-drying of the E2 nanoformulation was determined to be 5% trehalose and 1% glycine. This excipient formulation preserved both the E2 protein integrity and HMSA particle structure. Sheep were immunised three times at three week intervals by subcutaneous injection with 500 μg E2 adsorbed to 6.2 mg HMSA as either a non-freeze-dried or freeze-dried nanoformulation. The capacity of both nanovaccine formulations to generate humoral (antibody and cell-mediated responses in sheep were compared to the responses in sheep immunisation with Opti-E2 (500 μg together with the conventional adjuvant Quil-A (1 mg, a saponin from the Molina tree (Quillaja saponira. The level of the antibody responses detected to both the non-freeze-dried and freeze-dried Opti-E2/HMSA nanoformulations were similar to those obtained for Opti-E2 plus Quil-A, demonstrating the E2 nanoformulations were immunogenic in a large animal, and freeze-drying did not affect the immunogenicity of the E2 antigen. Importantly, it was demonstrated that the long term cell-mediated immune responses were detectable up to four months after immunisation. The cell-mediated immune responses were consistently high in all sheep immunised with the freeze-dried Opti-E2/HMSA nanovaccine formulation (>2,290 SFU/million cells compared to the non-freeze-dried nanovaccine formulation (213-500 SFU/million cells

  1. Optimization of Freeze-Drying Process Parameters for Qualitative Evaluation of Button Mushroom (Agaricus bisporus Using Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Ayon Tarafdar

    2017-01-01

    Full Text Available Button mushroom cubes of constant cross-sectional area (0.75 cm × 1.5 cm and varying thickness (2 mm, 5 mm, and 8 mm were freeze-dried. Pressure (0.04, 0.07, and 0.10 mbar, primary drying temperature (−2°C, −5°C, and −8°C, and secondary drying temperature (25°C, 28°C, and 31°C were taken as drying parameters. The protein, ascorbic acid, and antioxidant contents were taken as quality estimates for freeze-dried mushrooms. It was observed that the secondary drying temperature affected the protein (p<0.05 and antioxidant content (p<0.01 significantly, whereas all three freeze-drying parameters affected the ascorbic acid content with higher effect due to temperature parameters (p<0.01 as compared to pressure (p<0.05. The optimized values for protein, ascorbic acid, and antioxidant content obtained using response surface methodology were 7.28±0.56 mg/g, 26.92±0.87 mg/100 g, and 8.60±0.44 mg/g, respectively, as compared to 8.43±0.21 mg/g, 28.00±0.53 mg/100 g, and 9.10±0.10 mg/g, respectively, for fresh button mushrooms. The optimum values for process variables were obtained as 0.09 mbar, 0.36 cm, and −7.53°C and 25.03°C for pressure, sample thickness, and primary and secondary drying temperatures, respectively.

  2. Comparative study of subtalar arthrodesis after calcaneal frature malunion with autologous bone graft or freeze-dried xenograft.

    Science.gov (United States)

    Henning, Carlo; Poglia, Gabriel; Leie, Murilo Anderson; Galia, Carlos Roberto

    2015-12-01

    Calcaneal fracture malunion may evolve into arthrosis and severe foot deformities. The aim of this study was to identify differences in bony union following corrective subtalar arthrodesis with interposition of autologous tricortical bone graft or freeze-dried bovine xenograft. We prospectively evaluated 12 patients who underwent subtalar arthrodesis, six patients received autografts and 6 received freeze-dried bovine xenografts. After a mean followup of 58 weeks, the patients were clinical assessed using AOFAS scale and the visual analog scale (VAS) for pain and for final radiographic parameters measurement. Two blind raters evaluated the length of time required for solid union of the arthrodesis and graft integration by retrospective radiographic examination. In the autograft group, AOFAS score improved from a preoperative average of 37 to 64 points postoperatively (p = 0.02) and mean VAS score improved from 4.7 to 1.9 (p = 0.028). In the xenograft group, AOFAS score improved from 38 to 74 points (p = 0.02) and VAS from 5.5 to 2.7 (p = 0.046). Solid union was achieved in all cases in the autograft group at an average of 5.3 weeks and in five cases in the xenograft group at 8.8 weeks (p = 0.077). Graft integration occurred after an average of 10.7 weeks in the autograft group and 28.8 weeks in the xenograft group (p = 0.016). With the numbers available, no significant difference could be detected in the length of time required for solid union of subtalar arthrodesis between groups, although time to integration of freeze-dried bovine xenografts was statistically higher. Clinical and functional improvement was observed in both groups.

  3. Influence of Stress Treatments on the Resistance of Lactococcus lactis to Freezing and Freeze-Drying

    OpenAIRE

    Lin, Chan

    1998-01-01

    This study investigated the effect of cold, heat, or osmotic shock treatment on the resistance of L. lactis subsp. cremoris MM160 and MM310 and Lactococcus lactis subsp. lactis MM210 and FG2 cheese starter bacteria to freezing and freeze-drying. The ability to withstand freezing at -60°C for 24 h was variable among lactococci, but resistance to this treatment was significantly improved (P < 0.05) in most strains by a 2-h cold shock at l0°C or a 25-min heat shock at 39°C (L. lactis subsp. crem...

  4. Pilot-scale Production and Viability Analysis of Freeze-Dried Probiotic Bacteria Using Different Protective Agents

    Directory of Open Access Journals (Sweden)

    Alberto Cresci

    2010-03-01

    Full Text Available The functional food industry requires an improvement of probiotic strain stability during storage, especially when they are stored at room temperature. In this study, the viability of freeze-dried Lactobacillus rhamnosus IMC 501® and Lactobacillus paracasei IMC 502® using different protective agents (i.e., glycerine, mannitol, sorbitol, inulin, dextrin, Crystalean® was determined and compared with semi skimmed milk (SSM control. No significant differences were observed between the tested protectants and the control (SSM during storage at refrigerated conditions. During storage at room temperature, only glycerine was found to stabilize viability better than other tested substances.

  5. Effects of Freeze-dried Mulberry on Antioxidant Activities and Fermented Characteristics of Yogurt during Refrigerated Storage

    OpenAIRE

    2015-01-01

    This study investigated the effect of added freeze-dried mulberry fruit juice (FDMJ) (1, 3 and 5%) on the antioxidant activity and fermented characteristic of yogurt during refrigerated storage. A decrease in pH of yogurt and increase in acidity was observed during fermentation. The yogurts with FDMJ exhibited faster rate of pH reduction than control. Initial lactic acid bacteria count of yogurt was 6.49-6.94 Log CFU/g and increased above 9 Log CFU/g in control and 1% in FDMJ yogurt for 24 h....

  6. Freeze-Drying Technology and Strategies for Biological Products%生物制品冷冻干燥技术与策略

    Institute of Scientific and Technical Information of China (English)

    朱明文

    2012-01-01

    基于对现代冻干技术进展研究和多年生物制品实际冻干经验,探讨了影响冻干的重要因素、环节以及技术和对策。冷冻干燥技术研发和工业化是复杂的系统工程,仅靠传统方法已难于有效控制,应建立以科学为基础,通过质量设计、风险评估和过程控制,优化和控制冻干过程,获取优良冻干产品,提高生产效率,降低成本。通过冻干应用技术研究,为生物制品冻干研发和生产以及产品的质量控制提供参考。%Based on research on development of modern freeze drying technology and the experience in actual freezing and drying of biological products for years,this paper discusses important factors affecting freeze-dried effect,technologies and strategies.Freeze drying technology development and industrialization is a complex system engineering,traditional methods alone are difficult to effectively control.A kind of scientific basis should be established,the freeze drying process is optimized and controlled by quality design,risk assessment and process quality control to get excellent freeze dried product,improve freeze-dehydration production time,reduce costs.Through the research on application of the freeze drying technology,it provides the reference for freeze-dried biologicals development,production and product quality control.

  7. Effect of freeze dried powdered probiotics on gingival status and plaque inhibition: A randomized, double-blind, parallel study

    Directory of Open Access Journals (Sweden)

    Asif Yousuf

    2017-01-01

    Full Text Available Objective: The study aimed to evaluate the effectiveness of freeze dried powdered probiotics on gingival status and plaque inhibition among 12–15-year-old schoolchildren. Materials and Methods: This randomized controlled trial was conducted among 12–15-year-old schoolchildren in Jaipur. Commercially available freeze dried probiotics containing Lactobacillus acidophilus, Bifidobacterium longum, Bifidobacterium bifidum and Bifidobacterium lactis (Prowel, Alkem Laboratories, lactic acid bacillus only (Sporolac, Sangyo, and a placebo powder calcium carbonate 250 g (Calcium Sandoz, Novartis were assigned to two intervention groups and a placebo group each comprising 11 schoolchildren. All subjects were instructed to mix the powder in 30 ml of water and swish once daily for 3 min, for 3 weeks. Periodontal clinical parameters were assessed by examining the subjects for Turesky-Gilmore-Glickman plaque index (PI (Modification of Quigley-Hein PI and gingival index at baseline, 7th day, 14th day, and 21st day. Results: For both the probiotic groups, a statistically significant reduction (P < 0.05 in gingival status and plaque inhibition was recorded up to 2nd week of probiotic ingestion. However, no significant difference was observed in the placebo group. Conclusion: The use of probiotic mouth rinses improves the oral health in children by significantly reducing the plaque and gingival scores. Further studies are warranted to prove or refute the long-term effects, means of administering probiotics and the dosages needed to achieve different preventive or therapeutic purposes.

  8. Optimisation of phenolic extraction from Averrhoa carambola pomace by response surface methodology and its microencapsulation by spray and freeze drying.

    Science.gov (United States)

    Saikia, Sangeeta; Mahnot, Nikhil Kumar; Mahanta, Charu Lata

    2015-03-15

    Optimised of the extraction of polyphenol from star fruit (Averrhoa carambola) pomace using response surface methodology was carried out. Two variables viz. temperature (°C) and ethanol concentration (%) with 5 levels (-1.414, -1, 0, +1 and +1.414) were used to design the optimisation model using central composite rotatable design where, -1.414 and +1.414 refer to axial values, -1 and +1 mean factorial points and 0 refers to centre point of the design. The two variables, temperature of 40°C and ethanol concentration of 65% were the optimised conditions for the response variables of total phenolic content, ferric reducing antioxidant capacity and 2,2-diphenyl-1-picrylhydrazyl scavenging activity. The reverse phase-high pressure liquid chromatography chromatogram of the polyphenol extract showed eight phenolic acids and ascorbic acid. The extract was then encapsulated with maltodextrin (⩽ DE 20) by spray and freeze drying methods at three different concentrations. Highest encapsulating efficiency was obtained in freeze dried encapsulates (78-97%). The obtained optimised model could be used for polyphenol extraction from star fruit pomace and microencapsulates can be incorporated in different food systems to enhance their antioxidant property.

  9. Influence of compression on water sorption, glass transition, and enthalpy relaxation behavior of freeze-dried amorphous sugar matrices.

    Science.gov (United States)

    Imamura, Koreyoshi; Kagotani, Ryo; Nomura, Mayo; Tanaka, Kazuhiro; Kinugawa, Kohshi; Nakanishi, Kazuhiro

    2011-04-15

    An amorphous matrix comprised of sugar molecules are frequently used in the pharmaceutical industry. The compression of the amorphous sugar matrix improves the handling. Herein, the influence of compression on the water sorption of an amorphous sugar matrix was investigated. Amorphous sugar samples were prepared by freeze-drying, using several types of sugars, and compressed at 0-443 MPa. The compressed amorphous sugar samples as well as uncompressed samples were rehumidified at given RHs, and the equilibrium water content and glass transition temperature (T(g)) were then measured. Compression resulted in a decrease in the equilibrium water content of the matrix, the magnitude of which was more significant for smaller sized sugars. Diffusivity of water vapor in the sample was also decreased to one-hundredth by the compression. The T(g) value for a given RH remained unchanged, irrespective of the compression. Accordingly, the decrease in T(g) with increasing water content increased as the result of compression. The structural relaxation of the amorphous sugar matrices were also examined and found to be accelerated to the level of a non-porous amorphous sugar matrix as the result of the compression. The findings indicate that pores contained in freeze-dried sugar samples interfere with the propagation of structural relaxation.

  10. Novel budesonide particles for dry powder inhalation (DPI) prepared using a microfluidic reactor coupled with ultrasonic spray freeze drying.

    Science.gov (United States)

    Saboti, Denis; Maver, Uroš; Chan, Hak-Kim; Planinšek, Odon

    2017-03-09

    Budesonide is a potent active pharmaceutical ingredient, often administered using respiratory devices such as metered dose inhalers (MDI), nebulizers and dry powder inhalers (DPI). Inhalable drug particles are conventionally produced by crystallization followed by milling. This approach tends to generate partially amorphous materials that require post-processing to improve the formulations' stability. Other methods involve homogenization or precipitation and often require the use of stabilizers, mostly surfactants. The purpose of this study was therefore to develop a novel method for preparation of fine budesonide particles using a microfluidic reactor coupled with ultrasonic spray freeze drying, and hence avoiding the need of additional homogenization or stabilizer use. A T-junction microfluidic reactor was employed to produce particle suspension (using an ethanol-water, methanol-water and an acetone-water system), which was directly fed into an ultrasonic atomization probe, followed by direct feeding to liquid nitrogen. Freeze drying was the final preparation step. The result were fine crystalline budesonide powders which, when blended with lactose and dispersed in an Aerolizer at 100 L/min, generated fine particle fraction in the range 47.6±2.8% to 54.9±1.8%, thus exhibiting a good aerosol performance. Subsequent sample analysis confirmed the suitability of the developed method to produce inhalable drug particles without additional homogenization or stabilizers. The developed method provides a viable solution for particle isolation in microfluidics in general.

  11. Nanomaterial transformation and association with fresh and freeze-dried wastewater activated sludge: implications for testing protocol and environmental fate.

    Science.gov (United States)

    Kiser, Mehlika A; Ladner, David A; Hristovski, Kiril D; Westerhoff, Paul K

    2012-07-03

    Engineered nanomaterials (ENMs) are an emerging class of contaminants entering wastewater treatment plants (WWTPs), and standardized testing protocols are needed by industry and regulators to assess the potential removal of ENMs during wastewater treatment. A United States Environmental Protection Agency (USEPA) standard method (OPPTS 835.1110) for estimating soluble pollutant removal during wastewater treatment using freeze-dried, heat-treated (FDH) activated sludge (AS) has been recently proposed for predicting ENM fate in WWTPs. This study is the first to evaluate the use of FDH AS in batch experiments for quantifying ENM removal from wastewater. While soluble pollutants sorbed equally to fresh and FDH AS, fullerene, silver, gold, and polystyrene nanoparticles' removals with FDH AS were approximately 60-100% less than their removals with fresh AS. Unlike fresh AS, FDH AS had a high concentration of proteins and other soluble organics in the liquid phase, an indication of bacterial membrane disintegration due to freeze-drying and heat exposure. This cellular matter stabilized ENMs such that they were poorly removed by FDH AS. Therefore, FDH AS is not a suitable sorbent for estimating nanoparticle removal in WWTPs, whereas fresh AS has been shown to reasonably predict full-scale performance for titanium removal. This study indicates that natural or engineered processes (e.g., anaerobic digestion, biosolids decomposition in soils) that result in cellular degradation and matrices rich in surfactant-like materials (natural organic matter, proteins, phospholipids, etc.) may transform nanoparticle surfaces and significantly alter their fate in the environment.

  12. Microencapsulation by freeze-drying of potassium norbixinate and curcumin with maltodextrin: stability, solubility, and food application.

    Science.gov (United States)

    Sousdaleff, Mirian; Baesso, Mauro Luciano; Medina Neto, Antonio; Nogueira, Ana Cláudia; Marcolino, Vanessa Aparecida; Matioli, Graciette

    2013-01-30

    Stability of potassium norbixinate and curcumin by microencapsulation with maltodextrin DE20 and freeze-drying was evaluated as a function of exposition to light, air, different pH, water solubility, and in food applications. The best results were obtained with microencapsulated potassium norbixinate 1:20, which, when vacuum-packed and in the presence of natural light, showed color retention of 78%, while microencapsulated curcumin 1:20 showed color retention of 71%. Differential scanning calorimetry and thermogravimetry provided an indication of interaction between colorants and maltodextrin. Photoacoustic spectroscopy (PAS) showed that free and microencapsulated colorants exhibited high rates of absorption throughout the measured spectral region. This work evidenced that the freeze-drying process is favorable for microencapsulation of curcumin by maltodextrin, providing improved solubility to the microencapsulated colorant. Both microencapsulated colorants showed relevant results for use in a wide range of pH and food applications. The PAS technique was useful for the evaluation of the stability of free and microencapsulated colorants.

  13. Freeze drying of peptide drugs self-associated with long-circulating, biocompatible and biodegradable sterically stabilized phospholipid nanomicelles.

    Science.gov (United States)

    Lim, Sok Bee; Rubinstein, Israel; Onyüksel, Hayat

    2008-05-22

    The purpose of this study was to determine optimal lipid concentration range for lyophilization of sterically stabilized phospholipid nanomicelles (SSM) and the freeze drying feasibility of self-associated therapeutic peptide-SSM assemblies. SSM at 5-20 mM 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-methoxy-poly(ethylene glycol 2000) (DSPE-PEG(2000)) were analyzed for particle size and viscosity before and after freeze drying which showed no significant changes (p>0.05). However, a steep increase in viscosity was seen for SSM above 15 mM phospholipid implying micelle-micelle interaction. Greater shrinkage of lyophilized cakes was observed below 10 mM phospholipid while they were more fibrous above 15 mM. Therefore, 10-15 mM DSPE-PEG(2000) was chosen as the optimal phospholipid concentration for lyophilized SSM. When vasoactive intestinal peptide (VIP), glucagon-like peptide 1 (GLP-1) or gastric inhibitory peptide (GIP) (each, 67 microM) was added to SSM (10mM), formulations showed no significant change in particle size, peptide fluorescence and peptide alpha-helicity before and after lyophilization. In conclusion, we found that peptide drug-SSM interactions are conserved during lyophilization.

  14. Solubility enhancement of BCS Class II drug by solid phospholipid dispersions: Spray drying versus freeze-drying.

    Science.gov (United States)

    Fong, Sophia Yui Kau; Ibisogly, Asiye; Bauer-Brandl, Annette

    2015-12-30

    The poor aqueous solubility of BCS Class II drugs represents a major challenge for oral dosage form development. Using celecoxib (CXB) as model drug, the current study adopted a novel solid phospholipid nanoparticle (SPLN) approach and compared the effect of two commonly used industrial manufacturing methods, spray- and freeze-drying, on the solubility and dissolution enhancement of CXB. CXB was formulated with Phospholipoid E80 (PL) and trehalose at different CXB:PL:trehalose ratios, of which 1:10:16 was the optimal formulation. Spherical amorphous SPLNs with average diameters spray-drying; while amorphous 'matrix'-like structures of solid PL dispersion with larger particle sizes were prepared by freeze-drying. Formulations from both methods significantly enhanced the dissolution rates, apparent solubility, and molecularly dissolved concentration of CXB in phosphate buffer (PBS, pH 6.5) and in biorelevant fasted state simulated intestinal fluid (FaSSIF, pH 6.5) (pspray-dried SPLNs had a larger enhancement in apparent solubility (29- to 132-fold) as well as molecular solubility (18-fold) of CXB at equilibrium (pspray-dried SPLNs to attain 'true' supersaturation state makes them a promising approach for bioavailability enhancement of poorly soluble drugs.

  15. Vial freeze-drying, part 1: new insights into heat transfer characteristics of tubing and molded vials.

    Science.gov (United States)

    Hibler, Susanne; Wagner, Christophe; Gieseler, Henning

    2012-03-01

    In order to optimize a freeze-drying cycle, information regarding the heat transfer characteristics of the container system is imperative. Two most recently developed tubing (TopLyo™) and molded (EasyLyo™) vial designs were compared with a standard serum tubing and molded vial, a polymer vial (TopPac™), and an amber molded EasyLyo™. In addition, the impact of methodology on the determination of reliable vial heat transfer coefficient (K(v) ) data is examined in detail. All K(v) s were gravimetrically determined by sublimation tests with pure water at 50, 100, 200, and 400 mTorr. In contrast to the traditional assumption that molded vials exhibit inefficient heat transfer characteristics, these vials showed a very similar performance compared with their serum tubing counterparts in the relevant pressure range for freeze-drying. At 100 mTorr, the TopLyo™ center vials show only 4% higher K(v) values than the EasyLyo™ center vials. All glass vials outmatch the polymer vial in terms of heat transfer, up to 30% elevated heat transfer for the TopLyo™ center vials at 400 mTorr. Sublimation tests have demonstrated to be a valuable tool to investigate the heat transfer characteristics of vials, but results are dependent on methodology. New developments in molded vial manufacturing lead to improved heat transfer performance.

  16. Beef, chicken and lamb fatty acid analysis--a simplified direct bimethylation procedure using freeze-dried material.

    Science.gov (United States)

    Lee, M R F; Tweed, J K S; Kim, E J; Scollan, N D

    2012-12-01

    When fractionation of meat lipids is not required, procedures such as saponification can be used to extract total fatty acids, reducing reliance on toxic organic compounds. However, saponification of muscle fatty acids is laborious, and requires extended heating times, and a second methylation step to convert the extracted fatty acids to fatty acid methyl esters prior to gas chromatography. Therefore the development of a more rapid direct methylation procedure would be of merit. The use of freeze-dried material for analysis is common and allows for greater homogenisation of the sample. The present study investigated the potential of using freeze-dried muscle samples and a direct bimethylation to analyse total fatty acids of meat (beef, chicken and lamb) in comparison with a saponification procedure followed by bimethylation. Both methods compared favourably for all major fatty acids measured. There was a minor difference in relation to the C18:1 trans 10 isomer with a greater (Psaponification. However, numerically the difference was small and likely as a result of approaching the limits of isomer identification by single column gas chromatography. Differences (Psaponification to analyse total fatty acids from muscle samples.

  17. Evaluation of spin freezing versus conventional freezing as part of a continuous pharmaceutical freeze-drying concept for unit doses.

    Science.gov (United States)

    De Meyer, L; Van Bockstal, P-J; Corver, J; Vervaet, C; Remon, J P; De Beer, T

    2015-12-30

    Spin-freezing as alternative freezing approach was evaluated as part of an innovative continuous pharmaceutical freeze-drying concept for unit doses. The aim of this paper was to compare the sublimation rate of spin-frozen vials versus traditionally frozen vials in a batch freeze-dryer, and its impact on total drying time. Five different formulations, each having a different dry cake resistance, were tested. After freezing, the traditionally frozen vials were placed on the shelves while the spin-frozen vials were placed in aluminum vial holders providing radial energy supply during drying. Different primary drying conditions and chamber pressures were evaluated. After 2h of primary drying, the amount of sublimed ice was determined in each vial. Each formulation was monitored in-line using NIR spectroscopy during drying to determine the sublimation endpoint and the influence of drying conditions upon total drying time. For all tested formulations and applied freeze-drying conditions, there was a significant higher sublimation rate in the spin-frozen vials. This can be explained by the larger product surface and the lower importance of product resistance because of the much thinner product layers in the spin frozen vials. The in-line NIR measurements allowed evaluating the influence of applied drying conditions on the drying trajectories.

  18. Effects of cryoprotectants on the viability and activity of freeze dried recombinant yeasts as novel oral drug delivery systems assessed by an artificial digestive system.

    Science.gov (United States)

    Blanquet, Stéphanie; Garrait, Ghislain; Beyssac, Erick; Perrier, Céline; Denis, Sylvain; Hébrard, Géraldine; Alric, Monique

    2005-09-01

    The aim of this study was to investigate, in a gastric-small intestinal system TIM-1, the effect of cryoprotectants on the survival of freeze-dried Saccharomyces cerevisiae expressing the heterologous P450 73A1 and their ability to convert trans-cinnamic acid into p-coumaric acid. Yeasts were lyophilized in suspensions of trehalose, maltose, lactose, or a milk proteins/trehalose mix. Freeze-dried or native yeasts and trans-cinnamic acid were introduced simultaneously into TIM-1 at the beginning of digestion. Yeast survival rate was evaluated by cell counting in the ileal effluents. P450 73A1 activity was followed by HPLC assay of p-coumaric acid. Freeze-dried yeasts showed high tolerance to digestive conditions. Nevertheless, their survival rate was lower than that of non-dried cells (around 80% whatever the protective agent vs. 96%). The ability of recombinant freeze-dried S. cerevisiae to perform a bioconversion reaction in the digestive tract was shown with all the protectants. The highest trans-cinnamic acid conversion rate (24 vs. 41% for native yeasts) was obtained with the milk proteins/trehalose mix. These results show that freeze-drying might be considered for the pharmaceutical formulation of new drug delivery systems based on orally administered recombinant yeasts and that TIM-1 could be a helpful tool for the pre-screening of oral dosage forms.

  19. On the use of tert-butanol/water cosolvent systems in production and freeze-drying of poly-ε-caprolactone nanoparticles.

    Science.gov (United States)

    Zelenková, Tereza; Barresi, Antonello A; Fissore, Davide

    2015-01-01

    This work deals with the use of a water/tert-butyl alcohol (TBA) system in the manufacturing process of poly-ε-caprolactone (PCL) nanoparticles, namely in the synthesis stage, using the solvent displacement method in a confined impinging jet mixer (CIJM), and in the following freeze-drying stage. The experimental investigation evidenced that the nanoparticles size is significantly reduced with respect to the case where acetone is the solvent. Besides, the solvent evaporation step is not required before freeze-drying as TBA is fully compatible with the freeze-drying process. The effect of initial polymer concentration, flow rate, water to TBA flow rate ratio, and quench volumetric ratio on the mean nanoparticles size was investigated, and a simple equation was proposed to relate the mean nanoparticles size to these operating parameters. Then, freeze-drying of the nanoparticles suspensions was studied. Lyoprotectants (sucrose and mannitol) and steric stabilizers (Cremophor EL and Poloxamer 388) have to be used to avoid nanoparticles aggregation, thus preserving particle size distribution and mean nanoparticles size. Their effect, as well as that of the heating shelf temperature, has been investigated by means of statistical techniques, with the goal to identify which of these factors, or combination of factors, plays the key role in the nanoparticles size preservation at the end of the freeze-drying process.

  20. In-line near infrared spectroscopy during freeze-drying as a tool to measure efficiency of hydrogen bond formation between protein and sugar, predictive of protein storage stability

    OpenAIRE

    Mensink, Maarten A.; Van Bockstal, Pieter-Jan; Pieters, S; De Meyer, Laurens; Frijlink, Henderik W.; van der Voort Maarschalk, Kees; Hinrichs, Wouter L.J.; De Beer, Thomas

    2015-01-01

    Sugars are often used as stabilizers of protein formulations during freeze-drying. However, not all sugars are equally suitable for this purpose. Using in-line near-infrared spectroscopy during freeze-drying, it is shown here that hydrogen bond formation during freeze-drying, under secondary drying conditions in particular, can be related to the preservation of the functionality and structure of proteins during storage. The disaccharide trehalose was best capable of forming hydrogen bonds wit...

  1. Characterization and in vitro evaluation of freeze-dried microparticles composed of granisetron-cyclodextrin complex and carboxymethylcellulose for intranasal delivery.

    Science.gov (United States)

    Cho, Hyun-Jong; Balakrishnan, Prabagar; Shim, Won-Sik; Chung, Suk-Jae; Shim, Chang-Koo; Kim, Dae-Duk

    2010-11-15

    The aim of this study was to prepare microparticles (MPs) of granisetron (GRN) in combination with hydroxypropyl-β-cyclodextrin (HP-β-CD) and sodium carboxymethylcellulose (CMC-Na) by the simple freeze-drying method for intranasal delivery. The composition of MPs was determined from the phase-solubility study of GRN in various CDs. Fourier transform infrared spectroscopy (FT-IR), powder X-ray diffraction (PXRD) analysis and differential scanning calorimetry (DSC) studies were performed to evaluate possible interactions between GRN and excipients. The results indicated the formation of inclusion complex between GRN and CD, and the conversion of drug into amorphous state. The in vitro release of GRN from MPs was determined in phosphate buffered saline (pH 6.4) at 37°C. Cytotoxicity of the MPs and in vitro permeation study were conducted by using primary human nasal epithelial (HNE) cells and their monolayer system cultured by air-liquid interface (ALI) method, respectively. The MPs showed significantly higher GRN release profile compared to pure GRN. Moreover, the prepared MPs showed significantly lower cytotoxicity and higher permeation profile than that of GRN powder (p<0.05). These results suggested that the MPs composed of GRN, HP-β-CD and CMC-Na represent a simple and new GRN intranasal delivery system as an alternative to the oral and intravenous administration of GRN.

  2. Freeze-Dried Platelet-Rich Plasma Accelerates Bone Union with Adequate Rigidity in Posterolateral Lumbar Fusion Surgery Model in Rats

    Science.gov (United States)

    Shiga, Yasuhiro; Orita, Sumihisa; Kubota, Go; Kamoda, Hiroto; Yamashita, Masaomi; Matsuura, Yusuke; Yamauchi, Kazuyo; Eguchi, Yawara; Suzuki, Miyako; Inage, Kazuhide; Sainoh, Takeshi; Sato, Jun; Fujimoto, Kazuki; Abe, Koki; Kanamoto, Hirohito; Inoue, Masahiro; Kinoshita, Hideyuki; Aoki, Yasuchika; Toyone, Tomoaki; Furuya, Takeo; Koda, Masao; Takahashi, Kazuhisa; Ohtori, Seiji

    2016-11-01

    Fresh platelet-rich plasma (PRP) accelerates bone union in rat model. However, fresh PRP has a short half-life. We suggested freeze-dried PRP (FD-PRP) prepared in advance and investigated its efficacy in vivo. Spinal posterolateral fusion was performed on 8-week-old male Sprague-Dawley rats divided into six groups based on the graft materials (n = 10 per group): sham control, artificial bone (A hydroxyapatite–collagen composite) –alone, autologous bone, artificial bone + fresh-PRP, artificial bone + FD-PRP preserved 8 weeks, and artificial bone + human recombinant bone morphogenetic protein 2 (BMP) as a positive control. At 4 and 8 weeks after the surgery, we investigated their bone union–related characteristics including amount of bone formation, histological characteristics of trabecular bone at remodeling site, and biomechanical strength on 3-point bending. Comparable radiological bone union was confirmed at 4 weeks after surgery in 80% of the FD-PRP groups, which was earlier than in other groups (p < 0.05). Histologically, the trabecular bone had thinner and more branches in the FD-PRP. Moreover, the biomechanical strength was comparable to that of autologous bone. FD-PRP accelerated bone union at a rate comparable to that of fresh PRP and BMP by remodeling the bone with thinner, more tangled, and rigid trabecular bone.

  3. Safety assessment of freeze-dried powdered Tenebrio molitor larvae (yellow mealworm) as novel food source: Evaluation of 90-day toxicity in Sprague-Dawley rats.

    Science.gov (United States)

    Han, So-Ri; Lee, Byoung-Seok; Jung, Kyung-Jin; Yu, Hee-Jin; Yun, Eun-Young; Hwang, Jae Sam; Moon, Kyoung-Sik

    2016-06-01

    Worldwide demand for novel food source has grown and edible insects are a promising food sources for humans. Tenebrio molitor, as known as yellow mealworm, has advantages of being rich in protein, and easy to raise as a novel food source. The objective of this study was to evaluate subchronic toxicity, including potential hypersensitivity, of freeze-dried powdered T. molitor larvae (fdTML) in male and female Sprague-Dawley rats. The fdTML was administered orally once daily at dose levels of 0, 300, 1000 and 3000 mg/kg/day for 90 days. A toxicological assessment was performed, which included mortality, clinical signs, body and organ weights, food consumption, ophthalmology, urinalysis, hematology, serum chemistry, gross findings, histopathologic examination and allergic reaction. There were no fdTML- related findings in clinical signs, urinalysis, hematology and serum chemistry, gross examination, histopathologic examination or allergic reaction. In conclusion, the No Observed Adverse Effect Level (NOAEL) for fdTML was determined to be in excess of 3000 mg/kg/day in both sexes of rats under the experimental conditions of this study.

  4. Effect of acid whey and freeze-dried cranberries on lipid oxidation and fatty acid composition of nitrite-/nitrate-free fermented sausage made from deer meat

    Science.gov (United States)

    Karwowska, Małgorzata; Dolatowski, Zbigniew J.

    2017-01-01

    Objective This study evaluated the effect of acid whey and freeze-dried cranberries on the physicochemical characteristics, lipid oxidation and fatty acid composition of nitrite-free fermented sausage made from deer meat and pork fat. Antioxidant interactions between acid whey and cranberry compounds were also explored. Methods Four formulations of fermented venison sausage were prepared: F1 (control), F2 (with 5% liquid acid whey), F3 (with 0.06% of freeze-dried cranberries), and F4 (with 5% liquid acid whey and 0.06% of freeze-dried cranberries). Each sample was analyzed for pH, water activity (aw), heme iron content, 2-thiobarbituric acid reactive substances (TBARS) value and conjugated dienes at the end of the manufacturing process and at 30 and 90 days of refrigerated storage. Fatty acid composition was measured once at the end of the manufacturing process. Results At the end of ripening, all samples presented statistically different values for a pH range of 4.47 to pH 4.59. The sum of the unsaturated fatty acids was higher, while the conjugated diene and the TBARS values were lower in sausages with freeze-dried cranberries as compared to the control sausage. The highest content of heme iron (21.52 mg/kg) at day 90 was found in the sausage formulation with the addition of freeze-dried cranberries, which suggests that the addition of cranberries stabilized the porphyrin ring of the heme molecule during storage and thereby reduced the release of iron. The use of liquid acid whey in combination with cranberries appears to not be justified in view of the oxidative stability of the obtained products. Conclusion The results suggest that the application of freeze-dried cranberries can lower the intensity of oxidative changes during the storage of nitrite-free fermented sausage made from deer meat. PMID:27165018

  5. Short communication: Effects of vacuum freeze-drying on inactivation of Cronobacter sakazakii ATCC29544 in liquid media with different initial inoculum levels.

    Science.gov (United States)

    Jiao, Rui; Gao, Jina; Zhang, Xiyan; Zhang, Maofeng; Chen, Jiren; Wu, Qingping; Zhang, Jumei; Ye, Yingwang

    2017-03-01

    Vacuum freeze-drying is an important food-processing technology for valid retention of nutrients and bioactive compounds. Cronobacter sakazakii has been reported to be associated with severe infections in neonates through consumption of contaminated powdered infant formula. In this study, effects of vacuum freeze-drying treatment for 12, 24, and 36 h on inactivation of C. sakazakii with different initial inoculum levels in sterile water, tryptic soy broth (TSB), skim milk, and whole milk were determined. Results indicated that the lethality rate of C. sakazakii in each sample increased with the extension of vacuum freeze-drying time. With initial inoculum levels of 10(2) and 10(3) cfu/mL, the survival of C. sakazakii in different liquid media was significantly affected by vacuum freeze-drying for 12, 24, and 36 h. In addition, the lethality rates of C. sakazakii in whole milk, skim milk, and TSB was significantly reduced compared with those in sterile water. Furthermore, whole milk showed the strongest protective role for C. sakazakii cells, followed by skim milk and TSB medium. Using the scanning electron microscope, the intracellular damage and obvious distortion of C. sakazakii cells were observed after vacuum freeze-drying for 24 and 36 h compared with the untreated sample, and the injured cells increased with the extension of vacuum-drying time. We concluded that inactivation of vacuum freeze-drying on C. sakazakii cells is related to the food matrix, and a combination with other methods for inactivating C. sakazakii is required for ensuring microbial safety of powdered infant formula. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  6. Effect of acid whey and freeze-dried cranberries on lipid oxidation and fatty acid composition of nitrite-/nitrate-free fermented sausage made from deer meat

    Directory of Open Access Journals (Sweden)

    Małgorzata Karwowska

    2017-01-01

    Full Text Available Objective This study evaluated the effect of acid whey and freeze-dried cranberries on the physicochemical characteristics, lipid oxidation and fatty acid composition of nitrite-free fermented sausage made from deer meat and pork fat. Antioxidant interactions between acid whey and cranberry compounds were also explored. Methods Four formulations of fermented venison sausage were prepared: F1 (control, F2 (with 5% liquid acid whey, F3 (with 0.06% of freeze-dried cranberries, and F4 (with 5% liquid acid whey and 0.06% of freeze-dried cranberries. Each sample was analyzed for pH, water activity (aw, heme iron content, 2-thiobarbituric acid reactive substances (TBARS value and conjugated dienes at the end of the manufacturing process and at 30 and 90 days of refrigerated storage. Fatty acid composition was measured once at the end of the manufacturing process. Results At the end of ripening, all samples presented statistically different values for a pH range of 4.47 to pH 4.59. The sum of the unsaturated fatty acids was higher, while the conjugated diene and the TBARS values were lower in sausages with freeze-dried cranberries as compared to the control sausage. The highest content of heme iron (21.52 mg/kg at day 90 was found in the sausage formulation with the addition of freeze-dried cranberries, which suggests that the addition of cranberries stabilized the porphyrin ring of the heme molecule during storage and thereby reduced the release of iron. The use of liquid acid whey in combination with cranberries appears to not be justified in view of the oxidative stability of the obtained products. Conclusion The results suggest that the application of freeze-dried cranberries can lower the intensity of oxidative changes during the storage of nitrite-free fermented sausage made from deer meat.

  7. Ketahanan Hidup Sel Acetobacter xylinum pada Pengawetan secara Kering-Beku Menggunakan Medium Pembawa (Viability of A. xylinum Subjected to Freeze Drying Using Carrier Media

    Directory of Open Access Journals (Sweden)

    Noor Aini Habibah

    2009-03-01

    Full Text Available A research on the use of sucrose and lactose as carrier media to protect Acetobacter xylinum cell subjected to freeze drying has been done. The aim of the research was to know the number of the viable cells from dried culture and to know the concentration of the carrier medium that would give best result. The best result is sucrose at the concentration of 15% that produced 28.2 x 106 viable cells/ ml of rehidrated culture. The rehidrated culture used in the research was Schramm & Herstin medium. Key words : Acetobacter xylinum, freeze drying, carrier media

  8. 菠萝蜜真空冷冻干燥工艺的研究%The vacuum freeze-drying process of jackfruit

    Institute of Scientific and Technical Information of China (English)

    张容鹄; 万祝宁; 何艾; 谢辉; 窦志浩

    2012-01-01

    In this paper,vacuum freeze-drying method was applied to freezing-dry jackfruit.The eutectic point and consolute point were determined by electrical resistance method,freeze-drying curve was drew and the best freeze-drying procedure was definite by optimization.Then tests analyzed the influence factors on quality of freeze-drying jackfruit,such as pre-freezing method,different grade of maturity,slice wideth and soap method.Results indicated that the best freeze-drying procedure was:the first stage-20 ℃,5.5 h;the second-10 ℃,6 h;the third 20 ℃,4 h;the forth 30 ℃,4 h.Meanwhile,this showed little difference to the quality of products between two kinds of pre-freezing methods.Furthermore,in the addition of 90 percent maturity,4~7 mm incision wideth and 0.9% NaCl solution soaping,the products of freezing-dry was high of quality.Compared with the sale jackfruit products,the freeze-drying products had better quality.%采用真空冷冻干燥方法冻干菠萝蜜,电阻法测定菠萝蜜的共晶点和共熔点,绘制了冻干曲线,通过优化确定了最佳冻干程序。试验分析了预冻方式、浸泡方式、切割宽度对冻干菠萝蜜品质的影响。结果表明:最佳程序为第一段,-20℃,5.5h;第二段,-10℃,6h;第三段,20℃,4h;第四段,30℃,4h。进一步试验表明2种预冻方式对冻干产品影响不大,切条宽度为4~7mm,0.9%NaCl溶液浸泡后冻干得到产品品质好。冻干菠萝蜜与市售菠萝蜜脆片比较具有更好的品质。

  9. The influence of lysozyme on mannitol polymorphism in freeze-dried and spray-dried formulations depends on the selection of the drying process

    DEFF Research Database (Denmark)

    Grohganz, Holger; Lee, Yan-Ying; Rantanen, Jukka

    2013-01-01

    -infrared spectroscopy in combination with multivariate analysis and further, results were verified with X-ray powder diffraction. It was seen that the prevalence of the mannitol polymorphic form shifted from ß-mannitol to d-mannitol with increasing protein concentration in freeze-dried formulations. In spray......-dried formulations an increase in protein concentration resulted in a shift from ß-mannitol to a-mannitol. An increase in final drying temperature of the freeze-drying process towards the temperature of the spray-drying process did not lead to significant changes. It can thus be concluded that it is the drying...

  10. Bilateral maxillary sinus floor augmentation with tissue-engineered autologous osteoblasts and demineralized freeze-dried bone

    Directory of Open Access Journals (Sweden)

    Aashish Deshmukh

    2015-01-01

    Full Text Available The pneumatization of the maxillary sinus often results in a lack of sufficient alveolar bone for implant placement. In the last decades, maxillary sinus lift has become a very popular procedure with predictable results. Sinus floor augmentation procedures are generally carried out using autologous bone grafts, bone substitutes, or composites of bone and bone substitutes. However, the inherent limitations associated with each of these, have directed the attention of investigators to new technologies like bone tissue engineering. Bone marrow stromal cells have been regarded as multi-potent cells residing in bone marrow. These cells can be harvested from a person, multiplied outside his body using bioengineering principles and technologies and later introduced into a tissue defect. We present a case where tissue-engineered autologous osteoblasts were used along with demineralized freeze-dried bone for sinus floor augmentation.

  11. The influence of different polymers on viability of Bifidobacterium lactis 300b during encapsulation, freeze-drying and storage.

    Science.gov (United States)

    Pop, Oana Lelia; Brandau, Thorsten; Schwinn, Jens; Vodnar, Dan Cristian; Socaciu, Carmen

    2015-07-01

    Seven different types of natural polymers namely hydroxypropyl methylcellulose (HPMC), sodium-carboxymethyl cellulose (Na-CMC), microcrystalline cellulose (MCC), starch BR-07, starch BR-08, dextrin and pullulan were used in order to develop the optimal formula for the entrapment of Bifidobacterium lactis 300B in Ca-alginate based granules. Laminar flow drip casting with Brace-Encapsulator was used in order to prepare the granules. The results showed that alginate/pullulan and alginate/HPMC formulation provide high protection for the bacterial strain used for encapsulation. These two formulations were further used to obtain freeze dried granules, for which the viability in time and at different temperatures was tested. The final results showed a higher viability than the level of the therapeutic minimum (>10(7) CFU/g) after 15 days of storage. Other parameters like entrapment efficiency, production rate, sphericity, flowability were also discussed.

  12. Treatment of Periradicular Bone Defect by Periosteal Pedicle Graft as a Barrier Membrane and Demineralized Freeze-Dried Bone Allograft

    Science.gov (United States)

    Saxena, Anurag

    2017-01-01

    The purpose of this case report is to describe the usefulness of Periosteal Pedicle Graft (PPG) as a barrier membrane and Demineralized Freeze-Dried Bone Allograft (DFDBA) for bone regeneration in periradicular bone defect. A patient with intraoral discharging sinus due to carious exposed pulp involvement was treated by PPG and DFDBA. Clinical and radiological evaluations were done immediately prior to surgery, three months, six months and one year after surgery. Patient was treated using split-thickness flap, PPG, apicoectomy, defect fill with DFDBA and lateral displacement along with suturing of the PPG prior to suturing the flap, in order to close the communication between the oral and the periapical surroundings through sinus tract opening. After one year, successful healing of periradicular bone defect was achieved. Thus, PPG as a barrier membrane and DFDBA have been shown to have the potential to stimulate bone formation when used in periradicular bone defect. PMID:28274066

  13. Fabrication of highly porous keratin sponges by freeze-drying in the presence of calcium alginate beads

    Energy Technology Data Exchange (ETDEWEB)

    Hamasaki, Shinichi; Tachibana, Akira; Tada, Daisuke; Yamauchi, Kiyoshi [Department of Applied Chemistry and Bioengineering, Graduate School of Engineering, Osaka City University, 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka 558-8585 (Japan); Tanabe, Toshizumi [Department of Applied Chemistry and Bioengineering, Graduate School of Engineering, Osaka City University, 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka 558-8585 (Japan)], E-mail: tanabe@bioa.eng.osaka-cu.ac.jp

    2008-12-01

    Novel fabrication method of highly porous and flexible keratin sponges was developed by combining a particulate-leaching method and a freeze-drying method. Reduced keratin aqueous solution was mixed with dried calcium alginate beads and was lyophilized to give keratin/calcium alginate complex, which was subsequently treated with EDTA solution to leach out calcium alginate beads. The resultant keratin sponge was flexible enough to handle even in dried state because of its quite high porosity (98.9 {+-} 0.1%), which was brought about by the large and small pores formed by the elimination of calcium alginate beads and water. The sponge supported the attachment and the proliferation of mouse fibroblast cells. Thus, the keratin sponge given by the present fabrication method afforded one alternative as a cell scaffold for tissue engineering.

  14. Elemental distribution and sample integrity comparison of freeze-dried and frozen-hydrated biological tissue samples with nuclear microprobe

    Energy Technology Data Exchange (ETDEWEB)

    Vavpetič, P., E-mail: primoz.vavpetic@ijs.si [Jožef Stefan Institute, Jamova 39, SI-1000 Ljubljana (Slovenia); Vogel-Mikuš, K. [Biotechnical Faculty, Department of Biology, University of Ljubljana, Jamnikarjeva 101, SI-1000 Ljubljana (Slovenia); Jeromel, L. [Jožef Stefan Institute, Jamova 39, SI-1000 Ljubljana (Slovenia); Ogrinc Potočnik, N. [Jožef Stefan Institute, Jamova 39, SI-1000 Ljubljana (Slovenia); FOM-Institute AMOLF, Science Park 104, 1098 XG Amsterdam (Netherlands); Pongrac, P. [Biotechnical Faculty, Department of Biology, University of Ljubljana, Jamnikarjeva 101, SI-1000 Ljubljana (Slovenia); Department of Plant Physiology, University of Bayreuth, Universitätstr. 30, 95447 Bayreuth (Germany); Drobne, D.; Pipan Tkalec, Ž.; Novak, S.; Kos, M.; Koren, Š.; Regvar, M. [Biotechnical Faculty, Department of Biology, University of Ljubljana, Jamnikarjeva 101, SI-1000 Ljubljana (Slovenia); Pelicon, P. [Jožef Stefan Institute, Jamova 39, SI-1000 Ljubljana (Slovenia)

    2015-04-01

    The analysis of biological samples in frozen-hydrated state with micro-PIXE technique at Jožef Stefan Institute (JSI) nuclear microprobe has matured to a point that enables us to measure and examine frozen tissue samples routinely as a standard research method. Cryotome-cut slice of frozen-hydrated biological sample is mounted between two thin foils and positioned on the sample holder. The temperature of the cold stage in the measuring chamber is kept below 130 K throughout the insertion of the samples and the proton beam exposure. Matrix composition of frozen-hydrated tissue is consisted mostly of ice. Sample deterioration during proton beam exposure is monitored during the experiment, as both Elastic Backscattering Spectrometry (EBS) and Scanning Transmission Ion Microscopy (STIM) in on–off axis geometry are recorded together with the events in two PIXE detectors and backscattered ions from the chopper in a single list-mode file. The aim of this experiment was to determine differences and similarities between two kinds of biological sample preparation techniques for micro-PIXE analysis, namely freeze-drying and frozen-hydrated sample preparation in order to evaluate the improvements in the elemental localisation of the latter technique if any. In the presented work, a standard micro-PIXE configuration for tissue mapping at JSI was used with five detection systems operating in parallel, with proton beam cross section of 1.0 × 1.0 μm{sup 2} and a beam current of 100 pA. The comparison of the resulting elemental distributions measured at the biological tissue prepared in the frozen-hydrated and in the freeze-dried state revealed differences in elemental distribution of particular elements at the cellular level due to the morphology alteration in particular tissue compartments induced either by water removal in the lyophilisation process or by unsatisfactory preparation of samples for cutting and mounting during the shock-freezing phase of sample preparation.

  15. Elemental distribution and sample integrity comparison of freeze-dried and frozen-hydrated biological tissue samples with nuclear microprobe

    Science.gov (United States)

    Vavpetič, P.; Vogel-Mikuš, K.; Jeromel, L.; Ogrinc Potočnik, N.; Pongrac, P.; Drobne, D.; Pipan Tkalec, Ž.; Novak, S.; Kos, M.; Koren, Š.; Regvar, M.; Pelicon, P.

    2015-04-01

    The analysis of biological samples in frozen-hydrated state with micro-PIXE technique at Jožef Stefan Institute (JSI) nuclear microprobe has matured to a point that enables us to measure and examine frozen tissue samples routinely as a standard research method. Cryotome-cut slice of frozen-hydrated biological sample is mounted between two thin foils and positioned on the sample holder. The temperature of the cold stage in the measuring chamber is kept below 130 K throughout the insertion of the samples and the proton beam exposure. Matrix composition of frozen-hydrated tissue is consisted mostly of ice. Sample deterioration during proton beam exposure is monitored during the experiment, as both Elastic Backscattering Spectrometry (EBS) and Scanning Transmission Ion Microscopy (STIM) in on-off axis geometry are recorded together with the events in two PIXE detectors and backscattered ions from the chopper in a single list-mode file. The aim of this experiment was to determine differences and similarities between two kinds of biological sample preparation techniques for micro-PIXE analysis, namely freeze-drying and frozen-hydrated sample preparation in order to evaluate the improvements in the elemental localisation of the latter technique if any. In the presented work, a standard micro-PIXE configuration for tissue mapping at JSI was used with five detection systems operating in parallel, with proton beam cross section of 1.0 × 1.0 μm2 and a beam current of 100 pA. The comparison of the resulting elemental distributions measured at the biological tissue prepared in the frozen-hydrated and in the freeze-dried state revealed differences in elemental distribution of particular elements at the cellular level due to the morphology alteration in particular tissue compartments induced either by water removal in the lyophilisation process or by unsatisfactory preparation of samples for cutting and mounting during the shock-freezing phase of sample preparation.

  16. Multivariate analysis of phenol in freeze-dried and spray-dried insulin formulations by NIR and FTIR.

    Science.gov (United States)

    Maltesen, Morten Jonas; Bjerregaard, Simon; Hovgaard, Lars; Havelund, Svend; van de Weert, Marco; Grohganz, Holger

    2011-06-01

    Dehydration is a commonly used method to stabilise protein formulations. Upon dehydration, there is a significant risk the composition of the formulation will change especially if the protein formulation contains volatile compounds. Phenol is often used as excipient in insulin formulations, stabilising the insulin hexamer by changing the secondary structure. We have previously shown that it is possible to maintain this structural change after drying. The aim of this study was to evaluate the residual phenol content in spray-dried and freeze-dried insulin formulations by Fourier transform infrared (FTIR) spectroscopy and near infrared (NIR) spectroscopy using multivariate data analysis. A principal component analysis (PCA) and partial least squares (PLS) projections were used to analyse spectral data. After drying, there was a difference between the two drying methods in the phenol/insulin ratio and the water content of the dried samples. The spray-dried samples contained more water and less phenol compared with the freeze-dried samples. For the FTIR spectra, the best model used one PLS component to describe the phenol/insulin ratio in the powders, and was based on the second derivative pre-treated spectra in the 850-650 cm(-1) region. The best PLS model based on the NIR spectra utilised three PLS components to describe the phenol/insulin ratio and was based on the standard normal variate transformed spectra in the 6,200-5,800 cm(-1) region. The root mean square error of cross validation was 0.69% and 0.60% (w/w) for the models based on the FTIR and NIR spectra, respectively. In general, both methods were suitable for phenol quantification in dried phenol/insulin samples.

  17. Thermal ink-jet spray freeze-drying for preparation of excipient-free salbutamol sulphate for inhalation.

    Science.gov (United States)

    Mueannoom, Wunlapa; Srisongphan, Amon; Taylor, Kevin M G; Hauschild, Stephan; Gaisford, Simon

    2012-01-01

    The use of thermal ink-jet spray freeze-drying (TIJ-SFD) to engineer inhalable, excipient-free salbutamol sulphate (SS) particles was assessed. A modified Hewlett-Packard printer was used to atomise aqueous SS solutions into liquid nitrogen. The frozen droplets were freeze-dried. It was found that TIJ-SFD could process SS solutions up to 15%w/v; the porous particles produced had a physical diameter of ca. 35 μm. Next generation impactor (NGI) analysis indicated that the particles had a smaller aerodynamic size (MMAD ranging from 6 to 8.7 μm). Particles prepared from the lowest concentration SS solution were too fragile to withstand aerosolisation, but the 5%w/v solution yielded particles having the best combination of strength and aerodynamic properties. Comparison with a commercial SS formulation (Cyclocap®) showed that the SFD preparation had an almost equivalent FPF (6.4 μm) when analysed with a twin-stage impinger (TSI; 24.0 ± 1.2% and 26.4 ± 2.2%, respectively) and good performance when analysed with NGI (FPF (4.46 μm):16.5 ± 2.0 and 27.7 ± 1.7, respectively). TIJ-SFD appears to be an excellent method to prepare inhalable particles. It is scalable yet allows assessment of the viability of the pulmonary route early in the development since it can be used with very small volumes (<0.5 mL) of solution.

  18. Successful Resolution of Recurrent Clostridium difficile Infection using Freeze-Dried, Encapsulated Fecal Microbiota; Pragmatic Cohort Study.

    Science.gov (United States)

    Staley, Christopher; Hamilton, Matthew J; Vaughn, Byron P; Graiziger, Carolyn T; Newman, Krista M; Kabage, Amanda J; Sadowsky, Michael J; Khoruts, Alexander

    2017-06-01

    Fecal microbiota transplantation (FMT) is increasingly being used for treatment of recurrent Clostridium difficile infection (R-CDI) that cannot be cured with antibiotics alone. In addition, FMT is being investigated for a variety of indications where restoration or restructuring of the gut microbial community is hypothesized to be beneficial. We sought to develop a stable, freeze-dried encapsulated preparation of standardized fecal microbiota that can be used for FMT with ease and convenience in clinical practice and research. We systematically developed a lyophilization protocol that preserved the viability of bacteria across the taxonomic spectrum found in fecal microbiota and yielded physicochemical properties that enabled consistent encapsulation. We also treated a cohort of R-CDI patients with a range of doses of encapsulated microbiota and analyzed the associated changes in the fecal microbiome of the recipients. The optimized lyophilized preparation satisfied all our preset goals for physicochemical properties, encapsulation ease, stability at different temperatures, and microbiota viability in vitro and in vivo (germ-free mice). The capsule treatment was administered to 49 patients. Overall, 43/49 (88%) of patients achieved a clinical success, defined as no recurrence of CDI over 2 months. Analysis of the fecal microbiome demonstrated near normalization of the fecal microbial community by 1 month following FMT treatment. The simplest protocol using the lowest dose (2.1-2.5 × 10(11) bacteria in 2-3 capsules) without any colon purgative performed equally well in terms of clinical outcomes and microbiota engraftment. A single administration of encapsulated, freeze-dried fecal microbiota from a healthy donor was highly successful in treating antibiotic-refractory R-CDI syndrome.

  19. Dielectric properties of a BaTiO{sub 3} ceramic prepared by using the freeze drying method

    Energy Technology Data Exchange (ETDEWEB)

    Al-Shakarchi, Emad K. [Al-Nahrain University, Baghdad (Iraq)

    2010-08-15

    A modified catecholate process has been developed to synthesize high-purity barium titanate by using a freeze drying method to produce ultra-fine powders from a barium titanium catechol complex, Ba[Ti(C{sub 6}H{sub 4}O{sub 2}){sub 3}]. The complex prepared from TiCl{sub 4}, C{sub 6}H{sub 4}(OH){sub 2} and BaCO{sub 3}. The freeze drying of the complex Ba[Ti(C{sub 6}H{sub 4}O{sub 2}){sub 3}] under a primary vacuum at a freezing temperature of -50 .deg. C for a long time 24 hrs is necessary to transfer the complex Ba[Ti(C{sub 6}H{sub 4}O{sub 2}){sub 3}] from a liquid phase to a solid phase. A subsequent calcination of the complex for 12 hrs at a temperature of 700 .deg. C was very important to remove the acetates from the mixture. Finally, a sintering process was required for the pellets so that high density samples could be investigated. The dielectric properties, the structural phase, and the particle size of the sintered pellets have investigated as functions of frequency and temperature in order to determine the critical temperature for the phase transition. X-ray diffraction was used to investigate the structural properties and the particle size. The tetragonal phase of BaTiO{sub 3} with the lattice constants a = b = 3.9734 A, and c = 4.012 A was successfully obtained.

  20. Influence of different sugar cryoprotectants on the stability and physico-chemical characteristics of freeze-dried 5-fluorouracil plurilamellar vesicles

    Directory of Open Access Journals (Sweden)

    Mohamed Mahmoud Nounou

    2005-07-01

    Full Text Available Lyophilization increases the shelf-life of liposomes by preserving it in a dry form as lyophilized cake to be reconstituted with water immediately prior to administration. Aiming at increasing stability and availability of 5-Fluorouracil liposomal products, 5-Fluorouacil Stable Plurilamellar Vesicles were prepared. Freeze dried liposomal dispersions were prepared with or without cryoprotectants. The cryoprotectants used were glucose, mannitol or trehalose in 1, 2 and 4 grams per gram phospholipids. The results showed that lyophilized cake of liposomes without cryoprotectants was compact and difficult to reconstitute, in comparison with fluffy cakes which reconstituted easily and quickly when using cryoprotectants. The percentage of 5-Fluorouracil retained in liposomes freeze-dried without cryoprotectants was 18.29% ± 0.96% and the percentage of 5-Fluorouracil retained in stable plurilamellar vesicles was 31.22% ± 0.62% using 4 grams trehalose as cryoprotectant per gram of lipid. Physico-chemical and release stability studies showed superior potentials of the lyophilized product after reconstitution in comparison to dispersion product. It may be concluded that all tested sugars have cryoprotectant effects that stabilized liposomes in the freeze dried state, where trehalose offered the most superior cryoprotectant effect for freeze dried 5-fluorouracil liposomes.

  1. Encapsulation of antioxidant phenolic compounds extracted from spent coffee grounds by freeze-drying and spray-drying using different coating materials

    DEFF Research Database (Denmark)

    Ballesteros, Lina F.; Ramirez, Monica J.; Orrego, Carlos E.

    2017-01-01

    Freeze-drying and spray-drying techniques were evaluated for encapsulation of phenolic compounds (PC) extracted from spent coffee grounds. Additionally, the use of maltodextrin, 29 gum arabic and a mixture of these components (ratio 1:1) as wall material to retain the PC and preserve...

  2. Application of the freeze-dried bioluminescent bioreporter Pseudomonas putida mt-2 KG1206 to the biomonitoring of groundwater samples from monitoring wells near gasoline leakage sites.

    Science.gov (United States)

    Ko, Kyung-Seok; Kong, In Chul

    2017-02-01

    This study examined the applicability of a freeze-dried bioluminescent bioreporter, Pseudomonas putida mt-2 KG1206 (called KG1206), to the biomonitoring of groundwater samples. Samples were collected from the monitoring wells of gas station tanks or old pipeline leakage sites in Korea. In general, the freeze-dried strain in the presence of pure inducer chemicals showed low bioluminescence activity and a different activity order compared with that of the subcultured strain. The effects of KNO3 as a bioluminescence stimulant were observed on the pure inducers and groundwater samples. The stimulation rates varied according to the type of inducers and samples, ranging from 2.2 to 20.5 times (for pure inducers) and from 1.1 to 11 times (for groundwater samples) the total bioluminescence of the control. No considerable correlations were observed between the bioluminescence intensity of the freeze-dried strain and the inducer concentrations in the samples (R (2) < 0.1344). However, samples without a high methyl tertiary butyl ether (MTBE) level and those from the gas station leakage site showed reasonable correlations with the bioluminescence activity with R (2) values of 0.3551 and 0.4131, respectively. These results highlight the potential of using freeze-dried bioluminescent bacteria as a rapid, simple, and portable tool for the preliminary biomonitoring of specific pollutants at contaminated sites.

  3. The influence of lysozyme on mannitol polymorphism in freeze-dried and spray-dried formulations depends on the selection of the drying process.

    Science.gov (United States)

    Grohganz, Holger; Lee, Yan-Ying; Rantanen, Jukka; Yang, Mingshi

    2013-04-15

    Freeze-drying and spray-drying are often applied drying techniques for biopharmaceutical formulations. The formation of different solid forms upon drying is often dependent on the complex interplay between excipient selection and process parameters. The purpose of this study was to investigate the influence of the chosen drying method on the solid state form. Mannitol-lysozyme solutions of 20mg/mL, with the amount of lysozyme varying between 2.5% and 50% (w/w) of total solid content, were freeze-dried and spray-dried, respectively. The resulting solid state of mannitol was analysed by near-infrared spectroscopy in combination with multivariate analysis and further, results were verified with X-ray powder diffraction. It was seen that the prevalence of the mannitol polymorphic form shifted from β-mannitol to δ-mannitol with increasing protein concentration in freeze-dried formulations. In spray-dried formulations an increase in protein concentration resulted in a shift from β-mannitol to α-mannitol. An increase in final drying temperature of the freeze-drying process towards the temperature of the spray-drying process did not lead to significant changes. It can thus be concluded that it is the drying process in itself, rather than the temperature, that leads to the observed solid state changes.

  4. Effect of whey protein isolate and β-cyclodextrin wall systems on stability of microencapsulated vanillin by spray-freeze drying method.

    Science.gov (United States)

    Hundre, Swetank Y; Karthik, P; Anandharamakrishnan, C

    2015-05-01

    Vanillin flavour is highly volatile in nature and due to that application in food incorporation is limited; hence microencapsulation of vanillin is an ideal technique to increase its stability and functionality. In this study, vanillin was microencapsulated for the first time by non-thermal spray-freeze-drying (SFD) technique and its stability was compared with other conventional techniques such as spray drying (SD) and freeze-drying (FD). Different wall materials like β-cyclodextrin (β-cyd), whey protein isolate (WPI) and combinations of these wall materials (β-cyd + WPI) were used to encapsulate vanillin. SFD microencapsulated vanillin with WPI showed spherical shape with numerous fine pores on the surface, which in turn exhibited good rehydration ability. On the other hand, SD powder depicted spherical shape without pores and FD encapsulated powder yielded larger particle sizes with flaky structure. FTIR analysis confirmed that there was no interaction between vanillin and wall materials. Moreover, spray-freeze-dried vanillin + WPI sample exhibited better thermal stability than spray dried and freeze-dried microencapsulated samples.

  5. Rational design of an influenza subunit vaccine powder with sugar glass technology : preventing conformational changes of haemagglutinin during freezing and freeze-drying

    NARCIS (Netherlands)

    Amorij, J-P; Meulenaar, J; Hinrichs, W L J; Stegmann, T; Huckriede, A; Coenen, F; Frijlink, H W

    2007-01-01

    The development of a stable influenza subunit vaccine in the dry state was investigated. The influence of various carbohydrates, buffer types and freezing rates on the integrity of haemagglutinin after freeze-thawing or freeze-drying was investigated with a range of analytical and immunological meth

  6. Physical and immunogenic stability of spray freeze-dried influenza vaccine powder for pulmonary delivery : Comparison of inulin, dextran, or a mixture of dextran and trehalose as protectants

    NARCIS (Netherlands)

    Murugappan, Senthil; Patil, Harshad P; Kanojia, Gaurav; ter Veer, Wouter; Meijerhof, Tjarko; Frijlink, Henderik W; Huckriede, Anke; Hinrichs, Wouter L J

    2013-01-01

    One of the advantages of dry influenza vaccines over conventional liquid influenza vaccines is that they can be used for alternative routes of administration. Previous studies showed that spray freeze-drying is an excellent technique to prepare vaccine containing powders for pulmonary delivery U.P.

  7. Microbial adhesion to surface-grafted polyacrylamide brushes after long-term exposure to PBS and reconstituted freeze-dried saliva

    NARCIS (Netherlands)

    Fundeanu, Irina; van der Mei, Henny C.; Schouten, Arend J.; Busscher, Henk J.

    2010-01-01

    Polyacrylamide (PAAm) brushes, covalently grafted from silicon wafer surfaces were examined for their ability to inhibit microbial adhesion after long-term exposure to PBS or reconstituted freeze-dried saliva for time intervals from 48 h up to 1 month at 37 degrees C. Microbial adhesion after

  8. Effects of protectant and rehydration conditions on the survival rate and malolactic fermentation efficiency of freeze-dried Lactobacillus plantarum JH287.

    Science.gov (United States)

    Lee, Sae-Byuk; Kim, Dong-Hwan; Park, Heui-Dong

    2016-09-01

    In this study, Lactobacillus plantarum JH287 was used as a malolactic fermentation starter in Campbell Early wine production. L. plantarum JH287 was first lyophilized, and the malolactic fermentation potential of freeze-dried L. plantarum JH287 was investigated. Different protective media and rehydration conditions were tested to improve the survival rate of freeze-dried L. plantarum JH287. Optimal protective medium contained 10 % sorbitol and 10 % skim milk. The optimal rehydration condition was a 1-h rehydration time conducted in the same protective media, and the combination of these two methods produced a survival rate of 86.37 %. In addition, a 77.71 % survival rate was achieved using freeze-dried samples that were stored at 4 °C for 2 months. Freeze-dried L. plantarum JH287 and Saccharomyces cerevisiae Fermivin were used to inoculate the Campbell Early grape must to decrease its malic acid content. Using this mixed-fermentation method, wine showed a decrease in malic acid content after 9 days of fermentation. GC-MS analysis detected 15 volatile ester compounds in the wine. A sensory evaluation showed that the taste and aroma of mix-fermented wine were better than those of the control that had not been inoculated with L. plantarum JH287.

  9. Rational design of an influenza subunit vaccine powder with sugar glass technology : preventing conformational changes of haemagglutinin during freezing and freeze-drying

    NARCIS (Netherlands)

    Amorij, J-P; Meulenaar, J; Hinrichs, W L J; Stegmann, T; Huckriede, A; Coenen, F; Frijlink, H W

    2007-01-01

    The development of a stable influenza subunit vaccine in the dry state was investigated. The influence of various carbohydrates, buffer types and freezing rates on the integrity of haemagglutinin after freeze-thawing or freeze-drying was investigated with a range of analytical and immunological

  10. Effect of freeze-drying, cryoprotectants and storage conditions on the stability of secondary structure of insulin-loaded solid lipid nanoparticles.

    Science.gov (United States)

    Soares, Sandra; Fonte, Pedro; Costa, Ana; Andrade, José; Seabra, Vítor; Ferreira, Domingos; Reis, Salette; Sarmento, Bruno

    2013-11-18

    This study aims to monitor the secondary structure behaviour of insulin when it is encapsulated into solid lipid nanoparticles (SLN), under the influence of several critical processing parameters. Insulin was used as a therapeutic protein model. Physicochemical properties of insulin-loaded SLN (Ins-SLN) were assessed, with special focus on the insulin secondary structure after its encapsulation into SLN and after freeze-drying using different cryoprotectants (glucose, fructose and sorbitol). Additionally, a 6-month stability study was performed to evaluate the maintenance of insulin secondary structure over time at different storage conditions (4 °C/60% RH, 25 °C/60% RH, 40 °C/75% RH). Ins-SLN were successfully produced with a mean and narrow particle size around 400 nm, zeta potential around -13 mV, an insulin association efficiency of 84%. Physical-chemical properties of SLN were maintained after freeze-drying. FTIR results showed that encapsulated insulin maintained a native-like structure in a degree of similarity around 92% after production, and 84% after freeze-drying. After 6 months, freeze-dried Ins-SLN without cryoprotectant stored at 40 °C/75% RH presented the same degree of structure preservation and morphology. Results revealed that insulin structure can be significantly protected by SLN matrix itself, without a cryoprotectant agent, even using a non-optimized freeze-drying process, and under the harsher storage conditions. Multivariable experimental settled the process parameters to fit with the desired product quality attributes regarding protein and nanoparticle stability.

  11. In-line and real-time process monitoring of a freeze drying process using Raman and NIR spectroscopy as complementary process analytical technology (PAT) tools.

    Science.gov (United States)

    De Beer, T R M; Vercruysse, P; Burggraeve, A; Quinten, T; Ouyang, J; Zhang, X; Vervaet, C; Remon, J P; Baeyens, W R G

    2009-09-01

    The aim of the present study was to examine the complementary properties of Raman and near infrared (NIR) spectroscopy as PAT tools for the fast, noninvasive, nondestructive and in-line process monitoring of a freeze drying process. Therefore, Raman and NIR probes were built in the freeze dryer chamber, allowing simultaneous process monitoring. A 5% (w/v) mannitol solution was used as model for freeze drying. Raman and NIR spectra were continuously collected during freeze drying (one Raman and NIR spectrum/min) and the spectra were analyzed using principal component analysis (PCA) and multivariate curve resolution (MCR). Raman spectroscopy was able to supply information about (i) the mannitol solid state throughout the entire process, (ii) the endpoint of freezing (endpoint of mannitol crystallization), and (iii) several physical and chemical phenomena occurring during the process (onset of ice nucleation, onset of mannitol crystallization). NIR spectroscopy proved to be a more sensitive tool to monitor the critical aspects during drying: (i) endpoint of ice sublimation and (ii) monitoring the release of hydrate water during storage. Furthermore, via NIR spectroscopy some Raman observations were confirmed: start of ice nucleation, end of mannitol crystallization and solid state characteristics of the end product. When Raman and NIR monitoring were performed on the same vial, the Raman signal was saturated during the freezing step caused by reflected NIR light reaching the Raman detector. Therefore, NIR and Raman measurements were done on a different vial. Also the importance of the position of the probes (Raman probe above the vial and NIR probe at the bottom of the sidewall of the vial) in order to obtain all required critical information is outlined. Combining Raman and NIR spectroscopy for the simultaneous monitoring of freeze drying allows monitoring almost all critical freeze drying process aspects. Both techniques do not only complement each other, they also

  12. Nutritional, phytochemical and antioxidant evaluation and FT-IR analysis of freeze dried extracts of Ecballium elaterium fruit juice from three localities

    Directory of Open Access Journals (Sweden)

    Samir FELHI

    2016-01-01

    Full Text Available Abstract This study was designed to investigate chemical composition, the total phenolic content, flavonoid content, antioxidant activity and to analyze through FT-IR spectroscopy method the freeze-dried extract of Ecballium elaterium fruit from three different localities. The highest level of phenolic and flavonoid contents was recorded for the fruit juice from the Cap-Bon region, with 106.4 ± 0.4 mg GAE/g and 6.5 ± 0.2 mg QE/g, respectively. Antioxidant activity varied in dose-dependent manner with IC50 values for DPPH scavenging of the freeze-dried fruit juice extracts from Cap-Bon, Kef and Sidi Bouzid were 38.6 ± 0.2, 50.1 ± 0.7, and 50.7 ± 0.2 µg/mL, respectively. The results from the FRAP test showed that the freeze-dried extracts of Cap-Bon exhibited potent activity, followed by those from Kef and Sidi Bouzid. Similar trend were revealed for ABTS•+ test, with the fruit juice extract from Cap-Bon (IC50 = 0.6 ± 0.0 mg/mL. Furthermore, a good positive correlation was observed between the total phenols and three assays, especially DPPH. The freeze-dried extracts of fruit juice from Cap-Bon showed strong ability to act as antioxidants and can be considered as promising natural source of bioactive compounds. FT-IR analysis of each freeze-dried extract confirmed its richness on polyphenols and biological active functional groups.

  13. Raman spectroscopy and multivariate analysis for the rapid discrimination between native-like and non-native states in freeze-dried protein formulations.

    Science.gov (United States)

    Pieters, Sigrid; Vander Heyden, Yvan; Roger, Jean-Michel; D'Hondt, Matthias; Hansen, Laurent; Palagos, Bernard; De Spiegeleer, Bart; Remon, Jean-Paul; Vervaet, Chris; De Beer, Thomas

    2013-10-01

    This study investigates whether Raman spectroscopy combined with multivariate analysis (MVA) enables a rapid and direct differentiation between two classes of conformational states, i.e., native-like and non-native proteins, in freeze-dried formulations. A data set comprising of 99 spectra, both from native-like and various types of non-native freeze-dried protein formulations, was obtained by freeze-drying lactate dehydrogenase (LDH) as model protein under various conditions. Changes in the secondary structure in the solid freeze-dried proteins were determined through visual interpretation of the blank corrected second derivative amide I band in the ATR-FTIR spectra (further called FTIR spectra) and served as an independent reference to assign class labels. Exploratory analysis and supervised classification, using Principal Components Analysis (PCA) and Partial Least Squares - Linear Discriminant Analysis (PLS-LDA), respectively, revealed that Raman spectroscopy is with 95% accuracy able to correctly discriminate between native-like and non-native states in the tested freeze-dried LDH formulations. Backbone (i.e., amide III) and side chain sensitive spectral regions proved important for making the discrimination between both classes. As discrimination was not influenced by the spectral signals from the tested excipients, there was no need for blank corrections. The Raman model may allow direct and automated analysis of the investigated quality attribute, opening possibilities for a real time and in-line quality indication as a future step. However, the sensitivity of the method should be further investigated and where possible improved. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. Evolution of the Radio-sterilized Tissues Bank of the Instituto Nacional de Investigaciones Nucleares; Evolucion del Banco de Tejidos Radioesterilizados del Instituto Nacional de Investigaciones Nucleares

    Energy Technology Data Exchange (ETDEWEB)

    Martinez P, M. E.; Reyes F, M. L.; Luna Z, D., E-mail: esther.martinez@inin.gob.mx [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2013-10-15

    The Radio-sterilized Tissues Bank (RTB) of the Instituto Nacional de Investigaciones Nucleares (ININ) was established in 1997, as national project supported by the IAEA, who provided equipment, training and expert missions. In July of 1999, the Secretaria de Salud (Mexico) granted the sanitary license to the RTB. The first radio-sterilized tissue was the amnion. Later on, the process of frozen and lyophilized pig skin was development. Both tissue types are used as biological dressings in patient with burns, ulcers or on injuries difficult to heal, the amnion is also used for the damage treatment in the ocular surface. In 2003, the ININ improved the facilities of the RTB and in August of that same year the certification of the Quality Administration System was obtained under the standard ISO 9001:2000, at the present time ISO 9001:2008. The support of the IAEA granted to Mexico was of 1997-2004 and 2009-2012, by means of regional and inter regional projects where was obtained equipment and training mainly, for personal of the ININ and other institutions. With the last project supported by the IAEA, two very important documents were generated for the tissues bank of Argentina, Brazil, Colombia, Costa Rica, Cuba, Ecuador, El Salvador, Mexico, Peru, Uruguay and Venezuela, strengthening the interaction among these countries. To offer more radio-sterilized tissues to the medical community, in June of 2007 the RTB signed and agreement with the Secretaria de Salud of the Mexico State by means of the Centro Estatal de Transplantes del Estado de Mexico, for the process of muscle-skeletal tissue, skin and amnion. At present, besides amnion and pig skin, in the RTB there is in existence powdered and chips bone; concluding the validation stage the human skin process is. As a social function of the ININ, the RTB has contributed to the health improvement of patients of more than 50 hospital institutions, mainly those that assist to patient of low resources in different cities of

  15. Mechanism of protein stabilization by trehalose during freeze-drying analyzed by in situ micro-raman spectroscopy.

    Science.gov (United States)

    Hedoux, Alain; Paccou, Laurent; Achir, Samira; Guinet, Yannick

    2013-08-01

    Raman investigations were performed in situ during freeze-drying of two model proteins, lysozyme and chymotrypsinogen. The structures of proteins dissolved in 0-30 wt % solutions of trehalose in D2 O were monitored with the fingerprint (800-1800 cm(-1) ) spectrum, simultaneously with freezing, ice sublimation, and water desorption analyzed in the O-D stretching (2200-2700 cm(-1) ) region. In the absence of trehalose, the main changes were detected at the end of primary drying, and correspond to distortion and disordering of secondary structures. A stabilizing effect of trehalose was evidenced in primary and secondary drying stages. Raman images were calculated after freezing and primary drying, providing the distributions of trehalose, water, and protein which occur during the first two stages of the lyophilization cycle. Raman images show a slight heterogeneity in the degree of protein denaturation at the end of primary drying, in relation with the structure of the frozen product observed during freezing. The ability of trehalose to make the protein more rigid was determined as responsible for the protein stabilization during a lyophilization cycle.

  16. Influence of product thickness, chamber pressure and heating conditions on production rate of freeze-dried yoghurt

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, N.K. [G.B. Pant Univ., of Agriculture and Technology (India). Dept. of Mechanical Engineering; Arora, C.P. [Indian Inst. of Tech., New Delhi (India)

    1995-06-01

    The effects of product thickness, chamber pressure and heating conditions on product temperature profiles and production rate of freeze-dried yoghurt were investigated experimentally. Three sample thicknesses - 3.8 mm, 6.2 mm and 9.4 mm - were tested at chamber pressures of 0.01 and 0.5 mmHg. The production rate increased by decreasing product thickness in contact heating through the bottom of the frozen layer, whereas no significant change was observed in radiant heating. A reduction in chamber pressure from 0.50 to 0.01 mmHg increased the drying time in radiant heating. Maximum production rate was obtained when the thickness of dried product was 6.2 mm, when heat was transferred simultaneously through the frozen and dried layers, and the chamber pressure was at 0.01 mmHg. Use of the product tray developed in this study prevents the growth of dry layers at the contact surfaces. (Author)

  17. Breads Fortified with Freeze-Dried Vegetables: Quality and Nutritional Attributes. Part II: Breads Not Containing Oil as an Ingredient

    Directory of Open Access Journals (Sweden)

    Viren Ranawana

    2016-09-01

    Full Text Available The present article describes the second part of a study investigating the effect of adding vegetables on the nutritional, physico-chemical, and oxidative properties of wheat bread, and specifically focuses on bread that does not contain oil as an added ingredient. Wheat flour breads fortified with freeze-dried carrot, tomato, beetroot or broccoli were developed and assessed for their nutritional composition, antioxidant potential, oxidative stability, and storage properties. Using a simulated in vitro model, the study also examined the impact of vegetable addition on the oxidative stability of macronutrients during gastro-intestinal digestion. Adding vegetables improved the nutritional and functional attributes of the oil-free breads. However, they demonstrated a lower antioxidant potential compared to their oil-containing counterparts. Similarly, the textural and storage properties of the oil-free vegetable breads were poorer compared to the oil-containing breads. As expected, in the absence of oil the oil-free breads were associated with lower lipid oxidation both in their fresh form and during gastro-intestinal digestion. Adding vegetables reduced protein oxidation in the fresh oil-free breads but had no effect during gastro-intestinal digestion. The impact of vegetables on macronutrient oxidation in the oil-free breads during digestion appears to be vegetable-specific with broccoli exacerbating it and the others having no effect. Of the evaluated vegetables, beetroot showed the most promising nutritional and physico-chemical benefits when incorporated into bread that does not contain added oil.

  18. Study on foam freeze drying in vaccine%疫苗的泡沫冷冻干燥研究

    Institute of Scientific and Technical Information of China (English)

    张绍志; 施铭耀; 陈光明; 吕芳; 卢宇

    2013-01-01

    Freeze‐drying has been widely used in the production of pharmaceuticals , vaccines and high‐valued foods . Foam freeze‐drying is a new type of drying technology , in which the sample is foamed and frozen before drying . Compared with traditional freeze‐drying method , the new method can reduce operation time and cost significantly . Some foreign researchers have used this method to produce heat‐resistant vaccines which can endure higher temperature and remain effective after a longer storage in refrigerator . Up to now , little research about foam freeze‐drying has been reported domestically . In this study , newcastle disease vaccine was used as an example to illustrate the procedure of foam freeze‐drying method and to test its capability of producing heat‐resistant vaccine . The ingredient of the foam freeze drying ( FFD ) sample included w ( trehalose) = 10% , w ( hydrolyzed gelatin) = 5% , w( pluronic F‐108) = 3% , w( arginine) = 2% , 25 mmol/L phosphate buffer ( pH = 7 .2) . The sample was prepared through the following procedure:1) One milliliter sample was placed on the plate of the freeze dryer and cooled to 15 ℃ ;2) then the pressure was lowered to 5 Pa and foaming began;3) after one hour the plate temperature was increased up to 31 ℃ at a velocity of 0 .7 ℃ /min and kept for another 48 hours . The samples made by foam freeze drying were analyzed with thermal analysis and aging test , and were compared with live attenuated samples and heat‐resistant samples prepared by traditional freeze drying . The latter two kinds of sample were bought from market ( Tianbang Biotechnology Corporation , Nanjing , China) . Thermal analysis was done with a differential scanning calorimetry (DSC 200 F3 Maia , NETZSCH , Germany) . The procedure was as follows:1) the sample was cooled to -20 ℃ at a rate of 10 ℃ /min and held for 3 minutes;2) the sample was heated to 80 ℃ at the rate of 10 ℃/min and held for 3 minutes;3) the sample was cooled

  19. Advanced approach to build the design space for the primary drying of a pharmaceutical freeze-drying process.

    Science.gov (United States)

    Fissore, Davide; Pisano, Roberto; Barresi, Antonello A

    2011-11-01

    This paper deals with the design space of a pharmaceutical freeze-drying process. Mathematical modeling is used to investigate the effect of the operating conditions [shelf temperature (T(shelf)) and chamber pressure (P(c))] on product temperature (that has to remain below a limit value) and sublimation flux (that has to be lower than a level that would cause choked flow). The algorithm takes into account the variation of the design space with time due to the increase in the dried layer thickness. Besides T(shelf) and P(c), the dried layer thickness is used as the third coordinate of the diagram, thus resulting in just one graph that can be used to build recipes with variable operating conditions, as well as to analyze the effect of process failures. Such results are compared with those obtained when the variation of the design space with time is not accounted for; in this case, the design space comprises those operating conditions that fulfill the operation constraints throughout primary drying, thus giving a much more conservative recipe when designing the process or potentially misleading results when analyzing process failures. Finally, the proposed method has been used to design, and experimentally validate, a recipe for a pharmaceutical formulation. Copyright © 2011 Wiley-Liss, Inc.

  20. Freeze-dried mucoadhesive polymeric system containing pegylated lipoplexes: Towards a vaginal sustained released system for siRNA.

    Science.gov (United States)

    Furst, Tania; Dakwar, George R; Zagato, Elisa; Lechanteur, Anna; Remaut, Katrien; Evrard, Brigitte; Braeckmans, Kevin; Piel, Geraldine

    2016-08-28

    Topical vaginal sustained delivery of siRNA presents a significant challenge due to the short residence time of formulations. Therefore, a drug delivery system capable to adhere to the vaginal mucosa is desirable, as it could allow a prolonged delivery and increase the effectiveness of the therapy. The aim of this project is to develop a polymeric solid mucoadhesive system, loaded with lipoplexes, able to be progressively rehydrated by the vaginal fluids to form a hydrogel and to deliver siRNA to vaginal tissues. To minimize adhesive interactions with vaginal mucus components, lipoplexes were coated with different derivatives of polyethylene glycol: DPSE-PEG2000, DPSE-PEG750 and ceramide-PEG2000. Based on stability and diffusion properties in simulated vaginal fluids, lipoplexes containing DSPE-PEG2000 were selected and incorporated in hydroxyethyl cellulose (HEC) hydrogels. Solid systems, called sponges, were then obtained by freeze-drying. Sponges meet acceptable mechanical characteristics and their hardness, deformability and mucoadhesive properties are not influenced by the presence of lipoplexes. Finally, mobility and stability of lipoplexes inside sponges rehydrated with vaginal mucus, mimicking in situ conditions, were evaluated by advanced fluorescence microscopy. The release rate was found to be influenced by the HEC concentration and consequently by the viscosity after rehydration. This study demonstrates the feasibility of entrapping pegylated lipoplexes into a solid matrix system for a prolonged delivery of siRNA into the vagina.

  1. Tertiary combination of freeze-dried urine of Indian breeds of cow with plant products against snail Lymnaea acuminata.

    Science.gov (United States)

    Kumar, Shiv; Singh, D K; Singh, Vinay Kumar

    2012-10-15

    Snail Lymnaea acuminata is the intermediate host of liver fluke Fasciola gigantica, which cause endemic fasciolosis among cattle population of eastern Uttar Pradesh. Control of snail population by molluscicides is one of the effective methods to control fasciolosis. In the present study molluscicidal activity of tertiary combination of freeze-dried urine of different Indian breeds of cow Sahiwal, Geer and Tharparkar with Annona squamosa seed powder, Ferula asafoetida root latex, Azadirachta indica oil and Camellia sinensis leaves have been tested against Lymnaea acuminata. It was noted that the toxicity of tertiary combination (1:1:5) of cow urine kept for 15 days in sunlight or laboratory condition with different plant products were highly toxic against snail L. acuminata. 96 h LC50 of tertiary combinations with Sahiwal urine kept for 15 days in sunlight with A. squamosa, F. asafoetida, A. indica oil and C. sinensis were 35.47 mg L(-1), 37.13 mg L(-1), 33.66 mg L(-1), respectively higher than the Geer and Tharparkar. The toxicity of Sahiwal urine kept for 15 days in laboratory condition with A. squamosa and C. sinensis (96 h LC50 28.28 mg L(-1)) was more potent than the all other combinations. Cow urine in combination with plant product can be used for effective control of snail.

  2. {sup 68}Ga Labeling of DOTMP using Freeze-dried Kit for the Imaging of Bone Metastasis

    Energy Technology Data Exchange (ETDEWEB)

    Dho, So Hee; Choi, Sangmu; Kim, Sooyong; Cho, Eunha; Lee, Soyoung; Jung, Sunghee; Lim, Jaecheong [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-10-15

    Bone is a favorable site of metastasis and is invaded common primary tumors such as prostate, breast, and lung. Due to the progressive pain and mortality of the bone metastasis, effort has been focused on the detection of bone metastasis in the field of nuclear medicine (Mitterhauser, Toegel et al. 2007, Mirzaei, Jalilian et al. 2015). In designing suitable imaging agents for bone metastasis, multidentate polyaminophosphonate are regarded as the most promising candidates as carrier ligands owing to their high bone affinity, selective localization in skeletal lesions and ability to form metal chelates with high in-vivo stability (Chakraborty, Das et al. 2008). 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetramethylene. Freeze-dried DOTMP kit vial was consist of 400 μ of DOTMP, 19.27 mg of ammonium acetate and 17.62 mg of ascorbic acid. All the preparative steps were carried out under aseptic conditions, and the prepared kit vials were shown in Fig. 3(A). The easy and efficient labeling of this kit with 68Ga make them suitable for preparing 68Ga-DOTMP for imaging of bone metastasis.

  3. Freeze Dried Quetiapine-Nicotinamide Binary Solid Dispersions: A New Strategy for Improving Physicochemical Properties and Ex Vivo Diffusion

    Science.gov (United States)

    Al-Remawi, Mayyas Mohammad Ahmad

    2016-01-01

    Improving the physicochemical properties and oral bioavailability of quetiapine fumarate (QF) enabling enhanced antipsychotic attributes are the main aims of this research. The freeze dried solid dispersion strategy was adopted using nicotinamide (NIC) as highly soluble coformer. The prepared dispersions were characterized using scanning electron microscopy (SEM) differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). Static disc intrinsic dissolution rate and ex vivo diffusion through intestinal tissues were conducted and compared to pure quetiapine fumarate. The results demonstrated a highly soluble coamorphous system formed between quetiapine fumarate and nicotinamide at 1 : 3 molar ratio through H-bonding interactions. The results showed >14-fold increase in solubility of QF from the prepared dispersions. Increased intrinsic dissolution rate (from 0.28 to 0.603 mg cm−2 min−1) and faster flux rate through duodenum (from 0.027 to 0.041 mg cm−2 h−1) and jejunum (0.027 to 0.036 mg cm−2 h−1) were obtained. The prepared coamorphous dispersion proved to be effective in improving the drug solubility and dissolution rate and ex vivo diffusion. Therefore, binary coamorphous dispersions could be a promising solution to modify the physicochemical properties, raise oral bioavailability, and change the biopharmaceutics classification (BCS) of some active pharmaceutical ingredients. PMID:28042494

  4. Evaluation of protective effect of freeze-dried strawberry, grape, and blueberry powder on acrylamide toxicity in mice.

    Science.gov (United States)

    Zhao, Mengyao; Liu, Xin; Luo, Yinghua; Guo, Huan; Hu, Xiaosong; Chen, Fang

    2015-04-01

    Berries are dietary plants with high antioxidant activity. The aim of this study is to investigate the protective effect of berries (strawberry, grape, and blueberry) against the acrylamide (AA)-induced general toxicity, genotoxicity, and reproductive toxicity in mice model, respectively. Mice were treated with 50 mg/kg b.w./day AA intraperitoneal injection for 5 d after feeding control diet or diet containing freeze-dried strawberry, grape, and blueberry powder. The results showed that AA induced a significant general toxicity, genotoxicity, and reproductive toxicity in mice. Compared with the control diet, the diets containing berries could reverse the AA-induced alterations in liver antioxidant enzymes activities (P < 0.05). Moreover, the AA-induced genotoxicity could be prevented by the diet containing berries. The DNA damage in the lymphocyte and liver cells and the micronucleus formation in bone marrow cell were significantly alleviated (P < 0.05). Meanwhile, the mice fed with diets containing berries showed a recovery in the sperm count, the sperm activity rate, sperm motility parameters, and the abnormal sperm rate (P < 0.05). Berry powders have remarkable intervention against the AA-induced general toxicity, genotoxicity, reproductive toxicity. Abundant phenolics, especially anthocyanins, may contribute to the intervention.

  5. Evaluation of Different Holder Devices for Freeze-Drying in Dual-Chamber Cartridges With a Focus on Energy Transfer.

    Science.gov (United States)

    Korpus, Christoph; Friess, Wolfgang

    2017-04-01

    For freeze-drying in dual-chamber cartridges, a holder device to enable handling and safe positioning in the freeze-dryer is necessary. The aim of this study was to analyze 4 different types of holder devices and to define the best system based on energy transfer. The main criteria were drying homogeneity, ability to minimize the influence of atypical radiation on product temperatures, and heat transfer effectiveness. The shell holder reduced the influence of atypical radiation by almost 60% compared to a block system and yielded the most homogenous sublimation rates. Besides the most efficient heat transfer with values of 1.58E-4 ± 2.06E-6 cal/(s*cm(2)*K) at 60 mTorr to 3.63E-4 ± 1.85E-5 cal/(s*cm(2)*K) at 200 mTorr for Ktot, reaction times to shelf temperature changes were up to 4 times shorter compared to the other holder systems and even faster than for vials. The flexible holder provided a comparable shielding against atypical radiation as the shell but introduced a third barrier against energy transfer. Block and guardrail holder were the least efficient system tested. Hence, the shell holder provided the best radiation shielding, enhanced the transferability of the results to a larger scale, and improved the homogeneity between the dual-chamber cartridges.

  6. Mechanistic modelling of infrared mediated energy transfer during the primary drying step of a continuous freeze-drying process.

    Science.gov (United States)

    Van Bockstal, Pieter-Jan; Mortier, Séverine Thérèse F C; De Meyer, Laurens; Corver, Jos; Vervaet, Chris; Nopens, Ingmar; De Beer, Thomas

    2017-01-12

    Conventional pharmaceutical freeze-drying is an inefficient and expensive batch-wise process, associated with several disadvantages leading to an uncontrolled end product variability. The proposed continuous alternative, based on spinning the vials during freezing and on optimal energy supply during drying, strongly increases process efficiency and improves product quality (uniformity). The heat transfer during continuous drying of the spin frozen vials is provided via non-contact infrared (IR) radiation. The energy transfer to the spin frozen vials should be optimised to maximise the drying efficiency while avoiding cake collapse. Therefore, a mechanistic model was developed which allows computing the optimal, dynamic IR heater temperature in function of the primary drying progress and which, hence, also allows predicting the primary drying endpoint based on the applied dynamic IR heater temperature. The model was validated by drying spin frozen vials containing the model formulation (3.9mL in 10R vials) according to the computed IR heater temperature profile. In total, 6 validation experiments were conducted. The primary drying endpoint was experimentally determined via in-line near-infrared (NIR) spectroscopy and compared with the endpoint predicted by the model (50min). The mean ratio of the experimental drying time to the predicted value was 0.91, indicating a good agreement between the model predictions and the experimental data. The end product had an elegant product appearance (visual inspection) and an acceptable residual moisture content (Karl Fischer).

  7. Immunomodulatory effects of supercritical fluid CO2 extracts from freeze-dried powder of Tenebrio molitor larvae (yellow mealworm

    Directory of Open Access Journals (Sweden)

    QingFeng TANG

    2016-01-01

    Full Text Available Abstract In order to take full advantage of Tenebrio molitor larvae (yellow mealworm resources, the supercritical CO2 fluid freeze-dried powder of T. molitor larvae (fdTML extraction on the immune systems of mice was carried out. The results about the effects of supercritical CO2 fluid fdTML extraction on carbon expurgation and phagocytosis of peritoneal macrophages experiments of mice indicated that the fdTML extraction enhanced observably carbon expurgatory index, phagocytic rate and phagocytic index. The fdTML extraction could stimulate response of delayed hypersensitivity. The proliferation of ConA-induced mitogenic reponse for spleen lymphocyte was also increased. The amount of hemolytic antibody in mice serum increased compared with those of the control group mice. The half of hemolysis values in serum of treated mice increased compared to the control group. Furthermore, serum NO content in all treatment groups was higher than that of the control group whereas acid phosphatase and alkaline phosphatase activity was only significantly higher relative to the control group. Our findings suggest that supercritical CO2 fluid the fdTML extraction has potential as a health food supplement.

  8. Evaluation of shrinkage temperature of bovine pericardium tissue for bioprosthetic heart valve application by differential scanning calorimetry and freeze-drying microscopy

    Directory of Open Access Journals (Sweden)

    Virgilio Tattini Jr

    2007-03-01

    Full Text Available Bovine pericardium bioprosthesis has become a commonly accepted device for heart valve replacement. Present practice relies on the measurement of shrinkage temperature, observed as a dramatic shortening of tissue length. Several reports in the last decade have utilized differential scanning calorimetry (DSC as an alternative method to determine the shrinkage temperature, which is accompanied by the absorption of heat, giving rise to an endothermic peak over the shrinkage temperature range of biological tissues. Usually, freeze-drying microscope is used to determine collapse temperature during the lyophilization of solutions. On this experiment we used this technique to study the shrinkage event. The aim of this work was to compare the results of shrinkage temperature obtained by DSC with the results obtained by freeze-drying microscopy. The results showed that both techniques provided excellent sensitivity and reproducibility, and gave information on the thermal shrinkage transition via the thermodynamical parameters inherent of each method.

  9. Effect of Microencapsulation by Spray-Drying and Freeze-Drying Technique on the Antioxidant Properties of Blueberry (Vaccinium myrtillus Juice Polyphenolic Compounds

    Directory of Open Access Journals (Sweden)

    Wilkowska Agnieszka

    2016-03-01

    Full Text Available Blueberry juice with high polyphenol concentration was spray- or freeze-dried using different coating materials: HP-β-cyclodextrin and β-cyclodextrin. The quality of the obtained powders was characterised by their anthocyanin content, total polyphenols and antioxidant capacity. SEM was used for monitoring structures and size (2–20 μm of the microparticles. The losses of total phenolic compounds during spray-drying reached 76–78% on average, while these of anthocyanins about 57%. Freeze-dried powders showed better retention values of anthocyanins, which was about 1.5-fold higher than for the spray-dried counterparts. All blueberry preparations studied were characterised by very high radical scavenging activity.

  10. Gluten-free bread with an addition of freeze-dried red and purple potatoes as a source of phenolic compounds in gluten-free diet.

    Science.gov (United States)

    Gumul, Dorota; Ziobro, Rafał; Ivanišová, Eva; Korus, Anna; Árvay, Július; Tóth, Tomáš

    2017-02-01

    The basis for gluten-free diet is often gluten-free bread, which is usually characterized by a low-nutritional value, and lacks any pro-health properties. Only after an introduction of gluten-free raw materials, containing high level of bioactive compounds it would be possible to obtain the product with a pro-health potential. The aim of the study was to analyze the content of bioactive compounds (total phenolic content, phenolic acids, flavonoids, flavonols, anthocyanins and carotenoids) in gluten-free bread prepared with 5% addition of freeze-dried red and purple potatoes as well as to assess their antioxidant potential. Summarizing, among the analyzed gluten-free breads with an addition of freeze-dried red and purple potatoes, the best results could be obtained by using variety Magenta Love (red potato), which provided the highest levels of phenolic compounds and carotenoids and also antioxidant and antiradical activity.

  11. Effect of NaHCO3, MgSO4, Sodium Ascorbate, Sodium Glutamate, Phosphate Buffer on Survival of Lactobacillus bulgaricus During Freeze-drying

    Directory of Open Access Journals (Sweden)

    He Chen

    2013-06-01

    Full Text Available In the present study, the experiments were investigated the effects of different concentrations of cryoprotective agents, such as NaHCO3, MgSO4, sodium ascorbate, sodium glutamate, phosphate buffer, respectively, which used on survival of Lactobacillus bulgaricus during freeze drying. The number of viable cells and survival ratio were measured by the plate count method. The results were as follows: cryoprotective agents played important roles in survival of Lactobacillus bulgaricus during freeze drying. When the relative volume of phosphate buffer was 1.5 (v/v, the number of viable cells was highest, while the survival ratio reached highest, the concentration of sodium ascorbate was 4.5%.

  12. When less is more: a simple Western blotting amendment allowing data acquisition on human single fibers

    DEFF Research Database (Denmark)

    Jensen, Thomas Elbenhardt; Richter, Erik A

    2011-01-01

    This editorial discusses a simple western blotting-amendment allowing rapid data-acquisition on single fibers obtained from freeze-dried human skeletal muscle biopsies.......This editorial discusses a simple western blotting-amendment allowing rapid data-acquisition on single fibers obtained from freeze-dried human skeletal muscle biopsies....

  13. Radiosterilization process control in plants using electron accelerators; Kontrola procesu sterylizacji radiacyjnej w stacjach korzystajacych z akceleratorow elektronow

    Energy Technology Data Exchange (ETDEWEB)

    Stuglik, Z. [Institute of Nuclear Chemistry and Technology, Warsaw (Poland)

    1997-10-01

    Electron beam parameters deciding the irradiation dose in radiosterilization plants should be continuously controlled during the process. Dosimetric procedure suitable to irradiated material and dose range should be chosen. The practical advice and directions in this subject have been done. 7 refs.

  14. Temperature-sensitivity and cell biocompatibility of freeze-dried nanocomposite hydrogels incorporated with biodegradable PHBV

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Qingsong, E-mail: zqs8011@163.com; Chen, Li, E-mail: chenlis@tjpu.edu.cn; Dong, Youyu; Lu, Si

    2013-04-01

    The structure, morphology, thermal behaviors and cytotoxicity of novel hydrogels, composed of poly(N-isopropylacrylamide)(PNIPAM) and biodegradable polyester poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) under nanoclay hectorite “Laponite XLG” severed as physical cross-linker, were characterized by X-ray diffraction, scanning electron microscopy, gravimetric method, differential scanning calorimetry, and cell culture experiments. It was found that, due to the introduction of hydrophobic PHBV, the homogeneity of interior pore in the pure PNIPAM nanocomposite hydrogel was disrupted, the transparency and swelling degree gradually decreased. Although the weight ratio between PHBV and NIPAM increased from 5 to 40 wt.%, the volume phase transition temperature (VPTTs) of hydrogel were not altered compared with the pure PNIPAM nanocomposite hydrogel. No matter what PHBV content, the PHBV/PNIPAM/Hectorite hydrogels always exhibit good stimuli-responsibility. In addition, human hepatoma cells(HepG2) adhesion and spreading on the surface of PHBV-based hydrogels was greatly improved than that of pure PNIPAM nanocomposite hydrogel at 37 °C due to the introduction of PHBV. Highlights: ► Thermo-responsive and cell biocompatible hydrogels incorporated PHBV was synthesized. ► The introduction of PHBV decreases the transparency of nanocomposite hydrogel. ► The introduction of PHBV has a little shift on VPTTs of nanocomposite hydrogel. ► The HepG2 cells could adhere and spread on the surface of PHBV-based hydrogels. ► Cell sheet could be detached simultaneously from the surface of hydrogels.

  15. Freeze-drying synthesis of an amorphous Zn(2+) complex and its transformation to a 2-D coordination framework in the solid state.

    Science.gov (United States)

    Itakura, T; Horike, S; Inukai, M; Kitagawa, S

    2016-03-14

    An amorphous and metastable precursor for a Zn two-dimensional coordination framework was synthesised via freeze drying. The precursor comprises randomly packed discrete clusters of a Zn complex. The amorphous-to-crystalline framework transformation, which was triggered by the gentle application of heat or pressure, was accompanied by a change in the coordination geometry of the Zn(2+) ions from tetrahedral to octahedral symmetry.

  16. Improvement of a dry formulation of Pseudomonas fluorescens EPS62e for fire blight disease biocontrol by combination of culture osmoadaptation with a freeze-drying lyoprotectant.

    Science.gov (United States)

    Cabrefiga, J; Francés, J; Montesinos, E; Bonaterra, A

    2014-10-01

    To study the effect of lyoprotectants and osmoadaptation on viability of Pseudomonas fluorescens EPS62e during freeze-drying and storage and to evaluate the formulation in terms of efficacy in biocontrol and fitness on pear flowers. A wettable powder formulation of a biocontrol agent of fire blight was optimized by means of lyoprotectants and culture osmoadaptation. Freeze-drying was used to obtain dehydrated cells, and the best viability (70% of survival) was obtained using lactose as lyoprotectant. Survival during lyophilization was additionally improved using physiological adaptation of cells during cultivation under salt-amended medium (osmoadaptation). The procedure increased the survival of cells after freeze-drying attaining viability values close to a 100% in the lactose-formulated product (3 × 10(11) CFU g(-1) ), and through the storage period of 1 year at 4°C. The dry formulation showed also an improved biocontrol efficacy and survival of EPS62e on pear flowers under low relative humidity conditions. Cell viability after freeze-drying was improved using lactose as lyoprotectant combined with a procedure of osmoadaptation during cultivation. The powder-formulated product remained active for 12 months and retained biocontrol levels similar to that of fresh cells. The formulation showed an improved survival of EPS62e on flowers and an increase of the efficacy of biocontrol of fire blight at low relative humidity. The results have a potential value for commercial application in biocontrol agents not only of fire blight but also of other plant diseases. © 2014 The Society for Applied Microbiology.

  17. Radiosterilization of drugs in aqueous solutions may be achieved by the use of radioprotective excipients.

    Science.gov (United States)

    Maquille, Aubert; Jiwan, Jean-Louis Habib; Tilquin, Bernard

    2008-02-12

    The aim of this study was to assess the feasibility of radiosterilization of drugs aqueous solutions and to evaluate the effects of some additives, such as mannitol, nicotinamide and pyridoxine, which might protect the drug from degradation. Metoclopramide was selected as a model drug. The structures of the degradation products were determined to gain insight on the radiolysis mechanisms in aqueous solution in order to design strategies to lower the drug degradation. Metoclopramide hydrochloride aqueous solutions with and without excipients were irradiated either with gamma rays or high-energy electrons. HPLC-DAD was used to measure the loss of chemical potency and to quantify the degradation products which were also characterized by LC-APCI-MS-MS. Metoclopramide recovery for gamma and electron beam-irradiated solutions containing either mannitol, pyridoxine or nicotinamide meets the pharmacopoeial specifications for metoclopramide content up to a 15 kGy irradiation so that metoclopramide solutions containing these excipients might be radiosterilized at 15 kGy either with gamma rays or high-energy electrons. Structures are proposed for the majority of radiolysis products. Similar radiolysis products were detected for gamma and electron beam irradiations but the chromatographic profiles were different (differences in the distribution of radiolysis products).

  18. Protein crowding in solution, frozen and freeze-dried states: small-angle neutron and X-ray scattering study of lysozyme/sorbitol/water systems

    Science.gov (United States)

    Krueger, Susan; Khodadadi, Sheila; Clark, Nicholas; McAuley, Arnold; Cristiglio, Viviana; Theyencheri, Narayanan; Curtis, Joseph; Shalaev, Evgenyi

    2015-03-01

    For effective preservation, proteins are often stored as frozen solutions or in glassy states using a freeze-drying process. However, aggregation is often observed after freeze-thaw or reconstitution of freeze-dried powder and the stability of the protein is no longer assured. In this study, small-angle neutron and X-ray scattering (SANS and SAXS) have been used to investigate changes in protein-protein interaction distances of a model protein/cryoprotectant system of lysozyme/sorbitol/water, under representative pharmaceutical processing conditions. The results demonstrate the utility of SAXS and SANS methods to monitor protein crowding at different stages of freezing and drying. The SANS measurements of solution samples showed at least one protein interaction peak corresponding to an interaction distance of ~ 90 Å. In the frozen state, two protein interaction peaks were observed by SANS with corresponding interaction distances at 40 Å as well as 90 Å. On the other hand, both SAXS and SANS data for freeze-dried samples showed three peaks, suggesting interaction distances ranging from ~ 15 Å to 170 Å. Possible interpretations of these interaction peaks will be discussed, as well as the role of sorbitol as a cryoprotectant during the freezing and drying process.

  19. Design of self-dispersible dry nanosuspension through wet milling and spray freeze-drying for poorly water-soluble drugs.

    Science.gov (United States)

    Niwa, Toshiyuki; Danjo, Kazumi

    2013-11-20

    The purpose of the present research is to establish a novel nanosizing technique starting from wet nano-milling, named "dry nanosuspension" technique for poorly water-soluble drugs. The spray freeze-drying (SFD) method was applied instead of the spray-drying one previously developed. Drug particles were milled in the aqueous solution of dispersing agents using an oscillating beads-milling apparatus. The milled nanosuspension was sprayed to the surface of liquid nitrogen, and the resultant iced droplets were freeze-dried to obtain the powdery product. The loading ratio of a dispersing agent was investigated to enhance its redispersing property. Dry nanosuspension, which could be spontaneously dispersed into original nanosuspension in water, was obtained by SFD process. It was assumed that self dispersion property would be attributed to its structure with porous network, in which the primary milled drug crystals were embedded. Such unique structure contributed greatly to immediate release behaviors of the drug in gastrointestinal buffered media. These pharmaceutical properties were enhanced by increasing the ratio of the dispersing agent to the drug and the solid content in suspension to be sprayed. The present technique via wet milling and spray freeze-drying processes would be a novel dissolution-enhanced technology for poorly water-soluble drugs.

  20. Impact of different cryoprotectants on the survival of freeze-dried Lactobacillus rhamnosus and Lactobacillus casei/paracasei during long-term storage.

    Science.gov (United States)

    Jofré, A; Aymerich, T; Garriga, M

    2015-01-01

    The production of long shelf-life highly concentrated dried probiotic/starter cultures is of paramount importance for the food industry. The aim of the present study was to evaluate the protective effect of glucose, lactose, trehalose, and skim milk applied alone or combined upon the survival of potentially probiotic Lactobacillus rhamnosus CTC1679, Lactobacillus casei/paracasei CTC1677 and L. casei/paracasei CTC1678 during freeze-drying and after 39 weeks of storage at 4 and 22 °C. Immediately after freeze-drying, the percentage of survivors was very high (≥ 94%) and only slight differences were observed among strains and cryoprotectants. In contrast, during storage, survival in the dried state depended on the cryoprotectant, temperature and strain. For all the protectants assayed, the stability of the cultures was remarkably higher when stored under refrigeration (4 °C). Under these conditions, skim milk alone or supplemented with trehalose or lactose showed the best performance (reductions ≤ 0.9 log units after 39 weeks of storage). The lowest survival was observed during non-refrigerated storage and with glucose and glucose plus milk; no viable cells left at the end of the storage period. Thus, freeze-drying in the presence of appropriate cryoprotectants allows the production of long shelf-life highly concentrated dried cultures ready for incorporation in high numbers into food products as starter/potential probiotic cultures.

  1. Effect of co-solutes and process variables on crystallinity and the crystal form of freeze-dried myo-inositol.

    Science.gov (United States)

    Izutsu, Ken-Ichi; Kusano, Riho; Arai, Ryoko; Yoshida, Hiroyuki; Ito, Masataka; Shibata, Hiroko; Sugano, Kiyohiko; Goda, Yukihiro; Terada, Katsuhide

    2016-07-25

    The purpose of this study was to elucidate how co-solutes affect the crystallization of small solute molecules during freeze-drying and subsequent storage. Crystallization profiles of myo-inositol and its mixture with dextran 40k in frozen solutions and dried solids were assessed by thermal analysis (DSC), powder-X-ray diffraction, and simultaneous DSC and PXRD analysis. Higher mass ratios of dextran maintained myo-inositol in the non-crystalline mixture state, in frozen solutions, during freeze-drying process, and exposure of dried solids to higher temperatures. Co-lyophilization with a lower mass ratio of dextran resulted in solids containing a variety of myo-inositol crystal forms and crystallinity depending on the composition and thermal history of the process. Heating of some inositol-rich amorphous solids showed crystallization of myo-inositol in the metastable form and its transition to stable form before melting. Heat-treatment of inositol-rich frozen solutions resulted in high crystallinity stable-form inositol solids, leaving dextran in the amorphous state. Sufficient direct molecular interactions (e.g., hydrogen bonding) should explain the stability of dextran-rich amorphous solids. Optimizing solute composition and processes should be a potent way to control crystal form and crystallinity of components in freeze-dried formulations.

  2. Preliminary Study on Vacuum Freeze-drying Process of Lemon Piece%柠檬片真空冷冻干燥工艺初探

    Institute of Scientific and Technical Information of China (English)

    王玉玲; 李海滨

    2011-01-01

    以新鲜柠檬为试材,研究了柠檬片真空冷冻干燥的工艺条件.试验结果表明,冻干柠檬片的最佳工艺条件为:柠檬片切片厚度6.0mm,冻干时间10h,加热板温度60℃,冻干压力80Pa.此条件下加工的冻干柠檬片具有较好的感官品质及较高的柠檬酸及VC含量,褐变度较低,可保持新鲜柠檬原有的色、香、味和营养成分.%The technology of lemon vacuum freeze -drying was studied in this assay. It showed that the optimal conditions of vacuum freeze-drying were as follow: thickness of lemon piece was 6.0 mm, the time was 10 hours, the temperature of heating plate was 60℃ and freeze-drying pressure was 80 Pa. In this way, the lemon pieces were better in sensory quality, it kept high content of critic acids and vitamin C, and low lever of browning. The products which were produced by this condition was better in original color,fragrant character,flavor,shape and nutrition.

  3. Robustness testing in pharmaceutical freeze-drying: inter-relation of process conditions and product quality attributes studied for a vaccine formulation.

    Science.gov (United States)

    Schneid, Stefan C; Stärtzel, Peter M; Lettner, Patrick; Gieseler, Henning

    2011-01-01

    The recent US Food and Drug Administration (FDA) legislation has introduced the evaluation of the Design Space of critical process parameters in manufacturing processes. In freeze-drying, a "formulation" is expected to be robust when minor deviations of the product temperature do not negatively affect the final product quality attributes. To evaluate "formulation" robustness by investigating the effect of elevated product temperature on product quality using a bacterial vaccine solution. The vaccine solution was characterized by freeze-dry microscopy to determine the critical formulation temperature. A conservative cycle was developed using the SMART™ mode of a Lyostar II freeze dryer. Product temperature was elevated to imitate intermediate and aggressive cycle conditions. The final product was analyzed using X-ray powder diffraction (XRPD), scanning electron microscopy (SEM), Karl Fischer, and modulated differential scanning calorimetry (MDSC), and the life cell count (LCC) during accelerated stability testing. The cakes processed at intermediate and aggressive conditions displayed larger pores with microcollapse of walls and stronger loss in LCC than the conservatively processed product, especially during stability testing. For all process conditions, a loss of the majority of cells was observed during storage. For freeze-drying of life bacterial vaccine solutions, the product temperature profile during primary drying appeared to be inter-related to product quality attributes.

  4. Composition, thermotropic properties, and oxidative stability of freeze-dried and spray-dried milk fat globule membrane isolated from cheese whey.

    Science.gov (United States)

    Zhu, Dan; Damodaran, Srinivasan

    2011-08-24

    The milk fat globule membrane (MFGM) was isolated from cheese whey using a recently developed novel method. The cheese-derived MFGM contained about 17-19% lipids and 65-70% protein on a dry weight basis. About 50% of the lipids in MFGM were phospholipids. Compositional analysis of the cheese whey-derived MFGM showed that it is a rich source of phosphatidylserine, sphingomyelin, and bioactive proteins CD36, butyrophilin, xanthine oxidase, and mucin 1. Utilization of MFGM in foods as a source of nutraceutical lipids depends on its oxidative stability. In this context, the impact of drying methods, namely, freeze-drying versus spray-drying, on the storage stability of MFGM was studied. Freeze-dried (FD) and spray-dried (SD) MFGM samples were morphologically very different when examined by light microscope: The thermotropic phase transition temperature (T(m)) of lipids in the FD-MFGM was 37.8 °C, and it was 48 °C in SD-MFGM. This 10 °C difference in T(m) indicated that the drying method altered the thermodynamic state of phospholipids in MFGM. At all storage temperatures studied, the zero-order rate constant of lipid oxidation, as measured by hexanal production, was 1-2 orders of magnitude greater in the spray-dried than in the freeze-dried MFGM. The results clearly indicated that the choice of drying method affects morphological characteristics, the T(m) and oxidative stability of phospholipids in MFGM.

  5. Composition of w-3 and w-6 fatty acids in freeze-dried chicken embryo eggs with different days of development

    Directory of Open Access Journals (Sweden)

    Campos Célia Maria Teixeira de

    2004-01-01

    Full Text Available Fatty acids omega--3 and omega--6 composition and specially DHA were determined in freeze-dried chicken embryo eggs with pre-determined incubation periods. Fertile and embryo eggs presented palmitic (23.18 + 0.54%, stearic (7.70 + 0.28%, palmitoleic (3.00 + 0.19%, oleic (36.28 + 0.58%, linoleic (22.18 + 0.34%, linolenic (1.08 + 0.04%, arachidonic (2.04 + 0.03%, docosahexaenoic (0.91 + 0.03%, total omega-3 acids (2.26 + 0.10% and total omega-6 acids (24.62 + 0.33%. There were no significant differences in total contents of omega-3 fatty acids (p=0.1226 between freeze-dried chicken embryo eggs with different incubation periods (3, 5, 7, 9, and 11 days and fertile freeze-dried chicken eggs (day 0. However, there were significant differences in total medium contents of omega-6 fatty acids (p=0.0001. There was also a strong statistical evidence that quadratic model was related with expected values of DHA content (p= 0.0013.

  6. Impact of freeze-drying, mixing and horizontal transport on water vapor in the upper troposphere and lower stratosphere (UTLS)

    Science.gov (United States)

    Poshyvailo, Liubov; Ploeger, Felix; Müller, Rolf; Tao, Mengchu; Konopka, Paul; Abdoulaye Diallo, Mohamadou; Grooß, Jens-Uwe; Günther, Gebhard; Riese, Martin

    2017-04-01

    Water vapor in the upper troposphere and lower stratosphere (UTLS) is a key player in the global radiation budget. Therefore, a realistic representation of the water vapor distribution in this region and the involved control processes is critical for climate models, but largely uncertain hitherto. It is known that the extremely low temperatures around the tropical tropopause cause the dominant factor controlling water vapor in the lower stratosphere. Here, we focus on additional processes, such as horizontal transport between tropics and extratropics, small-scale mixing, and freeze-drying. We assess the sensitivities of simulated water vapor in the UTLS from simulations with the Chemical Lagrangian Model of the Stratosphere (CLaMS). CLaMS is a Lagrangian transport model, with a parameterization of small-scale mixing (model diffusion) which is coupled to deformations in the large-scale flow. First, to assess the robustness of water vapor with respect to the meteorological datasets we examine CLaMS driven by ECMWF ERA-Interim and the Japanese 55-year reanalysis. Second, to investigate the effects of small-scale mixing we vary the parameterized mixing strength in the CLaMS model between the reference case with the mixing strength optimized to reproduce atmospheric trace gas observations and a purely advective simulation with parameterized mixing turned off. Also calculation of Lagrangian cold points gives further insight of the processes involved. Third, to assess the effects of horizontal transport between the tropics and extratropics we carry out sensitivity simulations with horizontal transport barriers along latitude circles at the equator, 15°N/S and 35°N/S. Finally, the impact of Antarctic dehydration is estimated from additional sensitivity simulations with switched off freeze-drying in the model at high latitudes of 50°N/S. Our results show that the uncertainty in the tropical tropopause temperatures between current reanalysis datasets causes significant

  7. Atmospheric freeze drying for the reduction of powder electrostatics of amorphous, low density, high surface area pharmaceutical powders.

    Science.gov (United States)

    O'Donnell, K P; Cai, Z; Schmerler, P; Williams, R O

    2013-02-01

    Amorphous itraconazole (ITZ) was prepared by Thin Film Freezing (TFF) utilizing 1,4-dioxane as the solvent with subsequent solvent removal via conventional tray lyophilization (ITZ LYO) or atmospheric freeze drying (ITZ AFD). ITZ AFD was prepared under various drying conditions to assess the influence of drying parameters on powder properties. XRD analysis confirmed all products were amorphous and DSC analysis revealed both drying processes resulted in the formation of the nematic mesophase of ITZ. SEM revealed a larger pore size and agglomerate size with fewer fine particles (i.e. less than 10 microns in diameter) for ITZ AFD compared to ITZ LYO. Residual solvent analysis revealed a primary drying temperature of -10°C resulted in residual solvent levels above the acceptable limits set by the International Conference on Harmonization as a result of microcollapse. Primary drying temperatures of less than -10°C resulted in acceptable residual solvent levels. The extent of microcollapse did not alter the macrostructure of the resulting powder. Powder flowability was determined to be similar for ITZ AFD and ITZ LYO based on Carr's index and the Hausner ratio, as well as by dynamic angle of repose. All powders displayed poor flowability. Chargeability measurements demonstrated a lower charge transfer for ITZ AFD powders compared to ITZ LYO due to a combination of factors including differences in residual solvent level, particle size, pore size, surface area, and fine particles content. The reduction in chargeability as a result of AFD is highly desirable because it allows for improved powder handling and use post-production.

  8. Socket preservation using demineralized freezed dried bone allograft with and without plasma rich in growth factor: A canine study

    Directory of Open Access Journals (Sweden)

    Ahmad Mogharehabed

    2014-01-01

    Full Text Available Background: The accelerating effect of plasma rich in growth factors (PRGFs in the healing of extraction sockets has been demonstrated by some studies. The aim of the present study was to histologically and histomorphometrically evaluate whether bone formation would increase by the combined use of PRGF and demineralized freeze-dried bone allograft (DFDBA. Materials and Methods: In four female dogs, the distal root of the second, third and fourth lower premolars were extracted bilaterally and the mesial roots were preserved. The extraction sockets were randomly divided into DFDBA + PRGF, DFDBA + saline or control groups. Two dogs were sacrificed after 2 weeks and two dogs were sacrificed after 6 weeks. The extraction sockets were evaluated from both histological and histomorphometrical aspects. The data were analyzed by Mann-Whitney followed by Kruskal-Wallis tests using the Statistical Package for the Social Sciences version 20 (SPSS Inc., Chicago, IL, USA. Significant levels were set at 0.05. Results: The least decrease in socket height was observed in the DFDBA + PRGF group (0.73 ± 0.42 mm. The least decrease in the coronal portion was observed in the DFDBA + PRGF group (1.38 ± 1.35 mm². The least decrease in the middle surface was observed in the DFDBA group (0.61 ± 0.80 mm². The least decrease in the apical portion was observed in the DFDBA group (0.34 ± 0.39 mm². Conclusion: The present study showed better socket preservation subsequent to the application of DFDBA and PRGF combination in comparison with the two other groups. However, the difference was not statistically significant.

  9. Prevention and therapy of squamous cell carcinoma of the rodent esophagus using freeze-dried black raspberries

    Institute of Scientific and Technical Information of China (English)

    Gary D STONER; Robeena M AZIZ

    2007-01-01

    Aim: This study was conducted to determine if short-term treatment of N-nitrosomethylbenzylamine (NMBA)-induced tumors in the rat esophagus with dietary freeze-dried black raspberries (FBR) would result in tumor regression and enhanced survival of the animals. Methods: Four-week-old male Fisher-344 ratswere administered an AIN-76A control diet and injected subcutaneously with 0.5 mg/kg NMBA once per week for 15 weeks. At 19 weeks, when rats had an average of 5-6 tumors (papillomas) per esophagus, they were given a control diet contain-ing either 5%, 10%, or 20% FBR. After 7 weeks of berry treatment, all surviving rats were killed and tumor incidence, number and volume were determined. Results:Esophageal tumor incidences, numbers and volumes in NMBA-treated rats were not influenced by any of the berry treatments. There were progressive increases in the survival of NMBA-treated rats fed 5%-20% FBR diets; however, these increases were not significant. Conclusion: FBR at 5%, 10%, and 20% of the diet had no effect on the development of NMBA-induced tumors in the rat esophagus or on animal survival when administered for 7 weeks beginning at the papilloma stage of tumor development. Thus, FBR appear to have no therapeutic value in the treatment of esophageal tumors. In contrast, dietary FBR are highly effectivein preventing the development of NMBA-induced esophageal tumors in rats when administered before and during NMBA treatment or shortly after NMBA treat-ment when the esophagi contain preneoplastic (dysplastic) lesions of varyingdegrees of severity.

  10. Determination of orthodontic tooth movement and tissue reaction following demineralized freeze-dried bone allograft grafting intervention

    Directory of Open Access Journals (Sweden)

    Massoud Seifi

    2012-01-01

    Full Text Available Background: Socket preservation after tooth extraction is one of the indications of bone grafting to enhance preorthodontic condition. The aim of this study is to determine the effects of socket preservation on the immediate tooth movement, alveolar ridge height preservation and orthodontic root resorption. Materials and Methods: In a split-mouth technique, twelve sites in three dogs were investigated as an experimental study. Crushed demineralized freeze-dried bone allograft (DFDBA (CenoBone® was used as the graft material. The defects were made by the extraction of 3 rd premolar. On one side of each jaw, the defects were preserved by DFDBA and defects of the other side left opened as the control group. Simultaneously the teeth adjacent to the defects were pulled together by a NiTi coil spring. After eight weeks, the amount of (OTM, alveolar height, and root resorption were measured. Analysis of variance was used for purpose of comparison. Results: There was a slight increase in OTM at grafted sites as they were compared to the control sites (P<0.05. Also a significant bone resorption in control site and successful socket preservation in experimental site were observed. Reduction of root resorption at the augmented site was significant compared to the normal healing site (P<0.05. Conclusion: Using socket preservation, tooth movement can be immediately started without waiting for the healing of the recipient site. This can provide some advantages like enhanced rate of OTM, its approved effects on ridge preservation that reduces the chance of dehiscence and the reduction of root resorption.

  11. Spray-freeze-drying of nanosuspensions: the manufacture of insulin particles for needle-free ballistic powder delivery

    Science.gov (United States)

    Schiffter, Heiko; Condliffe, Jamie; Vonhoff, Sebastian

    2010-01-01

    The feasibility of preparing microparticles with high insulin loading suitable for needle-free ballistic drug delivery by spray-freeze-drying (SFD) was examined in this study. The aim was to manufacture dense, robust particles with a diameter of around 50 µm, a narrow size distribution and a high content of insulin. Atomization using ultrasound atomizers showed improved handling of small liquid quantities as well as narrower droplet size distributions over conventional two-fluid nozzle atomization. Insulin nanoparticles were produced by SFD from solutions with a low solid content (300 mg ml−1) consisting of trehalose, mannitol, dextran (10 kDa) and dextran (150 kDa) (abbreviated to TMDD) in order to maximize particle robustness and density after SFD. With the increase in insulin content, the viscosity of the nanosuspensions increased. Liquid atomization was possible up to a maximum of 250 mg of nano-insulin suspended in a 1.0 g matrix. However, if a narrow size distribution with a good correlation between theoretical and measurable insulin content was desired, no more than 150 mg nano-insulin could be suspended per gram of matrix formulation. Particles were examined by laser light diffraction, scanning electron microscopy and tap density testing. Insulin stability was assessed using size exclusion chromatography (SEC), reverse phase chromatography and Fourier transform infrared (FTIR) spectroscopy. Densification of the particles could be achieved during primary drying if the product temperature (Tprod) exceeded the glass transition temperature of the freeze concentrate (Tg′) of −29.4°C for TMDD (3∶3∶3∶1) formulations. Particles showed a collapsed and wrinkled morphology owing to viscous flow of the freeze concentrate. With increasing insulin loading, the d (v, 0.5) of the SFD powders increased and particle size distributions got wider. Insulin showed a good stability during the particle formation process with a maximum decrease in insulin monomer of

  12. Dry powder inhalers: physicochemical and aerosolization properties of several size-fractions of a promising alterative carrier, freeze-dried mannitol.

    Science.gov (United States)

    Kaialy, Waseem; Nokhodchi, Ali

    2015-02-20

    The purpose of this work was to evaluate the physicochemical and inhalation characteristics of different size fractions of a promising carrier, i.e., freeze-dried mannitol (FDM). FDM was prepared and sieved into four size fractions. FDMs were then characterized in terms of micromeritic, solid-state and bulk properties. Dry powder inhaler (DPI) formulations were prepared using salbutamol sulphate (SS) and then evaluated in terms of drug content homogeneity and in vitro aerosolization performance. The results showed that the crystalline state of mannitol was maintained following freeze-drying for all size fractions of FDM. All FDM particles showed elongated morphology and contained mixtures of α-, β- and δ-mannitol. In comparison to small FDM particles, FDMs with larger particle sizes demonstrated narrower size distributions, higher bulk and tap densities, lower porosities and better flowability. Regardless of particle size, all FDMs generated a significantly higher (2.2-2.9-fold increase) fine particle fraction (FPF, 37.5 ± 0.9%-48.6 ± 2.8%) of SS in comparison to commercial mannitol. The FPFs of SS were related to the shape descriptors of FDM particles; however, FPFs did not prove quantitative apparent relationships with either particle size or powder bulk descriptors. Large FDM particles were more favourable than smaller particles because they produced DPI formulations with better flowability, better drug content homogeneity, lower amounts of the drug depositing on the throat and contained lower fine-particle-mannitol. Optimized stable DPI formulations with superior physicochemical and pharmaceutical properties can be achieved using larger particles of freeze-dried mannitol (FDM). Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Research on preparing instant phytase by using freeze-drying method%冷冻干燥法制备速溶植酸酶的研究

    Institute of Scientific and Technical Information of China (English)

    马俊孝; 刘伟; 史衍鲁

    2011-01-01

    采用毕赤酵母发酵制备酶液,膜超滤浓缩、硫酸铵盐析法沉淀酶蛋白,结合冷冻干燥法制得速溶型植酸酶.结果表明,对酶活力达19 500 U/ml的发酵液进行浓缩后,以70%饱和度的硫酸铵进行盐析,分离后的酶蛋白经过冷冻干燥得到活力为500 000 U/g的植酸酶,速溶性好,溶解后清亮透明.酶的冻干粉50 ℃保存90 d内酶活力仍能维持96%以上的活力.为高酶活速溶植酸酶的工业化生产提供了一条可行的思路.%The freeze-drying technology for producing instant phytase was studied. The crude preparation was obtained by Pichia pastoris high cell density fermentation, microporous membrane ultrafiltration,ammonium sulfate precipitation and freeze-drying. Fermentation liquid, activity achieved 19 500 U/ml,was managed by ultrafiltration membrane, concentrated with ammonium sulphate in 70% saturation. After freeze-drying, the final product was obtained with up to 500 000 U/g. The preparation could soluble in water quickly with no turbidity, no precipitation and good transparency. The powder remained over 96%of its activity under 50 ℃ within 90 days. Our studies provide a feasible method for preparing instant phytase with higher activity.

  14. Optimization of the parameters of the daylily vacuum freeze-drying processing%黄花菜真空冷冻干燥工艺优化研究

    Institute of Scientific and Technical Information of China (English)

    许国宁; 吴素玲; 孙晓明; 张卫明

    2013-01-01

    为了提高黄花菜的干制品品质和优化真空冷冻干燥工艺,以还原糖含量、维生素C含量和复水比为评价指标,通过Design-Expert软件的Central Composite Design方法设计黄花菜干制的工艺,建立评价指标与物料装载量和加热板温度影响因素之间的回归数学模型.结合响应面分析方法对黄花菜真空冷冻干燥工艺进行优化,确定了真空冷冻干燥黄花莱的最佳工艺条件为:物料装载量为225g,加热板温度为50℃.%Taking the content of reducing sugar,the content of Vc and the rehydration as the evaluating indexes, to improve the qua ity of dried daylily and optimize the daylily vacuum freeze-drying process, central composite design of the Design-expert was used in the vacuum freeze-drying process of Daylily. Regression mathematical model between the index and impact factors was built. Central composite design was used to optimize experiments design and connect with the optimum method of response suraface methodology. The results showed that the optimal parameters of vacuum of freeze-drying process were as follows;material loadage was 225g and heating plate temperature was 50℃.

  15. Study on Freeze-drying of Water Chestnut%马蹄真空冷冻干燥实验的研究

    Institute of Scientific and Technical Information of China (English)

    陈学玲; 何建军; 关健; 梅新; 程薇; 熊光权; 叶丽秀; 陈玉霞

    2011-01-01

    利用真空冷冻干燥技术对马蹄进行保鲜加工研究.利用电阻法测量了马蹄的共晶点和共熔点,采用L12(35)正交试验方法,研究了影响冻干产品质量和设备生产能力的主要参数,评定了冻干产品的含水量、外观、复水性等特性.实验结果表明,马蹄冻干的最佳工艺为:速冻温度-36℃,速冻时间20h,干燥升华时仓压(120±10)Pa;干燥解析时仓压(40±10)Pa,解析时的搁板温度50℃,干燥时间14h.%Water Chestnut were stored and processed by Freeze-drying.Eutectic point and consolute point were measured by resistivity method.The main factors affecting the properties of freeze-drying product and production capacity of the equipment were studied using L12(35) orthogonal experiments.Water content of product,product form,rehydration character were evaluated.The optimal technics for freeze-drying Water Chestnut were following:deep freeze temperature-36℃,deep freeze time 20h,pressure of drying room while vacuum sublimation drying(120±10)Pa,pressure of drying room while vaccum resolution drying(40±10)Pa,shelf temperature while vacuum resolution drying 50℃,drying time 14h.

  16. 猪皮胶原海绵的冷冻干燥工艺%Studies on Collagen Sponge Freeze-drying Process

    Institute of Scientific and Technical Information of China (English)

    杨田义; 郭柏松; 张路; 代龙

    2011-01-01

    目的:优选猪皮胶原海绵的最佳冷冻干燥工艺.方法:以吸水性、复水性值为指标,通过正交试验法对猪皮胶原海绵的冷冻干燥工艺参数进行筛选,优选出猪皮胶原海绵的最佳冷冻干燥工艺.结果:预冻速率0.35℃·min(-1),预冻时间1.5h,预冻最低温度-35℃,一次升华温度-10℃.结论:优选的冷冻干燥工艺制备的猪皮胶原海绵疏松多孔,吸水性、复水性良好.%Objective: To optimize selection of collagen sponge freeze-drying process, such as collagen protein molecules of freeze-drying reference. Method: Orthogonal test was used to choose the best collagen sponge freeze-drying process with water imbibition and re-hydration values as index. Result: The rate of pre-freezing was 0. 35 ℃ · min- 1, the duration of pre-freezing was 1.5 h, the lowest temperature of pre-freezing was - 35 ℃ and the temperature of the first sublimation was - 10 ℃. Conclusion: The pigskin collagen sponge produced by the freezedrying process which has been chosen is osteoporosis and porous, the water imbibition and re-hydration of the pigskin collagen sponge are well.

  17. Study on Freeze-drying Process of Ademetionine Butanedisulfonate%丁二磺酸腺苷蛋氨酸冻干工艺研究

    Institute of Scientific and Technical Information of China (English)

    刘桂祯; 劳瑞雄; 黄炯威; 宋光明

    2011-01-01

    为建立合适的丁二磺酸腺苷蛋氨酸冻干工艺,采用真空冷冻干燥法,对丁二磺酸腺苷蛋氨酸冻干条件如共晶点、装量、预冻程序、升华温度、升华真空度及解吸干燥温度等进行研究。结果显示:冻干工艺:装量为液面高度小于10 mm,预冻程序为预冻至-40℃,然后回温至-10℃,再降至-50℃,在真空度10~30 Pa,-25℃下升华,35℃解吸干燥。此工艺制备的丁二磺酸腺苷蛋氨酸外观好,产品质量符合国家标准。%A suitable freeze-drying process of ademetionine butanedisulfonate was established.Methods:The vacuum freeze-drying method was modified by the process such as liquid altitude in bottle,the eutectic point,pre-freeing process,sublimating temperature,sublimating vacuum,and temperature of desorption.The acceptable freeze-drying process was that liquid altitude was NMT 10 mm in bottle,pre-freeing process was that fell the temperature to-40 ℃,then back to-10 ℃,then fell to-50 ℃,sublimating temperature was-25 ℃,sublimating vacuum was 10~30 Pa,and temperature of desorption was 35 ℃.The lyophilized agent of ademetionine butanedisulfonate prepared by this process had look good and met the requirement of the SFDA.

  18. Application of Optical Coherence Tomography Freeze-Drying Microscopy for Designing Lyophilization Process and Its Impact on Process Efficiency and Product Quality.

    Science.gov (United States)

    Korang-Yeboah, Maxwell; Srinivasan, Charudharshini; Siddiqui, Akhtar; Awotwe-Otoo, David; Cruz, Celia N; Muhammad, Ashraf

    2017-08-07

    Optical coherence tomography freeze-drying microscopy (OCT-FDM) is a novel technique that allows the three-dimensional imaging of a drug product during the entire lyophilization process. OCT-FDM consists of a single-vial freeze dryer (SVFD) affixed with an optical coherence tomography (OCT) imaging system. Unlike the conventional techniques, such as modulated differential scanning calorimetry (mDSC) and light transmission freeze-drying microscopy, used for predicting the product collapse temperature (Tc), the OCT-FDM approach seeks to mimic the actual product and process conditions during the lyophilization process. However, there is limited understanding on the application of this emerging technique to the design of the lyophilization process. In this study, we investigated the suitability of OCT-FDM technique in designing a lyophilization process. Moreover, we compared the product quality attributes of the resulting lyophilized product manufactured using Tc, a critical process control parameter, as determined by OCT-FDM versus as estimated by mDSC. OCT-FDM analysis revealed the absence of collapse even for the low protein concentration (5 mg/ml) and low solid content formulation (1%w/v) studied. This was confirmed by lab scale lyophilization. In addition, lyophilization cycles designed using Tc values obtained from OCT-FDM were more efficient with higher sublimation rate and mass flux than the conventional cycles, since drying was conducted at higher shelf temperature. Finally, the quality attributes of the products lyophilized using Tc determined by OCT-FDM and mDSC were similar, and product shrinkage and cracks were observed in all the batches of freeze-dried products irrespective of the technique employed in predicting Tc.

  19. Effect of freeze drying on the metabolic viability of lactic acid bacteria%冷冻干燥对乳酸菌代谢活力的影响

    Institute of Scientific and Technical Information of China (English)

    李宝坤; 田丰伟; 刘小鸣; 赵建新; 张灏; 宋元达; 陈卫

    2011-01-01

    The survival rates of Lactobacillus plantarum ST-Ⅲ and Lactobacillus bulgaricus in the presence of cryoprotectants such as 15%sucrose,10%trehalose,15%sucrose +2% sodium glutamate and 10%reconstituted skim milk(RSM)were estimated.In addition,we determined the activities of hexokinase(HK),pyruvate kinase(PK),lactate dehydrogenase(LDH),extracellular proteins was higher and intercellular Ca2+ immediately following the freeze-drying.The results showed that the differences in HK and PK activities with and without the cryoprotectants during freeze-drying were not significant,but activities of LDH were significantly different prior to and after freeze-drying.Meanwhile,the results showed extracellular proteins was higher and intercellular Ca2+ was lower in absence of cryoprotectants than in the presence of cryoprotectants.These results suggested that freeze-dying inactivated key enzymes(LDH)and damaged membrane structure and function.These led to decrease in viability of lactic acid bacteria during freeze-drying.%以保加利亚乳杆菌和植物乳杆菌ST-Ⅲ为研究对象,用15%蔗糖、10%海藻糖、15%蔗糖+2%谷氨酸钠及10%脱脂乳为冷冻保护剂,与不加冷冻保护剂的样品进行冻干后菌种活力的对比,测定冷冻干燥后菌体中己糖激酶、丙酮酸激酶、乳酸脱氢酶的活力,胞外蛋白及胞内Ca2+的浓度变化。结果表明:冷冻干燥对菌体的己糖激酶和丙酮酸激酶影响不显著,对乳酸脱氢酶具有显著性的影响。同时,不加保护剂菌体的胞外蛋白含量明显高于添加保护剂的,而胞内Ca2+却远低于其他组。这一结果说明,冷冻干燥使代谢关键酶如乳酸脱氢酶失活,同时对细胞膜造成了损伤,从而引起细胞代谢活力的下降。

  20. Survival rate of Saccharomyces boulardii adapted to a functional freeze-dried yoghurt, related to processing, storage and digestion by experimental Wistar rats

    Directory of Open Access Journals (Sweden)

    Eunice Tranquilino-Rodriguez

    2017-02-01

    Full Text Available Background: Saccharomycesboulardiiis a probiotic clinically effective inthe prevention and treatment of antibiotic induced diarrheain both children and adults, Clostridium difficile infections, inflammatory bowel disease, and other gastrointestinal disorders. However, the microorganisms need to survive the gastrointestinal transit and arrive to their action site alive in order to exert their beneficial effects. Microencapsulation is an alternative to improve the viability of probiotic in foods which can also survive in the gastrointestinal conditions. Freeze--drying is a method of dehydration that does not affect nutrients and bioactive compounds,such as probiotics contained in foods.All of them will increase the survival rate of S.boulardii.Purpose of this study:This study focused on formulae freeze-dried yogurt containing inulin, vegetable palm oil,and S.boulardii, both asfree cells and in microencapsulated form.Also,the effect of ampicillin associated S.boulardii. Methods. Yogurts were given to an “in vivo” digestion process, using male Wistar rats.The survival of S. boulardiiwas subsequently evaluated in colon and feces.For this study, six treatmentsof four of rats were used:i control rats ii rats fed with yogurt containing S. boulardiias free cells, iii rats fed with yogurt containing S. boulardiiinmicro-encapsulated form, iv control rats fed with penicillin,v rats fed with ampicillin plus yogurtcontaining S. boulardiias free cells, and vi rats fed with penicillin plus yogurt containing S. boulardiiin micro-encapsulated form. Results:The study demonstrated it was feasible to freeze-drythe S. boulardiiand incorporate it into a yogurtmade with skim milk,inulin, and unsaturated vegetable oil.The freeze-drying process not affected thesurvival of the S. boulardii(p<0.05. Microencapsulation increased the survival of S. boulardii on 1.77-Log CFU/g, and the presence of S. boulardii was only detected in colon and fecesof those rats which

  1. Comparative study of two drying techniques used in radioactive source preparation: freeze-drying and evaporation using hot dry nitrogen jets.

    Science.gov (United States)

    Branger, T; Bobin, C; Iroulart, M-G; Lépy, M-C; Le Garrères, I; Morelli, S; Lacour, D; Plagnard, J

    2008-01-01

    Quantitative solid sources are used widely in the field of radionuclide metrology. With the aim to improve the detection efficiency for electrons and x-rays, a comparative study between two source drying techniques has been undertaken at LNE-Laboratoire National Henri Becquerel (LNE-LNHB, France). In this paper, freeze-drying using commercial equipment is compared with a system of drying using hot jets of nitrogen developed at Institute for Reference Materials and Measurements (IRMM, Belgium). In order to characterize the influence of self-absorption, the detection efficiencies for (51)Cr sources have been measured by coincidence counting and photon spectrometry.

  2. Vacuum freeze-drying progress of purple sweet potato leaves%真空冷冻干燥紫甘薯叶的工艺研究

    Institute of Scientific and Technical Information of China (English)

    孙莉; 蒲传奋; 姜文利; 张岩; 杜善词; 王世清

    2012-01-01

    为了对采后紫甘薯叶进行充分的开发利用,提高农副产品的附加值及利用率,研究了紫甘薯叶真空冷冻干燥的最佳工艺参数。以冻干后紫甘薯叶的含水量为指标,利用正交试验对冻干过程的3个阶段进行了分析。并以色差变化为指标,采用正交试验研究了紫甘薯叶的最佳护色条件。研究表明:紫甘薯叶真空冷冻干燥最佳工艺过程为:预冻3h,升华干燥8h,解析干燥2h;最佳护色条件为:护色剂ZnCI2、质量浓度500mg/L、温度70℃、时N30s。%The best parameters of purple sweet potato leaves were studied by using vacuum freeze-drying technology in this paper, the water content of the purple sweet potato leaves after the freeze-drying was as an indicator, the three stages of freeze-drying process were analyzed by orthogonal experiment; the color change was as an indicator, the best conditions of color protection was studied through orthogonal experiment. The results showed that: the best vacuum freeze-drying process of purple sweet potato leaves as follow: the pre-freeze time was 3 h, the sublimation drying time was 8 h, the analytical drying time was 2 h; the best conditions of color protection as follow: the color fixative was ZnCI2, the density was 500 mg/L, temperature was 70 %, time was 30 s.

  3. Balancing mechanical strength with bioactivity in chitosan-calcium phosphate 3D microsphere scaffolds for bone tissue engineering: air- vs. freeze-drying processes.

    Science.gov (United States)

    Nguyen, D T; McCanless, J D; Mecwan, M M; Noblett, A P; Haggard, W O; Smith, R A; Bumgardner, J D

    2013-01-01

    The objective of this study was to evaluate the potential benefit of 3D composite scaffolds composed of chitosan and calcium phosphate for bone tissue engineering. Additionally, incorporation of mechanically weak lyophilized microspheres within those air-dried (AD) was considered for enhanced bioactivity. AD microsphere, alone, and air- and freeze-dried microsphere (FDAD) 3D scaffolds were evaluated in vitro using a 28-day osteogenic culture model with the Saos-2 cell line. Mechanical testing, quantitative microscopy, and lysozyme-driven enzymatic degradation of the scaffolds were also studied. FDAD scaffold showed a higher concentration (p mechanical strength was sacrificed through introduction of the less stiff, porous FD spheres.

  4. A botanical containing freeze dried açai pulp promotes healthy aging and reduces oxidative damage in sod1 knockdown flies

    OpenAIRE

    Laslo, Mara; Sun, Xiaoping; Hsiao, Cheng-Te; Wu, Wells W; Shen, Rong-Fong; Zou, Sige

    2012-01-01

    Superoxide dismutase 1 (SOD1), a critical enzyme against oxidative stress, is implicated in aging and degenerative diseases. We previously showed that a nutraceutical containing freeze-dried açai pulp promotes survival of flies fed a high-fat diet or sod1 knockdown flies fed a standard diet. Here, we investigated the effect of açai supplementation initiated at the early or late young adulthood on lifespan, physiological function, and oxidative damage in sod1 knockdown flies. We found that Aça...

  5. Treatment of endodontic perforations using guided tissue regeneration and demineralized freeze-dried bone allograft: two case reports with 2-4 year post-surgical evaluations.

    Science.gov (United States)

    Zenobio, Elton Golçalves; Shibli, Jamil Awad

    2004-08-15

    Clinicians often have difficulty with the diagnosis and treatment of root perforation. This paper reports two patients with root perforation treated with periodontal surgery associated with guided tissue regeneration (GTR) and demineralized freeze-dried bone allograft (DFDBA). This combined treatment resulted in minimal probing depths, minimal attachment loss, and radiographic evidence of bone gain after follow-up evaluations that ranged from 2 to 4 years. These case reports show a correct diagnosis and removal of etiologic factors can restore both periodontal and endodontic health.

  6. Radiosterilization of Fluoroquinolones and Cephalosporins: Assessment of Radiation Damage on Antibiotics by Changes in Optical Property and Colorimetric Parameters

    OpenAIRE

    2009-01-01

    A most common problem encountered in radiosterilization of solid drugs is discoloration or yellowing. By pharmacopoeia method, discoloration can be assessed by measuring absorbance of solutions of irradiated solid samples at 450 nm. We propose to evaluate discoloration of solid samples directly by recording their diffuse reflectance spectra. Further, the reflectance spectrum is used to compute various color parameters: CIE XYZ tristimulus value, CIE Lab, \\documentclass[12pt]{minimal} \\...

  7. Hypoxia Enhances Chondrogenic Differentiation of Human Cord Blood Multilineage Progenitor Cells Seeded on a Novel Scaffold of Freeze Dried Polycaprolactone

    DEFF Research Database (Denmark)

    Munir, Samir; Figueroa, Ryan Jude; Koch, Thomas Gadegaard;

    pattern in relation to the oxygen tension. Induced scaffolds showed cellularity and matrix deposition superficially and to adjacent scaffold fibres. Induced MLPCs pellets and scaffolds had significantly higher gene expression of aggrecan, SOX9, CD-RAP, collagen I, II and X compared with controls. Ratios...... for chondrogenic differentiation. According to recent studies combined three-dimensional (3D) culturing in low oxygen tension enhances differentiation. Aim This study evaluates the chondrogenic potential of MLPC culturing in a novel 3D-scaffold of polycaprolactone and 5% O2. Materials and methods MLPCs were...

  8. Computer-Aided Framework for the Design of Freeze-Drying Cycles: Optimization of the Operating Conditions of the Primary Drying Stage

    Directory of Open Access Journals (Sweden)

    Davide Fissore

    2015-05-01

    Full Text Available This paper deals with the freeze-drying process and, in particular, with the optimization of the operating conditions of the primary drying stage. When designing a freeze-drying cycle, process control aims at obtaining the values of the operating conditions (temperature of the heating fluid and pressure in the drying chamber resulting in a product temperature lower than the limit value of the product, and in the shortest drying time. This is particularly challenging, mainly due to the intrinsic nonlinearity of the system. In this framework, deep process knowledge is required for deriving a suitable process dynamic model that can be used to calculate the design space for the primary drying stage. The design space can then be used to properly design (and optimize the process, preserving product quality. The case of a product whose dried layer resistance, one of the key model parameters, is affected by the operating conditions is addressed in this paper, and a simple and effective method to calculate the design space in this case is presented and discussed.

  9. Influence of Freeze-Dried Yeast Starter Cultures on Volatile Compounds of Tchapalo, a Traditional Sorghum Beer from Côte d’Ivoire

    Directory of Open Access Journals (Sweden)

    Wahauwouélé Hermann Coulibaly

    2016-12-01

    Full Text Available The production of the Ivorian sorghum beer known as tchapalo remains more or less an empirical process. The use of starter cultures was therefore suggested as the appropriate approach to alleviate the problems of variations in organoleptic quality and microbiological stability. In this study, we evaluated the capacity of S. cerevisiae and C. tropicalis to produce sorghum beer as freeze-dried starter in mixed or pure cultures. Beers produced with mixed freeze-dried cultures of S. cerevisiae F12-7 and C. tropicalis C0-7 showed residual sugars and ethanol contents similar to beers obtained with S. cerevisiae F12-7 pure culture, but the total sum of organic acids analyzed was the highest with the mixed culture (15.71 g/L. Higher alcohols were quantitatively the largest group of volatile compounds detected in beers. Among these compounds, 2-phenyl ethanol, a higher alcohol that  plays an important role in beer flavor, was highly produced with the mixed culture (10,174.8 µg/L than with the pure culture (8749.9 µg/L.

  10. A comparative evaluation of extraction socket preservation with demineralized freeze-dried bone allograft alone and along with platelet-rich fibrin: A clinical and radiographic study

    Directory of Open Access Journals (Sweden)

    Dhaval J Thakkar

    2016-01-01

    Full Text Available Aims: To investigate clinically and radiographically, the bone fill in extraction sockets using demineralized freeze-dried bone allograft alone and along with platelet-rich fibrin (PRF. Materials and Methods: A randomized controlled clinical trial was carried out on 36 nonrestorable single-rooted teeth sites. Sites were randomized into demineralized freeze-dried bone allograft (DFDBA combined with PRF - test and DFDBA - control groups using a coin toss method. After the placement of graft material, collagen membrane was used to cover it. The clinical parameters recorded were ridge width and ridge height. All the parameters were recorded at baseline and at 90 and 180 days. Statistical Analysis Used: Independent t-test and paired t-test. Results: In both groups, there is significant reduction in loss of ridge width and ridge height from baseline to 90 days (P < 0.001, baseline to 180 days (P < 0.001, and 90-180 days (P < 0.001. However, when both the groups were compared the test group favored in the reduction of ridge width while there was no statistical difference in reduction of ridge height among at different intervals. Conclusions: Although DFDBA is considered as an ideal graft material, PRF can be used as an adjunctive with DFDBA for socket preservation.

  11. Product mass transfer resistance directly determined during freeze-drying cycle runs using tunable diode laser absorption spectroscopy (TDLAS) and pore diffusion model.

    Science.gov (United States)

    Kuu, Wei Y; O'Bryan, Kevin R; Hardwick, Lisa M; Paul, Timothy W

    2011-08-01

    The pore diffusion model is used to express the dry layer mass transfer resistance, [Formula: see text], as a function of the ratio r(e)/?, where r(e) is the effective pore radius and ? is the tortuosity factor of the dry layer. Using this model, the effective pore radius of the dry layer can be estimated from the sublimation rate and product temperature profiles measured during primary drying. Freeze-drying cycle runs were performed using the LyoStar II dryer (FTS Systems), with real-time sublimation rate profiles during freeze drying continuously measured by tunable diode laser absorption spectroscopy (TDLAS). The formulations chosen for demonstration of the proposed approach include 5% mannitol, 5% sucrose, 5% lactose, 3% mannitol plus 2% sucrose, and a parenteral nutrition formulation denoted VitaM12. The three different methods used for determination of the product resistance are: (1) Using both the sublimation rate and product temperature profiles, (2) using the sublimation rate profile alone, and (3) using the product temperate profile alone. Unlike the second and third methods, the computation procedure of first method does not need solution of the complex heat and mass transfer equations.

  12. The effect of excipients on the stability and aerosol performance of salmon calcitonin dry powder inhalers prepared via the spray freeze drying process

    Directory of Open Access Journals (Sweden)

    Poursina Narges

    2016-06-01

    Full Text Available Spray freeze drying was developed to produce dry powders suitable for applications such as inhalation delivery. In the current study, the spray freeze drying technique was employed to produce inhalable salmon calcitonin microparticles. Effects of the carrier type, concentration of hydroxyl propyl-β-cyclodextrin and the presence of Tween 80 on the chemical and structural stability, as well as on the aerosol performance of the particles were investigated. The results indicated that hydroxyl propyl-β-cyclodextrin had the most important effect on the chemical stability of the powder and strongly increased its stability by increasing its concentration in the formulation. Chemically stable formulations (over 90 % recovery were selected for further examinations. Fluorescence spectroscopy and circular dichroism suggested that the formulations were structurally stable. Aerosol performance showed that the Tween-free powders produced higher fine particle fraction values than the formulations containing Tween (53.7 vs. 41.92 % for trehalose content and 52.85 vs. 43.06 % for maltose content.

  13. The effect of excipients on the stability and aerosol performance of salmon calcitonin dry powder inhalers prepared via the spray freeze drying process.

    Science.gov (United States)

    Poursina, Narges; Vatanara, Alireza; Rouini, Mohammad Reza; Gilani, Kambiz; Najafabadi, Abdolhossein Rouholamini

    2016-06-01

    Spray freeze drying was developed to produce dry powders suitable for applications such as inhalation delivery. In the current study, the spray freeze drying technique was employed to produce inhalable salmon calcitonin microparticles. Effects of the carrier type, concentration of hydroxyl propyl-β-cyclodextrin and the presence of Tween 80 on the chemical and structural stability, as well as on the aerosol performance of the particles were investigated. The results indicated that hydroxyl propyl-β-cyclodextrin had the most important effect on the chemical stability of the powder and strongly increased its stability by increasing its concentration in the formulation. Chemically stable formulations (over 90 % recovery) were selected for further examinations. Fluorescence spectroscopy and circular dichroism suggested that the formulations were structurally stable. Aerosol performance showed that the Tween-free powders produced higher fine particle fraction values than the formulations containing Tween (53.7 vs. 41.92 % for trehalose content and 52.85 vs. 43.06 % for maltose content).

  14. Genetic stability of strains preserved on LENTICULE discs and by freeze-drying: a comparison using fluorescent amplified fragment length polymorphism analysis.

    Science.gov (United States)

    Desai, Meeta; Russell, Julie Elizabeth; Gharbia, Saheer

    2006-04-01

    Fluorescent amplified fragment length polymorphism (FAFLP) analysis, a high-resolution genome fingerprinting method, was used to ascertain the DNA integrity of bacterial strains during preservation by lenticulation and by traditional freeze-drying into glass ampoules. This was achieved by comparing FAFLP genotypes of a range of paired bacterial isolates recovered from LENTICULE discs (preserved between 1995 and 2004) and from freeze-dried (FD) cultures in glass ampoules (preserved between 1966 and 2000). A choice of two endonuclease combinations EcoRI/MseI or HindIII/HhaI was used for FAFLP analysis of the five different bacterial genera comprising of 10 strains. Each of these 10 strains exhibited unique FAFLP profiles. However, there were no detectable differences between the FAFLP profiles for each of the individual strains, irrespective of their preservation format or their year of preservation. Thus, the FAFLP data suggests that LENTICULE production does not result in any detectable genetic changes during drying onto LENTICULE discs and storage for at least 5 years. The provision of such FD reference cultures on LENTICULE discs rather than FD glass ampoules will provide a cost-effective format that is easier to use.

  15. Microcrystalline cellulose, a useful alternative for sucrose as a matrix former during freeze-drying of drug nanosuspensions - a case study with itraconazole.

    Science.gov (United States)

    Van Eerdenbrugh, Bernard; Vercruysse, Sofie; Martens, Johan A; Vermant, Jan; Froyen, Ludo; Van Humbeeck, Jan; Van den Mooter, Guy; Augustijns, Patrick

    2008-10-01

    Itraconazole nanosuspensions, stabilized with 10% TPGS (relative to the weight of itraconazole), were transformed into nanoparticulate powders by freeze-drying. The crystalline itraconazole nanoparticles showed peak broadening in the X-ray powder diffraction spectra and a lower melting point as inferred from differential scanning calorimetry. As it was found that freeze-drying compromised dissolution behavior, sucrose was added as a matrix, former (50,100 and 200%, relative to the weight of itraconazole). Higher amounts of sucrose unexpectedly resulted in a decrease in the dissolution rate. After thorough evaluation of the powders, it was found that whereas higher sucrose content showed a cryoprotective effect, agglomeration during the final phase of the subsequent drying step tended to increase with higher amounts of sucrose. Therefore, microcrystalline cellulose (MCC) was evaluated as an alternative matrix former. The inclusion of MCC resulted in fast dissolution that increased with increasing amounts of MCC [for powders containing 50%,100% and 200% MCC, (relative to the weight of itraconazole), the times required for 63.2% release were 10.5+/-0.7, 6.4+/-1.2 and 3.1+/-0.5min, respectively]. The dissolution profiles showed an initial phase of burst dissolution, followed by a phase of slower release. As the fraction showing burst dissolution increased with higher MCC content, the system holds promise to maintain the dissolution enhancing properties of nanoparticles in the dry form.

  16. Freeze Drying Technology of Lost Foam Casting Pattern%消失模模样的冷冻干燥技术

    Institute of Scientific and Technical Information of China (English)

    杨先锋

    2011-01-01

    The drying mechanism of lost foam casting pattern was discussed, and a freeze drying technology was presented, which is different with the traditional drying method, and is suitable for use in the drying room of medium-small foundry. Comparing with the traditional drying method, this technology not only has advantages of less investment, safety, automatic control and simple maintenance, but also gets a breakthrough in both of labor protection and energy saving, which is the most .important. The production practices show that the freeze drying technology can be applied to the foundry industry.%论述了消失模铸造生产中模样干燥的机理,介绍了一种不同于传统烘干干燥,适合用在中小铸造车间干燥室的冷冻干燥技术.生产实践结果表明,冷冻除湿干燥技术与传统的干燥技术相比,不仅具备投资少、生产安全、自动控制和维护简单的特点,更重要的是在劳动保护和节能降耗两方面取得了突破性的进步,具有在在铸造行业推广应用的价值.

  17. Encapsulation of antioxidant phenolic compounds extracted from spent coffee grounds by freeze-drying and spray-drying using different coating materials.

    Science.gov (United States)

    Ballesteros, Lina F; Ramirez, Monica J; Orrego, Carlos E; Teixeira, José A; Mussatto, Solange I

    2017-12-15

    Freeze-drying and spray-drying techniques were evaluated for encapsulation of phenolic compounds (PC) extracted from spent coffee grounds. Additionally, the use of maltodextrin, gum arabic and a mixture of these components (ratio 1:1) as wall material to retain the PC and preserve their antioxidant activity was also assessed. The contents of PC and flavonoids (FLA), as well as the antioxidant activity of the encapsulated samples were determined in order to verify the efficiency of each studied condition. Additional analyses for characterization of the samples were also performed. Both the technique and the coating material greatly influenced the encapsulation of antioxidant PC. The best results were achieved when PC were encapsulated by freeze-drying using maltodextrin as wall material. Under these conditions, the amount of PC and FLA retained in the encapsulated sample corresponded to 62% and 73%, respectively, and 73-86% of the antioxidant activity present in the original extract was preserved. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. 食品微波冻干技术及装备研究进展%Research progress on technology and equipment for freeze - drying food by microwave

    Institute of Scientific and Technical Information of China (English)

    王玉川; 张慜

    2016-01-01

    Freeze - drying technology used in food drying can maximize the retention of nutrients in food. The foods dried by freeze - drying are mainly exported at present since long drying period,large energy consumption and high cost. Microwave has the characteristics of inner heat source. Microwave freeze -drying technology is developed by the combination of microwave heating technology and traditional freeze- drying technology,which has been widely concerned by foreign scholars and business community since the middle of the last century. But the key technical problem has been restricting its commercial applica-tion because of the phenomenon of very obvious uneven and low - pressure gas discharge. In recent years,microwave freeze drying technology and the theory has been continuously improved due to the rapid development of science and technology and the interdisciplinary intersection and mutual penetration, which provide technical and economic support for research of the key technologies,equipment develop-ment and commercial application. The research progress of microwave drying technology at home and a-broad in high efficiency,energy saving,uniform and equipment is summarized.%冻干技术能够最大限度地保留食品的营养成分,在我国食品干燥行业得到了一定的应用。由于冻干技术存在干燥周期长、能耗大、成本高等缺点,目前我国冻干食品以出口为主。微波具有内热源特性,采用微波高效加热技术与传统冻干技术相结合而发展的微波冻干技术从上世纪中期已受到国外学者与企业界广泛关注。但是,微波冻干存在非常明显的不均匀与低压气体放电现象,这一关键技术问题一直以来制约其商业化应用。近些年来,由于科学技术的迅猛发展和学科领域的交叉、相互渗透,为微波冻干关键技术的研究、装备开发及商业化应用提供了技术及经济支撑,微波冻干技术、理论得到不断完善。综

  19. Mannitol/l-Arginine-Based Formulation Systems for Freeze Drying of Protein Pharmaceuticals: Effect of the l-Arginine Counter Ion and Formulation Composition on the Formulation Properties and the Physical State of Mannitol.

    Science.gov (United States)

    Stärtzel, Peter; Gieseler, Henning; Gieseler, Margit; Abdul-Fattah, Ahmad M; Adler, Michael; Mahler, Hanns-Christian; Goldbach, Pierre

    2016-10-01

    Previous studies have shown that protein storage stability in freeze-dried l-arginine-based systems improved in the presence of chloride ions. However, chloride ions reduced the glass transition temperature of the freeze concentrate (Tg') and made freeze drying more challenging. In this study, l-arginine was freeze dried with mannitol to obtain partially crystalline solids that can be freeze dried in a fast process and result in elegant cakes. We characterized the effect of different l-arginine counter ions on physicochemical properties of mannitol compared with mannitol/sucrose systems. Thermal properties of formulations with different compositions were correlated to thermal history during freeze drying and to physicochemical properties (cake appearance, residual moisture, reconstitution time, crystallinity). Partially crystalline solids were obtained even at the highest l-arginine level (mannitol:l-arginine of 2:1) used in this study. All l-arginine-containing formulations yielded elegant cakes. Only cakes containing l-arginine chloride and succinate showed a surface "crust" formed by phase separation. X-ray powder diffraction showed that inhibition of mannitol crystallization was stronger for l-arginine compared with sucrose and varied with the type of l-arginine counter ion. The counter ion affected mannitol polymorphism and higher levels of mannitol hemi-hydrate were obtained at high levels of l-arginine chloride.

  20. Extended release promethazine HCl using acrylic polymers by freeze-drying and spray-drying techniques: formulation considerations

    Directory of Open Access Journals (Sweden)

    Ruchi Tiwari

    2009-12-01

    Full Text Available The present study investigated a novel extended release system of promethazine hydrochloride (PHC with acrylic polymers Eudragit RL100 and Eudragit S100 in different weight ratios (1:1 and 1: 5, and in combination (0.5+1.5, using freeze-drying and spray-drying techniques. Solid dispersions were characterized by Fourier-transformed infrared spectroscopy (FT-IR, differential scanning calorimetry (DSC, Powder X-ray diffractometry (PXRD, Nuclear magnetic resonance (NMR, Scanning electron microscopy (SEM, as well as solubility and in vitro dissolution studies in 0.1 N HCl (pH 1.2, double-distilled water and phosphate buffer (pH 7.4. Adsorption tests from drug solution to solid polymers were also performed. A selected solid dispersion system was developed into capsule dosage form and evaluated for in vitro dissolution studies. The progressive disappearance of drug peaks in thermotropic profiles of spray-dried dispersions were related to increasing amount of polymers, while SEM studies suggested homogenous dispersion of drug in polymer. Eudragit RL100 had a greater adsorptive capacity than Eudragit S100, and thus its combination in (0.5+1.5 for S100 and RL 100 exhibited a higher dissolution rate with 97.14% drug release for twelve hours. Among different formulations, capsules prepared by combination of acrylic polymers using spray-drying (1:0.5 + 1.5 displayed extended release of drug for twelve hours with 96.87% release followed by zero order kinetics (r²= 0.9986.O presente trabalho compreendeu estudo de um novo sistema de liberação prolongada de cloridrato de prometazina (PHC com polímeros acrílicos Eudragit RL100 e Eudragit S100 em diferentes proporções em massa (1:1 e 1:5 e em combinação (0,5+1,5, utilizando técnicas de liofilização e de secagem por aspersão As dispersões sólidas foram caracterizadas por espectrofotometria no infravermelho por transformada de Fourier (FT-IR, calorimetria diferencial de varredura (DSC, difratometria

  1. In-line near infrared spectroscopy during freeze-drying as a tool to measure efficiency of hydrogen bond formation between protein and sugar, predictive of protein storage stability.

    Science.gov (United States)

    Mensink, Maarten A; Van Bockstal, Pieter-Jan; Pieters, Sigrid; De Meyer, Laurens; Frijlink, Henderik W; van der Voort Maarschalk, Kees; Hinrichs, Wouter L J; De Beer, Thomas

    2015-12-30

    Sugars are often used as stabilizers of protein formulations during freeze-drying. However, not all sugars are equally suitable for this purpose. Using in-line near-infrared spectroscopy during freeze-drying, it is shown here that hydrogen bond formation during freeze-drying, under secondary drying conditions in particular, can be related to the preservation of the functionality and structure of proteins during storage. The disaccharide trehalose was best capable of forming hydrogen bonds with the model protein, lactate dehydrogenase, thereby stabilizing it, followed by the molecularly flexible oligosaccharide inulin 4kDa. The molecularly rigid oligo- and polysaccharides dextran 5kDa and 70kDa, respectively, formed the least amount of hydrogen bonds and provided least stabilization of the protein. It is concluded that smaller and molecularly more flexible sugars are less affected by steric hindrance, allowing them to form more hydrogen bonds with the protein, thereby stabilizing it better.

  2. Optimization of Freeze-drying Technology of Albendazole Nanosuspension%阿苯达唑纳米混悬液的冻干工艺优化

    Institute of Scientific and Technical Information of China (English)

    任洁如; 马运芳; 王建华; 陈迹

    2015-01-01

    OBJECTIVE:To optimize freeze-drying technology of albendazole nanosuspension so as to prepare albendazole nanometer powder. METHODS:By adopting freeze-drying method,with particle size and Zeta potential as the indexes,single fac-tor test and verification were made on pre-freezing temperature and the type,ratio and mass fraction of cryoprotectants,and then the albendazole nanosuspension prepared by liquid phase precipitation method was made into albendazole nanometer powder. RE-SULTS:When the pre-freezing temperature was-20℃and the cryoprotectant was 4%glucose-mannitol(3∶7),the average parti-cle size of the prepared nanometer powder was (208.03 ± 2.13) nm,and average Zeta potential was (-15.53 ± 0.18) mV. CON-CLUSIONS:Albendazole nanometer powder with better particle size and potential can be prepared by freeze-drying technology.%目的:优化阿苯达唑纳米混悬液的冻干工艺,制备阿苯达唑纳米微粉。方法:采用冷冻干燥法,以粒径、Zeta电位为指标,对预冻温度和冻干保护剂的种类、配比及质量分散进行单因素试验考察及验证,将液相沉淀法制备的阿苯达唑纳米混悬液,制备成阿苯达唑纳米微粉。结果:预冻温度为-20℃、冻干保护剂为4%葡萄糖-甘露醇(3∶7)时,所制纳米微粉的平均粒径为(208.03±2.13)nm,平均Zeta电位为(-15.53±0.18)mV。结论:该冻干工艺可制得粒径、电位较优的阿苯达唑纳米微粉。

  3. Study on the vacuum characteristics of a freeze-drying chamber for mannitol%甘露醇冷冻干燥室内真空压力特性的研究

    Institute of Scientific and Technical Information of China (English)

    夏鹏

    2011-01-01

    The vacuum system of a freeze-drying chamber provide an environment for the freeze-drying process, so the vacuum characteristics are a vital issue in the process. Taking the mannitol freeze-drying for an example, the characteristics of the vacuum freeze-drying chamber was studied in three ways: The influence of vacuum pressure on the mass weighing of the freeze-drying materials; The effect of vacuum pressure on the temperature in the freeze-drying bottle; The influence of vacuum on the primary drying rate of the freeze-drying materials. It was concluded that in the vacuum environment, the materials weighing can be used to judge whether the first drying process is ended or not. In view of the mannitol freeze-drying process, if the vacuum chamber is maintained at lPa, high quality drying products can be ensured, and meanwhile the heat transfer process is even.%冷冻干燥室的真空系统为冷冻干燥提供了真空环境,真空压力特性对冷冻干燥过程顺利进行至关重要,本文以甘露醇溶液的冷冻干燥过程为例,从三个方面对冷冻干燥室内真空压力特性进行了研究:一、真空度对冷冻干燥物料质量称量的影响;二、真空度对冷冻干燥物料瓶内温度的影响;三、真空度对冷冻干燥物料一次干燥速率的影响.通过实验,得出结论:真空环境下,物料质量的称量值可用来判断一次干燥过程是否结束.针对甘露醇溶液的冻干工艺,将冻干室的真空压力维持在1Pa可以保证干燥物料的质量,同时该工艺过程传热均匀.

  4. Determination of volatile components in fresh, frozen, and freeze-dried Padrón-type peppers by gas chromatography-mass spectrometry using dynamic headspace sampling and microwave desorption.

    Science.gov (United States)

    Oruña-Concha, M J; López-Hernández, J; Simal-Lozano, J A; Simal-Gándara, J; González-Castro, M J; de la Cruz García, C

    1998-12-01

    "Padrón-type" peppers are a small variety of Capsicum annuum cultivated mainly in Galicia, Spain. To compare the effects of freezing and freeze-drying on the volatile components of Padrón-type peppers, preserved samples are analyzed by means of dynamic headspace sampling on an adsorbent followed by microwave desorption into a gas chromatograph equipped with a mass spectrometric detector. Sixty-five compounds are identified, including hydrocarbons, terpenes, alcohols, phenols, ethers, aldehydes, ketones, esters, pyrroles, pyrazines, and sulfurous compounds. Fresh whole, homogenized, and freeze-dried peppers have characteristic volatile-component profiles, whereas frozen peppers have a highly variable volatile-component profile.

  5. 微波真空冷冻干燥对芒果干制品品质特性的影响%Effect of Microwave Vacuum Freeze Drying on the Quality of Dried Mango

    Institute of Scientific and Technical Information of China (English)

    姜唯唯; 刘刚; 张晓喻; 范辉建; 张宏

    2012-01-01

    为获得较优的芒果干燥方法,以复水性、感官为评价指标,比较微波真空冷冻干燥、热板真空冷冻干燥和热风干燥3种不同干燥方法对芒果干制品品质的影响。结果表明:真空冷冻干燥法的产品各项指标均优于热风干燥法。微波真空冷冻干燥的产品复水性最好,25℃与100℃最大复水比分别为3.363、3.674;其次为热板真空冷冻干燥,两温度条件下与微波真空冷冻干燥产品复水比相差较小;热风干燥产品复水性最差,分别为2.140、3.028。感官指标中色泽、香气和口味3方面均为:微波真空冷冻干燥〉热板真空冷冻干燥〉热风干燥。%In order to obtain a better drying method for mango products, the effects of microwave vacuum freeze drying, hot- plate vacuum freeze drying and hot air drying on the rehydration rate and sensory quality of dried mango were comparatively analyzed. The results indicated that vacuum freeze drying could provide better indices of dried products when compared with hot-air drying. Microwave vacuum freeze dried mango exhibited the best rehydration performance with rehydration rates of 3.363 and 3.674 at 25 ~C and 100 ~C, respectively, followed by hot-plate vacuum freeze dried mango with rehydration rates comparable to those of microwave vacuum freeze dried mango at 25 ℃ and 100 ℃; the worst rehydration properties were obtained when mango was dried by hot air drying with rehydration rates of 2.140 and 3.028 at 25 ~C and 100 ~C, respectively. Similarly, microwave vaccum freeze drying resulted in the best color, aroma and taste in dried mango, followed by hot-plate vacuum freeze drying; hot air dried mango showed the worst color, aroma and taste.

  6. Investigation of radiosterilization of Benzydamine Hydrochloride by electron spin resonance spectroscopy

    Science.gov (United States)

    Çolak, Şeyda

    2016-10-01

    The use of ionizing radiation for sterilization of pharmaceuticals is an attractive and growing technology. In the present work, the spectroscopic and kinetic features of the radicals induced in gamma irradiated solid Benzydamine Hydrochloride (BH) sample is investigated in the dose range of 3-34 kGy at different temperatures using Electron Spin Resonance (ESR) spectroscopy. Gamma irradiated BH indicated eight resonance peaks centered at g=2.0029 originating from two different radical species. Decay activation energy of the radical mostly responsible from central intense resonance line was calculated to be 25.6±1.5 kJ/mol by using the signal intensity decay data derived from annealing studies performed at high temperatures. A linear function of the applied dose was found to describe best the experimental dose-response data. However, the discrimination of irradiated BH from unirradiated one was possible even 3 months after storage at normal conditions. Basing on these findings it was concluded that BH and BH containing drugs could be safely sterilized by gamma radiation and that ESR spectroscopy could be successfully used as a potential technique for monitoring their radiosterilizations.

  7. Mating competitiveness of Aedes albopictus radio-sterilized males in large enclosures exposed to natural conditions.

    Science.gov (United States)

    Bellini, R; Balestrino, F; Medici, A; Gentile, G; Veronesi, R; Carrieri, M

    2013-01-01

    Mating competitiveness trials have been conducted in large net-screened enclosures (8 by 5 by 2.8 m) built in a natural shaded environment, in the summers of 2006, 2007, 2008, and 2009 in northern Italy. Aedes albopictus (Skuse) males were radio-sterilized by applying gamma radiations at doses in the range 30-60 Gy. Gamma radiation was administered to aged pupae at the rate of 2.3 Gy/min. Reared radiated males (originally collected in Rimini, Forli, Bologna, Matera, Pinerolo) and hybrid radiated males were tested against wild fertile males (originated from eggs collected in Rimini and Cesena) and reared fertile males, in multiple comparisons for mating competitiveness with reared or wild females. The ratio was kept constant at 100-100_100 (fertile males-radiated males_virgin females). Mating competitiveness was estimated through the calculation of the hatching rate of the eggs laid in oviposition traps positioned inside enclosures. No clear effect of the strains tested (reared, wild, or hybrid) was found. Results demonstrated that reducing the radiation dose from 60 to 30 Gy increases males' competitiveness. Laboratory investigations conducted after controversial results in the 2006 preliminary trials, showed that radiation induces precociousness in adult male emergence.

  8. Fabrication of FOX-7 quasi-three-dimensional grids of one-dimensional nanostructures via a spray freeze-drying technique and size-dependence of thermal properties.

    Science.gov (United States)

    Huang, Bing; Qiao, Zhiqiang; Nie, Fude; Cao, Minhua; Su, Jing; Huang, Hui; Hu, Changwen

    2010-12-15

    1,1-Diamino-2,2-dinitroethylene (C(2)H(4)N(4)O(4), FOX-7) quasi-three-dimensional (3D) grids, a promising high-energy-density material with superior sensitivity properties, were synthesized by a spray freeze-drying technique. The FOX-7 3D grids were constructed from one-dimensional nanostructures. The sizes and structures of the FOX-7 3D grids strongly depend on the concentration of the aqueous solution of FOX-7. A possible formation mechanism of this structure was proposed in detail. Thermal analysis reveals that decrease in average particle sizes of FOX-7 grids results in a lower decomposition temperature and a much higher decomposition rate, which is in agreement with those reported about inorganic nanomaterials.

  9. Freeze-dried allograft-mediated gene or protein delivery of growth and differentiation factor 5 reduces reconstructed murine flexor tendon adhesions

    DEFF Research Database (Denmark)

    Svensson, Sys Hasslund; Dadali, Tulin; Ulrich-Vinther, Michael

    2014-01-01

    Advances in allograft processing have opened new horizons for clinical adaptation of flexor tendon allografts as delivery scaffolds for antifibrotic therapeutics. Recombinant adeno-associated-virus (rAAV) gene delivery of the growth and differentiation factor 5 (GDF-5) has been previously...... associated with antifibrotic effects in a mouse model of flexor tendoplasty. In this study, we compared the effects of loading freeze-dried allografts with different doses of GDF-5 protein or rAAV-Gdf5 on flexor tendon healing and adhesions. We first optimized the protein and viral loading parameters using...... reverse transcription polymerase chain reaction (RT-PCR), enzyme-linked immunosorbent assay (ELISA), and in vivo bioluminescent imaging. We then reconstructed flexor digitorum longus (FDL) tendons of the mouse hindlimb with allografts loaded with low and high doses of recombinant GDF-5 protein and r...

  10. Placement of implants in an ossifying fibroma defect obliterated with demineralized, freeze-dried bone allograft and Plasma-rich growth factor

    Directory of Open Access Journals (Sweden)

    Umashankar Pal

    2012-01-01

    Full Text Available There has been considerable clinical interest in combining the grafts, particularly bone allografts for support for dental implants, soft-tissue support, periodontal maintenance, and ovate pontic formation. The use of demineralized, freeze-dried bone allograft (DFDBA offers certain advantages over other graft materials and can avoid the need for a second-site surgery for autogenous donor bone. The advantages of DFDBA include handling properties, osteoinductivity, membrane tenting, and less susceptibility to migration after placement. This article will review available grafting materials and demonstrate a case of ossifying fibroma of the mandible, which was treated by curettage and hollow cavity filled with DFDBA. Six months follow-up period showed successful graft result and this grafted bone form was utilized for implant supported prosthesis.

  11. Vacuum freeze-drying process of chestnut kernel%真空冷冻干燥板栗仁加工工艺研究

    Institute of Scientific and Technical Information of China (English)

    刘鹏飞; 周家华; 常虹; 马良; 张宇昊

    2011-01-01

    With fresh chestnut as raw materials,we studied the vacuum freeze-drying chestnut kernel processing technology.Results show that the color protection liquid composition for 0.2% ascorbic acid,0.3 % citric acid,0.1% ethylenediamine tetraacetate(EDTA) and 0.1% sodium chloride.Best temperature is 40 ℃.The best vacuum freeze-drying conditions is the material quantity 4.85 kg/m2,45 ℃ with 12 hours.Processed chestnut kernel water content is about 3%,taste sweet and crisp,chestnut original color,fragrance,taste to maintain good.%以新鲜板栗为原料,研究了真空冷冻干燥板栗仁的加工工艺。结果表明:板栗仁护色液组成为0.2%抗坏血酸、0.3%柠檬酸、0.1%乙二胺四乙酸(EDTA)和0.1%氯化钠;护色温度为40℃。最佳真空冷冻干燥条件是单位面积的物料量4.85kg/m2、隔板温度45℃、冻干时间为12h,制得的冷冻干燥板栗仁含水量为3%,口感香甜松脆,板栗原有色、香、味保持良好。

  12. Novel spray freeze-drying technique using four-fluid nozzle-development of organic solvent system to expand its application to poorly water soluble drugs.

    Science.gov (United States)

    Niwa, Toshiyuki; Shimabara, Hiroko; Danjo, Kazumi

    2010-02-01

    Spray freeze-drying (SFD) technique using four-fluid nozzle (4N), which is a novel particle design technique previously developed by authors, has been further developed to expand its application in pharmaceutical industry. The organic solvent was utilized as a spray solvent to dissolve the poorly soluble drug instead of conventional aqueous solution. Acetonitrile solution of the drug and aqueous solution of the polymeric carrier were separately and simultaneously atomized through 4N, and collided each other at the tip of nozzle edge. The spray mists were immediately frozen in the liquid nitrogen to form a suspension. Then, the iced droplets were freeze-dried to prepare the composite particles of the drug and carrier according to our proprietary method developed before. The resultant composite particles with phenytoin prepared by using acetonitrile (4N-SFD-MeCN system) were deeply characterized compared to those using aqueous solution (4N-SFD-aqua system) from morphological and physicochemical perspectives. The characteristic porous structure was observed in 4N-SFD-MeCN particles as well as 4N-SFD-aqua particles. However, it was found that the size and quantity of pore in 4N-SFD-MeCN particles were smaller than those of 4N-SFD-aqua particles. As a result, the former particles had 2- to 3-times smaller specific surface area than the latter particles independent of the type of carrier loaded. The slight difference of release profiles from the particles prepared between both systems was discussed from the microscopically structural viewpoint. In addition, ciclosporin was applied to organic solvent SFD system because this drug was poorly water soluble and cannot be applied to conventional aqueous SFD system. The release profiles from SFD particles were dramatically improved compared to the bulk material, suggesting that the new SFD technique using organic solvent has potential to develop the novel solubilized formulation for poorly water-soluble active pharmaceutical

  13. Biochip-based instruments development for space exploration: influence of the antibody immobilization process on the biochip resistance to freeze-drying, temperature shifts and cosmic radiations

    Science.gov (United States)

    Coussot, G.; Moreau, T.; Faye, C.; Vigier, F.; Baqué, M.; Le Postollec, A.; Incerti, S.; Dobrijevic, M.; Vandenabeele-Trambouze, O.

    2017-04-01

    Due to the diversity of antibody (Ab)-based biochips chemistries available and the little knowledge about biochips resistance to space constraints, immobilization of Abs on the surface of the biochips dedicated to Solar System exploration is challenging. In the present paper, we have developed ten different biochip models including covalent or affinity immobilization with full-length Abs or Ab fragments. Ab immobilizations were carried out in oriented/non-oriented manner using commercial activated surfaces with N-hydroxysuccinic ester (NHS-surfaces) or homemade surfaces using three generations of dendrimers (dendrigraft of poly L-lysine (DGL) surfaces). The performances of the Ab -based surfaces were cross-compared on the following criteria: (i) analytical performances (expressed by both the surface density of immobilized Abs and the amount of antigens initially captured by the surface) and (ii) resistance of surfaces to preparation procedure (freeze-drying, storage) or spatial constraints (irradiation and temperature shifts) encountered during a space mission. The latter results have been expressed as percentage of surface binding capacity losses (or percentage of remaining active Abs). The highest amount of captured antigen was achieved with Ab surfaces having full-length Abs and DGL-surfaces that have much higher surface densities than commercial NHS-surface. After freeze-drying process, thermal shift and storage sample exposition, we found that more than 80% of surface binding sites remained active in this case. In addition, the resistance of Ab surfaces to irradiation with particles such as electron, carbon ions or protons depends not only on the chemistries (covalent/affinity linkages) and strategies (oriented/non-oriented) used to construct the biochip, but also on the type, energy and fluence of incident particles. Our results clearly indicate that full-length Ab immobilization on NHS-surfaces and DGL-surfaces should be preferred for potential use in

  14. Construction and Application of HACCP System for Freeze-dried Pleurotus eryngii%冻干杏鲍菇HACCP质量控制体系的建立与应用

    Institute of Scientific and Technical Information of China (English)

    惠俊爱; 刘念

    2012-01-01

    为确保冻干杏鲍菇产品质量稳定、可控,在科学制定冻干杏鲍菇加工工艺的基础上,通过对加工过程中各工艺环节在整个产品质量体系中的重要性和可能性危害进行分析,确定出四个关键控制点,并提出了与之相适应的预防措施.为提高冻干杏鲍菇产品的质量与食用安全性提供了重要保证,也为其它冻干食品的质量管理与控制提供了借鉴.%To ensure product quality, stability and controllability of freeze-dried Pleurotus eryngii, four critical control points were identified based on the importance and hazard analysis of freeze-drying processing technology of Pleurotus eryngii throughout the product quality system. Preventive measures for adaptation were suggested to improve the quality and safety of freeze-dried products of Pleurotus eryngii, and provide a reference for quality management and control of other freeze dried foods.

  15. Selection of protectants for freezing and freeze-drying of acetic acid bacteria%醋酸菌冷冻、冷干保护剂的选择

    Institute of Scientific and Technical Information of China (English)

    王娜; 国石磊; 张永祥; 彭利沙; 李军

    2015-01-01

    In order to increase their freezing survival rate and freeze-drying survival rate,the effect of different protectants on the survival of Acetobacter aceti and Acetobacter pasteurianus ssp.pasteurianus during different processes including freezing and freeze-drying were studied herein.The protection effects of the different protectants on freezing and freeze-drying were also estimated.The results showed that the freezing survival rate of Acetobacter aceti was as follows:trehalose(73.58%) > corn dextrin(62.26%) > skim milk powder(60.38%),which were significantly higher than that of the control group (24.53%).The freezing survival rate of Acetobacter pasteurianus ssp.pasteurianus was as follows:dextran (95.35%) > skim milk powder (89.53%) > corn dextrin (88.37%) > trehalose (52.32%),which were significantly higher than that of the control group (2.23%).The freeze-drying survival rate of Acetobacter aceti was as follows:skim milk powder(92.86%) > lactose(81.25%) > glucose(46.88%),which were significantly higher than that of the control group (22.25%).The freeze-drying survival rate of Acetobacter pasteurianus ssp.pasteurianus was as follows:skim milk powde(72.92%) > trehalose(31.25%),which were significantly higher than that of the control group (12.08%).The other protectants showed varying degrees of protection effect on the strains.Trehalose and skim milk powder were prior selection for the protections of Acetobacter.%为提高醋酸菌在冷冻及冷干过程中的存活率,考察了10种不同保护剂分别对醋化醋杆菌和巴氏醋杆菌巴士亚种存活率的影响,评价了10种不同保护剂对醋酸菌的冷冻及冷干保护作用.结果发现,醋化醋杆菌的冷冻存活率:海藻糖(73.58%)>玉米糊精(62.26%)>脱脂乳粉(60.38%),明显高于对照的24.53% (P<0.05);巴氏醋杆菌巴士亚种的冷冻存活率:葡聚糖(95.35%)>脱脂乳粉(89.53%)>玉米糊精(88.37

  16. Study on Process Optimization of Freeze-dried Pleurotus ostreatus and its Effect on Quality%平菇冻干预处理工艺优化及其对品质的影响

    Institute of Scientific and Technical Information of China (English)

    孙亚男; 赵淑芳; 李文香; 胡欣蕾; 樊铭聪

    2015-01-01

    本文以平菇为试验材料,采用真空冷冻干燥技术进行平菇冻干。单因素试验探讨了烫漂温度、烫漂时间、麦芽糊精浸渍液浓度、预冻终温对冻干平菇品质影响,在此基础上,利用正交试验进一步优化平菇冻干预处理工艺,确定了最佳预处理工艺参数为:烫漂温度80益,烫漂时间90s,麦芽糊精浸渍液浓度2.5%,预冻终温-19益。此条件下可最大程度保持平菇原有的色泽与风味,提高冻干平菇的品质。%Based on the Pleurotus ostreatus as the experimental material, made freeze-dried Pleurotus ostreatus with vacuum freeze drying technology. The single factor and orthogonal experiment were used to study the four factors(blanching temperature, blanching time, the concentration of the impregnation liquid, precool final temperature)on the quality of freeze-dried sensory score, determining the best Pleurotus ostreatus freeze-drying process: blanching temperature 80℃, blanching time 90s, impregnation liquid concentration 2.5%, the precool final temperature -19℃. The process can maintain the Pleurotus ostreatus own color flavor in the greatest extent, and improve the quality of freeze-dried Pleurotus ostreatus .

  17. 微波真空冷冻干燥蜂蛹工艺的研究%Study on microwave vacuum freeze-drying process of Honeybee Pupae

    Institute of Scientific and Technical Information of China (English)

    平丽娟; 方晟; 毛建卫; 蔡成岗; 陈文斌

    2013-01-01

    Drying process of Honeybee Pupae by microwave vacuum freeze-drying and Optical fiber/infrared temperature measurement and control system were studied.The microwave intensities were set at 0.20,0.24,0.28, 0.32W/g and the results showed that the optimal dried product were got at 0.28W/g microwave intensity and the highest set temperature of 30℃,after drying 420min,the water content of the dried Honeybee Pupae was 2.84% , the final product was uniform with the original color and good taste flavor,and the electron micrograph showed that the product had sponge porous shape section,The dried Honeybee Pupae rehydrated 1.9 times of water in 20℃ water for Is,rehydrated effect was good,the SOD activity of the dried product slightly increased firstly and then decreased with level of 36.9U/mg protein after dried 420min,and the water content of the product was of 2.84%, Microwave vacuum freeze-drying decreased the drying time for 65% and tow viable microorganisms compared with the traditional vacuum freeze-drying method,while the SOD activity was almost at the same level,%采用微波真空冷冻干燥及光纤/红外温度测试控制等技术集成进行蜂蛹冻干中试工艺研究,用0.20、0.24、0.28、0.32W/g四个微波强度进行工艺优化,获得优化工艺参数为微波强度0.28W/g、最高解析温度30℃,微波冻干时间420min,最终产品水分含量为2.84%,产品品质好,无干瘪变形,保持蜂蛹原有色泽,电镜观察显示切面呈海绵多孔状,口味鲜美,于20℃水中复水1s,复水率达1.9倍,复水效果好,解析干燥过程中蜂蛹超氧化物歧化酶(SOD)活力呈现先略有增加后有所降低的趋势,蜂蛹冻于至水分含量为2.84%时,SOD活性为36.9U/mg prot,与真空冷冻干燥对比,所需干燥时间减少65%以上,并使存活微生物菌落数显著降低,SOD酶活力相近.

  18. The influence of freeze drying and ϒ-irradiation in pre-clinical studies of flurbiprofen polymeric nanoparticles for ocular delivery using D-(+-trehalose and polyethylene glycol

    Directory of Open Access Journals (Sweden)

    Ramos Yacasi GR

    2016-08-01

    Full Text Available Gladys Rosario Ramos Yacasi, María Luisa García López, Marta Espina García, Alexander Parra Coca, Ana Cristina Calpena Campmany Department of Pharmacy and Pharmaceutical Technology and Physical Chemistry, University of Barcelona, Barcelona, Spain Abstract: This study investigated the suspension of poly(ε-caprolactone nanoparticles as an ocular delivery system for flurbiprofen (FB-PεCL-NPs in order to overcome the associated problems, such as stability, sterility, tolerance, and efficacy, with two different FB-PεCL-NP formulations. The formulations were stabilized with poloxamer 188 (1.66% and 3.5% and submitted individually for freeze-drying and γ-irradiation with polyethylene glycol 3350 (PEG3350 and d-(+-trehalose (TRE. Both formulations satisfied criteria according to all physicochemical parameters required for ocular pharmaceuticals. The FB-PεCL-NP formulations showed non-Newtonian behavior and sustained drug release. Ex vivo permeation analysis using isolated ocular pig tissues suggested that the presence of PEG3350 results in a reduction of FB transcorneal permeation. Moreover, TRE improved the penetration of FB across the cornea, especially after γ-irradiation. In addition, both formulations did not show a significant affinity in increasing FB transscleral permeation. Both formulations were classified as nonirritating, safe products for ophthalmic administration according to hen’s egg test-chorioallantoic membrane and Draize eye test. Furthermore, an in vivo anti-inflammatory efficacy test showed that irradiated FB-PεCL-NPs prepared with PEG3350 (IR-NPsPEG have longer anti-inflammatory effects than those presented with irradiated FB-PεCL-NPs prepared with TRE (IR-NPsTRE. IR-NPsPEG showed a suitable physical stability after an aqueous reconstitution over .30 days. This study concludes that both formulations meet the Goldman’s criteria and demonstrate how irradiated nanoparticles, with innovative permeation characteristics

  19. Research on energy consumption in actual production of vacuum freeze-dried garlic slice%真空冷冻干燥蒜丁实际生产的能耗研究

    Institute of Scientific and Technical Information of China (English)

    刘业凤; 周国梁; 李续

    2014-01-01

    为了研究真空冷冻干燥蒜丁实际生产的能耗组成及节能措施,该文根据实地考察食品冷冻干燥厂蒜丁的真空冷冻干燥生产过程所得的资料,研究了冻干蒜丁实际生产过程的能耗,得到实际生产时单位脱水能耗为1.19 kW·h/kg,满足行业标准JB/T 10285-2001规定的冻干设备单位脱水量能耗不高于规定值即蒸汽加热单位脱水耗电量1.22 kW·h/kg的105%的要求。分析了生产过程中产品冻结、冻干过程中制冷系统、真空系统、加热系统、控制系统4大部分的能耗组成,从适当提高制冷系统蒸发温度及提高干燥仓压力等方面提出一些建议并达到了节能的目的,为以后食品冷冻干燥生产的节能设计提供一定参考。%Vacuum Freeze Drying has a great impact upon the production of dehydrated food because of the superior quality of the product obtained. Whereas, due to the slow rate of vacuum freeze drying, the long operation cycle, the high energy consumption generated by the vacuum freeze drying machine at run time, the development of freeze drying food will be restricted. In order to find energy-efficient approaches and seek lower cost productions, investigation was made on the process of freeze-dried garlic slice production in the freeze-dried food factory. In this paper, through analyzing the basic principle and drying process of vacuum freeze-dried garlic slice, energy consumption of refrigerating system, heating system and vacuum pump system was studied. By asking technicians and production manager from the factory, the main processing technology was learned. In addition, according to the experiences and field investigation, the technical date of lyophilized system including compressor, evaporator, condenser, ammonia pump, drying chamber and industrial boiler was learned as well as the stable parameter during the actual production process. Based on the obtained datum, using the principle of refrigeration

  20. Polifenoles y Actividad Antioxidante del Fruto Liofilizado de Palma Naidi (Açai Colombiano (Euterpe oleracea Mart Polyphenols and Antioxidant Activity of the Freeze-Dried Palm Naidi (Colombian Açai (Euterpe oleracea Mart

    Directory of Open Access Journals (Sweden)

    Benjamín Alberto Rojano

    2011-12-01

    Full Text Available Euterpe oleracea es una palmera indígena autóctona de América del Sur. El fruto conocido como açaí en Brasil y palma naidi en Colombia, es de gran valor económico para los pueblos nativos. Para los análisis se usó una pulpa liofilizada, proveniente del Pacifico colombiano. Entre los muchos hallazgos, se presenta un alto porcentaje de minerales (6,94%, específicamente sodio, hierro y potasio. La palma naidi es rica en compuestos polifenólicos, tipo antocianinas (268,5 mg Cianidin-3-Glucosido/ 100 g de liofilizado donde el 95% de las antocianinas corresponden al Cianidin-3-Glucosido (255,1 mg/ 100 g de liofilizado y de otros compuestos fenólicos como los ácidos fenólicos: ferúlico (10,27 mg/100 g de liofilizado, caféico (7,06 mg/100 g de liofilizado, p-coumárico (2,81 mg/100 g de liofilizado y menor cantidad clorogénico 0,30 mg/100 g de liofilizado. Los polifenoles contribuyen a la capacidad antioxidante del naidi; medida por las técnicas ABTS, DPPH y FRAP y específicamente un valor ORAC (Hidrofílico (Oxygen Radical Absorbance Capacity de 98142,0 Micromol Tx/100 g de liofilizado; además un valor ORAC Lipofílico de 3194,1 Micromol Tx/ 100 g de liofilizado. Un valor ORAC total igual a 101336,1 Micromol Tx/ 100 g de liofilizado.Euterpe oleracea Mart is a native palm tree native of South America. The fruit known as açaí in Brazil and naidi palm in Colombia and is of great economic value to the native peoples. For the analysis was used freeze-dried pulp, from the Colombian Pacific. This fruit has a high percentage of minerals (6.94%, specifically sodium, potassium and iron. Naidi palm is rich in polyphenolic compounds, especially anthocyanins (268.5 mg cyanidin-3-glucoside per 100 g of freeze dried and phenolic acid as ferulic (10.27 mg/100 g of freeze dried , caffeic (7.06 mg/100 g of freeze dried, p-Coumaric (2.81 mg/100 g of freeze dried and fewer chlorogenic (0.30 mg/100 g of freeze dried; which provides high antioxidant

  1. Myrtus communis L. Freeze-Dried Aqueous Extract Versus Omeprazol in Gastrointestinal Reflux Disease: A Double-Blind Randomized Controlled Clinical Trial.

    Science.gov (United States)

    Zohalinezhad, Mohammad E; Hosseini-Asl, Mohammad Kazem; Akrami, Rahimeh; Nimrouzi, Majid; Salehi, Alireza; Zarshenas, Mohammad M

    2016-01-01

    The current work assessed a pharmaceutical dosage form of Myrtus communis L. (myrtle) in reflux disease compared with omeprazol via a 6-week double-blind randomized controlled clinical trial. Forty-five participants were assigned randomly to 3 groups as A (myrtle berries freeze-dried aqueous extract, 1000 mg/d), B (omeprazol capsules, 20 mg/d), and C (A and B). The assessment at the beginning and the end of the study was done by using a standardized questionnaire of frequency scale for the symptoms of gastroesophageal reflux disease (FSSG). In all groups, both reflux and dyspeptic scores significantly decreased in comparison with the respective baselines. Concerning each group, significant changes were found in FSSG, dysmotility-like symptoms and acid reflux related scores. No significant differences were observed between all groups in final FSSG total scores (FSSG2). Further studies with more precise design and larger sample size may lead to a better outcome to suggest the preparation as an alternative intervention.

  2. The use of 90% Aloe vera freeze drying as the modulator of collagen density in extraction socket of incicivus Cavia cobaya

    Directory of Open Access Journals (Sweden)

    Ester Arijani

    2008-06-01

    Full Text Available Wound healing is basically a complex process in which cellular and matrix act in concern to re-establish the integrity of injury tissues. This process can be simplified to be healing process consisted of haemostatic, inflammation, cell proliferation and tissue remodeling. The aimed of this research was to know the influence of freeze drying 90% Aloe vera application as mandible collagen density modulator in extraction socket of incisive Cavia cobaya. This research was done using Post Test Only Control Groups Design and Cavia cobaya as the sample. Six samples of each control group and 90% Aloe vera group applied to test each collagen density for three days and seven days. Then, the data was analyzed statistically using Mann Whitney with 5% significance rate. The result of the study indicates that administering 90% Aloe vera can accelerate the growth of collagen density in healing process of extraction socket. The conclusion is 90% Aloe vera can modulate the density of collageneous fiber in socket of extraction incicivus tooth wound of Cavia cobaya.

  3. Water absorption of freeze-dried meat at different water activities: a multianalytical approach using sorption isotherm, differential scanning calorimetry, and nuclear magnetic resonance.

    Science.gov (United States)

    Venturi, Luca; Rocculi, Pietro; Cavani, Claudio; Placucci, Giuseppe; Dalla Rosa, Marco; Cremonini, Mauro A

    2007-12-26

    Hydration of freeze-dried chicken breast meat was followed in the water activity range of aw=0.12-0.99 by a multianalytical approach comprising of sorption isotherm, differential scanning calorimetry (DSC), and nuclear magnetic resonance (NMR). The amount of frozen water and the shape of the T2-relaxogram were evaluated at each water content by DSC and NMR, respectively. Data revealed an agreement between sorption isotherm and DSC experiments about the onset of bulk water (aw=0.83-0.86), and NMR detected mobile water starting at aw=0.75. The origin of the short-transverse relaxation time part of the meat NMR signal was also reinvestigated through deuteration experiments and proposed to arise from protons belonging to plasticized matrix structures. It is proved both by D2O experiments and by gravimetry that the extra protons not contributing to the water content in the NMR experiments are about 6.4% of the total proton NMR CPMG signal of meat.

  4. Gastroprotective Effect of Freeze Dried Stripped Snakehead Fish (Channa striata Bloch.) Aqueous Extract against Aspirin Induced Ulcerogenesis in Pylorus Ligated Rats.

    Science.gov (United States)

    Ali Khan, Mohammed Safwan; Mat Jais, Abdul Manan; Hussain, Javeed; Siddiqua, Faiza; Gopala Reddy, A; Shivakumar, P; Madhuri, D

    2014-01-01

    Channa striata (Bloch.) is a fresh water fish belonging to the family Channidae. The stripped snakehead fish possesses wide range of medicinal properties. In view of traditional use of C. striata for wound healing, the present study was undertaken to investigate the beneficial effects of orally administered freeze dried aqueous extract of Channa striata (AECS) in experimentally induced gastric ulcers in Wistar rats. Aspirin induced ulcerogenesis in pyloric ligation model was used for the assessment of antiulcer activity and Ranitidine (50 mg/kg) was employed as the standard drug. The various gastric parameters like volume of gastric juice, pH, free and total acidities, ulcer index, and levels of antioxidant enzymes like catalase, superoxide dismutase, and lipid peroxidation marker malondialdehyde were determined. AECS at concentrations of 40% and 50% w/v significantly decreased the volume of gastric juice and increased the levels of catalase while considerable decrease in free and total acidities and increase in superoxide dismutase were observed with the treatment of standard drug and AECS (50% w/v). All the test doses of AECS markedly decreased ulcer index and malondialdehyde compared to the standard drug whereas AECS 30% w/v did not alter volume of gastric juice, pH, free and total acidities, catalase, and superoxide dismutase. From these findings, it can be concluded that AECS is devoid of acid neutralizing effects at lower doses and possesses antisecretory and antiulcer activities and this could be related to its antioxidant mechanism.

  5. Stability of α-tocopherol in freeze-dried sugar-protein-oil emulsion solids as affected by water plasticization and sugar crystallization.

    Science.gov (United States)

    Zhou, Yankun; Roos, Yrjö H

    2012-08-01

    Water plasticization of sugar-protein encapsulants may cause structural changes and decrease the stability of encapsulated compounds during storage. The retention of α-tocopherol in freeze-dried lactose-milk protein-oil, lactose-soy protein-oil, trehalose-milk protein-oil, and trehalose-soy protein-oil systems at various water activities (a(w)) and in the presence of sugar crystallization was studied. Water sorption was determined gravimetrically. Glass transition and sugar crystallization were studied using differential scanning calorimetry and the retention of α-tocopherol spectrophotometrically. The loss of α-tocopherol followed lipid oxidation, but the greatest stability was found at 0 a(w) presumably because of α-tocopherol immobilization at interfaces and consequent reduction in antioxidant activity. A considerable loss of α-tocopherol coincided with sugar crystallization. The results showed that glassy matrices may protect encapsulated α-tocopherol; however, its role as an antioxidant at increasing aw accelerated its loss. Sugar crystallization excluded the oil-containing α-tocopherol from the protecting matrices and exposed it to surroundings, which decreased the stability of α-tocopherol.

  6. Synthesis of high-performance Li2FeSiO4/C composite powder by spray-freezing/freeze-drying a solution with two carbon sources

    Science.gov (United States)

    Fujita, Yukiko; Iwase, Hiroaki; Shida, Kenji; Liao, Jinsun; Fukui, Takehisa; Matsuda, Motohide

    2017-09-01

    Li2FeSiO4 is a promising cathode active material for lithium-ion batteries due to its high theoretical capacity. Spray-freezing/freeze-drying, a practical process reported for the synthesis of various ceramic powders, is applied to the synthesis of Li2FeSiO4/C composite powders and high-performance Li2FeSiO4/C composite powders are successfully synthesized by using starting solutions containing both Indian ink and glucose as carbon sources followed by heating. The synthesized composite powders have a unique structure, composed of Li2FeSiO4 nanoparticles coated with a thin carbon layer formed by the carbonization of glucose and carbon nanoparticles from Indian ink. The carbon layer enhances the electrochemical reactivity of the Li2FeSiO4, and the carbon nanoparticles play a role in the formation of electron-conducting paths in the cathode. The composite powders deliver an initial discharge capacity of 195 and 137 mAh g-1 at 0.1 C and 1 C, respectively, without further addition of conductive additive. The discharge capacity at 1 C is 72 mAh g-1 after the 100th cycle, corresponding to approximately 75% of the capacity at the 2nd cycle.

  7. A comparison between use of spray and freeze drying techniques for preparation of solid self-microemulsifying formulation of valsartan and in vitro and in vivo evaluation.

    Science.gov (United States)

    Singh, Sanjay Kumar; Vuddanda, Parameswara Rao; Singh, Sanjay; Srivastava, Anand Kumar

    2013-01-01

    The objective of the present study was to develop self micro emulsifying formulation (SMEF) of valsartan to improve its oral bioavailability. The formulations were screened on the basis of solubility, stability, emulsification efficiency, particle size and zeta potential. The optimized liquid SMEF contains valsartan (20% w/w), Capmul MCM C8 (16% w/w), Tween 80 (42.66% w/w) and PEG 400 (21.33% w/w) as drug, oil, surfactant and co-surfactant, respectively. Further, Liquid SMEF was adsorbed on Aerosol 200 by spray and freeze drying methods in the ratio of 2 : 1 and transformed into free flowing powder. Both the optimized liquid and solid SMEF had the particle size drying methods are equally capable for producing stable solid SMEF and immediate release of drug in in vitro and in vivo conditions. However, the solid SMEF produced by spray drying method showed high flowability and compressibility. The solid state characterization employing the FTIR, DSC and XRD studies indicated insignificant interaction of drug with lipid and adsorbed excipient. The relative bioavailability of solid SMEF was approximately 1.5 to 3.0 folds higher than marketed formulation and pure drug. Thus, the developed solid SMEF illustrates an alternative delivery of valsartan as compared to existing formulations with improved bioavailability.

  8. A comparison between spray drying and spray freeze drying for dry powder inhaler formulation of drug-loaded lipid-polymer hybrid nanoparticles.

    Science.gov (United States)

    Wang, Yajie; Kho, Katherine; Cheow, Wean Sin; Hadinoto, Kunn

    2012-03-15

    Lipid-polymer hybrid nanoparticles - polymeric nanoparticles enveloped by lipid layers - have emerged as a potent therapeutic nano-carrier alternative to liposomes and polymeric nanoparticles. Herein we perform comparative studies of employing spray drying (SD) and spray freeze drying (SFD) to produce inhalable dry-powder form of drug-loaded lipid-polymer hybrid nanoparticles. Poly(lactic-co-glycolic acid), lecithin, and levofloxacin are employed as the polymer, lipid, and drug models, respectively. The hybrid nanoparticles are transformed into micro-scale nanoparticle aggregates (or nano-aggregates) via SD and SFD, where the effects of (1) different excipients (i.e. mannitol, polyvinyl alcohol (PVA), and leucine), and (2) nanoparticle to excipient ratio on nano-aggregate characteristics (e.g. size, flowability, aqueous reconstitution, aerosolization efficiency) are examined. In both methods, PVA is found more effective than mannitol for aqueous reconstitution, whereas hydrophobic leucineis needed to achieve effective aerosolization as it reduces nano-aggregate agglomeration. Using PVA, both methods are equally capable of producing nano-aggregates having size, density, flowability, yield and reconstitutibility in the range ideal for inhaled delivery. Nevertheless, nano-aggregates produced by SFD are superior to SD in terms of their aerosolization efficiency manifested in the higher emitted dose and fine particle fraction with lower mass median aerodynamic diameter.

  9. Heat Transfer Analysis of an Optimized, Flexible Holder System for Freeze-Drying in Dual Chamber Cartridges Using Different State-of-the-Art PAT Tools.

    Science.gov (United States)

    Korpus, Christoph; Pikal, Michael; Friess, Wolfgang

    2016-11-01

    The aim of this study was to determine the heat transfer characteristics of an optimized flexible holder device, using Tunable Diode Laser Absorption Spectroscopy, the Pressure Rise Test, and the gravimetric procedure. Two different controlled nucleation methods were tested, and an improved sublimation process, "preheated plate," was developed. Tunable Diode Laser Absorption Spectroscopy identified an initial sublimation burst phase. Accordingly, steady-state equations were adapted for the gravimetric procedure, to account for this initial non-steady-state period. The heat transfer coefficient, KDCC, describing the transfer from the holder to the DCC, was the only heat transfer coefficient showing a clear pressure dependence with values ranging from 3.81E-04 cal/(g·cm(2)·K) at 40 mTorr to 7.38E-04 cal/(g·cm(2)·K) at 200 mTorr. The heat transfer coefficient, Ktot, reflecting the overall energy transfer via the holder, increased by around 24% from 40 to 200 mTorr. This resulted in a pressure-independent sublimation rate of around 42 ± 1.06 mg/h over the whole pressure range. Hence, this pressure-dependent increase in energy transfer completely compensated the decrease in driving force of sublimation. The "flexible holder" shows a substantially reduced impact of atypical radiation, improved drying homogeneity, and ultimately a better transferability of the freeze-drying cycle for process optimization.

  10. Lactobacillus pentosus DSM 16366 starter added to brine as freeze-dried and as culture in the nutritive media for Spanish style green olive production

    Directory of Open Access Journals (Sweden)

    Peres, Cidália

    2008-09-01

    Full Text Available Lactobacillus pentosus DSM 16366, a strain originally isolated from olive fermentation, was used as a starter culture for "Azeiteira" the preparation of Spanish style green olives. Inoculum was added to the fermentors as a freezedried starter culture or as a culture in the nutritive media. Lactic acid fermentation induction produced a more rapid acidification of brines and reduced the survival period of Enterobacteriaceae compared with the uninoculated process. The best results were obtained using the nutritive media as a culture carrier rather than the freeze-dried starter.En este trabajo se empleo el inóculo Lactobacillus pentosus DSM 16366 liofilizado y en caldo nutritivo para preparación de aceitunas "Azeiteira" tipo verde, estilo sevillano. En las salmueras inoculadas se observó una acidificación más rápida y reducción del periodo de supervivencia de las Enterobacteriaceae, especialmente cuando se aplicó el inóculo en caldo nutritivo.

  11. Eudragit nanoparticles loaded with silybin: a detailed study of preparation, freeze-drying condition and in vitro/in vivo evaluation.

    Science.gov (United States)

    Varshosaz, Jaleh; Minaiyan, Mohsen; Khaleghi, Nifiseh

    2015-01-01

    The objective of this work was use of silybin nanoparticles in treatment of ulcerative colitis (UC). Eudragit RL PO nanoparticles loaded with silybin were produced using solvent-evaporation emulsification technique. Then, they were coated by Eudragit FS30D. Drug release was studied in different physiological environments. Colitis was induced by 4% of acetic acid in rats which received freeze-dried nanoparticles of silybin (75 mg/kg/day), dexamethasone (1 mg/kg/day), blank nanoparticles and normal saline orally for 5 days. Then macroscopic, histopathological evaluation and biochemical analysis, including myeloperoxidase (MPO) activity, tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) levels in colon tissues were determined using enzyme-linked immunosorbent assay (ELISA) kits. Macroscopic and histopathological scores were improved by the optimised nanoparticles. The optimised nanoparticles had a particle size of 109 ± 6 nm, zeta potential of 15.4 ± 2 mV, loading efficiency of 98.3 ± 12% and release efficiency of 40.8 ± 5.5% at 24 h. TNF-α, IL-6 and MPO activity were reduced significantly by nanoparticles compared to control group (p < 0.05).

  12. Efficacy of autograft and freeze-dried allograft to enhance fixation of porous coated implants in the presence of interface gaps.

    Science.gov (United States)

    Kienapfel, H; Sumner, D R; Turner, T M; Urban, R M; Galante, J O

    1992-05-01

    Autogenous cancellous bone and freeze-dried allogeneic cancellous bone were tested in a total of 41 adult male mongrel dogs. In each humerus, an implant with a commercially pure titanium fiber metal porous coating was placed in an overreamed cavity so that a uniform 3-mm gap was present between the implant and host cancellous bone. Graft material was placed in the gap of one humerus while the gap of the other humerus was left empty and served as a paired negative control. Histologically, both autograft and allograft appeared to aid repair of the defect, but quantitatively only autograft enhanced new bone formation within the defect. Treatment with autograft significantly increased the amount of bone ingrowth within the implants by nearly three-fold at 4 weeks and eight-fold at 8 weeks. The enhancing effect was recognizable as early as 2 weeks. The strength of fixation was increased by nearly seven-fold at 4 weeks and two-fold at 8 weeks in the autograft group, but this was only statistically significant at 4 weeks. Treatment with allograft did not enhance bone ingrowth at any time period, but had a small positive effect on strength of fixation at 4 weeks.

  13. 牡蛎冷冻干燥后复水特性及微观结构的研究%Rehydration characteristics and microstructure of freeze-dried oyster

    Institute of Scientific and Technical Information of China (English)

    董秀萍; 朱蓓薇; 金文刚; 吴海涛; 孙黎明; 陈雪娇

    2011-01-01

    To study the effect of drying methods on rehydration properties of the dried oyster, the fresh oysters were divided into three groups, direct freeze drying (Fresh + FD>. Freeze drying after boiling pretreatment (Boiled + FD) and natural drying group( Fresh + ND), respectively. Drying ratio, rehydration ratio, rehydration percentage and microstructural differences were investigated. The results showed that the water content of the two freeze-dried groups was far lower than the Fresh+ND oysters. And the two freeze-dried oyster groups both had a higher rehydration ratio and rehydration velocity than the Fresh+ND oyster in water bath at room temperature and 100 ℃ .suggesting that freeze drying facilitated the oysters for waterremoval and rehydration. The effect of drying method on the adduct muscle's structure was in a superior to inferior order: Fresh+FD> Boiled + FD>Fresh+ND. The adduct muscle fibre of Fresh + FD was slender, and stretched with well-distributed interfibrillar gaps, whereas the tissue of Fresh + ND group was compacted with aggregated muscle fibres. After rehydration at room temperature for 80 min, rehydration coefficient and rehydration percentage of the two freeze-dried oyster were higher than that of naturally dried oyster.%研究牡蛎冷冻干燥后的复水特性,将新鲜牡蛎分为直接冻干组(Fresh+ FD组)、预煮处理后冻干组(Boiled+ FD组)和自然干燥组(Fresh+ ND组),考察干燥后牡蛎的干燥比,复水比、复水率和微观结构的差异.结果表明:两冻干组牡蛎的含水量远低于自然干燥组,在常温和沸水中的复水比和复水速率均大于自然干燥组,冷冻干燥更有利于牡蛎中水分的去除和复水;干燥后牡蛎闭壳肌微观形态优劣程度依次为Fresh+FD组>Boiled+ FD组>Fresh+ ND组,其中Fresh+FD组闭壳肌纤维细长、舒展,间隙均匀,Fresh+ ND组闭壳肌纤维束堆叠,组织致密:常温复水80 min,两冻干组牡蛎的复重系教和复水率均高于自然干燥组.

  14. Effect of Spray Freeze Drying on Antioxidant Activity of Phycocyprotein from Nostoc sphaeroides KUting%喷雾冷冻干燥对葛仙米藻胆蛋白抗氧化特性的影响

    Institute of Scientific and Technical Information of China (English)

    程超; 朱玉婷; 田瑞; 汪兴平; 潘思轶

    2012-01-01

    研究喷雾冷冻干燥对葛仙米藻胆蛋白抗氧化特性的影响,并与冷冻干燥技术进行比较。主要测定ABTS+·、铁还原抗氧化能力(FRAP)、对羟自由基(·OH)清除作用和H2O2诱导的脂质过氧化的抑制作用,结果发现,喷雾冷冻干燥(SFD)对葛仙米藻胆蛋白的抗氧化特性有一定的影响,在基于电子转移和氢原子转移的抗氧化测定方法中,SFD与冷冻干燥(FD)制备的样品差异不明显,但在基于活性氧自由基清除的测定方法中,SFD显著优于FD。表明SFD非常适合于高活性成分的干燥。%In this study, the effect of spray freeze drying on the antioxidant activity of phycobiliprotein fromNostoc sphaeroides KUting was studied and compared with that of common freeze drying. The scavenging effect of phycobiliprotein on ABTS+· and hydroxyl radicals (·OH), H2O2-induced lipid peroxidation and ferric-ion reducing power (FRAP) were evaluated. The results indicated that spray freeze drying method had obvious effect on antioxidant activity of phycobiliprotein from Nostoc sphaeroides Kuting. The samples dried by two different methods showed no significant difference in the antioxidant activity determined based on electron transfer and hydrogen atom transfer. The free radical scavenging activity of the sample dried by spray freeze drying method was markedly higher than that of the sample dried by common freeze drying method. These data suggest that spray freeze drying is more suitable for drying active substances.

  15. A Novel Approach for Treatment of an Unusual Presentation of Radicular Cysts Using Autologous Periosteum and Platelet-Rich Fibrin in Combination with Demineralized Freeze-Dried Bone Allograft

    Directory of Open Access Journals (Sweden)

    Veena A. Patil

    2013-01-01

    Full Text Available Radicular cysts are the most common cystic lesions affecting the jaws. They are most commonly found at the apices of the involved teeth. This condition is usually asymptomatic but can result in a slow-growth tumefaction in the affected region. The following case report presents the successful treatment of radicular cysts using autologous periosteum and platelet-rich fibrin with demineralized freeze-dried bone allograft.

  16. 利福平冻干粉针治疗55例结核性脑膜炎临床分析%Rifabutin freeze-dried needle treatment 55 cases of tuberculous meningitis clinical analysis

    Institute of Scientific and Technical Information of China (English)

    刘利荣; 尹平辉; 陈欣

    2011-01-01

    Objective To evaluate the domestic injectable rifabutin freeze-dried needle (weaver hin) treatment of tuberculous meningitis clinical efficacy and safety , and rifampacin capsule comparison. Methods wil155 patients with tuberculosis patients were randomly divided into rifabutin freeze-dried needle group and rifampacin capsule group contrast, observe thc curative effect. Results rifabutin freeze-dried needle curative effect of exact and more oral rifabutin group gastrointestinal side effects less, the effect - acting faster.Conclusion rifabutin freeze-dried needle in the treatment of tuberculous meningitis with local drug concentration high effect, fast, side effect was small characteristics, has good value of clinical applications.%目的 评价国产注射用利福平冻干粉针(维夫欣)治疗结核性脑膜炎的临床有效性和安全性,并与利福平胶囊比较.方法 将55例肺结核患者随机分为利福平冻干粉针组和利福平胶囊组对照,观察疗效.结果 利福平冻干粉针组疗效确切且较口服利福平组胃肠道副作用少,起效更快.结论 利福平冻干粉针在结核性脑膜炎的治疗中具有局部药物浓度高,作用快,副作用小的特点,有较好的临床应用价值.

  17. A comparative evaluation of the effectiveness of guided tissue regeneration by using a collagen membrane with or without decalcified freeze-dried bone allograft in the treatment of infrabony defects: A clinical and radiographic study

    OpenAIRE

    Kher, Vishal Kiran; Manohar L. Bhongade; Shori, Tony D.; Kolte, Abhay P.; Dharamthok, Swarup B.; Shrirao, Tushar S.

    2013-01-01

    Background: The present, randomized, controlled clinical and radiographic study was undertaken to compare the effectiveness of guided tissue regeneration (GTR) by using a collagen membrane barrier with or without decalcified freeze-dried bone allograft (DFDBA) in the treatment of periodontal infrabony defects characterized by unfavorable architecture. Materials and Methods: Sixteen systemically healthy patients with 20 periodontal infrabony defects were selected for the study. Each patient ha...

  18. A comparative evaluation of freeze-dried bone allograft with and without bioabsorbable guided tissue regeneration membrane Healiguide® in the treatment of Grade II furcation defects: A clinical study

    OpenAIRE

    Deept Jain; Dhruvakumar Deepa

    2015-01-01

    Background: Furcation defects represent one of the most demanding therapeutic challenges for periodontal therapy. Various treatment modalities have been tried with different success rates. The present study was undertaken to evaluate the efficacy of freeze-dried bone allograft (FDBA) with and without bioabsorbable guided tissue regeneration (GTR) membrane Healiguide® in the treatment of Grade II furcation defects. Materials and Methods: Ten patients with bilateral Grade II furcation defects w...

  19. Freeze-drying of hemoglobin solutions without adjuvant and in presence of glucose, tris, and beta-alanine: a study by electron spin resonance of the oxidized compounds produced.

    Science.gov (United States)

    Chaillot, B; Labrude, P; Vigneron, C; Simatos, D

    1981-06-01

    Hemoglobin cannot be freeze-dried without the presence of protective compounds. Carbohydrates are a well-known example of such compounds, but we have shown that some amine buffer and amino acids are also very effective. The mechanism of action of all these molecules is unknown. We report here experimental data showing that the protective effect is not the result of a direct bond between iron and the protective compound added.

  20. 冷应激及包埋对乳酸菌冻干发酵剂的影响%Effect of cold shock and embedding on the freezing dried lactic acid bacteria culture

    Institute of Scientific and Technical Information of China (English)

    陈贺佳; 牟光庆

    2012-01-01

    Freezing dried lactic acid bacteria culture was prepared by strains matching ratios of Streptococcus thermophils, Lactobacillus bulgaricus, Lactobacillus acidophilus are 3:2:1. Effects of cold shock treatment with different temperatures on survival rate of freezing dried bacteria were studied. The results show that survival rate of lactic acid bacteria after freeze drying was 96.3% under cold shock of 20℃, deal with 4h. The immobilization conditions for fermentation were as follows: sodium alginate 2.25g/L, CaCl2 4.0g/L, and the survival rate of lactic acid bacteria after embedding was 95.6%.%将嗜热链球菌、保加利亚乳杆菌、嗜酸乳杆菌按3∶2∶1比例制备乳酸菌冻干发酵剂.比较不同温度冷应激处理对乳酸菌冻干存活率的影响,结果表明,20℃,处理4h时,冻干存活率为96.3%.选择发酵的固定化细胞制作条件:海藻酸钠2.25g/L、CaCl2 4.0g/L.包埋后乳酸菌冻干存活率为95.6%.

  1. Ice Crystal Sizes and Their Impact on Microwave Assisted Freeze Drying%冰晶尺寸及其对微波辅助冷冻干燥的影响

    Institute of Scientific and Technical Information of China (English)

    吴宏伟; 陶治; 高平; 陈国华

    2004-01-01

    Freeze drying of an aqueous solution would result in the non-uniform distribution of solute concentration.Because ice is almost transparent to microwave, therefore such a non-uniform distribution may affect the microwave assisted freeze drying. The direct observation of the ice crystals formed under microscope reveals that the ice crystal sizes formed from de-ionized water depend on the cooling rate with fast cooling rate giving smaller ice crystals as expected. Once there is a sufficient amount of solute mixed with the de-ionized water, for example the reactive red,the size and its distribution are not very much dependent on either cooling rate or the final temperature provided there is sufficient time of cooling and the final temperature is not too low. The size of ice crystals formed within the solution of reactive red is usually below 100μm with a freezing rate of 1℃·min-1 for a droplet of the size of less than 1 mm. A simplified simulation indicates that such a small ice crystal would not cause a significant non-uniform distribution of temperature for microwave assisted freeze drying. When the ice crystal size is larger than 5 mm, heat conduction from the solute concentrated region to the ice region may need to be considered.

  2. Identifying efficacious approaches to chemoprevention with chlorophyllin, purified chlorophylls and freeze-dried spinach in a mouse model of transplacental carcinogenesis.

    Science.gov (United States)

    Castro, David J; Löhr, Christiane V; Fischer, Kay A; Waters, Katrina M; Webb-Robertson, Bobbie-Jo M; Dashwood, Roderick H; Bailey, George S; Williams, David E

    2009-02-01

    The carcinogenic potential of dibenzo[a,l]pyrene (DBP) has been well characterized in numerous animal models. We have previously documented that a single dose of 15 mg/Kg DBP to pregnant mice late in gestation (GD 17) produces an aggressive T-cell lymphoma as well as lung and liver cancer in offspring. The current study examines the chemopreventative properties of chlorophyllin (CHL) and chlorophyll (Chl) in this transplacental carcinogenesis model. Pregnant B6129SF1 females, bred to 129S1/SvIm males, received purified diets incorporated with either 2000 p.p.m. CHL, 2000 p.p.m. Chl or 10% freeze-dried spinach beginning at gestation day 9. Lymphoma-dependent mortality was not significantly altered by maternal consumption of any of the diet and little effect on lung tumor burden in mice surviving to 10 months of age was observed. However, coadministration of CHL at 380 mg/Kg with DBP by gavage (molar ratio of 10:1, CHL:DBP) provided significant protection against DBP-initiated carcinogenesis. Offspring born to dams receiving CHL co-gavaged with DBP exhibited markedly less lymphoma-dependent mortality (P < 0.001). The degree of protection by CHL, compared with controls dosed with DBP in tricaprylin (TCP) as the vehicle, was less marked, but still significant. Coadministration of CHL (TCP as vehicle) also reduced lung tumor multiplicity in mice by approximately 50% and this was observed throughout the study (P < 0.005). This is the first demonstration that CHL can provide potent chemoprotection in a transplacental carcinogenesis model and support a mechanism involving complex-mediated reduction of carcinogen uptake.

  3. Microbial diversity of a Camembert-type cheese using freeze-dried Tibetan kefir coculture as starter culture by culture-dependent and culture-independent methods.

    Science.gov (United States)

    Mei, Jun; Guo, Qizhen; Wu, Yan; Li, Yunfei

    2014-01-01

    The biochemical changes occurring during cheese ripening are directly and indirectly dependent on the microbial associations of starter cultures. Freeze-dried Tibetan kefir coculture was used as a starter culture in the Camembert-type cheese production for the first time. Therefore, it's necessary to elucidate the stability, organization and identification of the dominant microbiota presented in the cheese. Bacteria and yeasts were subjected to culture-dependent on selective media and culture-independent polymerase chain reaction (PCR)-denaturing gradient gel electrophoresis (DGGE) analysis and sequencing of dominant bands to assess the microbial structure and dynamics through ripening. In further studies, kefir grains were observed using scanning electron microscopy (SEM) methods. A total of 147 bacteria and 129 yeasts were obtained from the cheese during ripening. Lactobacillus paracasei represents the most commonly identified lactic acid bacteria isolates, with 59 of a total of 147 isolates, followed by Lactococcus lactis (29 isolates). Meanwhile, Kazachstania servazzii (51 isolates) represented the mainly identified yeast isolate, followed by Saccharomyces cerevisiae (40 isolates). However, some lactic acid bacteria detected by sequence analysis of DGGE bands were not recovered by plating. The yeast S. cerevisiae and K. servazzii are described for the first time with kefir starter culture. SEM showed that the microbiota were dominated by a variety of lactobacilli (long and curved) cells growing in close association with a few yeasts in the inner portion of the grain and the short lactobacilli were observed along with yeast cells on the exterior portion. Results indicated that conventional culture method and PCR-DGGE should be combined to describe in maximal detail the microbiological composition in the cheese during ripening. The data could help in the selection of appropriate commercial starters for Camembert-type cheese.

  4. An Eco-Safety Assessment of Glyoxal-Containing Cellulose Ether on Freeze-Dried Microbial Strain, Cyanobacteria, Daphnia, and Zebrafish

    Science.gov (United States)

    Park, Chang-Beom; Song, Min Ju; Choi, Nak Woon; Kim, Sunghoon; Jeon, Hyun Pyo; Kim, Sanghun; Kim, Youngjun

    2017-01-01

    The objective of this study was to investigate the aquatic-toxic effects of glyoxal-containing cellulose ether with four different glyoxal concentrations (0%, 1.4%, 2.3%, and 6.3%) in response to global chemical regulations, e.g., European Union Classification, Labeling and Packaging (EU CLP). Toxicity tests of glyoxal-containing cellulose ether on 11 different microbial strains, Microcystis aeruginosa, Daphnia magna, and zebrafish embryos were designed as an initial stage of toxicity screening and performed in accordance with standardized toxicity test guidelines. Glyoxal-containing cellulose ether showed no significant toxic effects in the toxicity tests of the 11 freeze-dried microbial strains, Daphnia magna, and zebrafish embryos. Alternatively, 6.3% glyoxal-containing cellulose ether led to a more than 60% reduction in Microcystis aeruginosa growth after 7 days of exposure. Approximately 10% of the developmental abnormalities (e.g., bent spine) in zebrafish embryos were also observed in the group exposed to 6.3% glyoxal-containing cellulose ether after 6 days of exposure. These results show that 6.3% less glyoxal-containing cellulose ether has no acute toxic effects on aquatic organisms. However, 6.3% less glyoxal-containing cellulose ether may affect the health of aquatic organisms with long-term exposure. In order to better evaluate the eco-safety of cellulosic products containing glyoxal, further studies regarding the toxic effects of glyoxal-containing cellulose ether with long-term exposure are required. The results from this study allow us to evaluate the aquatic-toxic effects of glyoxal-containing cellulosic products, under EU chemical regulations, on the health of aquatic organisms. PMID:28335565

  5. A comparision of two types of decalcified freeze-dried bone allograft in treatment of dehiscence defects around implants in dogs

    Directory of Open Access Journals (Sweden)

    Ahmad Moghareh Abed

    2011-01-01

    Full Text Available Background: Decalcified freeze-dried bone allograft (DFDBA may have the potential to enhance bone formation around dental implants. Our aim in this study was the evaluation and comparison of two types of DFDBA in treatment of dehiscence defects around Euroteknika® implants in dogs. Methods : In this prospective clinical trial animal study, all mandibular premolars of three Iranian dogs were extracted. After 3 months of healing, fifteen SLA type Euroteknika® dental implants (Natea with 4.1mm diameter and 10mm length were placed in osteotomy sites with dehiscence defects of 5mm length, 4 mm width, and 3mm depth. Guided bone regeneration (GBR procedures were performed using Cenobone and collagen membrane for six implants, the other six implants received Dembone and collagen membrane and the final three implants received only collagen membrane. All implants were submerged. After 4 months of healing, implants were uncovered and stability (Implant Stability Quotient of all implants was measured. Then, block biopsies of each implant site were taken and processed for ground sectioning and histomorphometric analysis. The data was analyzed by ANOVA and Pearson tests. P value less than 0.05 was considered to be significant. Results: All implants osseointegrated after 4 months. The mean values of bone to implant contact for histomorphometric measurements of Cenobone, Denobone, and control groups were 77.36 ± 9.96%, 78.91 ± 11.9% and 71.56 ± 5.61% respectively, with no significant differences among the various treatment groups. The correlation of Implant Stability Quotient and histomorphometric techniques was 0.692. Conclusion: In treating of dehiscence defects with GBR technique in this study, adding DFDBA did not significantly enhance the percentages of bone-to-implant contact measurements; and Implant Stability Quotient Resonance Frequency Analysis appeared to be a precise technique.

  6. Evaluation of bioactive glass and demineralized freeze dried bone allograft in the treatment of periodontal intraosseous defects: A comparative clinico-radiographic study

    Directory of Open Access Journals (Sweden)

    Kishore Kumar Katuri

    2013-01-01

    Full Text Available Aim: The purpose of this study was to evaluate the efficacy of demineralized freeze dried bone allograft (DFDBA and bioactive glass by clinically and radiographically in periodontal intrabony defects for a period of 12 months. Materials and Methods: Ten systemically healthy patients diagnosed with chronic periodontitis, with radiographic evidence of at least a pair of contralateral vertical osseous defects were included in this study. Defect on one-side is treated with DFDBA and the other side with bioactive glass. Clinical and radiographic measurements were made at baseline 6 month and 12 month after the surgery. Results: Compared to baseline, the 12 month results indicated that both treatment modalities resulted in significant changes in all clinical parameters (gingival index, probing depth, clinical attachment level (CAL and radiographic parameters (bone fill; P < 0.001FNx01. However, sites treated with DFDBA exhibited statistically significantly more changes compared to the bioactive glass in probing depth reduction (2.5 ± 0.1 mm vs. 1.8 ± 0.1 mm CAL gain 2.4 ± 0.1 mm versus 1.7 ± 0.2 mm; ( P < 0.001FNx01. At 12 months, sites treated with bioactive glass exhibited 56.99% bone fill and 64.76% bone fill for DFDBA sites, which is statistically significant ( P < 0.05FNx01. Conclusion: After 12 months, there was a significant difference between the two materials with sites grafted with DFDBA showing better reduction in probing pocket depth, gain in CAL and a greater percentage of bone fill when compared to that of bioactive glass.

  7. Influence of freeze-drying and γ-irradiation in preclinical studies of flurbiprofen polymeric nanoparticles for ocular delivery using d-(+)-trehalose and polyethylene glycol.

    Science.gov (United States)

    Ramos Yacasi, Gladys Rosario; García López, María Luisa; Espina García, Marta; Parra Coca, Alexander; Calpena Campmany, Ana Cristina

    This study investigated the suspension of poly(ε-caprolactone) nanoparticles as an ocular delivery system for flurbiprofen (FB-PεCL-NPs) in order to overcome the associated problems, such as stability, sterility, tolerance, and efficacy, with two different FB-PεCL-NP formulations. The formulations were stabilized with poloxamer 188 (1.66% and 3.5%) and submitted individually for freeze-drying and γ-irradiation with polyethylene glycol 3350 (PEG3350) and d-(+)-trehalose (TRE). Both formulations satisfied criteria according to all physicochemical parameters required for ocular pharmaceuticals. The FB-PεCL-NP formulations showed non-Newtonian behavior and sustained drug release. Ex vivo permeation analysis using isolated ocular pig tissues suggested that the presence of PEG3350 results in a reduction of FB transcorneal permeation. Moreover, TRE improved the penetration of FB across the cornea, especially after γ-irradiation. In addition, both formulations did not show a significant affinity in increasing FB transscleral permeation. Both formulations were classified as nonirritating, safe products for ophthalmic administration according to hen's egg test-chorioallantoic membrane and Draize eye test. Furthermore, an in vivo anti-inflammatory efficacy test showed that irradiated FB-PεCL-NPs prepared with PEG3350 (IR-NPsPEG) have longer anti-inflammatory effects than those presented with irradiated FB-PεCL-NPs prepared with TRE (IR-NPsTRE). IR-NPsPEG showed a suitable physical stability after an aqueous reconstitution over >30 days. This study concludes that both formulations meet the Goldman's criteria and demonstrate how irradiated nanoparticles, with innovative permeation characteristics, could be used as a feasible alternative to a flurbiprofen solution for ocular application in clinical trials.

  8. Effect of mangosteen peel extract combined with demineralized freezed-dried bovine bone xenograft on osteoblast and osteoclast formation in post tooth extraction socket

    Directory of Open Access Journals (Sweden)

    Utari Kresnoadi

    2016-12-01

    Full Text Available Background: Tooth extraction, a common procedure in dentistry, can cause bone resorption during socket healing. Therefore, it is important to perform socket preservation procedure to maintain alveolar bone. Providing a combination of mangosteen peel extract with demineralized freezed-dried bovine bone xenograft (DFDBBX in tooth extraction socket was expected to accelerate alveol bone formation. Purpose: This study aims to determine the effect of mangosteen peel extract combined with DFDBBX introduced into the socket of post tooth extraction on the formation of osteoblasts and osteoclasts. Method: Twenty-eight (28 Cavia cobayas were divided into four groups. Extraction to the lower left incisor of Cavia cobaya was performed. The extraction socket was filled with 25 gram of PEG (group I as a control, active materials consisted of mangosteen peel extract and DFDBBX 0.5% (group II, active materials consisted of mangosteen peel extract and DFDBBX 1% (group III, and active materials consisted of mangosteen peel extract and DFDBBX 2% (group IV. After thirty days, those Cavia cobayas were sacrificed. By using HE on Histopatological examination, the number of osteoblasts and osteoclasts were measured by light microscope with 400 times of magnification. The statistical analysis was then performed using oneway Anova & TukeyHSD test. Result: The component active materials consisted of mangosteen peel extract and DFDBBX 2% had the most significant results related to the formation of osteoblasts and osteoclasts. Conclusion: Mangosteen peel extract combined with DFDBBX can increase osteoblasts and decrease osteoclasts in the socket of tooth extraction in Cavia cobaya. The combination of mangosteen peel extract and DFDBBX 2% is the most effective material in increasing osteoblast and decreasing osteoclast.

  9. Identifying Efficacious Approaches to Chemoprevention with chlorophyllin, purified chlorophylls and freeze-dried spinach in a Mouse Model of Transplacental Carcinogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Castro, David J.; Lohr, Christiane V.; Fischer, Kay A.; Waters, Katrina M.; Webb-Robertson, Bobbie-Jo M.; Dashwood, Roderick H.; Bailey, George S.; Williams, David E.

    2009-02-01

    The carcinogenic potential of dibenzo[a,l]pyrene (DBP) has been well characterized in numerous animal models. We have previously documented that a single dose of 15 mg/Kg DBP to pregnant mice late in gestation (GD 17) produces an aggressive T-cell lymphoma as well as lung and liver cancer in offspring. The current study examines the chemopreventative properties of chlorophyllin (CHL) and chlorophyll (Chl) in this transplacental carcinogenesis model. Pregnant B6129SF1 females, bred to 129S1/SvIm males, received purified diets incorporated with either 2000 ppm CHL, 2000 ppm Chl, or 10% freeze-dried spinach beginning at gestation day 9. Lymphoma-dependent mortality was not significantly altered by maternal consumption of any of the diet and little effect on lung tumor burden in mice surviving to 10 months of age was observed. However, co-administration of CHL at 380 mg/Kg with DBP by gavage (molar ratio of 10:1, CHL:DBP) provided significant protection against DBP initiated carcinogenesis. Offspring born to dams receiving CHL co-gavaged with DBP exhibited markedly fewer lymphoma-dependent mortalities (p< 0.001). The degree of protection by CHL, compared to controls dosed with DBP in tricaprylin (TCP) as the vehicle, were less marked, but still significant. Co-administration of CHL (TCP as vehicle) also reduced lung tumor multiplicity in mice by approximately 50% and this was observed throughout the study (p< 0.005). This is the first demonstration that CHL can provide potent chemoprotection in a transplacental carcinogenesis model and supports a mechanism involving complex-mediated reduction of carcinogen uptake.

  10. Influence of freeze-drying and γ-irradiation in preclinical studies of flurbiprofen polymeric nanoparticles for ocular delivery using d-(+)-trehalose and polyethylene glycol

    Science.gov (United States)

    Ramos Yacasi, Gladys Rosario; García López, María Luisa; Espina García, Marta; Parra Coca, Alexander; Calpena Campmany, Ana Cristina

    2016-01-01

    This study investigated the suspension of poly(ε-caprolactone) nanoparticles as an ocular delivery system for flurbiprofen (FB-PεCL-NPs) in order to overcome the associated problems, such as stability, sterility, tolerance, and efficacy, with two different FB-PεCL-NP formulations. The formulations were stabilized with poloxamer 188 (1.66% and 3.5%) and submitted individually for freeze-drying and γ-irradiation with polyethylene glycol 3350 (PEG3350) and d-(+)-trehalose (TRE). Both formulations satisfied criteria according to all physicochemical parameters required for ocular pharmaceuticals. The FB-PεCL-NP formulations showed non-Newtonian behavior and sustained drug release. Ex vivo permeation analysis using isolated ocular pig tissues suggested that the presence of PEG3350 results in a reduction of FB transcorneal permeation. Moreover, TRE improved the penetration of FB across the cornea, especially after γ-irradiation. In addition, both formulations did not show a significant affinity in increasing FB transscleral permeation. Both formulations were classified as nonirritating, safe products for ophthalmic administration according to hen’s egg test-chorioallantoic membrane and Draize eye test. Furthermore, an in vivo anti-inflammatory efficacy test showed that irradiated FB-PεCL-NPs prepared with PEG3350 (IR-NPsPEG) have longer anti-inflammatory effects than those presented with irradiated FB-PεCL-NPs prepared with TRE (IR-NPsTRE). IR-NPsPEG showed a suitable physical stability after an aqueous reconstitution over >30 days. This study concludes that both formulations meet the Goldman’s criteria and demonstrate how irradiated nanoparticles, with innovative permeation characteristics, could be used as a feasible alternative to a flurbiprofen solution for ocular application in clinical trials. PMID:27601897

  11. Microbial diversity of a Camembert-type cheese using freeze-dried Tibetan kefir coculture as starter culture by culture-dependent and culture-independent methods.

    Directory of Open Access Journals (Sweden)

    Jun Mei

    Full Text Available The biochemical changes occurring during cheese ripening are directly and indirectly dependent on the microbial associations of starter cultures. Freeze-dried Tibetan kefir coculture was used as a starter culture in the Camembert-type cheese production for the first time. Therefore, it's necessary to elucidate the stability, organization and identification of the dominant microbiota presented in the cheese. Bacteria and yeasts were subjected to culture-dependent on selective media and culture-independent polymerase chain reaction (PCR-denaturing gradient gel electrophoresis (DGGE analysis and sequencing of dominant bands to assess the microbial structure and dynamics through ripening. In further studies, kefir grains were observed using scanning electron microscopy (SEM methods. A total of 147 bacteria and 129 yeasts were obtained from the cheese during ripening. Lactobacillus paracasei represents the most commonly identified lactic acid bacteria isolates, with 59 of a total of 147 isolates, followed by Lactococcus lactis (29 isolates. Meanwhile, Kazachstania servazzii (51 isolates represented the mainly identified yeast isolate, followed by Saccharomyces cerevisiae (40 isolates. However, some lactic acid bacteria detected by sequence analysis of DGGE bands were not recovered by plating. The yeast S. cerevisiae and K. servazzii are described for the first time with kefir starter culture. SEM showed that the microbiota were dominated by a variety of lactobacilli (long and curved cells growing in close association with a few yeasts in the inner portion of the grain and the short lactobacilli were observed along with yeast cells on the exterior portion. Results indicated that conventional culture method and PCR-DGGE should be combined to describe in maximal detail the microbiological composition in the cheese during ripening. The data could help in the selection of appropriate commercial starters for Camembert-type cheese.

  12. Comparison on mechanical properties of single layered and bilayered chitosan-gelatin coated porous hydroxyapatite scaffold prepared through freeze drying method

    Science.gov (United States)

    Effendi, M. D.; Gustiono, D.; Lukmana; Ayu, D.; Kurniawati, F.

    2017-02-01

    Biopolymer coated porous hydroxyapatite (HA) scaffolds were prepared for tissue engineering trough freeze drying method and impregnation. in this study, to mimic the mineral and organic component of natural bone, synthetic hydroxapatite (HA) scaffolds coated by polymer were prepared. Highly porous Hap scaffolds, fabricated by synthetic HA impregnation method on polyurethane foam, were coated with polymer coating solution, consisting of chitosan, Gelatin, and bilayered chitosan-gelatin prepared by aging and impregnating technique. For the purpose of comparison, The bare scaffolds without polymer coating layer were investigated. The Bare scaffolds were highly porous and interconnected with a pore size of around 150 µm–714 µm, has porosity at around 67,7% -85,7%, and has mechanical strength at around 0.06 Mpa - 0.071 Mpa, which is suitable for osteoblast cell Proliferation. Chitosan coated porous HA scaffold and gelatin coated porous HA scaffold had mechanical strength at around 0.81-0.85 Mpa, and 1.32-1.34 Mpa, respectively, with weight ratio of biopolymer and Hap was around 18%-22%. To compare these results, the coating on the bare scaffold with gelatin and chitosan had been conducted. Based on the result of FTIR, it could be concluded that coating procedure applied on porous hydroxy apatite (HA) coated by gelatin, chitosan coated HA scaffold, and bilayered Gelatin-chitosan coated porous HA scaffold, confirming that for allsampleshad no significant chemical effect on the coating structure. The compressive strength of bilayered Gelatin-chitosan coated HA scaffold had middle values between the rest, at around 1,06-1.2 Mpa for the samples at the same weight ratio of biopolymer: HA (around 18% - 22%). These results also confirming that coating by gelatin on porous hydroxyapatite was highest compresive strength and can be applied to improve mechanical properties of porous hydroxyapatite bare scaffold

  13. Microbial Diversity of a Camembert-Type Cheese Using Freeze-Dried Tibetan Kefir Coculture as Starter Culture by Culture-Dependent and Culture-Independent Methods

    Science.gov (United States)

    Mei, Jun; Guo, Qizhen; Wu, Yan; Li, Yunfei

    2014-01-01

    The biochemical changes occurring during cheese ripening are directly and indirectly dependent on the microbial associations of starter cultures. Freeze-dried Tibetan kefir coculture was used as a starter culture in the Camembert-type cheese production for the first time. Therefore, it's necessary to elucidate the stability, organization and identification of the dominant microbiota presented in the cheese. Bacteria and yeasts were subjected to culture-dependent on selective media and culture-independent polymerase chain reaction (PCR)-denaturing gradient gel electrophoresis (DGGE) analysis and sequencing of dominant bands to assess the microbial structure and dynamics through ripening. In further studies, kefir grains were observed using scanning electron microscopy (SEM) methods. A total of 147 bacteria and 129 yeasts were obtained from the cheese during ripening. Lactobacillus paracasei represents the most commonly identified lactic acid bacteria isolates, with 59 of a total of 147 isolates, followed by Lactococcus lactis (29 isolates). Meanwhile, Kazachstania servazzii (51 isolates) represented the mainly identified yeast isolate, followed by Saccharomyces cerevisiae (40 isolates). However, some lactic acid bacteria detected by sequence analysis of DGGE bands were not recovered by plating. The yeast S. cerevisiae and K. servazzii are described for the first time with kefir starter culture. SEM showed that the microbiota were dominated by a variety of lactobacilli (long and curved) cells growing in close association with a few yeasts in the inner portion of the grain and the short lactobacilli were observed along with yeast cells on the exterior portion. Results indicated that conventional culture method and PCR-DGGE should be combined to describe in maximal detail the microbiological composition in the cheese during ripening. The data could help in the selection of appropriate commercial starters for Camembert-type cheese. PMID:25360757

  14. Clinical and biometrical evaluation of socket preservation using demineralized freeze-dried bone allograft with and without the palatal connective tissue as a biologic membrane.

    Science.gov (United States)

    Moghaddas, Hamid; Amjadi, Mohammad Reza; Naghsh, Narges

    2012-11-01

    Alveolar ridge preservation following tooth extraction has the ability to maintain the ridge dimensions and allow the implant placement in an ideal position fulfilling both functional and aesthetic results. The aim of this study was to evaluate the efficacy of the palatal connective tissue as a biological membrane for socket preservation with demineralized freeze-dried bone allograft (DFDBA). Twelve extraction sites were treated with DFDBA with (case group) and without (control group) using autogenous palatal connective tissue membrane before placement of implants. Alveolar width and height, amount of keratinized tissue, and gingival level were measured at pre-determined points using a surgical stent at two times, the time of socket preservation surgery. In both groups a decrease in all socket dimensions was found. The average decrease in socket width, height, keratinized tissue, and gingival level in case group was 1.16, 0.72, 3.58, and 1.27 mm, and in control group was 2.08, 0.86, 4.52, and 1.58 mm respectively. Statistical analysis showed that decrease in socket width (P = 0.012), keratinized tissue (P ≤ 0.001), and gingival level (P = 0.031) in case group was significantly lower than that of the control group. Results showed no meaningful difference in socket height changes when compared with case and control groups (P = 0.148). Under the limits of this study, connective tissue membrane could preserve socket width, amount of keratinized tissue, and the gingival level more effectively than DFDBA alone.

  15. Formulation and evaluation of freeze-dried DOTMP kit for the preparation of clinical-scale {sup 177}Lu-DOTMP and {sup 153}Sm-DOTMP at the hospital radiopharmacy

    Energy Technology Data Exchange (ETDEWEB)

    Das, Tapas; Banerjee, Sharmila [Bhabha Atomic Research Centre, Radiopharmaceuticals Chemistry Section, Mumbai (India); Chakraborty, Sudipta [Bhabha Atomic Research Centre, Isotope Production and Applications Div., Mumbai (India); Sarma, Haladhar D. [Bhabha Atomic Research Centre, Radiation Biology and Health Sciences Div., Mumbai (India)

    2015-07-01

    The objective of the present work is to develop and evaluate freeze-dried DOTMP kit, which could be utilized for the convenient and single-step preparation of clinical-scale {sup 177}Lu-DOTMP and {sup 153}Sm-DOTMP, both of which have shown potential as alternative agents for metastatic bone pain palliation. Freeze-dried DOTMP kits, each comprising a lyophilized mixture of 20 mg DOTMP and 8.75 mg NaOH, were prepared. The kits were used for the preparation of clinical-scale {sup 177}Lu-DOTMP and {sup 153}Sm-DOTMP complexes. The agents were prepared by dissolving the lyophilized powder in 1 mL of normal saline and incubating with {sup 177}LuCl{sub 3} or {sup 153}SmCl{sub 3}, produced in-house, for 15 min at room temperature. Pharmacokinetic behavior and biological distribution of the agents were studied by carrying out biodistribution as well as scintigraphic studies in normal male Wistar rats. Shelf-life of the freeze-dried kits was also ascertained. Clinical-scale {sup 177}Lu-DOTMP and {sup 153}Sm-DOTMP complexes, comprising up to 3.7 GBq (100 mCi) of activity, were prepared with > 99% radiochemical purity using the freeze-dried kits. The complexes exhibited high in vitro stability when stored at room temperature. Biological studies showed selective skeletal accumulation and insignificant uptake of the radiotracers in any of the vital organs/tissue. The non-accumulated activity exhibited primary urinary clearance. The kits had a shelf-life of 2 years when stored at 4 C temperature. Freeze-dried DOTMP kits, suitable for the preparation of clinical-scale {sup 177}Lu-DOTMP and {sup 153}Sm-DOTMP, have been developed and the radiochemical and biological behaviors of the radiolabeled agents have been studied. The use of the kit at the hospital radiopharmacy is expected to make the preparations easy and convenient. This in turn will enable the widespread dissemination of these promising agents towards their application for regular use.

  16. 微波与真空冷冻组合干燥加工佛手的工艺研究%Research on Processing Bergamot by Microwave Combined with Vacuum Freeze-Drying

    Institute of Scientific and Technical Information of China (English)

    章斌; 侯小桢; 饶强; 王泽彬

    2011-01-01

    [目的]探讨微波-真空冷冻组合干燥方式对佛手片加工的影响.[方法]以真空冷冻干燥总时间和成品复水率为主要指标,采用微波-真空冷冻组合干燥方式加工佛手片,并采用L9(33)正交试验优化工艺参数;同时,以成品Vc含量和精油含量为指标,对比不同干燥方法对佛手片品质的影响.[结果]相比单一的真空冷冻干燥,微波-真空冷冻组合干燥方法可明显缩短冻干总时间和提高成品复水率,该组合干燥的最优工艺参数为微波功率560 W,微波干燥时间2.5 min,物料厚度7mm,此条件下的冻干总时间为9.8h.[结论]微波-真空冷冻组合干燥相比微波干燥和真空冷冻干燥更能保证产品品质.%[Objective] To explore the effects of combined drying methods on processing of bergamot slices. [ Method ] Taking vacuum freeze-dr-ying time and rehydration rate as main indexes, processing bergamot slices by drying method of microwave combined with vacuum freeze-drying and optimum of parameters through L9(33) orthogonal experiments was studied; meanwhile, taking Vc content and essential oil content of bergamot product as indexes, the effect of quality by different drying methods was explored in this paper. [ Results ] Compared with vacuum freeze-drying, combined drying method can shorten freeze-drying time and improve rehydration rate significantly, under conditions of microwave 560 W, microwave processing time 2.5 min and material thickness 7 mm, the whole freeze-drying time is 9.8 h. [Conclusion] Combined drying method can improve products qualities better than microwave drying and vacuum freeze-drying.

  17. Bioequivalence study on the effect of freeze -dry powder of Si -Ni -San on sleep time%四逆散冻干粉及其拆方镇静催眠作用的等效性研究

    Institute of Scientific and Technical Information of China (English)

    李越峰; 李廷利; 严兴科

    2014-01-01

    目的:研究四逆散冻干粉及其拆方对睡眠影响的等效性研究。方法用四逆散冻干粉与其拆方对阈剂量戊巴比妥钠致小鼠睡眠时间影响,研究其对睡眠的影响。结果四逆散冻干粉与其拆方可明显延长戊巴比妥钠所致小鼠睡眠时间,与空白组比较,差异有统计学意义( P<0.01)。四逆散整方组明显优于其拆方组( P>0.01)。结论四逆散冻干粉与其拆方在延长阈剂量戊巴比妥钠所致小鼠睡眠时间上确实有效,且实验重现性较好。%Objective To study on the effects of freeze -dry powder of Si-Ni-San and its recipes on sleep time.Methods Freeze-dry pow-der of Si-Ni-San and its recipes were adopted to prolong the sleep time of mice induced by pentobarbital sodium , and then its effects on sleeping were investigated.Results Freeze-dry powder of Si -Ni -San and its recipes significantly prolonged the sleep time of mice induced by pentobarbi-tal sodium, and there was statistical difference when compared with blank group (P<0.01).The efficacy of freeze-dry powder of Si-Ni-San was better than its recipes.Conclusion Freeze-dry powder of Si -Ni -San and its recipes are effective to prolong the sleep time of mice induced by pentobarbital sodium , and the trial is reliable with good reproducibility.

  18. PENGGUNAAN BERBAGAI JENIS BAHAN PELINDUNG UNTUK MEMPERTAHANKAN VIABILITAS BAKTERI ASAM LAKTAT YANG DI ISOLASI DARI AIR SUSU IBU PADA PROSES PENGERINGAN BEKU [Utilization of various cryogenic agents during freeze drying to Maintain the viability of Lactic Acid Bacteria Isolated from breast milk

    Directory of Open Access Journals (Sweden)

    Ni Nyoman Puspawati1*

    2010-06-01

    Full Text Available Lactic acid bacteria are the most important bacteria having potential as probiotic. The objectives of the present study were to examine the growth of Lactic Acid Bacteria, identify the Lactic Acid Bacteria capable of surviving and evaluate the best cryogenic agents that protect the viability of Lactic Acid Bacteria during freeze drying. Four cryogenic agents, i.e. sucrose, lactose, skim milk and maltodextrin, were used in freeze drying of three species of Lactic Acid Bacteria, i.e. Pediococcus pentosaceus A16, Lactobacillus brevis A17 and Lactobacillus rhamnosus R21 isolated from breast milk. Evaluation included viability before and after freeze drying, survival of freeze dried culture in 0.5 % bile salt and low pH for 5 hours. The result showed that three of cryogenics, i.e. sucrose, lactose and skim milk improved the viability of freeze dried of all lactobacilli, except maltodextrin that did not give protection to L. rhamnosus R21. Evaluation on the survival of LAB in 0.5 % bile salt showed that cryogenic agents improved the survival rate of all Lactic Acid Bacteria during freeze drying. The cryogenic also improved the survival rate of LAB at low pH, with the best protection given by skim milk on L. rhamnosus R21.

  19. Comparative evaluation of platelet-rich fibrin with demineralized freeze-dried bone allograft in periodontal infrabony defects: A randomized controlled clinical study

    Directory of Open Access Journals (Sweden)

    Monali Shah

    2015-01-01

    Full Text Available Introduction: Several bone graft materials have been used in the treatment of infrabony defects. Demineralized freeze-dried bone allograft (DFDBA has been histologically proven to be the material of choice for regeneration. However, platelet-rich fibrin (PRF has been said to have several properties that aid in healing and regeneration. Hence, this study focuses on the regenerative capacity of PRF when compared with DFDBA. Materials and Methods: A total of 40 sites with intrabony defects were selected and were assigned to the test group (open flap debridement [OFD] and PRF, n = 20 and the control group (OFD + DFDBA, n = 20. At the test sites, two PRF plugs were placed in the intrabony defect after debridement of the site and flap was sutured in place. The parameters measured were probing depth (PD, relative attachment level (RAL, and gingival marginal level (GML. These parameters were measured just before surgery (baseline and at 6 months postsurgery. The changes in PD, RAL, and GML were analyzed at baseline and postsurgically after 6 months in each group with paired t-test and between the two groups with unpaired t-test. Results: The mean reduction in PD after 6 months in the test PRF group is 3.67 ± 1.48 mm where in control DFDBA group is 3.70 ± 1.78 mm. Gain in RAL in the test PRF group is 2.97 ± 1.42 mm where in control DFDBA group, it is 2.97 ± 1.54 mm. Gingival margin migrated apically in the test PRF group by 0.43 ± 1.31 mm where in control DFDBA group by 0.72 ± 2.3 mm. It was seen that the differences in terms of PD (P = 0.96, RAL (P = 1.00 and GML (P = 0.62 were not significant. Conclusion: Platelet-rich fibrin has shown significant results after 6 months, which is comparable to DFDBA for periodontal regeneration in terms of clinical parameters. Hence, it can be used in the treatment of intrabony defects.

  20. 喷雾冷冻干燥对颗粒产品形态的影响%Morphology of particle produced by spray-freeze drying

    Institute of Scientific and Technical Information of China (English)

    徐庆; 耿县如; 李占勇

    2013-01-01

    喷雾冷冻干燥作为一种新型颗粒制备技术,产品具有尺寸可控、多孔、速溶、流动性好等优点.鉴于该技术在医药、食品、化工等行业生产独特产品的优势,本文综述了国内外喷雾冷冻干燥过程中有关颗粒形成及其形态变化的影响因素,具体介绍了其冻结过程对蛋白质颗粒形态、脂质体颗粒稳定性、疫苗颗粒、无机材料形态等产品的影响.同时还指出了喷雾冷冻干燥技术存在过程不连续、规模化程度不高、低温液体处理不便等问题需要解决,表明合理优化喷雾冷冻干燥工艺及强化干燥过程将是该技术未来研究的重点.%Spray Freeze Drying (SFD) is a novel engineering technology for production of size-controlled, porous, instant-solubility, good-flowability powders. SFD has advantages in the production of specific particles especially in pharmaceutical, food, and chemical industries, the recent developments in SFD have been reviewed in this paper. Particle formation and morphology characteristics resulting from the steps of SFD process were discussed. The effects of freezing on the products of protein, liposome, vaccine particles, inorganic materials were also included in the discussion. SFD disadvantages, such as discontinuity, time-consuming and inconvenient handing of cryogenic liquids, were mentioned. Finally, optimization of the SFD process and drying intensification were pointed out as the future research directions.

  1. Rapid diagnosis of avian influenza virus in wild birds: Use of a portable rRT-PCR and freeze-dried reagents in the field

    Science.gov (United States)

    Takekawa, John Y.; Hill, N.J.; Schultz, A.K.; Iverson, S.A.; Cardona, C.J.; Boyce, W.M.; Dudley, J.P.

    2011-01-01

    Wild birds have been implicated in the spread of highly pathogenic avian influenza (HPAI) of the H5N1 subtype, prompting surveillance along migratory flyways. Sampling of wild birds for avian influenza virus (AIV) is often conducted in remote regions, but results are often delayed because of the need to transport samples to a laboratory equipped for molecular testing. Real-time reverse transcriptase polymerase chain reaction (rRT-PCR) is a molecular technique that offers one of the most accurate and sensitive methods for diagnosis of AIV. The previously strict lab protocols needed for rRT-PCR are now being adapted for the field. Development of freeze-dried (lyophilized) reagents that do not require cold chain, with sensitivity at the level of wet reagents has brought on-site remote testing to a practical goal. Here we present a method for the rapid diagnosis of AIV in wild birds using an rRT-PCR unit (Ruggedized Advanced Pathogen Identification Device or RAPID, Idaho Technologies, Salt Lake City, UT) that employs lyophilized reagents (Influenza A Target 1 Taqman; ASAY-ASY-0109, Idaho Technologies). The reagents contain all of the necessary components for testing at appropriate concentrations in a single tube: primers, probes, enzymes, buffers and internal positive controls, eliminating errors associated with improper storage or handling of wet reagents. The portable unit performs a screen for Influenza A by targeting the matrix gene and yields results in 2-3 hours. Genetic subtyping is also possible with H5 and H7 primer sets that target the hemagglutinin gene. The system is suitable for use on cloacal and oropharyngeal samples collected from wild birds, as demonstrated here on the migratory shorebird species, the western sandpiper (Calidrus mauri) captured in Northern California. Animal handling followed protocols approved by the Animal Care and Use Committee of the U.S. Geological Survey Western Ecological Research Center and permits of the U.S. Geological Survey

  2. Preparation and Quality Evaluation of Freeze-dried Powder of Quercetin-loaded Nano-liposomes%槲皮素纳米脂质体冻干粉针的制备及其质量评价

    Institute of Scientific and Technical Information of China (English)

    王刚; 余学英; 常明泉; 曾南; 王佳; 杜士明; 杨光义; 刘文嘉

    2012-01-01

    Objective: To prepare freeze-dried powder of quercetin-loaded nano-liposomes ( QUE-LN ) and evaluate the quality. Method: QUE-NL containing different cryoprotectants was prepared by emulsification evaporation-low temperature solidification and freeze-drying methods. The drug loading, encapsulation efficiency ( EE ), mean diameter and span of dispersity as the evaluation indices , the single-factor test was applied to screen the optimal formula and preparation process. The stress testing was applied to study the stability of QUE-NL. Result: Promising EE was achieved with the optimal formula and preparation method. The EE of QUE-NL was significantly affected by the ratio of drug and lipid,while the ratio of cholesterol and phospholipid showed little effect on the EE. The optimal lyophilized powder of QUE-NL could be obtained using 5% maltose and 5% mannitol as the cryoprotectants, and the freeze-dried powder was sensitive to temperature, light and humidity. Conclusion: Freeze-dried powder of QUE-NL with high EE can be obtained by the emulsification evaporation-low temperature solidification and freeze-drying methods with 5% maltose and 5% mannitol as the cryoprotectants. The preliminary stability assessment suggests the freeze-dried powder of QUE-NL be stored in the sealed and light-avoiding conditions with low temperature.%目的:研究槲皮素纳米脂质体冻干粉针的制备方法,并对其进行初步的质量评价.方法:以乳化蒸发-低温固化法和冷冻干燥法制备含有不同冻干保护剂的槲皮素纳米脂质体(QUE-NL)冻干粉,以包封率为评价指标,对制备工艺和处方进行单因素考察,并考察其理化性质,筛选出最佳配方.并对冻于粉针进行稳定性影响因素试验.结果:该法制得的脂质体包封率较佳;制备过程中,槲皮素纳米脂质体的包封率受药脂比影响较大,受胆固醇磷脂比影响较小;采用5%甘露醇+5%麦芽糖作为冻干保护剂冻干效果更好;所得冻于粉针

  3. 真空冷冻干燥过程神经网络模拟研究%Intelligent simulation of vacuum freeze-drying process by artificial neural network

    Institute of Scientific and Technical Information of China (English)

    郭树国; 王丽艳; 李成华

    2012-01-01

    Freeze drying is the best method to ensure the quality of dried products, but the high costs limit its application. BP neural network was used to simulate the vacuum freeze-drying process. After training of BP neural network with the results of ginseng slice in orthogonal experiment, the drying process conditions were predicted and optimized, and the simulation results fit well with the experiment datas. The results show that the BP neural network can simulate the vacuum freeze-drying process precisely.%真空冷冻干燥能够最好的保证干燥后产品质量,但干燥成本高已成为真空冷冻干燥技术大规模工业应用的技术瓶颈.因此利用BP神经网络理论对真空冷冻干燥过程进行了模拟研究,结果表明,BP神经网络能较精确的模拟真空冷冻干燥过程.采用人参切片干燥正交试验结果对BP神经网络进行训练后,对真空冷冻干燥工艺条件进行了预测和优化,预测值与试验实测值的相对误差较小,表明用BP神经网络理论模拟真空冷冻干燥过程具有较高的准确性.

  4. 全营养冻干方便米饭的配方设计与研究%STUDY ON FORMULA OF FULL-NUTRITION FREEZE-DRIED INSTANT RICE

    Institute of Scientific and Technical Information of China (English)

    李建芳; 严佩峰; 周枫; 蒲彪

    2012-01-01

    采用线性规划法(LP),结合SPSS进行配方设计,得到冻干方便米饭的最佳配方为:主食大米650 g;配菜分别为猪肉140.195 g(20.67%)、豌豆167.740 g(24.73%)、菠菜186.946 g(27.56%)、土豆96.184 g(14.18%)、带鱼47.749 g(7.04%)、绿油菜39.465 g(5.82%).结合真空冷冻干燥技术,从营养和感官两个角度与四川得益方便米饭和贵州伊妹方便米饭进行比较,对产品进行综合评价.结果表明,方便米饭配方产品较四川得益和贵州伊妹具有一定的优势.%In this paper,we studied the optimum formula of the freeze-dried instant rice by linear programming (LP) in combination with SPSS. The optimum formula was as follows: rice 650 g,pork 140.195 g(20.67%),pea 167.740 g (24.73%),spinach 186.946 g (27.56%),potato 96.184 g (14.18%),hair-tail 47.749 g (7.04%),and green rape 39.465 g (5.82%). The freeze-dried instant rice was comprehensively evaluated from the nutrient and appearance, and the result showed that the freeze-dried instant rice was superior to Sichuan Deyi instant rice and Guizhou Yimei instant rice.

  5. An improved high performance liquid chromatography-photodiode array detection-atmospheric pressure chemical ionization-mass spectrometry method for determination of chlorophylls and their derivatives in freeze-dried and hot-air-dried Rhinacanthus nasutus (L.) Kurz.

    Science.gov (United States)

    Kao, Tsai Hua; Chen, Chia Ju; Chen, Bing Huei

    2011-10-30

    Rhinacanthus nasutus (L.) Kurz, a traditional Chinese herb possessing antioxidant and anti-cancer activities, has been reported to contain functional components like carotenoids and chlorophylls. However, the variety and amount of chlorophylls remain uncertain. The objectives of this study were to develop a high performance liquid chromatography-photodiode array detection-atmospheric pressure chemical ionization-mass spectrometry (HPLC-DAD-APCI-MS) method for determination of chlorophylls and their derivatives in hot-air-dried and freeze-dried R. nasutus. An Agilent Eclipse XDB-C18 column and a gradient mobile phase composed of methanol/N,N-dimethylformamide (97:3, v/v), acetonitrile and acetone were employed to separate internal standard zinc-phthalocyanine plus 12 cholorophylls and their derivatives within 21 min, including chlorophyll a, chlorophyll a', hydroxychlorophyll a, 15-OH-lactone chlorophyll a, chlorophyll b, chlorophyll b', hydroxychlorophyll b, pheophytin a, pheophytin a', hydroxypheophytin a, hydroxypheophytin a' and pheophytin b in hot-air-dried R. nasutus with flow rate at 1 mL/min and detection at 660 nm. But, in freeze-dried R. nasutus, only 4 chlorophylls and their derivatives, including chlorophyll a, chlorophyll a', chlorophyll b and pheophytin a were detected. Zinc-phthalocyanine was found to be an appropriate internal standard to quantify all the chlorophyll compounds. After quantification by HPLC-DAD, both chlorophyll a and pheophytin a were the most abundant in hot-air-dried R. nasutus, while in freeze-dried R. nasutus, chlorophyll a and chlorophyll b dominated.

  6. The research advance on the application of cryoprotectants in improving the quality of freeze-dried food%冷冻干燥保护剂在改善冻干食品品质中的应用进展

    Institute of Scientific and Technical Information of China (English)

    吴宝川; 李敏

    2012-01-01

    阐述了冷冻干燥保护剂在冻干过程中起保护作用的基本原理和在改善冻干食品品质上的应用现状.由于冻干条件的欠缺可能导致冻干食品品质下降,适当使用并匹配合适的冻干保护剂可有效提高冻干品的品质.文中特别针对糖类、醇类、氨基酸类和不同聚合物类等冻干保护剂的保护机制和作用对象进行了综述分析,说明了在如何结合物料的特点独立或组合使用冻干保护剂以改善冻干条件上仍然具有较大的探索空间.拟为不同食品材料冻干条件的选择提供理论依据,并为改善食品冻干工艺提供理论指导.%The protective function and its mechanism, and the application of ciyoprotectants used in improving the quality of freeze - dried food were elaborated in this paper. The quality of freeze - dried food may be declined due to the shortage conditions, however, by properly using cryoprotectants can improve the food quality effectively. This article described a review analysis about the protection mechanism of various cryoprotectants especially carbohydrate, alcohols, amino acids and polymers and their protecting subjects. Further researches need to be done on either using one or combined cryoprotectants based on the characteristics of the protecting materials. A theoretical basis for the freeze - drying conditions choice of different food materials and theoretical guidance to improve food freeze - drying process were proposed.

  7. 基于响应面的黄花菜冷冻干燥工艺参数优化%Optimization of Parameters for Vacuum Freeze-drying of Daylily Flower at Low Energy Consumption

    Institute of Scientific and Technical Information of China (English)

    郭向明; 崔清亮; 李斐; 贠慧星

    2013-01-01

    In order to determine the optimal parameters for low energy consumption in vacuum freeze-drying daylily flo wer , an experiment was designed according to the method of response surface analysis of three factors and five levels . Selected variables were temperature of heating plate , chamber pressure and loading capacity of the plate as well as freeze-drying energy consumption per unit moisture content taken as the response variable .The results indicated that the signif-icant experimental factors on energy consumption during vacuum freeze-drying were:the plate loading capacity , heating plate temperature and chamber pressure .The optimum parameters were 78 .0℃,3680 .6 g/m2 , 40 .0 Pa respectively and the response value 142.705 MJ/kg.The results would be valuable for vacuum freeze-drying daylily flower at low energy consumption .%为确定黄花菜低能耗冷冻干燥工艺参数,以冷冻干燥单位水分能耗为响应值,以加热板温度、冻干室压力和装盘量为试验因素,采用3因素5水平响应面设计法进行试验。结果表明:3个因素对黄花菜冷冻干燥能耗影响的大小顺序依次为装盘量、加热板温度、冻干室压力;冷冻干燥黄花菜时单位水分能耗最低的最优工艺参数为加热板温度78.0℃、冻干室压力40.0Pa、装盘量3680.6g/m2、单位水分能耗为142.7050MJ/kg。研究结果可为黄花菜实现低能耗冷冻干燥提供技术依据。

  8. Expression of clpL1 and clpL2 genes in Lactobacillus rhamnosus VTT E-97800 after exposure to acid and heat stress treatments or to freeze-drying.

    Science.gov (United States)

    Simões, C; Alakomi, H-L; Maukonen, J; Saarela, M

    2010-09-01

    The aim of the study was to evaluate the potential of utilising the information on expression levels of selected stress genes in assessing the quality of probiotic products. For this purpose RT-qPCR methods were developed to study the expression of clpL1 and clpL2 stress genes in Lactobacillus rhamnosus VTT E-97800 (E800) cells after exposure to processing-related stress conditions or to freeze-drying. Heat treatments in laboratory scale were performed with E800 cells incubated at 47 °C or 50 °C for 60 min. Acid treatments were performed both at laboratory and fermenter scale. At laboratory scale E800 cells were inoculated into General Edible Medium (GEM) adjusted to pH 4.0 and pH 3.5 and incubated at 37 °C for 180 min, whereas fermenter-grown cells were exposed to pH 4.0 for 60 min at the end of the fermentation. RNA from fresh cells and freeze-dried powders was reverse transcribed after isolation, quantification and standardisation. clpL1 and clpL2 transcripts were analysed by RT-qPCR with SYBR Green I. clpL1 was induced in L. rhamnosus E800 cells exposed to 50 °C and to a much lesser extent to 47 °C. No induction was observed for clpL2 in E800 cells during either acid or heat treatment, in any of the conditions applied. RNA isolation from freeze-dried powders was unsuccessful although several attempts were made with high quality products. In conclusion, our results suggest that developing quality indicators for probiotic products based on differences in the expression of stress genes is a challenging task for several reasons: at least with some genes (like in the present study with clpL) quite harsh conditions are needed to detect differences in the gene expression; mRNA isolation from freeze-dried powders was unsuccessful which hampers the quality analysis of large proportion of probiotic products; and furthermore RT-qPCR proved to be a too laborious procedure for routine use.

  9. Efficacy and safety profile of LCR35 complete freeze-dried culture in irritable bowel syndrome: A randomized,double-blind study

    Institute of Scientific and Technical Information of China (English)

    Michel Dapoigny; Thierry Piche; Philippe Ducrotte; Bernard Lunaud; Jean-Michel Cardot; Annick Bernalier-Donadille

    2012-01-01

    AIM:To assess the effects and safety of lactobacillus casei rhamnosus LCR35 complete freeze-dried culture (LCR35) in patients suffering from irritable bowel syndrome (IBS).METHODS:A randomized,double-blind pilot study was performed in 50 patients complaining of IBS symptoms complying with Rome Ⅲ criteria.Patients were allocated to receive either LCR35 (n =25) at a minimum daily dose of 6 x 108 colony forming units or placebo (n =25) for 4 wk.At inclusion,after treatment and2 wk later,patients completed the IBS severity scale.Change from baseline in the IBS severity score at the end of treatment was the primary efficacy criterion.Changes were compared between groups in the whole population and in IBS subtypes (IBS with predominance of constipation,IBS with predominance of diarrhoea,mixed IBS,unsubtyped IBS).The presence of lactobacillus casei rhamnosus in stools was investigated at inclusion and at the end of treatment.The gastrointestinal quality of life questionnaire and the hospital anxiety and depression (HAD) scale were also completed.RESULTS:Both groups were balanced for baseline characteristics.In 85% of patients,stool analyses showed that lactobacillus casei rhamnosus able to survive in the digestive tract.In the whole population,improvements in the IBS severity score did not differ significantly between treatments with a 25% decrease after 4-wk treatment,and a 15% decrease from baseline 2 wk later in both groups.In IBS subgroups,statistical analysis could not be performed due to small sample size,but a clinical response in favour of LCR35 was observed in IBS patients with predominance of diarrhoea:no change in the symptom severity score was seen with the placebo after 4 wk treatment,whereas a clinically relevant decrease occurred with LCR35 (-37%vs-3%).Furthermore,in spite of an increase in symptom intensity,the IBS severity score was maintained below the baseline value 2 wk later with LCR35 (-19%from baseline),whilst a slight 5% increase

  10. Comparison of 2 regenerative procedures--guided tissue regeneration and demineralized freeze-dried bone allograft--in the treatment of intrabony defects: a clinical and radiographic study.

    Science.gov (United States)

    Parashis, A; Andronikaki-Faldami, A; Tsiklakis, K

    1998-07-01

    The purpose of this study was to compare clinically and radiographically the effectiveness of guided tissue regeneration (GTR), using a bioabsorbable polylactic acid softened with citric acid ester barrier and commercially available demineralized freeze-dried bone allograft (DFDBA) in the treatment of 2- and 3-wall intrabony defects. Twelve patients each with one treated defect comprised each group. Conservative treatment was completed 2 to 4 months prior to surgery. Clinical measurements, plaque index, gingival index, probing depths (PD), clinical attachment levels (CAL) and recession (REC), were comparable in both groups at baseline. They were repeated at 12 months. Surgical measurements were also comparable at baseline in both groups. In the GTR group, at baseline the mean distance between the cemento-enamel junction (CEJ) and base of the defect was 12.3 +/- 2.9 mm and in the DFDBA group 11.3 +/- 1.8 mm. The defect depth was 6.3 +/- 2.0 mm and 5.4 +/- 1.3 mm, respectively. Radiographs were taken at baseline and 12 months later and compared using non-standardized digital subtraction radiography. In the GTR group, mean PD decreased from 7.9 +/- 2.5 mm to 3.5 +/- 1.4 mm and mean CAL from 10.8 +/- 2.8 mm to 7.0 +/- 1.6 mm, the differences being statistically significant (P = 0.002), while REC increased from 2.9 +/- 1.2 mm to 3.5 +/- 1.1 mm. In the DFDBA group, mean PD decreased from 7.1 +/- 1.1 mm to 3.5 +/- 1.1 mm and mean CAL from 9.8 +/- 1.5 mm to 6.6 +/- 1.7 mm (P = 0.002), while REC increased from 2.8 +/- 1.0 mm to 3.1 +/- 1.2 mm. No significant differences were found when the clinical results of the 2 groups were compared. Radiographic differences between the baseline and reconstructed images 12 months later were observed in both groups. Mean crestal bone resorption was 15.3 +/- 22.5% in the GTR group and 10.4 +/- 31.8% in the DFDBA group, and mean improvement in the distance between the CEJ and the base of the defect was 22.8 +/- 18.1% in the GTR group and 15

  11. Effect of freeze-drying and self-ignition process on the microstructural and electrochemical properties of Li{sub 4}Ti{sub 5}O{sub 12}

    Energy Technology Data Exchange (ETDEWEB)

    Jamin, Claire [GREEnMat/LCIS, Department of Chemistry, B6a, University of Liège, Sart-Tilman, 4000 Liège (Belgium); Traina, Karl [GREEnMat/LCIS, Department of Chemistry, B6a, University of Liège, Sart-Tilman, 4000 Liège (Belgium); APTIS, Department of Physics, B5a, University of Liège, Sart-Tilman, 4000 Liège (Belgium); Eskenazi, David [Chemical Engineering Laboratory, Department of Applied Chemistry, B6a, University of Liège, Sart-Tilman, 4000 Liège (Belgium); Krins, Natacha; Cloots, Rudi; Vertruyen, Bénédicte [GREEnMat/LCIS, Department of Chemistry, B6a, University of Liège, Sart-Tilman, 4000 Liège (Belgium); Boschini, Frédéric, E-mail: frederic.boschini@ulg.ac.be [GREEnMat/LCIS, Department of Chemistry, B6a, University of Liège, Sart-Tilman, 4000 Liège (Belgium); APTIS, Department of Physics, B5a, University of Liège, Sart-Tilman, 4000 Liège (Belgium)

    2013-11-15

    Graphical abstract: - Highlights: • Li{sub 4}Ti{sub 5}O{sub 12} is prepared by a method involving self-ignition of a freeze-dried gel. • Addition of NH{sub 4}NO{sub 3} modifies the self-ignition propagation mode. • Well-crystallized Li{sub 4}Ti{sub 5}O{sub 12} phase is obtained after only 2 h at 800 °C. • Li{sub 4}Ti{sub 5}O{sub 12} powder has 161 mAh g{sup −1} capacity and good retention at C/4 rate. - Abstract: Crystalline Li{sub 4}Ti{sub 5}O{sub 12} is synthesized by a method involving the freeze-drying and self-ignition of a gel prepared from titanium isopropoxide, lithium nitrate and hydroxypropylmethylcellulose (HPMC). This synthesis route yields crystalline Li{sub 4}Ti{sub 5}O{sub 12} particles after calcination at 800 °C for 2 h. In an alternative route, addition of ammonium nitrate shifts the self-ignition mode from wave-like propagation to simultaneous. Powders with different microstructures are thereby obtained. Electrochemical characterization shows that the best results for Li{sup +} intercalation/desintercalation are obtained for the powder prepared without ammonium nitrate addition. These results highlight the necessity for a control of the self-ignition mode to obtain adequate properties.

  12. Fabrication and laser performance of highly transparent Nd:YAG ceramics from well-dispersed Nd:Y{sub 2}O{sub 3} nanopowders by freeze-drying

    Energy Technology Data Exchange (ETDEWEB)

    Gong Hua, E-mail: gonghua@ntu.edu.sg; Zhang Jian; Tang Dingyuan; Xie Guoqiang; Huang Hui [Nanyang Technological University, Photonics Research Centre, School of Electrical and Electronic Engineering (Singapore); Ma Jan [Nanyang Technological University, School of Material Science and Engineering (Singapore)

    2011-09-15

    Well-dispersed Nd:Y{sub 2}O{sub 3} powders with uniform particle size of about 60 nm were synthesized from freeze-dried precursors. Highly transparent 2 at.% Nd:YAG ceramics were fabricated from the as-synthesized Nd:Y{sub 2}O{sub 3} powders and commercial Al{sub 2}O{sub 3} powders by vacuum sintering at 1,750 Degree-Sign C for 5 h. Phase evolution, microstructures, and spectroscopic properties of the Nd:YAG transparent ceramics were investigated. Freeze-drying played an important role in the synthesis of high-quality Nd:Y{sub 2}O{sub 3} nanosized powders, which were essential for the fabrication of highly transparent Nd:YAG ceramics. Optical transmittance of a 3-mm thick sample reached 82% in the wavelength range of 200-900 nm. 5.23 W output power was obtained with 14.3 W diode laser pumping, giving a slope efficiency of 36.5%.

  13. The Research Status and Prospects of the Hot Air Drying and Freeze Drying for Papaya%木瓜热风干燥和冷冻干燥的研究现状和展望

    Institute of Scientific and Technical Information of China (English)

    李铭; 陈冬梅; 侯萍; 赵鹤飞; 余善鸣

    2013-01-01

    果蔬的干燥主要有热干、微波、冻干和组合干燥。木瓜的干燥以热干为主,冻干能最大程度保持木瓜的色泽、风味和营养价值,但研究报道较少。今后木瓜干燥研究的主要内容将是提高品质和降低产品成本。因此,木瓜的热干和冻干的组合干燥将是研究的重点。%The primary drying technologys of fruits and vegetables are hot-air drying , microwave drying , freeze drying and combined drying. The mainly drying method of papaya is hot-air drying. The freeze-dried can keep the greatest degree of color, flavor and nutritional value of papaya, However, it is lack of references on that. Future research of the drying technology of papaya will be improvement of the quality and to reduce product cost. Therefore, the combined drying technology of hot-air and freeze of papaya will become a study emphasis in further research.

  14. 药品真空冷冻干燥过程监控技术研究进展%Research progress in monitoring and control technology for pharmaceutical freeze-drying process

    Institute of Scientific and Technical Information of China (English)

    李俊奇; 李保国

    2015-01-01

    对药品冻干过程进行优化的关键是在保证药品质量不受损害的情况下尽量缩短干燥时间。因此,对冻干过程进行准确的监控是十分重要的,既要保证药品的温度保持在合理的范围内,对干燥结束时间进行准确地判断,同时又要对冻干过程压力和温度进行良好的控制以达到冻干过程的最优化。本文对近年来药品真空冷冻干燥过程监控技术的研究进展进行了综述,主要有基于动态参数估计法(DPE)的监控系统、基于卡尔曼滤波法的监测系统、露点法判断一次干燥结束点、模型预测控制法(MPC)。提出药品真空冷冻干燥监控技术的研究应着重于以下几点:考虑辐射、对流和导热3种传热方式在冻干传热过程中所占的比重,建立二维、三维冻干模型以更加精确地监测药品冻干过程的参数,在此基础上研究对加热隔板温度和冻干室压力的实时最优控制策略,以对药品冻干过程进行及时、有效地控制。%For the optimization of pharmaceutical freeze-drying process,the key is to shorten the drying time as much as possible and keep the good quality of the product. Therefore,it is very important to monitor and control the freeze-drying process precisely,i.e.,to keep the temperature of product within a reasonable range,judge the end point of drying time accurately,and a good control of chamber pressure and shelf temperature is needed to optimize the process. Research progress in pharmaceutical freeze-drying process monitoring and control technology in recent years is summarized in this paper,including monitoring system based on dynamic parameters estimation(DPE), monitoring system based on Kalman filter method,dew point method to judge the end point of primary drying,and model predictive control(MPC). The following points should be taken into account for further research on pharmaceutical freeze-drying monitoring and control

  15. Study on preparation and stability of doxycycline chitosan nanoparticles freeze-dried powder%强力霉素壳聚糖纳米粒冻干粉的制备及其稳定性研究

    Institute of Scientific and Technical Information of China (English)

    沈丹怡; 丁运敏; 艾晓辉; 刘永涛; 余少梅; 索纹纹

    2011-01-01

    采用离子交联法和冷冻干燥法制备强力霉素壳聚糖纳米粒冻干粉,并以包封率为评价指标,正交试验优化处方与工艺,用透射电镜观测其形态,纳米粒度及电位分析仪测定其粒径大小、分布和电位,并考察其热、光和高湿稳定性.结果显示,按壳聚糖浓度为2.5 mg/mL、三聚磷酸钠浓度为1.2 mg/mL、强力霉素用量为8.0mg、pH值为5.5的处方制备的强力霉素壳聚糖纳米粒冻干粉表面蓬松,复溶性良好,电镜下观测发现纳米粒形态圆整、粒径大小均匀,平均粒径为(126.3±17.8)nm,平均包封率为(56.52±2.1)%,平均载药量为(16.83±0.27)%.与原料药相比,10 d强力霉素壳聚糖纳米粒冻干粉的(4500±500)Lx强光降解率减少22.97%,40、60℃热降解率分别减少18.72%和31.41%,75%、92.5%高湿降解率分别减少20.45%和26.90%.强力霉素壳聚糖纳米粒冻干粉制备工艺切实可行,稳定性良好.%Doxycycline Chitosan Nanopaiticles (DC-CS-NPs) freeze dried powder was prepared by using freeze drying and ionic gelation method. The preparation was optimized by orthogonal experimental design with encapsulation efficiency as e-valuation index. The particle morphology, size and potential were determined respectively by transmission electron microscopy, particle and potentiometric analyzer. The ultraviolet, thermal and humid stabilities were measured at the same time. The optimal preparation process of DC-CS-NPs was 2. 5 mg/mL chitosan solution, 1. 2 mg/mL sodium tripolyphos-phate solution, 8 mg doxycycline and pH 5.5. The DC-CS-NP8 freeze dried powder had a fluffy surface and good solubility. The DC-CS-NP8 were discrete and uniform spheres under transmission electron microscopy with a mean particle size of (126. 3 ±17. 8 ) nm. The encapsulation efficiency and drug loading of DC-CS-NPs were (56. 52 ±2.1) % and (16. 83 ± 0. 27)% , respectively. Compared to DC raw material drug, the ultraviolet degradation of DC-CS-NPs freeze-dried

  16. 冻干b型流感嗜血杆菌结合疫苗稳定性研究%Study on stability of a freeze-dried Haemophilus influenzae type b conjugate vaccine

    Institute of Scientific and Technical Information of China (English)

    袁军; 李新国

    2011-01-01

    目的 对以乳糖作为稳定剂的b型流感嗜血杆菌(Haemophilus influenzae type b,Hib)结合疫苗冻干剂型进行稳定性研究.方法 选取3批冻干Hib结合疫苗,分别于2~8℃保存42个月,20~25℃保存7个月,37℃保存5周.并于考察期内对疫苗进行外观检查、检测回收率(KD <0.2)、游离多糖含量、水分和小鼠效力试验,观察其是否发生降解.结果 在考察期内,冻干疫苗小鼠效力试验阳转率均为100%,外观检查均符合规定,回收率(KD<0.2)均≥68%,游离多糖均≤18%,水分均≤3.0%.各项指标均达到中国药典要求.结论 冻干疫苗于2~8℃保存42个月,20~25℃保存7个月,37℃保存5周质量稳定.%Objective To research the stability of a freeze-dried Haemophilus influenzae type b (Hib)conjugate vaccine using lactose as a stabilizer.Methods Three batches of the freeze-dried Hib conjugate vaccine were selected to be stored at 2-8 ℃ for 42 months,20-25 ℃ for 7 months and 37 ℃ for 5 weeks,respectively.Tests for appearance,recovery rate of polysaccharide (KD < 0.2),free polysaccharide content,moisture content and mouse potency test were performed during observation to see whether degradation of the vaccine occurred.Results The seroconversion rate in mouse potency test was 100%,the appearance of vaccine was fit for the standard,recovery rate of polysaccharide (KD <0.2) was≥68%,free polysaccharide content≤ 18%,moisture content ≤3.0% for all three batches of the freeze-dried vaccine during observation.All the indexes of freeze-dried vaccine reach the requirements of Chinese Pharmacopeia.Conclusion The freeze-dried Hib conjugate vaccine has stable quality when stored at 2-8℃ for 42 months,20-25℃ for 7 months and 37℃ for 5 weeks.

  17. Preparation and Quality Control of Mitomycin Freeze-Dried Powder for Ocular Use%丝裂霉素眼用冻干粉的研制及质量控制

    Institute of Scientific and Technical Information of China (English)

    马珂; 俞佳; 郑水莲; 俞振伟; 黄绳武

    2011-01-01

    目的 制备丝裂霉素眼用冻干粉,并建立质量控制方法,为临床使用提供安全的药物.方法 以氯化钠为辅料制备丝裂霉素眼用冻干粉,考察活性炭使用量、pH值、冻干时间等因素对制剂质量的影响;建立酸碱度、渗透压等检查的方法,使用HPLC测定含量和有关物质;进行稳定性研究.结果 活性炭使用量为0.005%,pH值为6.5-8.0,冻干总时间为35 h时制剂的质量最佳;本品的渗透压为(307.3±2.1)mOsm ·kg-1,pH值为6.94±0.03,干燥失重为(0.74±0.03)%,其余检查项均符合质量标准.丝裂霉素眼用冻干粉对光照和高温敏感,本品采用避光包装在加速实验下6个月和长期稳定性实验下12个月是稳定的.结论 丝裂霉素眼用冻干粉制备简单,质量稳定;所建立的质量控制方法可靠,可用于本品的质量控制.%OBJECTIVE To prepare mitomycin freeze-dried powder for ocular use and to establish its quality control method, thus to provide a safe drug for clinical use. METHODS The mitomycin powder was prepared using sodium chloride as the excipienL The influence, of activated carbon amount, pH value and freeze-drying time on the powder quality was investigated. The contents of mitomycin and related substances were investigated by HPLC. The stability test was also performed. RESULTS The optimal preparation was obtained with 0. 005% activated carbon, pH value of 6. 5 - 8. 0 and freeze-drying time of 35 h. The osmotic pressure of the final product was (307. 3 ±2. 1 )mOsm · kg-1 , pH value was 6. 94 ±0. 03, loss on drying was(0. 74 ±0. 03)% , and the other parameters were all in accordance with the quality standard. Mitomycin freeze-dried powder was sensitive to light and high temperature. It was stable for 6 months under accelerate condition and 12 months under long-term test condition in light resistant packages. CONCLUSION The preparation technique of mitomycin freeze-dried powder is simple. The formulation is stable, and the

  18. 高效价冻干人用狂犬病疫苗暴露后免疫程序的研究%The PEP Schedule of Freeze-Dried Rabies Vaccine with High Potency

    Institute of Scientific and Technical Information of China (English)

    汝东宇; 雷连成

    2011-01-01

    初步确定高效价冻干人用狂犬病疫苗(6.0 IU/剂)暴露后免疫程序.制备高效价的冻干人用狂犬病疫苗(6.0 IU/剂),以狂犬病街毒CNX8601和BD06分别攻击小鼠和比格犬的咬肌,接种不同效价的狂犬病疫苗,以RFFIT法检测中和抗体,根据动物死亡情况,计算暴露后疫苗保护率,对不同效价的疫苗进行中和抗体测定和保护率统计分析.在以小鼠为实验动物的疫苗保护率研究中,冻干人用狂犬病疫苗(3.1 IU/剂)0/3/7/14/28免疫程序的保护率为40.6%,高效价的冻干人用狂犬病疫苗(6.0 IU/剂)0/3/14免疫程序的保护率为56.2%,中和抗体比较,P<0.05,2组间有显著性差异;在以比格犬为实验动物的保护效果研究中,冻干人用狂犬病疫苗的保护率(3.1 IU/剂)为70%;高效价的冻干人用狂犬病疫苗(6.0 IU/剂)的保护率为80%,中和抗体的比较,P>0.05,没有显著性差异.高效价冻干人用狂犬病疫苗暴露后免疫程序可初步确定为0、3、14 d免疫.%The PEP ( post-exposure prophylaxis) schedule of freeze-dried rabies vaccine with high potency (HPRabV) (6.0 IU/dose) was established preliminarily. The HPRabV (6.0 IU/dose) was prepared, the BALB/c mice and Beagles were challenged with the street virus CNX8601 or BD06 at the masseter muscle, then inoculated with rabies vaccine of different potency (3. 1 IU/dose or 6.0 IU/dose). The rapid fluorescent focus inhibition test (RFFIT) was used to detect rabies virus neutralizing antibody (RVNA) in mouse and beagles sera. The protection efficacy against street rabies virus was calculated according to the animal' 8 death rates and carried out statistic analyses. The results showed that HPRabV (6.0 IU/dose) could induce the more vigorous production of RVNA in BALB/ c mice and beagles. The data indicated that the three-shot HPRabV could achieve a higher protection rate ( survival rate 56.2% ) by 0/3/14 PEP schedule as compared with that of the RabV group

  19. 双孢菇微波冷冻干燥特性及干燥品质%Drying characteristics and quality of button mushrooms during microwave freeze drying

    Institute of Scientific and Technical Information of China (English)

    段续; 刘文超; 任广跃; 庞玉琪; 刘云宏

    2016-01-01

    Button mushroom is the most widely cultivated and consumed mushroom throughout the world and it contributes about 40% of the total world production of mushroom. Button mushrooms are extremely perishable and their shelf life is only about 24 h in ambient conditions. Various physiological and morphological changes occur after harvest, which make these mushrooms unacceptable for consumption. Hence, they should be consumed or processed promptly after harvest and for this reason the mushrooms are traded mostly in dried form in the world market. The convective drying method is the most commonly used to dry mushrooms. Nevertheless, due to long drying time and high drying temperature at industrial scale, the problems of darkening in color, shrinkage, loss in flavor and decrease in rehydration ability easily occur. In recent years, microwave freeze drying (MFD) has been investigated as a potential method for obtaining high quality dried food products with low energy consumption. Thus, to achieve faster drying rate with high product quality, MFD was applied to dry button mushrooms. The drying curves, effective moisture diffusivity, rehydration ratio, shrinkage ratio, vitamin C retention ratio, energy consumption and the sensory evaluation based on the fuzzy reasoning were investigated, which were considered to reflect the drying and quality characteristics of button mushrooms under different microwave loading levels (0.25, 1.0 and 0.75 W/g) and system pressure (50, 100 and 150 Pa). The drying models were obtained by the nonlinear fitting of drying curves. The weighted comprehensive evaluation of button mushroom MFD processes were also carried out based on energy consumption, drying time, rehydration ratio, whiteness index and vitamin C retention ratio. Results showed that, when changing the microwave loading level, the reduction ratio of the minimum value to the maximum value of drying time, effective moisture diffusion coefficient, whiteness index, rehydration ratio and

  20. Crestal bone resorption in augmented bone using mineralized freeze-dried bone allograft or pristine bone during submerged implant healing: a prospective study in humans.

    Science.gov (United States)

    Huang, Hsiang-yun; Ogata, Yumi; Hanley, James; Finkelman, Matthew; Hur, Yong

    2016-02-01

    There is limited evidence on the crestal bone level changes around implants placed in bone augmented by guided bone regeneration (GBR) during submerged healing. The purpose of this study was to prospectively compare radiographic crestal bone changes around implants placed in augmented bone with changes around implants placed in pristine bone. Patients receiving dental implants in the augmented or pristine mandibular posterior edentulous ridge were included in the study. The digital standardized radiographs from the implant placement procedure were compared to the radiographs from the second-stage procedure to evaluate the peri-implant marginal bone level changes. The soft tissue thickness (ST), width of keratinized mucosa (wKM), and early cover screw exposure (eIE) were measured at the time of the second-stage procedure. A total of 29 implants in 26 patients, 11 in augmented bone (test group) and 18 in pristine bone (control group), were analyzed. The mean peri-implant bone loss (ΔBL) was 0.74 ± 0.74 mm (mean ± SD) in the test group and 0.25 ± 0.55 mm (mean ± SD) in the control group. The differences between the test and control groups in the mesial, distal, and mean peri-implant crestal bone level changes were statistically significant (P = 0.009, P = 0.004, and P = 0.001, respectively). The confounding factors (ST, wKM, and eIE) were adjusted. More peri-implant crestal bone loss during the submerged healing period was observed in augmented bone than in pristine bone. Augmented bone may not exhibit the same characteristics as pristine bone during the implant submerged healing period. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  1. 冻干对红阳猕猴桃果浆还原型抗坏血酸的影响%Effects of Freeze-drying Conditions on Reduced Ascorbic Acid of Hongyang Kiwifruit Pulps

    Institute of Scientific and Technical Information of China (English)

    郑晓琴; 陈彦; 李竞晋; 王林琳; 李明章

    2009-01-01

    The effects of pre-freezing methods,relative ratio surface(RRS) and the positions of container loading Hongyang Kiwifruit pulps in freezing chamber on the preservation rate of reduced ascorbic acid (RAA) during the freeze-drying processing were studied by orthogonal experimerits.The results showed that the pre-freezing methods and the RRS affected the preservation rate of RAA significandy in the freeze-drying process(p0.05).The preservation rate of RAA of Hongyang Kiwifruit pulps was more than 98% under the optimum freeze-drying conditions.The comparison of the lyophilized products and the hot-air drying products was also conducted in view of their sensory properties and physical-chemical indexes.Tne physical-chemical indexes (i.e.RAA preservation rate) and sensory properties of lyophilized Hongyang Kiwifruit pupls were superior to that of hot-air drying products.%以还原型抗坏血酸保存率为指标,采用正交试验方法研究了冻干中红阳(Hongyang)猕猴桃果浆料的预冻方式、相对比表面积、放置位置因素等的影响.结果表明,在冻干加工处理中,果浆料的预冻方式、相对比表面积因素等冻干工艺参数对红阳猕猴桃果浆还原型抗坏血酸的保存率影响极显著(p0.05),在优化冻干工艺条件下获得的红阳猕猴桃果浆干制品的还原型抗坏血酸保存率超过98%.此外,从理化指标(主要为抗坏血酸的保存率)与感官指标方面比较了冻干制品与热风干燥制品的差异,红阳猕猴桃果浆冻干加工制品的指标值均大大优于热风干制加工制品的指标值.

  2. Numerical Simulation on Freeze Drying with Dielectric Material Assisted Microwave Heating%介电材料辅助的微波冷冻干燥的数值模拟

    Institute of Scientific and Technical Information of China (English)

    王维; 许英梅; 马鸿信; 陈国华

    2012-01-01

    The effects of the dielectric material on the microwave freeze-drying process were theoretically studied by mathematically solving the heat and mass transfer model considering the hygroscopic effect with a moving boundary in the porous media. Sintered silicon carbide (SiC) was used as the dielectric material, and the mannitol, a typical pharmaceutical excipient, was selected as the solute in aqueous solution. Simulation results show that the dielectric material can significantly enhance the microwave freeze drying rate under the experimental operating conditions, especially when the solid content in the freeze dried solution is very low or the solid product has a very small dielectric loss factor. Comparisons of the drying curves display good agreements between experimental measurements and model predictions. Based on the profiles of ice saturation and temperature, mechanisms of heat and mass transfer inside the material were analyzed, and the drying rate-controlling factor was discussed.%通过数值求解一个考虑吸湿效应的带有移动升华界面的多孔介质热、质传递耦合模型,理论考察介电材料对微波加热冷冻干燥过程的影响.介电材料用烧结的碳化硅(SiC).甘露醇,一种典型的药物赋形剂被选为待干溶液中的溶质.模拟结果表明在微波冷冻干燥过程中使用介电材料可以加快冷冻干燥速率,特别是在待干溶液的固含量很低或者固体产品的介电损耗因子很小的情况下尤为有效.模型预测和实验测定的干燥曲线相比较显示了良好的一致性.通过考察冰饱和度和温度的分布侧形,研究分析了物料内部的质热传递机理,并讨论了干燥速率的控制因素.

  3. Process of Freeze-dried Ready to Eat Sea Cucumber Health Soup%冻干速溶即食海参汤的加工工艺研究

    Institute of Scientific and Technical Information of China (English)

    李银塔

    2013-01-01

    Discussed the impacts of modified starch and freeze-dried sea cucumber on the quality of the sea cucumber soup ingredients by vacuum freeze-drying technique. We had determined the making process and optimum technology parameter of instant sea cucumber soup through orthogonal experiment as follows: corn starch and potato starch mixed in ratio of 1∶1, which dosage is 1%. The best pore size of preparing frangipani is 0.1 cm×0.4 cm;Freeze drying after soaking and slicing is the best way to deal with sea cucumber. Mixed starch 0.65 g, medlar 1 g, salt 1 g, American ginseng 0.3 g, the sea cucumber 8 g, nori 20 g, frangipani 35 g, this recipe can obtain well instant sea cucumber soup. Product 10 g with water 200 g which above 90 ℃, we will obtain delicious instant sea cucumber soup after soaking 1min.%采用真空冷冻干燥技术,探讨变性淀粉、冻干海参及海参汤配料对质量的影响,通过正交试验确定了速溶海参养生汤的制作工艺及最佳工艺参数:玉米淀粉和马铃薯淀粉按1∶1(质量比)混合,混合淀粉用量是1%;制备鸡蛋花最佳孔径为0.1 cm×0.4 cm;海参最佳处理方式为泡发后切片进行冷冻干燥。混合淀粉0.65 g、枸杞子1 g、西洋参0.3 g、盐度1 g、海参8 g、紫菜20 g、鸡蛋花35 g组成的配方,可获得良好冲调性的速溶海参汤。10 g本产品,加温度90℃以上水200 g,浸泡1 min可获得色、香、味俱佳的速溶海参汤。

  4. PREPARATION OF ORIENTED POROUS CERAMICS BY DIRECTIONAL SOLIDIFICATION AND FREEZE-DRYING METHOD%定向凝固和冷冻干燥制备定向多孔陶瓷

    Institute of Scientific and Technical Information of China (English)

    李利娟; 董寅生; 林萍华; 储成林; 盛晓波; 郭超

    2009-01-01

    采用定向凝固和冷冻干燥法制备定向多孔陶瓷材料,考察主要制备参数对多孔陶瓷材料性能的影响.以Al_2O_3,SiO_2为原料,Na_2O·SiO_2为添加剂,明胶为粘结剂,将陶瓷原料与蒸馏水混合制成浆料,预冻,冷冻干燥,烧结得到多孔陶瓷材料,通过扫描电镜观察其孔结构,并对其孔隙率和收缩率进行测试.制备过程中,浆料的固含量,冷冻温度,烧结温度对多孔陶瓷材料的孔隙率、收缩率、微观结构有较大影响.采用定向凝固和冷冻干燥法可以制备定向多孔陶瓷材料,通过控制工艺参数可以调整多孔陶瓷孔隙结构和性能,以满足不同需求.%Objectives To prepare oriented porous ceramics by directional solidification and freeze-drying method, the main preparation parameters that affect the properties of porous ceramics were investigated. Methods The solid materials, including alumina, silicon dioxide, sodium metassilicate and glutin, were mixed with distilled water at certain ratios to obtain slurry. The slurry was solidified directionally, freeze-dried and then sintered to get oriented porous ceramics. The microstructure of the porous ceramics was observed by scanning electron microscopy (SEM) and the properties were characterized by shrinkage and porosity. Results The solid content of slurry, the freezing and sintering temperatures affected the microstructure, shrinkage and porosity of the porous ceramics. Conclusion Oriented porous ceramics can be successfully prepared by directional solidification and freeze-drying method. By controlling the technique parameters, the pore structure and properties can be adjusted to satisfy different needs.

  5. 冻干重组人三突变型低氧诱导因子-1α腺病毒的制备%Preparation of freeze-dried recombinant adenovirus expressing hypoxia inducible factor-1 alpha of triple mutant

    Institute of Scientific and Technical Information of China (English)

    陶宇; 杨丽; 魏旋; 李明琰; 陈建威; 吴平生

    2011-01-01

    目的:研制冻干重组人三突变型低氧诱导因子-1α(HIF-1α)腺病毒.方法:将重组人三突变型HIF-1α腺病毒与不同配比的保护剂按适当比例混合,进行冻干,根据冻干后外观、病毒滴度测定、热稳定性试验、PCR、基因测序等结果,筛选冻干保护剂并评价冻干品质量.结果:冻干腺病毒所携带的目的基因信息无丢失或变异;以10%海藻糖、0.5%明胶、3%山梨醇等成分配制的保护剂作用较好,冻干后腺病毒感染性滴度下降0.33 LgPFU/mL;37℃放置3周,滴度下降0.8 LgPFU/mL.结论:以合适的保护剂制备冻干重组人三突变型HIF-1α腺病毒能达到较满意的效果.%Objective To prepare freeze-dried recomhinant adenovirus expressing hypoxia inducible factor-1 alpha (HIF-lα) of triple mutant (Ad-HIF-lα-564/402/803). Methods Ad-HIF-Iα-564/402/803 were mixed with different stabilizers in an appropriate proportion and then lyophilized. The optimum stabilizer was selected and the product quality was evaluated according to appearance, virus titer, thermostahility, PCR and DNA sequence analvsis. Results PCR and gene sequence suggested the correct construction of freeze-dried recombinant adenovirus. The protective agent containing 10% trehalose , 0.5% gelatin, 3% sorbitol had better protecting effects. After lyophilization, the infectious titer of adenovirus was decreased by 0.33 LgPFU/mL, the titer of lyophilized adenovirus was decreased by 0.8 LgPFU/mL for 3 weeks at 37℃. Conclusions When prepared with proper stabilizer, the freeze-dried recombinant adenovirus expressing HIF-Iα of triple mutant can have a good performance.

  6. Freeze-drying synthesis of three-dimensional porous LiFePO4 modified with well-dispersed nitrogen-doped carbon nanotubes for high-performance lithium-ion batteries

    Science.gov (United States)

    Tu, Xiaofeng; Zhou, Yingke; Song, Yijie

    2017-04-01

    The three-dimensional porous LiFePO4 modified with uniformly dispersed nitrogen-doped carbon nanotubes has been successfully prepared by a freeze-drying method. The morphology and structure of the porous composites are characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), and the electrochemical performances are evaluated using the constant current charge/discharge tests, cyclic voltammetry and electrochemical impedance spectroscopy. The nitrogen-doped carbon nanotubes are uniformly dispersed inside the porous LiFePO4 to construct a superior three-dimensional conductive network, which remarkably increases the electronic conductivity and accelerates the diffusion of lithium ion. The porous composite displays high specific capacity, good rate capability and excellent cycling stability, rendering it a promising positive electrode material for high-performance lithium-ion batteries.

  7. Study on Strengthening Course Construction of Freeze- drying of Pharmaceutical and Food Products%加强《药品、食品冷冻干燥技术》课程建设的思考

    Institute of Scientific and Technical Information of China (English)

    周新丽; 刘宝林; 周国燕; 王欣

    2011-01-01

    The course construction of Freeze - drying of Pharmaceutical and Food Products was very necessary to develop were inter- disciplinary talent in pharmacetutical and food industry fields. The thought and aim of course construction brought forward from sever%《药品、食品的冷冻干燥技术》课程建设对于培养制药界、食品界一专多能的复合型人才非常必要。本文从课程体系的构建、加强教材建设、加强师资力量、加强实践教学等几方面提出了课程建设的思路和预期目标。

  8. Long palatal connective tissue rolled pedicle graft with demineralized freeze-dried bone allograft plus platelet-rich fibrin combination: A novel technique for ridge augmentation - Three case reports

    Directory of Open Access Journals (Sweden)

    Pathakota Krishnajaneya Reddy

    2015-01-01

    Full Text Available Replacement of missing maxillary anterior tooth with localized residual alveolar ridge defect is challenging, considering the high esthetic demand. Various soft and hard tissue procedures were proposed to correct alveolar ridge deformities. Novel techniques have evolved in treating these ridge defects to improve function and esthetics. In the present case reports, a novel technique using long palatal connective tissue rolled pedicle graft with demineralized freeze-dried bone allografts (DFDBAs plus Platelet-rich fibrin (PRF combination was proposed to correct the Class III localized anterior maxillary anterior alveolar ridge defect. The present technique resulted in predictable ridge augmentation, which can be attributed to the soft and hard tissue augmentation with a connective tissue pedicle and DFDBA plus PRF combination. This technique suggests a variation in roll technique with DFDBA plus PRF and appears to promise in gaining predictable volume in the residual ridge defect and can be considered for the treatment of moderate to severe maxillary anterior ridge defects.

  9. Eletrólise de resíduos poluidores: I - Efluente de uma indústria liofilizadora de condimentos Electrolysis of polluting wastes: I - Wastewater from a seasoning freeze-drying industry

    Directory of Open Access Journals (Sweden)

    Dejanira F. de Angelis

    1998-02-01

    Full Text Available Wastewater from a seasoning freeze-drying industry was electrolysed to increase its biodegradability. Stainless-steel electrodes were used at 9.09 A/m², for up to 80 min. Conductivity, pH, biochemical (BOD and chemical (COD oxygen demands, Daphnia similis acute toxicity bioassays, and bacteria counting through the plate count agar method were determined after different times of electrolysis. The results (e.g. higher BOD and lower COD showed that the biodegradability of the wastewater was significantly increased; furthermore, Fe2+ ions liberated by the electrodes cause microorganisms to die and, when oxidised to Fe3+, contribute for the flocculation and sedimentation of solid residues.

  10. 提高冻干鱿鱼熟片复水性的初步研究%The preliminary research on improving rehydration of freeze-dried cooked squid

    Institute of Scientific and Technical Information of China (English)

    刘娟娟; 丁顒; 方旭波; 陈小娥; 余辉

    2012-01-01

    Freeze-dried cooked squid was regarded as research subject, the impact of 6 kinds of amendment such as fucose, hydrogenated starch hydrolysates, dextrin, sucrose, sorbitol and fructooligosaccharide on the rehydration it was studyed. The best combination was gained from single factors and orthogonal experiments. The results showed that fucose, hydrogenated starch hydrolysates and sucrose could get better effect. The best combination was fucose 3%, hydrogenated starch hydrolysates 4% and sucrose 2%. Under this condition, the rehydration ratio of freeze-dried squid was observed to be 5.163.%以冷冻干燥鱿鱼熟片为研究对象,研究了海藻糖、还原淀粉水解物、糊精、蔗糖、山梨糖醇及低聚果糖6种改良剂对冻干鱿鱼熟片的复水效果影响,并通过单因素、正交实验筛选出复配的优化组合,结果表明:复水效果较好的分别为海藻糖、还原淀粉水解物和蔗糖。3种改良剂的优化配比是海藻糖3%,还原淀粉水解物4%,蔗糖2%。此条件下测得冻干鱿鱼复水比高达5.163。

  11. 保加利亚乳杆菌冷冻干燥保护剂的研究%Study on the freeze-drying protective agents of Lactobacillus Bulgaricus

    Institute of Scientific and Technical Information of China (English)

    赵斌; 张建志; 李妍; 张列兵

    2013-01-01

    In order to obtain the optimal vacuum freeze-drying protectant formula for Lactobarillus bulgaricus, the effect of different protective agents on the survival rate of Lactobacillus bulgaricus was detected, while the 10% skim milk was utilized as the basic protectant. According to results of single-factor test and the L9(34)orthogonal optimization experiments, the optimal protectant formula was finally obtained: skim milk, 100 g/L; sodium glutamate, 25 g/L; ascorbic acid 0.5 g/L; glycerol 60 mL/L and yeast extract 1 g/L. Under this protectant formula, the survival rate of Lactobacillus bulgaricus after vacuum freeze-drying reached 60.59%.%为获得对保加利亚乳杆菌最佳的真空冷冻干燥保护剂的配方,在以10%脱脂乳为基础保护剂的情况下,采用单因素和正交试验设计,以冻干后的存活率为指标,考察了不同冻干保护剂对保加利亚乳杆菌冷冻干燥的保护效果,获得了最优的保护剂配方,即脱脂乳100 g/L,谷氨酸钠25 g/L,抗坏血酸0.5 g/L,甘油60mL/L,酵母浸粉1 g/L.使用此保护剂配方,保加利亚乳杆菌冻干后的存活率可达60.59%.

  12. PENGARUH DEFATTING, FREKUENSI PENCUCIAN DAN JENIS DRYOPROTECTANT TERHADAP MUTU TEPUNG SURIMI IKAN LELE KERING BEKU [Effect of Defatting, Washing Cycle and Dryoprotectant Type on the Quality of Freeze Dried Catfish Surimi Powder

    Directory of Open Access Journals (Sweden)

    Wahyu Ramadhan*

    2014-06-01

    Full Text Available Freeze dried surimi powder is a surimi type processed by freeze drying. To utilize oversized catfish and to reduce surimi handling cost, oversized catfish has been used as raw material of surimi powder. The study aimed to determine the effect of defatting (NaHCO3 concentration and soaking duration, washingcycle,and dryoprotectant type on catfish surimi, as well as quality differences between surimi powder and wet surimi. With regard to defatting step, soaking in NaHCO3 0.75% for 10 minutes was found as the best treatment and resulting in a fat content of 1.52%. Moreover, one time of washing cycle was found as the most appropriate procedure to obtain a superior quality of surimi with whiteness value 57.21%, water holding capacity 73.28%, salts soluble protein 7.17%, pH 6.69, and gel strength 482.3 g/cm2, folding value of 4.84, and teeth cutting value of 8.26. Trehalose 6% was the most suitable dryoprotectant resulting in surimi powder with water holding capacity of 8.01 mL/g, gel strength 826.3 g/cm2, salt soluble protein 18.98%, density 4.06 mL/10 g, rehydration capacity 3.81, emulsion capacity 69.3%, emulsion stability 59.3%, foaming capacity 25.33% and foaming stability 9.40%. The microstructure profile of surimi powder added with trehalose had more compact tissues, without any damage and clots, than that treated with other dryoprotectants. However, surimi powder still had lower protein content than wet surimi, and lower physical and chemical properties, particularly in its teeth cutting and folding characteristics.

  13. Release characteristics of doxycycline chitosan nanoparticles freeze-dried powder in vitro and in vivo%强力霉素壳聚糖纳米粒冻干粉的体内外释药特性

    Institute of Scientific and Technical Information of China (English)

    沈丹怡; 艾晓辉; 刘永涛; 丁运敏; 余少梅; 索纹纹

    2012-01-01

    This paper is to study the release characteristics of doxycycline (DC) raw material drug and doxycycline chitosan nanoparticles (DC-CS-NPs) freeze-dried powder in vitro and in vivo by ultraviolet spectrophotometry and ultra performance liquid chromatography, respectively. Results showed that the release behaviors of DC raw material drug were simulated the most in the zero order dynamic equation in artificial gastric juice, artificial intestinal juice and pH 7.4 buffer phosphate. The release of DC raw material drug was fast which could completely dissolve in one hour; The DC-CS-NPs freeze-dried powder had a significant slow-release characteristic. The release behaviors were simulated the most in the biexponential equation. The drug released fast in the early stage while it released slowly later. The order of release speed of DC-CS-NPs freeze-dried powder from fast to slow was pH 2.0 artificial gastric juice, pH 3.0 artificial gastric juice, pH 4.0 artificial gastric juice, artificial intestinal juice and pH 7.4 buffer phosphate. When DC raw material drug became DC-CS-NPs freeze-dried powder, after a single oral administration at a dose of 20 mg/kg at (25±1) ℃, the double-peak phenomenon of plasma in channel catfish was turned into single-peak, and the pharmacokinetic parameters of DC-CS-NPs freeze-dried powder were changed. Compared to DC raw material drug, the peak concentration (Cmax) decreased. The peak time (Tmax) and terminal elimination half-life (T1/2β) prolonged. The area under concentration-time curve (AUC) was larger. The DC-CS-NPs freeze-dried powder will become an ideal DC new formulation.%分别采用紫外分光光度法和超高效液相色谱法研究强力霉素原料药与强力霉素壳聚糖纳米粒冻干粉的体内外释药特性.结果表明:强力霉素原料药在人工胃液、肠液和pH7.4磷酸缓冲液中的体外释放均可用零级动力学方程拟合,释放较快,在1h内能完全溶出;强力霉素壳聚糖纳米粒冻干

  14. Freeze-drying process optimization and characteristics of PEG modified artemisinin-loaded nanostructured lipid carriers%聚乙二醇修饰青蒿素脂质纳米粒冻干工艺优化及其表征

    Institute of Scientific and Technical Information of China (English)

    赵青; 王芳; 王锐利; 张丽锋; 张淑秋

    2015-01-01

    Objective To screen the optimal formula of cryoprotectants for PEG modified artemisinin-loaded nanostructured lipid carriers (PEG-ART-NLC) and to investigate its freeze-drying process and characteristics. Methods Different cryoprotectants were used to prepare PEG-ART-NLC freeze-drying powder. The cryoprotectants were optimized based on the appearance, redispersibility, redissolved appearance, particle size and Zeta potential of the PEG-ART-NLC freeze-drying powder. The quality changes of PEG-ART-NLC before and after freeze-drying were compared. Results The mixture of 4%mannitol and 4%sucrose showed good protective effect and redispersibility. The PEG-ART-NLC par-ticle size was increased by 14.0 nm, and the Zeta potential absolute value and encapsulation efficiency were decreased by 8.8 mV and 14.5%, respectively. The morphology of the PEG-ART-NLC freeze-drying powder was round or oval un-der electron microscope before and after freeze-drying, without significant differences. Conclusion A stable kind of PEG-ART-NLC freeze-drying powder can be prepared by the optimal cryoprotectants of 4%mannitol and 4%sucrose.%目的:筛选聚乙二醇(PEG)修饰青蒿素脂质纳米粒(PEG-ART-NLC)最优冻干保护剂处方,研究其冷冻干燥工艺及质量表征。方法制备含不同冻干保护剂的PEG-ART-NLC冻干粉,以外观、再分散性、复溶后外观、粒径、Zeta电位为指标,优化保护剂处方,并对比冻干前后脂质纳米粒质量变化。结果4%甘露醇和4%蔗糖具良好的保护作用和再分散性,冻干后纳米粒粒径增大14.0 nm,Zeta电位绝对值降低8.8 mV,包封率降低14.5%,电镜下冻干前后纳米粒形态均为圆形或椭圆形,无明显差异。结论4%甘露醇和4%蔗糖为最优保护剂处方,可用于制备稳定的PEG-ART-NLC冻干粉。

  15. Preparation of freeze-dried recombinant hepatitis B vaccine (CHO cells) reference%重组乙型肝炎疫苗(CHO细胞)冻干参考品的研制

    Institute of Scientific and Technical Information of China (English)

    邱少辉; 郭玉芬; 钟熙; 胡忠玉; 方鑫; 何鹏; 梁争论; 张红霞; 张卫婷; 赵坤福; 李德桂; 周根喜

    2012-01-01

    目的 制备重组乙型肝炎疫苗(CHO细胞)冻干参考品,用于重组乙型肝炎疫苗(CHO细胞)的效力评价.方法 选取检定合格的重组乙型肝炎疫苗(CHO细胞)原液,经协作标定表面抗原蛋白含量后,加入氢氧化铝佐剂和冻于保护剂,冷冻干燥制备重组乙型肝炎疫苗(CHO细胞)冻干参考品,并按《中国药典》三部(2010版)要求进行各项检定.经10次独立试验测定冻干参考品小鼠效力,采用Reed-Münch计算ED50值;将冻干参考品置4℃(8周)、37℃(4和8周)后分别检测疫苗效力,分析其稳定性,依据Q10法进行效期推测;并对2个生产企业10批疫苗进行效力测定,分析其适用性.结果 制备的冻干参考品各项指标均符合规定,小鼠ED50均值为0.183μg,CV为50.5%;该CHO细胞效力冻干参考品蛋白含量定为20 μg/ml,规格为10 μg/0.5 ml;冻干保护剂、冻干工艺对乙型肝炎疫苗(CHO细胞)的效力影响较小,冻干参考品在37℃放置不同时间,效力变化不明显,表明冻干参考品稳定性较好,有效期约为7年;10批疫苗中,不合格率为10%,表明该参考品可用于乙型肝炎疫苗(CHO细胞)效力质控.结论 制备的冻干参考品可作为重组乙型肝炎疫苗(CHO细胞)效力检定的质控参考品.%Objective To prepare freeze-dried recombinant hepatitis B vaccine(CHO cells) reference for evaluation of potency of recombinant hepatitis B vaccine (CHO cells). Methods Bulk of qualified recombinant hepatitis B vaccine (CHO cells) was se-lected as the raw material of reference. After collaborative calibration of HBsAg content, the bulk was added with aluminium adjuvant and preservative, then lyophilized to prepared freeze-dried recombinant hepatitis B vaccine reference on which overall control tests were performed according to the requirements in Chinese Pharmacopoeia (Volume Ⅲ, 2010 edition). The potency of the freeze-dried reference was determined by ten independent tests in mice, and

  16. 益生菌冻干保护剂优化及菌粉保存稳定性研究%Optimization of cryoprotectants and stability of freeze-dried probiotics during storage

    Institute of Scientific and Technical Information of China (English)

    田芬; 陈俊亮; 霍贵成

    2012-01-01

    以嗜酸乳杆菌KLDS AD1和KLDS AD2和双歧杆菌KLDS 2.0604为研究对象,研究冻干保护剂脱脂乳、蔗糖、海藻糖、葡聚糖和Vc钠盐对各菌株冻干存活率的影响,通过单因素、正交实验筛选出优化组合,得出冻干存活率均在87.81%以上。并研究采用优化后的冻干保护剂制备的各菌粉在4℃和25℃下的保存稳定性。保存稳定性实验表明:3株益生菌菌粉在4℃和25℃下保存12个月后,菌粉的活菌数最多下降2个数量级,其活菌数均在1.0×108cfu/g以上。%This paper regards two L.acidophilus of KLDS AD1 and KLDS AD2 and one Bifidobacterium of KLDS 2.0604 as research subjects, assessing the impact of cryoprotectants skim milk, saccharose, trehalose, dextran and Vc sodium salt on the survival rate of each freeze-dried probiotic powder during storage. The optimal combination gained from single factors and orthogonal experiments demonstrates that the freeze-dried survival rates of three strains are all above 87.81%. It also assesses the stability of each probiotic powder made of cryoprotectants after optimization during storage under 4 % and 25 ℃. The stability dates suggests that the viable cell counts of three probiotic powder are all above 1.0×10^8cfu/g after 12 months' storage under 4 % and 25℃, and viable cell counts of probiotic powder declines 2 order of magnitude at maximum

  17. 酶解加工多肽兔肉松工艺%Optimization of Enzymatic Hydrolysis Rabbit Meat and Formulation and Vacuum Freeze-drying of Rabbit Meat Floss

    Institute of Scientific and Technical Information of China (English)

    王卫; 李翔; 张佳敏; 刘达玉; 张崟

    2011-01-01

    目的:研究将现代生物酶解技术与传统肉松加工技术结合,并通过添加富含维生素的胡萝卜等成分,开发集营养、保健、消闲为一体的方便肉松制品。方法:应用单因素比较结合正交试验设计,对兔肉蛋白酶解条件,影响肉粉松感官质量的配方,以及冷冻干燥工艺参数进行实验研究。结果:酶解用木瓜蛋白酶在温度50℃、时间6h、加酶量2%、pH7.0、固液比1:4条件下进行;在兔肉糜中添加4%大豆分离蛋白和50%复合果蔬泥时,兔肉松的质量最好;真空冷冻干燥最优工艺条件确定为装料厚度3mm,预冻温度-25~-30℃、干燥仓压力40Pa、升华%Rabbit meat was hydrolyzed with papain and the hydrolysate was used to develop nutritional and healthcare floss with the addition of carrot rich in vitamins and other ingredients. In order to maximize hydrolysis degree, the optimization of the hydrolysis conditions of rabbit meat were performed using one-factor-at-a-time combined with orthogonal array design method, and this method was also used to optimize process conditions for the vacuum freeze-drying of rabbit meat floss for achieving maximum comprehensive sensory score. The optimal hydrolysis conditions were found as follows: temperature 50 ℃, hydrolysis lime 6 h, pH 7.0, enzyme dosage 2%, and solid-to-liquid ratio 1:4. Rabbit meat floss formulated with the hydrolysate obtained under the optimal hydrolysis conditions and 4% soybean protein isolate and 50% compound fruit puree showed the best quality. The optimal vacuum freeze-drying conditions were filling thickness of 3 mm, pre-freeze temperature between - 25 and - 30 ℃ ,dry container pressure of 40 Pa, sublimation temperature of 60 ℃, analytical temperature of 20℃, and analytical pressure 40 Pa.

  18. Determination of plasma protein binding rate both in Polygonum orientale L.extract and compound Hongcao freeze-dried powder for injection by equilibrium dialysis%平衡透析法研究荭草及其制剂的人血浆蛋白结合率

    Institute of Scientific and Technical Information of China (English)

    黄勇; 陈慧; 何峰; 张治蓉; 王永林

    2012-01-01

    OBJECTIVE To determine and compare the plasma protein binding rate of two kinds of compounds in the extraction of Polygonum orientate and compound Hongcao freeze-dned powder for injection by equilibrium dialysis method. METHODS Equilibrium dialysis method combined with liquid chromatography-tandem mass spectrometry (UPLC-ESI-MS/MS) was employed to determine t