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Sample records for preparation pharmaceutical compositions

  1. [Bioequivalence studies of pharmaceutical preparations].

    Science.gov (United States)

    Vetchý, D; Frýbortová, K; Rabisková, M; Danecková, H

    2007-01-01

    Bioequivalence studies are very important for the development of a pharmaceutical preparation in the pharmaceutical industry. Their rationale is the monitoring of pharmacokinetic and pharmacodynamic parameters after the administration of tested drugs. The target of such study is to evaluate the therapeutic compatibility of tested drugs (pharmaceutical equivalents or pharmaceutical alternatives). The importance of bioequivalence studies is increasing also due to the large growth of the production and consumption of generic products. Generic products represent approximately 50 % of the whole consumption in many European countries and USA. The search output of bioequivalence study is together with the pharmaceutical quality data of medical product one of the main part of the registration file submitted to a national regulatory authorities. The registration of generic products does not demand complicated and expensive clinical study contrary to original product. The comparison of the original and the generic product via bioequivalence study is suggested as sufficient. The aim of this article is to provide to a medical public a summary about the types of bioequivalence studies, their range, rules of their practise and let them gain their own attitude to this question.

  2. Sample Preparation for Bioanalytical and Pharmaceutical Analysis.

    Science.gov (United States)

    Clark, Kevin D; Zhang, Cheng; Anderson, Jared L

    2016-12-06

    Biological and pharmaceutical samples represent formidable challenges in sample preparation that hold important consequences for bioanalysis and genotoxic impurity quantification. This Feature will emphasize significant advances toward the development of rapid, sensitive, and selective sample preparation methods.

  3. Pharmaceutical compositions and methods for treating tuberculosis

    NARCIS (Netherlands)

    van der Geize, Robert; Dijkhuizen, Lubbert; Ostendorf, Martin; van der Meijden, Peter

    2010-01-01

    A pharmaceutical composition for the treatment of a disease caused by a bacterium that belongs to the group of nocardioform actinomycetes, said composition comprising an effective amount of a compound selected from compound I, (+)-compound II, (-)- compound II, compound III, or mixtures thereof.

  4. Spectrofluorimetric determination of fluoroquinolones in pharmaceutical preparations

    Science.gov (United States)

    Ulu, Sevgi Tatar

    2009-02-01

    Simple, rapid and highly sensitive spectrofluorimetric method is presented for the determination of four fluoroquinolone (FQ) drugs, ciprofloxacin, enoxacin, norfloxacin and moxifloxacin in pharmaceutical preparations. Proposed method is based on the derivatization of FQ with 4-chloro-7-nitrobenzofurazan (NBD-Cl) in borate buffer of pH 9.0 to yield a yellow product. The optimum experimental conditions have been studied carefully. Beer's law is obeyed over the concentration range of 23.5-500 ng mL -1 for ciprofloxacin, 28.5-700 ng mL -1 for enoxacin, 29.5-800 ng mL -1 for norfloxacin and 33.5-1000 ng mL -1 for moxifloxacin using NBD-Cl reagent, respectively. The detection limits were found to be 7.0 ng mL -1 for ciprofloxacin, 8.5 ng mL -1 for enoxacin, 9.2 ng mL -1 for norfloxacin and 9.98 ng mL -1 for moxifloxacin, respectively. Intra-day and inter-day relative standard deviation and relative mean error values at three different concentrations were determined. The low relative standard deviation values indicate good precision and high recovery values indicate accuracy of the proposed methods. The method is highly sensitive and specific. The results obtained are in good agreement with those obtained by the official and reference method. The results presented in this report show that the applied spectrofluorimetric method is acceptable for the determination of the four FQ in the pharmaceutical preparations. Common excipients used as additives in pharmaceutical preparations do not interfere with the proposed method.

  5. Compounds, compositions, pharmaceutical compositions, and methods of use

    Energy Technology Data Exchange (ETDEWEB)

    Hammond, Gerald B.; Jin, Zhuang; Bates, Paula J.; Reyes-Reyes, Elsa Merit

    2016-11-15

    Certain embodiments of the invention include compositions comprising a compound of Formula (I), and salts, isomers, and derivatives thereof. Pharmaceutical compositions of some embodiments of the present invention comprise a compound of Formula (I), and salts, isomers, and derivatives thereof. Other embodiments of this invention include methods for treating disease (e.g., cancer) and methods for administering a compound of Formula (I), and salts, isomers, and derivatives thereof.

  6. Compounds, compositions, pharmaceutical compositions, and methods of use

    Science.gov (United States)

    Hammond, Gerald B.; Jin, Zhuang; Bates, Paula J.; Reyes-Reyes, Elsa Merit

    2016-11-15

    Certain embodiments of the invention include compositions comprising a compound of Formula (I), and salts, isomers, and derivatives thereof. Pharmaceutical compositions of some embodiments of the present invention comprise a compound of Formula (I), and salts, isomers, and derivatives thereof. Other embodiments of this invention include methods for treating disease (e.g., cancer) and methods for administering a compound of Formula (I), and salts, isomers, and derivatives thereof.

  7. Spectrophotometric determination of cefaclor in pharmaceutical preparations

    Directory of Open Access Journals (Sweden)

    Ivama Viviane M.

    1999-01-01

    Full Text Available A simple spectrophotometric method is proposed for the determination of cefaclor. The method involves alkaline hydrolysis of the drug in ammonia buffer solution at pH 10 to yield diketopiperazine-2,5-dione derivative and subsequent measurement at 340 nm. Beer's law is obeyed in the concentration range 1.8 - 55 mg/mL. The proposed method was successfully applied to the determination of cefaclor in pharmaceutical formulations.

  8. Lipids in pharmaceutical and cosmetic preparations

    Directory of Open Access Journals (Sweden)

    González Rodríguez, María Luisa

    2000-04-01

    Full Text Available In this paper, a review of the applications of lipids in the pharmaceutical field has been reported. In a first stage, different lipids used as excipients in cosmetics and medicines have been described. Many vegetable oils are used in this sense: almond oil, apricot oil, avocado oil, borage oil, coffee oil, safflower oil, etc.; from de animal source, fish oil and bird oil can be employed as excipients in cosmetical formulations. Fats and waxes may be also used for this purpose. A broad range of phospholipids are suitable for use in cosmetics, pharmaceuticals and diagnosis. These substances are used as vehicle for therapeutic substances, such as liposomes. Finally, a study of lipids, as a function of their biological activity, as active substances for the elaboration of pharmaceuticals, cosmetics or nutritional supplements, was carried out. Carotenoids, retinoids, tocopherols are used for their antioxidant properties, that are important to health and diagnostic medicine.En el presente trabajo se ha llevado a cabo una revisión sobre las aplicaciones de los lípidos en el campo famacéutico. En un primer apartado, se describieron los diferentes lípidos utilizados como excipientes en cosmética y medicina. En este sentido, se utilizan muchos aceites vegetales, como el aceite de almendra, albaricoque, aguacate, borraja, café, cártamo, etc.; a partir de fuente animal, pueden emplearse como excipientes en formulaciones cosméticas los aceites de pescados y de aves. También se utilizan con este propósito las grasas y las ceras. Así mismo se revisan los fosfolípidos empleados en cosmética y en diagnosis, que actúan como vehículos transportadores de sustancias activas, como los liposomas. Finalmente, se llevó a cabo un estudio de los lípidos, en función de su actividad biológica, como sustancias activas que forman parte de la elaboración de formulaciones cosméticas, farmacéuticas o suplementos nutricionales. Los carotenoides, retinoides

  9. Polarographic determination of loratadine in pharmaceutical preparations.

    Science.gov (United States)

    Squella, J A; Sturm, J C; Diaz, M A; Pessoa, H; Nuñez-Vergara, L J

    1996-12-01

    Loratadine, a potent antihistamine drug, is not directly electroreducible at a dropping mercury electrode; however, by means of a nitration procedure it is possible to obtain a nitro-loratadine derivative which has been identified as 4-(8-chloro-7-nitro-5,6-dihydro-11 H-benzo-[5,6]-cyclohepta-[l,2-b]-pyridin-l l-ylidene)-1-piperidine carboxylic acid ethyl ester. The electrochemical reduction of this derivative at different pHs and concentrations using polarography and cyclic voltammetry was studied. The derivative exhibits a differential pulse polarographic peak due to the reduction of the nitro group. This peak was used in order to develop an analytical procedure for determining loratadine in pharmaceutical dosage forms. The recovery study shows adequate accuracy and precision for the developed assay and the excipients do not interfere in the determination.

  10. WHO Expert Committee on Specifications for Pharmaceutical Preparations.

    Science.gov (United States)

    2014-01-01

    The Expert Committee on Specifications for Pharmaceutical Preparations works towards clear, independent and practical standards and guidelines for the quality assurance of medicines. Standards are developed by the Committee through worldwide consultation and an international consensus-building process. The following new guidelines were adopted and recommended for use, in addition to 20 monographs and general texts for inclusion in The International Pharmacopoeia and 11 new International Chemical Reference Substances. The International Pharmacopoeia--updating mechanism for the section on radiopharmaceuticals; WHO good manufacturing practices for pharmaceutical products: main principles; Model quality assurance system for procurement agencies; Assessment tool based on the model quality assurance system for procurement agencies: aide-memoire for inspection; Guidelines on submission of documentation for prequalification of finished pharmaceutical products approved by stringent regulatory authorities; and Guidelines on submission of documentation for a multisource (generic) finished pharmaceutical product: quality part.

  11. Stability of urea in solution and pharmaceutical preparations.

    Science.gov (United States)

    Panyachariwat, Nattakan; Steckel, Hartwig

    2014-01-01

    The stability of urea in solution and pharmaceutical preparations was analyzed as a function of temperature (25°-60°C), pH (3.11-9.67), and initial urea concentration (2.5%-20%). This study was undertaken to (i) obtain more extensive, quantitative information relative to the degradation of urea in both aqueous and non-aqueous solutions and in pharmaceutical preparations, and (ii) test the effects of initial urea concentration, pH, buffer, and temperature values on urea degradation. The stability analysis shows that urea is more stable at the pH range of 4-8 and the stability of urea decreases by increase in temperature for all pH values. Within the experimental range of temperature and initial urea concentration values, the lowest urea degradation was found with lactate buffer pH 6.0. The urea decomposition rate in solution and pharmaceutical preparations shows the dependence of the initial urea concentrations. At higher initial urea concentrations, the rate of degradation is a decreasing function with time. This suggests that the reverse reaction is a factor in the degradation of concentrated urea solution. For non-aqueous solvents, isopropanol showed the best effort in retarding the decomposition of urea. Since the losses in urea is directly influenced by its stability at a given temperature and pH, the stability analysis of urea by the proposed model can be used to prevent the loss and optimize the operating condition for urea-containing pharmaceutical preparations.

  12. Desloratadine analysis: as a pharmaceutical preparation and after accelerating ageing

    OpenAIRE

    Bober Katarzyna; Płonka Marlena; Miszczyk Marek

    2015-01-01

    Desloratadine is a biologically active compound that is not described in the Polish Pharmacopoeia IX, hence, its study is particular important. The aim of this work was to establish a procedure for desloratadine analysis by way of HPTLC in combination with densitometry, so as to be able to ascertain its presence and degree of presence within pharmaceutical preparations. In our work, a mixture of ethyl acetate, n-butanol, ammonia and methanol was used as the mobile phase. Moreover, HPTLC plate...

  13. WHO Expert Committee on Specifications for Pharmaceutical Preparations. Fiftieth report.

    Science.gov (United States)

    2016-01-01

    The Expert Committee on Specifications for Pharmaceutical Preparations works towards clear, independent and practical standards and guidelines for the quality assurance of medicines. Standards are developed by the Committee through worldwide consultation and an international consensus-building process. The following new guidelines were adopted and recommended for use. Good pharmacopoeial practices; FIP-WHO technical guidelines: points to consider in the provision by health-care professionals of children-specific preparations that are not available as authorized products; Guidance on good manufacturing practices for biological products; Guidance on good manufacturing practices: inspection report, including Appendix 1: Model inspection report; Guidance on good data and record management practices; Good trade and distribution practices for starting materials; Guidelines on the conduct of surveys of the quality of medicines; Collaborative procedure between the World Health Organization (WHO) prequalification team and national regulatory authorities in the assessment and accelerated national registration of WHO-prequalified pharmaceutical products and vaccines; Guidance for organizations performing in vivo bioequivalence studies; and World Health Organization (WHO) general guidance on variations to multisource pharmaceutical products.

  14. Determination of levodopa in pharmaceutical preparations by irreversible biamperometry

    Institute of Scientific and Technical Information of China (English)

    Li Jun Li; Qi Feng Chen; Hao Cheng; Lai Bo Yu; Jian Ling Wu

    2008-01-01

    Based on the electrocatalytic oxidation of levodopa at gold electrode and the reduction of permanganate at platinum electrode, a novel flow injection irreversible biamperometric method is developed for the determination of levodopa under the potential difference of 0 V imposed between two electrodes. In H2SO4 solution, the linear relationships between currents and the concentrations of levodopa are obtained in the range from 0.04mg/L to 20mg/L with the detection limit of 0.012mg/L. The proposed method is applied to the determination of levodopa in pharmaceutical preparations.

  15. ANTIBACTERIAL PROPERTIES OF PHARMACEUTICAL COMPOSITION OF HEPATOPROTECTORS

    Directory of Open Access Journals (Sweden)

    Aslanian MA

    2016-12-01

    Full Text Available Pathology problemof hepatobiliary system (HBS of contagious origin becomes relevant with the increase of disturbance and complications of lipid metabolism and bile pigments among young people. Leading role in prophylaxis and treatment in the context of this pathology belongs to antibacterialc hemotherapeutic agents. However, along with antimicrobial activity, numerous side effects can be observed during treatment with antibacterial agents. According to the recent study on hepatobiliary system (HBS, therapeutic effect can be seen only while using herbal medicine with choleretic action as well as their various compositions.Amountof medicine with the appropriate effect is insufficient, that is why the study was conducted towards finding effective combinations of plant substances of different groups for the purpose of creatingan effective medicine for treatment of hepatobiliary system (HBS of contagious origin. Aim of the work The purpose of study was to examine antibacterial properties of different combinations with flamin and lavender oil in combined medicine during the course of treatment of cholecystitis and cholangitis. Materials and methods. It the result of study 61 microbial strains were distinguished and identified from the pathological material taken from 53 patients with cholecystitis and cholangitis. All distinguished clinical microbial strains taken from the patients were tested for sensitivity to combined medicine in the form of tablets with flamin and lavender oil. Minimal inhibitory concentration for S. aureus АТСС 25923 amounted to 250-350 ug/ml, for E. coli АТСС 25922 - 350±50,0 ug/ml, for P. aeruginosa АТСС 27853 750±100,0 ug/ml, for Р. vulgaris АТСС 4636 - 850±100,0 ug/ml, minimal inhibitory concentration to the tablets № 2 та № 3 amounted to > 1000 мкг/мл. Minimal inhibitory concentration for B. subtilis АТСС 6633 amounted to 250±50,0 ug/ml, for C. albicans ATCC 885/653 300±50,0 ug

  16. Gravimetric method for the determination of diclofenac in pharmaceutical preparations.

    Science.gov (United States)

    Tubino, Matthieu; De Souza, Rafael L

    2005-01-01

    A gravimetric method for the determination of diclofenac in pharmaceutical preparations was developed. Diclofenac is precipitated from aqueous solution with copper(II) acetate in pH 5.3 (acetic acid/acetate buffer). Sample aliquots had approximately the same quantity of the drug content in tablets (50 mg) or in ampules (75 mg). The observed standard deviation was about +/- 2 mg; therefore, the relative standard deviation (RSD) was approximately 4% for tablet and 3% for ampule preparations. The results were compared with those obtained with the liquid chromatography method recommended in the United States Pharmacopoeia using the statistical Student's t-test. Complete agreement was observed. It is possible to obtain more precise results using higher aliquots, for example 200 mg, in which case the RSD falls to 1%. This gravimetric method, contrary to what is expected for this kind of procedure, is relatively fast and simple to perform. The main advantage is the absolute character of the gravimetric analysis.

  17. 75 FR 18548 - In the Matter of Certain Products and Pharmaceutical Compositions Containing Recombinant Human...

    Science.gov (United States)

    2010-04-12

    ... From the Federal Register Online via the Government Publishing Office INTERNATIONAL TRADE COMMISSION In the Matter of Certain Products and Pharmaceutical Compositions Containing Recombinant Human... pharmaceutical compositions containing recombinant human erythropoietin by reason of infringement of claims 1...

  18. Spectral analysis of pharmaceutical formulations prepared according to ancient recipes in comparison with old museum remains.

    Science.gov (United States)

    Gamberini, M Cristina; Baraldi, C; Freguglia, G; Baraldi, P

    2011-10-01

    A study of the composition of the remains of ancient ointments from museums was undertaken to enable understanding of the preparation techniques. Comparison of ancient recipes from different historical periods and spectroscopic characteristics of inorganic and/or organic remains recovered in museum vessels enabled preparation of ancient pharmaceutical-cosmetic formulations. Farmacopea Augustana by Occo was one the most important books studied for the 14 formulations prepared in the laboratory. Three formulations are discussed in detail and raw materials and new preparations were proposed for ozone ageing. The most important micro Raman results are discussed. The spectra of the raw materials lipids, beeswax, and resins are discussed; beeswax and pig suet (axŭngia) Raman spectra were found to be similar, but different from those of the aged oils. SERS was applied to ancient ointments and galbanum and the Raman spectra are reported and discussed for the first time.

  19. Pharmaceutical compositions comprising lubricants for preventing or reducing aseptic loosening in a subject

    DEFF Research Database (Denmark)

    2013-01-01

    The present invention relates to pharmaceutical compositions comprising one or more amphiphilic polymer lubricants for use in association with artificial orthopaedic implants. Additionally, the invention relates to medical use of the lubricants of the invention in connection with conditions...... associated with artificial5 orthopaedic implants. The invention furthermore relates to artificial joint implants comprising the polymer lubricants according to the invention and methods for preparing such implants....

  20. Toxic element contamination of natural health products and pharmaceutical preparations.

    Directory of Open Access Journals (Sweden)

    Stephen J Genuis

    Full Text Available BACKGROUND: Concern has recently emerged regarding the safety of natural health products (NHPs-therapies that are increasingly recommended by various health providers, including conventional physicians. Recognizing that most individuals in the Western world now consume vitamins and many take herbal agents, this study endeavored to determine levels of toxic element contamination within a range of NHPs. METHODS: Toxic element testing was performed on 121 NHPs (including Ayurvedic, traditional Chinese, and various marine-source products as well as 49 routinely prescribed pharmaceutical preparations. Testing was also performed on several batches of one prenatal supplement, with multiple samples tested within each batch. Results were compared to existing toxicant regulatory limits. RESULTS: Toxic element contamination was found in many supplements and pharmaceuticals; levels exceeding established limits were only found in a small percentage of the NHPs tested and none of the drugs tested. Some NHPs demonstrated contamination levels above preferred daily endpoints for mercury, cadmium, lead, arsenic or aluminum. NHPs manufactured in China generally had higher levels of mercury and aluminum. CONCLUSIONS: Exposure to toxic elements is occurring regularly as a result of some contaminated NHPs. Best practices for quality control-developed and implemented by the NHP industry with government oversight-is recommended to guard the safety of unsuspecting consumers.

  1. Desloratadine analysis: as a pharmaceutical preparation and after accelerating ageing

    Directory of Open Access Journals (Sweden)

    Bober Katarzyna

    2015-09-01

    Full Text Available Desloratadine is a biologically active compound that is not described in the Polish Pharmacopoeia IX, hence, its study is particular important. The aim of this work was to establish a procedure for desloratadine analysis by way of HPTLC in combination with densitometry, so as to be able to ascertain its presence and degree of presence within pharmaceutical preparations. In our work, a mixture of ethyl acetate, n-butanol, ammonia and methanol was used as the mobile phase. Moreover, HPTLC plates precoated with silica gel 60F254 were also employed. The proposed method was tested and subsequently validated. Spectrodensitometric analysis was then performed to determine the optimal wavelength for the quantitative determination (λ=276 nm, and following this, a quantitative analysis of desloratadine within certain pharmaceutical preparations was performed. Our research also took into consideration an analysis of the products of desloratadine decomposition that come about as a result of the accelerated aging of its solutions. The employed procedure for accelerating the aging of such desloratadine solutions consisted of heating these at 40℃ and then irradiating the solution surfaces with UV light. The changing color of these solutions after 2 hours of exposure served to indicate that degradation had occurred. Of note: as a result of irradiation with UV light, desloratadine content was seen to decrease with time, declining to almost zero after 30 hours. However, heating a solution of desloratadine alone did not induce a change in its content. Solutions of desloratadine that had previously undergone irradiation and heating were also analyzed to ascertain whether new substances were present. For this purpose, the GC-MS process was employed. As a result of this procedure, the spectrum of the solution after aging showed the presence of several new peaks that displayed retention several times larger and smaller than the normal desloratadine peak.

  2. Magnetic nanop articles for use in a pharmaceutical composition

    OpenAIRE

    Morales, M. P.; Gómez Roca, Alejandro; Serna, C. J.; Veintemillas-Verdaguer, S; Barber, Domingo F.; Mejías, Raquel; Pérez-Yagüe, Sonia

    2010-01-01

    [EN] The invention relates to a pharmaceutical composition that includes a magnetic nanoparticle and at least one active ingredient, preferably an antineoplastic or immunomodulator, for treating illnesses, in particular cancer. The nucleus of the magnetic nanoparticle includes a magnetic iron AA oxide. The surface of the nanoparticle includes ligands 'c".,,,' BB bonded thereto by means of an ionic bond, a covalent bond, a hydrogen bridge, a hydrophobic bond, an electro...

  3. Magnetic nanop articles for use in a pharmaceutical composition

    OpenAIRE

    Morales, M. P.; Roca, Alejandro G.; Serna, C. J.; Veintemillas-Verdaguer, S.; Domingo F. Barber; Mejías, Raquel; Pérez-Yagüe, Sonia

    2010-01-01

    [EN] The invention relates to a pharmaceutical composition that includes a magnetic nanoparticle and at least one active ingredient, preferably an antineoplastic or immunomodulator, for treating illnesses, in particular cancer. The nucleus of the magnetic nanoparticle includes a magnetic iron AA oxide. The surface of the nanoparticle includes ligands 'c".,,,' BB bonded thereto by means of an ionic bond, a covalent bond, a hydrogen bridge, a hydrophobic bond, an electro...

  4. Method for preparing ceramic composite

    Science.gov (United States)

    Alexander, Kathleen B.; Tiegs, Terry N.; Becher, Paul F.; Waters, Shirley B.

    1996-01-01

    A process for preparing ceramic composite comprising blending TiC particulates, Al.sub.2 O.sub.3 particulates and nickle aluminide and consolidating the mixture at a temperature and pressure sufficient to produce a densified ceramic composite having fracture toughness equal to or greater than 7 MPa m.sup.1/2, a hardness equal to or greater than 18 GPa.

  5. Preparation of liposomal brucine and its pharmaceutical/pharmacodynamic characterization

    Institute of Scientific and Technical Information of China (English)

    Xiang-qi QIN; Yuan YUAN; Chang-sheng LIU; Qiu-yun WANG; Xi SHEN; Bai-can YANG

    2007-01-01

    Aim:To prepare a novel transdermal preparation of liposomal brucine (LB) and investigate its pharmaceutical/pharmacodynamic characterization. Methods:LB was prepared by a modified ethanol-dripping method. Its drug encapsulation efficiency (EE),particle size,in vitro release,and skin permeation were studied.Furthermore,a safety evaluation and pharmacodynamic analysis of LB,including acute dermal toxicity,skin irritation,and analgesic and anti-inflammatory effects were investigated. Results:the EE of LB was 72% and the mean particle size of the liposomes was 55.4 nm. The in vitro release profile indicated that less than 68% of the encapsulated brucine was released in 10 h. A skin permeation study showed that compared with the free brucine,LB exhibited higher cumulative drug permeation through the skin and lower drug accumulation in skin tissue,indicative of an obvious promotion of skin permeation with liposomal encapsulation.The acute dermal LDs0 of LB was greater than 100 mg/kg (brucine content) and skin irritation tests revealed that LB had no irritation to both integrity and broken skin. A pharmacodynamic evaluation of LB was performed by xylene-induced mouse ear edema test and acetic acid-induced writhing test at the dosage of 1.5,3,and 6 mg/kg,respectively. The results showed that anti-inflammatory activities and analgesic effects of brucine encapsulated were significantly higher than that of the free brucine (P<0.01). Moreover,LB maintained a remarkably longer antiinflammatory and analgesic duration. Conclusion:It can be proposed that LB prepared here could represent a safe,effective and promising transdermal formulation for analgesic and anti-inflammatory effects.

  6. Novel HPLC Analysis of Hydrocortisone in Conventional and Controlled-Release Pharmaceutical Preparations

    Science.gov (United States)

    Oppong Bekoe, Samuel; Appiah, Enoch; Peprah, Paul

    2017-01-01

    An isocratic sensitive and precise reverse phase high-performance liquid chromatography (RP-HPLC) method was developed and validated for the determination and quantification of hydrocortisone in controlled-release and conventional (tablets and injections) pharmaceutical preparations. Chromatographic separation was achieved on an ODS (C18), 5 μm, 4.6 × 150 mm, with an isocratic elution using a freshly prepared mobile phase of composition methanol : water : acetic acid (60 : 30 : 10, v/v/v) at a flow rate of 1.0 ml/min. The detection of the drug was successfully achieved at a wavelength of 254 nm. The retention time obtained for the drug was 2.26 min. The proposed method produced linear detectable responses in the concentration range of 0.02 to 0.4 mg/ml of hydrocortisone. High recoveries of 98–101% were attained at concentration levels of 80%, 100%, and 120%. The intraday and interday precision (RSD) were 0.19–0.55% and 0.33–0.71%, respectively. A comparison of hydrocortisone analyses data from the developed method and the official USP method showed no significant difference (p > 0.05) at a 95% confidence interval. The method was successfully applied to the determination and quantification of hydrocortisone in six controlled-release and fifteen conventional release pharmaceutical preparations. PMID:28660092

  7. Development and Validation of a Chromatographic Method for the Analysis of Multicompound Pharmaceutical Preparations

    OpenAIRE

    Ferreyra, Carola; Ortiz, Cristina; Bertorello, M. M. De

    2000-01-01

    A reverse phase high performance liquid chromatographic assay was carried out for the simultaneous determination of two out of three active principles present in a pharmaceutical preparation. This method was developed to assess the quality of the product.

  8. A validated high performance thin layer chromatography method for determination of yohimbine hydrochloride in pharmaceutical preparations

    OpenAIRE

    Badr, Jihan M.

    2013-01-01

    Background: Yohimbine is an indole alkaloid used as a promising therapy for erectile dysfunction. A number of methods were reported for the analysis of yohimbine in the bark or in pharmaceutical preparations. Materials and Method: In the present work, a simple and sensitive high performance thin layer chromatographic method is developed for determination of yohimbine (occurring as yohimbine hydrochloride) in pharmaceutical preparations and validated according to International Conference of Ha...

  9. Pharmaceutical films made from the waste material from the preparation of propolis extracts: development and characterization

    Directory of Open Access Journals (Sweden)

    Lucas de Alcântara Sica de Toledo

    2015-12-01

    Full Text Available abstract This study investigated the development and characterized the physicochemical properties of films obtained from by-products (BP from the preparation of propolis extracts. Films were produced in the presence and absence of a polymeric adjuvant (gelatin or ethylcellulose and propylene glycol by a solvent casting method. Density, surface topography by scanning electron microscopy, mechanical properties (folding endurance, tensile strength and percentage elongation, water vapour permeability (WVP, moisture uptake capacity, thermogravimetry, differential scanning calorimetry and Fourier transform infrared spectroscopy (FTIR were determined. The films were a transparent, light greenish-yellow colour, with a uniform surface, and were flexible and easy to handle. The thickness and density of the preparations indicated that the compounds were homogeneously dispersed throughout the film. Mechanical properties were influenced by the film composition; films containing gelatin were more resistant to stress, while those containing ethylcellulose were more flexible. Increasing the adjuvant concentration decreased the elasticity and the rupture resistance, but increased the moisture uptake capacity and WVP of the formulations. BP was thermally stable as were the films. FTIR tests suggested interactions between BP and the adjuvants. This work could contribute to the utilization of BP to prepare films for food and pharmaceutical uses

  10. Preparative chromatographic resolution of racemates using HPLC and SFC in a pharmaceutical discovery environment.

    Science.gov (United States)

    Miller, Larry; Potter, Matt

    2008-11-01

    The preparative chromatographic resolution of racemates has become a standard approach for the generation of enantiomers in pharmaceutical discovery laboratories. This paper will discuss the use of preparative HPLC and SFC to generate individual enantiomers for discovery activities. Analytical HPLC and SFC method development to rapidly screen chiral stationary phases and solvent combinations will be presented. The usefulness of preparative chromatographic resolution of racemates will be demonstrated through the presentation of numerous non-routine case studies from the laboratories at Amgen.

  11. PREPARATION OF LEUCITE-BASED COMPOSITES

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    Alexandra Kloužková

    2012-12-01

    Full Text Available The aim of this study was to prepare leucite dental composites from two separately synthesized components - tetragonal leucite and glassy matrix. The newly developed procedure is based on the preparation of crystalline tetragonal leucite powder by relatively low temperature synthesis under hydrothermal conditions. Matrix powder was prepared by a classical melting process and subsequent milling of the quenched glass. The dental composites were prepared by mixing of 10 wt. %, 20 wt. % and 30 wt. % of synthesized tetragonal leucite with glass powder followed by pressing and firing. The sintering process was observed by optical microscope and the optimal firing temperature for each composite was determined. Optical and electron microscopy was used to characterise the microstructure of the composites, especially the distribution of the leucite particles in the matrix. Dilatometric measurements proved that the coefficient of thermal expansion of the composites increased up to 44 % in comparison with the basic matrix.

  12. Infrared imaging spectroscopy and chemometric tools for in situ analysis of an imiquimod pharmaceutical preparation presented as cream

    Science.gov (United States)

    Carneiro, Renato Lajarim; Poppi, Ronei Jesus

    2014-01-01

    In the present work the homogeneity of a pharmaceutical formulation presented as a cream was studied using infrared imaging spectroscopy and chemometric methodologies such as principal component analysis (PCA) and multivariate curve resolution with alternating least squares (MCR-ALS). A cream formulation, presented as an emulsion, was prepared using imiquimod as the active pharmaceutical ingredient (API) and the excipients: water, vaseline, an emulsifier and a carboxylic acid in order to dissolve the API. After exposure at 45 °C during 3 months to perform accelerated stability test, the presence of some crystals was observed, indicating homogeneity problems in the formulation. PCA exploratory analysis showed that the crystal composition was different from the composition of the emulsion, since the score maps presented crystal structures in the emulsion. MCR-ALS estimated the spectra of the crystals and the emulsion. The crystals presented amine and C-H bands, suggesting that the precipitate was a salt formed by carboxylic acid and imiquimod. These results indicate the potential of infrared imaging spectroscopy in conjunction with chemometric methodologies as an analytical tool to ensure the quality of cream formulations in the pharmaceutical industry.

  13. Analysis of pharmaceutical preparations containing antihistamine drugs by micellar liquid chromatography.

    Science.gov (United States)

    Martínez-Algaba, C; Bermúdez-Saldaña, J M; Villanueva-Camañas, R M; Sagrado, S; Medina-Hernández, M J

    2006-02-13

    Rapid chromatographic procedures for analytical quality control of pharmaceutical preparations containing antihistamine drugs, alone or together with other kind of compounds are proposed. The method uses C18 stationary phases and micellar mobile phases of cetyltrimethylammonium bromide (CTAB) with either 1-propanol or 1-butanol as organic modifier. The proposed procedures allow the determination of the antihistamines: brompheniramine, chlorcyclizine, chlorpheniramine, diphenhydramine, doxylamine, flunarizine, hydroxyzine, promethazine, terfenadine, tripelennamine and triprolidine, in addition to caffeine, dextromethorphan, guaifenesin, paracetamol and pyridoxine in different pharmaceutical presentations (tablets, capsules, suppositories, syrups and ointments). The methods require minimum handling sample and are rapid (between 3 and 12 min at 1 mLmin(-1) flow rate) and reproducible (R.S.D. values<5%). Limits of detection are lower than 1 microgmL(-1) and the recoveries of the analytes in the pharmaceutical preparations are in the range 100+/-10%.

  14. Pharmaceutical Composition of Valsartan: β-Cyclodextrin: Physico–Chemical Characterization and Anti-Hypertensive Evaluation

    Directory of Open Access Journals (Sweden)

    Carlos Eduardo de Matos Jensen

    2010-06-01

    Full Text Available Valsartan, a water-insoluble drug, is mainly used in the treatment of hypertension albeit with reduced oral bioavailability. The aim of work was to develop a valsartan:β-cyclodextrin (VAL:β-CD pharmaceutical composition in order to improve its water solubility and bioavailability. The VAL:β-CD complexes were prepared by the kneading, solid dispersion and freeze-drying methods, of which the freeze-drying method (FDY was found to be the best to prepare an inclusion complex. A physical mixtyure PM was also prepared. Complexes were characterized by thermal analysis, Fourier transformed- infrared (FTIR spectroscopy, Powder X-ray diffractometry, intrinsic dissolution and NMR (2D-ROESY. Phase-solubility analysis showed AL-type diagrams with β-cyclodextrin (β-CD. Microcalorimetric titrations suggested the formation of 1:1 inclusion complex between VAL and β-CD. The apparent stability constants K1:1 calculated from phase-solubility plots were 165.4 M-1 (298 K, 145.0 M-1 (303 K and 111.3 M-1 (310 K. In vivo experiments in rats showed that reduction in arterial pressure for the FDY complex is better than with valsartan used alone. The better activity of FDY can be attributed to the higher solubility of valsartan after inclusion in the cyclodextrin cavity, as suggest by the intrinsic dissolution studies.

  15. The method of production and modification of highly disperse silica for pharmaceutical and cosmetic preparations

    Directory of Open Access Journals (Sweden)

    Nina N. Mofa

    2015-12-01

    Full Text Available The change in the dispersity, morphology and state of amorphous silicon dioxide (silica powder depending on the conditions of mechanochemical treatment (MCT in the mill of dynamic action and ultrasonic treatment (UST in different aqueous solution is considered. Production of silicon dioxide in a highly disperse state is of importance, when using it in cosmetic and pharmaceutical preparations. Nanosilicic compositions are effective for delivering medicines to the connective tissues of the skin structure. When dispersing powder as surfactant and modifying additives, we used monoatomic and triatomic alcohols as well as succinic and acetylsalicylic acids, which provide a high level of grinding, modification of the particle surface and stabilization of a highly active state of silicon dioxide. Electron-microscopic investigations on the morphology of particles showed their capsulation into dense modifying films under the conditions of MCT and UST. The use of acid modifiers in the process of MCT and UST of silicon dioxide powder resulted in formation of complex composition systems consisting of an inorganic nucleus and organic capsulating film. The state of the obtained modified powders was evaluated by the change of electrical resistance as one of the most sensitive indices of structural changes of the system being treated. The use of triatomic alcohol glycerine, when treating the powder, noticeably decreased its specific electrical resistance after UST, due to formation of hydroxylic groups on the surface of particles and accumulation of charged particles, which provide a high chemical activity of the systems. An important role of the capsulating polymer component on the surface of highly disperse particles of silicon dioxide for stabilization of a highly active state of the powder is shown.

  16. Preparation of Conductive Polymer Graphite (PG) Composites

    Science.gov (United States)

    Munirah Abdullah, Nur; Saddam Kamarudin, M.; Rus, Anika Zafiah M.; Abdullah, M. F. L.

    2017-08-01

    The preparation of conductive polymer graphite (PG) composites thin film is described. The thickness of the PG composites due to slip casting method was set approximately ~0.1 mm. The optical microscope (OM) and fourier transform infra-red spectroscopy (FTIR) has been operated to distinguish the structure-property relationships scheme of PG composites. It shows that the graphite is homogenously dispersed in polymer matrix composites. The electrical characteristics of the PG composite were measured at room temperature and the electrical conductivity (σ) was discovered with respect of its resistivity (Ω). By achieving conductivity of 103 S/m, it is proven that at certain graphite weight loading (PG20, PG25 and PG30) attributes to electron pathway in PG composites.

  17. Determination of bosentan in pharmaceutical preparations by linear sweep, square wave and differential pulse voltammetry methods.

    Science.gov (United States)

    Atila, Alptug; Yilmaz, Bilal

    2015-01-01

    In this study, simple, fast and reliable cyclic voltammetry (CV), linear sweep voltammetry (LSV), square wave voltammetry (SWV) and differential pulse voltammetry (DPV) methods were developed and validated for determination of bosentan in pharmaceutical preparations. The proposed methods were based on electrochemical oxidation of bosentan at platinum electrode in acetonitrile solution containing 0.1 M TBACIO4. The well-defined oxidation peak was observed at 1.21 V. The calibration curves were linear for bosentan at the concentration range of 5-40 µg/mL for LSV and 5-35 µg/mL for SWV and DPV methods, respectively. Intra- and inter-day precision values for bosentan were less than 4.92, and accuracy (relative error) was better than 6.29%. The mean recovery of bosentan was 100.7% for pharmaceutical preparations. No interference was found from two tablet excipients at the selected assay conditions. Developed methods in this study are accurate, precise and can be easily applied to Tracleer and Diamond tablets as pharmaceutical preparation.

  18. Pharmaceutical compositions for antihypertensive treatments: a patent review.

    Science.gov (United States)

    Kellici, Tahsin F; Liapakis, George; Tzakos, Andreas G; Mavromoustakos, Thomas

    2015-01-01

    New drug formulations against hypertension have a vital role in the quality of human life, as this risk factor for cardiovascular disease can be life threatening. A modern life style characterized by less exercise, smoking, drinking and poor diet has increased the risk of developing hypertension, the so-called silent killer, in civilized communities and thus an urgent defense is needed against this enemy. In this review, the authors provide extensive information on pharmaceutical formulations containing anti-hypertensive drugs, as well as on general and specific patents. Thus, readers can understand the advances and new trends in the field. A considerable effort has been made to provide new and improved formulations, comprising anti-hypertensive drugs with new excipients, appropriate particle size, containing alkaline salts or included in cyclodextrins in an attempt to avoid known existing problems. New types of formulations are expected to emerge in the near future that will allow for more effective and spatiotemporally controlled drug delivery, which will be better tolerated by the patients and will provide better pharmaceutical treatment. Such an example is the new cocktail formulations that contain more than one active component, act synergistically and therefore have optimized pharmacological benefits. Formulations using multitarget antihypertensive drugs are also expected to be commercially available in the near future.

  19. Extractive Spectrophotometric Method for the Determination of Lamivudine and Zidovudine in Pharmaceutical Preparations Using Bromocresol Purple

    Directory of Open Access Journals (Sweden)

    Serife Evrim Kepekci Tekkeli

    2013-01-01

    Full Text Available A new spectrophotometric method has been established for the quantitation of lamivudine (LVD and zidovudine (ZVD in pharmaceutical preparations. The method is based on the reaction between the investigated drug substances and bromocresol purple (BCP producing ion-pair complexes in acidic buffers which are suitable for chloroform extraction. The maximum absorbance of these complexes was measured at 424 nm in chloroform. All variables were studied to optimize the reaction conditions. Linearity ranges were found to be 25–250 μg mL−1 for LVD-BCP and 50–300 μg mL−1 for ZVD-BCP. The developed method was successfully applied for the determination of these drugs in pharmaceutical preparations. Excipients in pharmaceutical formulations did not interfere in the analysis. The results were compared statistically with those obtained by the HPLC method reported in the literature. According to the results, the proposed method can be recommended for quality control and routine analysis.

  20. Quantitation of antihistamines in pharmaceutical preparations by liquid chromatography with a micellar mobile phase of sodium dodecyl sulfate and pentanol.

    Science.gov (United States)

    Gil-Agustí, M; Monferrer-Pons, L; Esteve-Romero, J; García-Alvarez-Coque, M C

    2001-01-01

    A reversed-phase liquid chromatographic procedure with a micellar mobile phase of sodium dodecyl sulfate (SDS), containing a small amount of pentanol, was developed for the control of 7 antihistamines of diverse action in pharmaceutical preparations (tablets, capsules, powders, solutions, and syrups): azatadine, carbinoxamine, cyclizine, cyproheptadine, diphenhydramine, doxylamine, and tripelennamine. The retention times of the drugs were <9 min with a mobile phase of 0.15M SDS-6% (v/v) pentanol. The recoveries with respect to the declared compositions were in the range of 93-110%, and the intra- and interday repeatabilities and interday reproducibility were <1.2%. The results were similar to those obtained with a conventional 60 + 40 (v/v) methanol-water mixture, with the advantage of reduced toxicity, flammability, environmental impact, and cost of the micellar-pentanol solutions. The lower risk of evaporation of the organic solvent dissolved in the micellar solutions also increased the stability of the mobile phase.

  1. New spectrofluorimetric method for the determination of nizatidine in bulk form and in pharmaceutical preparations

    Science.gov (United States)

    Karasakal, Ayça; Ulu, Sevgi Tatar

    2013-08-01

    A simple, accurate and highly sensitive spectrofluorimetric method has been developed for determination of nizatidine in pure form and in pharmaceutical dosage forms. The method is based on the reaction between nizatidine and 1-dimethylaminonaphthalene-5-sulphonyl chloride in carbonate buffer, pH 10.5, to yield a highly fluorescent derivative peaking at 513 nm after excitation at 367 nm. Various factors affecting the fluorescence intensity of nizatidin-dansyl derivative were studied and conditions were optimized. The method was validated as per ICH guidelines. The fluorescence concentration plot was rectilinear over the range of 25-300 ng/mL. Limit of detection and limit of quantification were calculated as 11.71 and 35.73 ng/mL, respectively. The proposed method was successfully applied to pharmaceutical preparations.

  2. Simultaneous determination of acetylsalicylic and salicylic acids by first derivative spectrometry in pharmaceutical preparations

    Science.gov (United States)

    Rogić, Dunja

    1993-03-01

    A multicomponent first derivative UV spectrometric procedure for determination of acetylsalicylic acid (aspirin) and salicylic acid in the solution containing 1 % (w/v) of citric acid in some pharmaceutical preparations is presented. The method is based on the use of the first derivative minimum spectrometric measurements at 286 nm for aspirin and at 318 nm for salicylic acid. Four kinds of cmmercial Aspirin tablets were assayed without a long pretreatment of the pharmaceuticals from the tablet additives. Beer's law is obeyed from 13.62-68.1 μg ml -1 of aspirin and from 2.723-13.616 μg ml -1 of salicylic acid. Detection limits at the 0.05 level of significance were calculated to be 1.24 and 0.25 μg ml -1 with relative standard deviations of 1.09 % and 1.2 % of aspirin and salicylic acid, respectively.

  3. Preparation and Properties of Polyaniline Composite Films

    Institute of Scientific and Technical Information of China (English)

    ZHANG Qing-hua

    2002-01-01

    Polyaniline (PAn) was synthesized by chemical oxidation polymerization. The conductive polymer doped by camphor sulfonic acid (CSA) and a matrix polymer,polyamide- 66, polyamide - 1010 or polyamide- 11, were dissolved in m-cresol and the blend solution was cast in a glass and dried for preparing polyaniline composite films.Conductivity was from 10 -6 to 10 0Ω-1·cm-1 with different weight fraction of PAn-CSA. The crystallizttion of the films was studied by means of differential scanning calorimeter (DSC). The treatment of the composite films in different pH value solution would result in decrease of conductivity, especially in an alkaline solution.

  4. Influence of process parameters on the preparation of pharmaceutical films by electrostatic powder deposition.

    Science.gov (United States)

    Prasad, Leena Kumari; LaFountaine, Justin S; Keen, Justin M; Williams, Robert O; McGinity, James W

    2016-12-30

    Electrostatic powder deposition (ESPD) has been developed as a solvent-free method to prepare pharmaceutical films. The aim of this work was to investigate the influence of process parameters during (1) electrostatic powder deposition, (2) curing, and (3) removal of the film from the substrate on the properties of the film. Polyethylene oxide (PEO) was used as the model polymer and stainless steel 316 as the substrate. Deposition efficiency (i.e. deposited weight) was measured with varying charging voltage, gun tip to substrate distance, and environmental humidity. Scanning electron microscopy was utilized to assess film formation, and adhesive and mechanical strength of films were measured with varying cure temperature and time. Adhesive strength was measured for films prepared on substrates of varying surface roughness. When deposition was performed at low humidity conditions, 25%RH, process parameters did not significantly affect deposition behavior. At 40%RH, increasing deposition efficiency with decreasing gun tip to substrate distance and increasing voltage (up to 60kV) was observed. Complete film formation was seen by 30min at 80°C, compared to lower curing temperatures and times. All films were readily removed from the substrates. The results show the ESPD process can be modified to produce films with good mechanical properties (e.g. tensile strength>0.06MPa), suggesting it is a promising dry powder process for preparing pharmaceutical films.

  5. Spectrophotometric determination of dopaminergic drugs used for Parkinson's disease, cabergoline and ropinirole, in pharmaceutical preparations.

    Science.gov (United States)

    Onal, Armağan; Cağlar, Sena

    2007-04-01

    Simple and reproducible spectrophotometric methods have been developed for determination of dopaminergic drugs used for Parkinson's disease, cabergoline (CAB) and ropinirole hydrochloride (ROP), in pharmaceutical preparations. The methods are based on the reactions between the studied drug substances and ion-pair agents [methyl orange (MO), bromocresol green (BCG) and bromophenol blue (BPB)] producing yellow colored ion-pair complexes in acidic buffers, after extracting in dichloromethane, which are spectrophotometrically determined at the appropriate wavelength of ion-pair complexes. Beer's law was obeyed within the concentration range from 1.0 to 35 microg ml(-1). The developed methods were applied successfully for the determination of these drugs in tablets.

  6. A strategy for the identification of plants in illegal pharmaceutical preparations and food supplements using chromatographic fingerprints.

    Science.gov (United States)

    Deconinck, E; De Leersnijder, C; Custers, D; Courselle, P; De Beer, J O

    2013-03-01

    The detection of regulated and forbidden herbs in pharmaceutical preparations and nutritional supplements is a growing problem for laboratories charged with the analysis of illegal pharmaceutical preparations and counterfeit medicines. This article presents a feasibility study of the use of chromatographic fingerprints for the detection of plants in pharmaceutical preparations. Fingerprints were developed for three non-regulated common herbal products--Rhamnus purshiana, Passiflora incarnata L. and Crataegus monogyna--and this was done by combining three different types of detection: diode-array detection, evaporative light scattering detection and mass spectrometry. It is shown that these plants could be detected in respective triturations of the dry extracts with lactose and three different herbal matrices as well as in commercial preparations purchased on the open market.

  7. Determination of sulpiride in pharmaceutical preparations and biological fluids using a Cr (III) enhanced chemiluminescence method.

    Science.gov (United States)

    Khan, Muhammad Naeem; Jan, Muhammad Rasul; Shah, Jasmin; Lee, Sang Hak; Kim, Young Ho

    2013-01-01

    A highly sensitive and simple method for identifying sulpiride in pharmaceutical formulations and biological fluids is presented. The method is based on increased chemiluminescence (CL) intensity of a luminol-H2O2 system in response to the addition of Cr (III) under alkaline conditions. The CL intensity of the luminol-H2O2-Cr (III) system was greatly enhanced by the addition of sulpiride and the CL intensity was proportional to the concentration of sulpiride in a sample solution. Various parameters affecting the CL intensity were systematically investigated and optimized for determination of the sulpiride in a sample. Under the optimum conditions, the CL intensity was proportional to the concentration of sulpiride in the range of 0.068-4.0 µg/mL, with a good correlation coefficient of 0.997. The limit of detection (LOD) and limit of quantification (LOQ) were found to be 8.50 × 10(-6) µg/mL and 2.83 × 10(-5) µg/mL, respectively. The method presented here produced good reproducibility with a relative standard deviation (RSD) of 2.70% (n = 7). The effects of common excipients and metal ions were studied for their interference effect. The method was validated statistically through recovery studies and successfully applied for the determination of sulpiride in pure form, pharmaceutical preparations and spiked human plasma samples. The percentage recoveries were found to range from 99.10 to 100.05% for pure form, 98.12 to 100.18% for pharmaceutical preparations and 97.9 to 101.4% for spiked human plasma.

  8. Development and Validation of Spectrophotometric Methods for the Determination of Rasagiline in Pharmaceutical Preparations

    Directory of Open Access Journals (Sweden)

    Serife Evrim Kepekci Tekkeli

    2013-01-01

    Full Text Available This study presents three simple, rapid, and accurate spectrophotometric methods for the determination of Rasagiline (RSG in pharmaceutical preparations. The determination procedures depend on the reaction of RSG with chloranilic acid for method A, tetrachloro-1,4-benzoquinone for method B, and 7,7,8,8-tetracyanoquinodimethane for method C. The colored products were quantitated spectrophotometrically at 524, 535, and 843 nm for methods A, B, and C, respectively. Different variables affecting the reaction were optimized. Linearity ranges of the methods with good correlation coefficients (0.9988–0.9996 were observed as 25–300 µg mL−1, 25–350 µg mL−1, and 50–500 µg mL−1 for methods A, B, and C, respectively. The formation of products takes place through different mechanisms. The sites of interaction were confirmed by elemental analysis using IR and 1H-NMR spectroscopy. The validation of the methods was carried out in terms of specificity, linearity, accuracy, precision, robustness, limit of detection, and limit of quantitation. No interference was observed from concomitants usually present in dosage forms. The methods were applied successfully to the determination of RSG in pharmaceutical preparations.

  9. Negatively charged silver nanoparticles with potent antibacterial activity and reduced toxicity for pharmaceutical preparations.

    Science.gov (United States)

    Salvioni, Lucia; Galbiati, Elisabetta; Collico, Veronica; Alessio, Giulia; Avvakumova, Svetlana; Corsi, Fabio; Tortora, Paolo; Prosperi, Davide; Colombo, Miriam

    2017-01-01

    The discovery of new solutions with antibacterial activity as efficient and safe alternatives to common preservatives (such as parabens) and to combat emerging infections and drug-resistant bacterial pathogens is highly expected in cosmetics and pharmaceutics. Colloidal silver nanoparticles (NPs) are attracting interest as novel effective antimicrobial agents for the prevention of several infectious diseases. Water-soluble, negatively charged silver nanoparticles (AgNPs) were synthesized by reduction with citric and tannic acid and characterized by transmission electron microscopy, dynamic light scattering, zeta potential, differential centrifuge sedimentation, and ultraviolet-visible spectroscopy. AgNPs were tested with model Gram-negative and Gram-positive bacteria in comparison to two different kinds of commercially available AgNPs. In this work, AgNPs with higher antibacterial activity compared to the commercially available colloidal silver solutions were prepared and investigated. Bacteria were plated and the antibacterial activity was tested at the same concentration of silver ions in all samples. The AgNPs did not show any significant reduction in the antibacterial activity for an acceptable time period. In addition, AgNPs were transferred to organic phase and retained their antibacterial efficacy in both aqueous and nonaqueous media and exhibited no toxicity in eukaryotic cells. We developed AgNPs with a 20 nm diameter and negative zeta potential with powerful antibacterial activity and low toxicity compared to currently available colloidal silver, suitable for cosmetic preservatives and pharmaceutical preparations administrable to humans and/or animals as needed.

  10. Development and validation of microbial bioassay for quantification of Levofloxacin in pharmaceutical preparations

    Institute of Scientific and Technical Information of China (English)

    Nishant A. Dafale; Uttam P. Semwal; Piyush K. Agarwal; Pradeep Sharma; G.N. Singh

    2015-01-01

    The aim of this study was to develop and validate a simple, sensitive, precise and cost-effective one-level agar diffusion (5þ1) bioassay for estimation of potency and bioactivity of Levofloxacin in pharmaceutical preparation which has not yet been reported in any pharmacopoeia. Among 16 microbial strains, Bacillus pumilus ATCC-14884 was selected as the most significant strain against Levofloxacin. Bioassay was optimized by investigating several factors such as buffer pH, inoculums concentration and reference standard concentration. Identification of Levofloxacin in commercial sample Levoflox tablet was done by FTIR spectroscopy. Mean potency recovery value for Levofloxacin in Levoflox tablet was estimated as 100.90%. A validated bioassay method showed linearity (r2 ¼ 0.988), precision (Interday RSD ¼ 1.05%, between analyst RSD ¼ 1.02%) and accuracy (101.23%, RSD ¼ 0.72%). Bioassay was correlated with HPLC using same sample and estimated potencies were 100.90%and 99.37%, respectively. Results show that bioassay is a suitable method for estimation of potency and bioactivity of Levofloxacin pharmaceutical preparations.

  11. Conductive ceramic composition and method of preparation

    Science.gov (United States)

    Smith, J.L.; Kucera, E.H.

    1991-04-16

    A ceramic anode composition is formed of a multivalent metal oxide or oxygenate such as an alkali metal, transition metal oxygenate. The anode is prepared as a non-stoichiometric crystalline structure by reaction and conditioning in a hydrogen gas cover containing minor proportions of carbon dioxide and water vapor. The structure exhibits a single phase and substantially enhanced electrical conductivity over that of the corresponding stoichiometric structure. Unexpectedly, such oxides and oxygenates are found to be stable in the reducing anode fuel gas of a molten carbonate fuel cell. 4 figures.

  12. Preparation, characterization, and potential application of chitosan, chitosan derivatives, and chitosan metal nanoparticles in pharmaceutical drug delivery

    Directory of Open Access Journals (Sweden)

    Ahmed TA

    2016-01-01

    Full Text Available Tarek A Ahmed1,2 Bader M Aljaeid11Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, King Abdulaziz University, Jeddah, Kingdom of Saudi Arabia; 2Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, Al-Azhar University, Cairo, EgyptAbstract: Naturally occurring polymers, particularly of the polysaccharide type, have been used pharmaceutically for the delivery of a wide variety of therapeutic agents. Chitosan, the second abundant naturally occurring polysaccharide next to cellulose, is a biocompatible and biodegradable mucoadhesive polymer that has been extensively used in the preparation of micro- as well as nanoparticles. The prepared particles have been exploited as a potential carrier for different therapeutic agents such as peptides, proteins, vaccines, DNA, and drugs for parenteral and nonparenteral administration. Therapeutic agent-loaded chitosan micro- or nanoparticles were found to be more stable, permeable, and bioactive. In this review, we are highlighting the different methods of preparation and characterization of chitosan micro- and nanoparticles, while reviewing the pharmaceutical applications of these particles in drug delivery. Moreover, the roles of chitosan derivatives and chitosan metal nanoparticles in drug delivery have been illustrated.Keywords: nanoparticles, microparticles, preparation, characterization, pharmaceutical application

  13. Stability indicating LC method for simultaneous determination of irbesartan and hydrochlorothiazide in pharmaceutical preparations.

    Science.gov (United States)

    Rane, V P; Patil, K R; Sangshetti, J N; Yeole, R D; Shinde, D B

    2010-08-01

    A simple and precise stability-indicating liquid chromatography method is developed and validated for the quantitative simultaneous estimation of irbesartan (IRB) and hydrochlorothiazide (HCTZ) in combined pharmaceutical dosage form. A chromatographic separation of the two drugs was achieved with an Ace5 C(18) 25-cm analytical column using buffer-acetonitrile (70:30 v/v). The buffer used in mobile phase contains 50 mM ammonium acetate pH adjusted 5.5 with acetic acid. The instrumental settings are flow rate of 1.5 mL/min, column temperature at 30 degrees C, and detector wavelength of 235 nm using a photodiode array detector. IRB, HCTZ, and their combination drug products were exposed to thermal, photolytic, hydrolytic, and oxidative stress conditions, and the stressed samples were analyzed by the proposed method. Peak homogeneity data of IRB and HCTZ is obtained using photodiode array detector. In the stressed sample chromatograms, it demonstrated the specificity of the assay method for their estimation in presence of degradation products. The described method shows excellent linearity over a range of 10-200 microg/mL for IRB and 5-100 microg/mL for HCTZ. Methylparaben was used as internal standard. The correlation coefficient for IRB and HCTZ are 0.998 and 0.999. The mean recovery values for IRB and HCTZ ranged from 100.45% to 101.25%. The limit of detection for IRB and HCTZ were 0.019 and 0.023 microg/mL, respectively, and the limit of quantification were 0.053 and 0.070 microg/mL, respectively. The proposed method was suitable for quantitative determination and stability study of IRB and HCTZ in pharmaceutical preparations and also can be used in the quality control of bulk manufacturing and pharmaceutical dosage forms.

  14. Comparison of pharmaceutical properties of topical non-steroidal anti-inflammatory drug preparations on quality of life.

    Science.gov (United States)

    Shibata, Yuuka; Ikeda, Hiroaki; Kondou, Yoshihiro; Kihira, Kenji

    2005-05-01

    To compare the effects of different pharmaceutical properties of commercially available topical nonsteroidal antiinflammatory drugs (NSAIDs) on the quality of life, we administered a questionnaire to 65 healthy volunteers. We investigated five creams, five gels, and four solutions of topical NSAID preparations in this study. The survey was conducted to clarify the relationship of their answers and pharmaceutical properties of the topical NSAID preparations. Questions addressed spreadability, smell, viscosity, and comfort level of the topical NSAID preparations. Among the five creams, Napageln had lower spreadability, less smell, and greater viscosity than the other preparations. Because of its easy spreadability, weak smell, and low viscosity, the volunteers favored Sector cream among the cream preparations. Among the five gel preparations, Inteban had less spreadability, stronger smell, and higher viscosity than the other preparations. The volunteers favored Epatec over the other gel preparations. All four solutions had the odor of menthol and other artificial ingredients, except for Napageln. These findings indicate that information on the pharmaceutical properties of commercially available topical NSAID preparations will be helpful to physicians and pharmacists in conducting medical treatment and prescribing.

  15. Spectrophotometric determination of some histamine H1-antagonists drugs in their pharmaceutical preparations

    Science.gov (United States)

    Hassan, Wafaa S.; El-Henawee, Magda M.; Gouda, Ayman A.

    2008-01-01

    Two rapid, simple and sensitive extractive specrophotometric methods has been developed for the determination of three histamine H1-antagonists drugs, e.g., chlorphenoxamine hydrochloride (CPX), diphenhydramine hydrochloride (DPH) and clemastine (CMT) in bulk and in their pharmaceutical formulations. The first method depend upon the reaction of molybdenum(V) thiocyanate ions (Method A) with the cited drugs to form stable ion-pair complexes which extractable with methylene chloride, the orange red color complex was determined colorimetrically at λmax 470 nm. The second method is based on the formation of an ion-association complex with alizarin red S as chromogenic reagents in acidic medium (Method B), which is extracted into chloroform. The complexes have a maximum absorbance at 425 and 426 nm for (DPH or CMT) and CPX, respectively. Regression analysis of Beer-Lambert plots showed a good correlation in the concentration ranges of 5.0-40 and 5-70 μg mL -1 for molybdenum(V) thiocyanate (Method A) and alizarin red S (Method B), respectively. For more accurate analysis, Ringbom optimum concentration ranges were calculated. The molar absorptivity, Sandell sensitivity, detection and quantification limits were calculated. Applications of the procedure to the analysis of various pharmaceutical preparations gave reproducible and accurate results. Further, the validity of the procedure was confirmed by applying the standard addition technique and the results obtained in good agreement well with those obtained by the official method.

  16. Development and Validation of Selective Spectrophotometric Methods for the Determination of Pregabalin in Pharmaceutical Preparation

    Institute of Scientific and Technical Information of China (English)

    ARMA(G)AN,(O)nal

    2009-01-01

    Three simple,quick and sensitive methods are described for the spectrophotometric determination of pregabalin (Pgb) in pharmaceutical preparations.Among them,the first two methods are based on the reaction of Pgb as n-electron donors with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) and 7,7,8,8-tetracyanoquinodimethane (TCNQ) as π-acceptors to give highly colored complex species.The colored products were quantitated spectrophotometrically at 494 and 841 nm for DDQ and TCNQ,respectively.Optimization of the different experimental conditions was conducted.Beer's law was obeyed in the concentration ranges 2.0-30.0 and 1.5-10 μg·mL-1 for DDQ and TCNQ methods,respectively.The third method is based on the interaction of ninhydrin (NN) with primary amine present in the pregabaline.This reaction produces a blue coloured product in N,N-dimethylformamide (DMF) medium,which absorbs maximally at 573 nm.Beer's law was found in the concentration range 40.0-180.0 μg·mL-1.The methods were applied successfully to the determination of this drug in pharmaceutical dosage forms.

  17. Kinetic spectrophotometric determination of some fluoroquinolone antibiotics in bulk and pharmaceutical preparations

    Directory of Open Access Journals (Sweden)

    S. Abou Taleb

    2013-09-01

    Full Text Available A simple and sensitive kinetic spectrophotometric method was developed for the determination of some fluoroquinolonea antibiotics; gemifloxacin mesylate, moxifloxacin hydrochloride and gatifloxacin in bulk and in pharmaceutical preparations. The method is based upon a kinetic investigation of the oxidation reaction of the drugs with alkaline potassium permanganate at room temperature for a fixed time of 20 min for gemifloxacin and 15 min for moxifloxacin or gatifloxacin. The absorbance of the coloured manganate ion was measured at 610 nm. The absorbance–concentration plots were rectilinear over the ranges of 2.0-20, 4.0-24 and 4.0-40 µg mL−1 for gemifloxacin, moxifloxacin and gatifloxacin, respectively. The concentrations of the studied drugs were calculated using the corresponding calibration equations for the fixed-time method. The determination of the studied drugs by the fixed concentration and rate constant methods was also feasible with the calibration equations obtained but the fixed time method has been found to be more applicable. The different experimental parameters affecting the development and stability of the colors were carefully studied and optimized. The proposed method was applied to the determination of the studied drugs in pharmaceutical formulations.DOI: http://dx.doi.org/10.4314/bcse.v27i3.2

  18. Supercritical CO2 generation of nanometric structure from Ocimum basilicum mucilage prepared for pharmaceutical applications.

    Science.gov (United States)

    Akbari, Iman; Ghoreishi, Seyyed M; Habibi, Neda

    2015-04-01

    Plant-derived polymers are widely used in the pharmaceutical industry due to their emollient, lack of toxicity, and irritating nature and low cost. In this work, basil seed mucilage was dried using supercritical carbon dioxide phase inversion technique to form a nanometric structure. The obtained polymeric structures were characterized by scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) method, and Fourier transform infrared spectroscopy (FTIR) and compared with the oven-derived sample group. It was demonstrated that the product morphology could be controlled by altering the composition of methanol which functioned as the co-solvent in the nonsolvent stream. The most homogeneous product (60-nm mean pore size diameter, 78 m(2)/g BET surface area with no agglomeration) was obtained with 2.5% methanol. The FTIR data showed that the presence of hydroxyl and carboxyl groups suggested the bioadhesive property of basil seed mucilage was good and many active pharmaceutical compounds might be loaded to the resultant nanometric structure to enhance drug release. Furthermore, the FTIR analyses indicated that the nature of the final product did not change during the supercritical drying procedure.

  19. Preparation of composite electroheat carbon film

    Institute of Scientific and Technical Information of China (English)

    XIA Jin-tong; TU Chuan-jun; LI Yan; HU Li-min; DENG Jiu-hua

    2005-01-01

    A kind of conductive and heating unit, which can reach a high surface electroheat temperature at a low voltage, was developed in view of the traditional electroheat coating which has a low surface electroheat temperature and an insufficient heat resistance of its binder. The coating molded electroheat carbon film(CMECF) was prepared by carbonizing the coating which was prepared by adding modified resin into flake graphite and carbon fiber, coating molded onto the surface of the heat resisting matrix after dried, while the hot pressing molded electroheat thick carbon film(HPMETCF) was prepared by carbonizing the bodies whose powders were hot pressing molded directly.The surface and inner microstructure of the carbon film was characterized and analyzed by SEM and DSC/TG, while electroheat property was tested by voltage-current volume resistivity tester and electrical parameter tester. The results show that, close-packed carbon network configuration is formed within the composite electroheat carbon film film after anti-oxidizable treatment reaches a higher surface electroheat temperature than that of the existing electroheat coatings at a low voltage, and has excellent electroheat property, high thermal efficiency as well as stable physicochemical property. It is found that, at room temperature(19± 2 ℃) and 22 V for 5 min, the surface electroheat temperature of the self-produced CMECF (mfiller/mresin = 1. 8/1) reaches 112 ℃ while HPMETCF (mfiller/mresin = 3. 6/1) reaches 265 ℃.

  20. A sensitive spectrofluorimetric method for the determination of ranitidine hydrochloride in pharmaceutical preparation

    Science.gov (United States)

    Ulu, Sevgi Tatar; Çakar, Mahmut Bülent

    2012-08-01

    A simple, precise and sensitive spectrofluorimetric method was developed and validated for the determination of ranitidine in pharmaceutical preparations. The method is based on derivatization of ranitidine with 4-fluoro-7-nitrobenzofurazan (NBD-F). The method was successfully validated in accordance to ICH guidelines. The validation characteristics included linearity, limit of detection, limit of quantification, accuracy, precision, specificity and robustness. The method is linear over the range of 40-1200 ng/mL. The recoveries were ranged from 98.97 to 99.43%. The proposed method was applied for the determination of ranitidine in commercially available tablets. The results were compared with those obtained by reference method using t and F-tests.

  1. Determination of diclofenac in pharmaceutical preparations by voltammetry and gas chromatography methods

    Institute of Scientific and Technical Information of China (English)

    Bilal Yilmaz; Ulvihan Ciltas

    2015-01-01

    Rapid, sensitive and specific methods were developed for the determination of diclofenac in pharmaceutical preparations by linear sweep voltammetry (LSV) and gas chromatography (GC) with mass spectrometry (MS) detection. The linearity was established over the concentration range of 5–35μg/mL for LSV and 0.25–5μg/mL for GC–MS method. The intra- and inter-day relative standard deviation (RSD) was less than 4.39% and 4.62% for LSV and GC–MS, respectively. Limits of quantification (LOQ) were determined as 4.8 and 0.15μg/mL for LSV and GC–MS, respectively. No interference was found from tablet excipients at the selected assay conditions. The methods were applied for the quality control of commercial diclofenac dosage forms to quantify the drug and to check the formulation content uniformity.

  2. Determination of Lamotrigine in Pharmaceutical Preparations by Adsorptive Stripping Voltammetry Using Screen Printed Electrodes

    Science.gov (United States)

    Domínguez-Renedo, Olga; Calvo, M. Encarnación Burgoa; Arcos-Martínez, M. Julia

    2008-01-01

    This paper describes a procedure that has been optimized for the determination of lamotrigine by Differential Pulse Adsorptive Stripping Voltammetry (DPAdSV) using carbon screen-printed electrodes (CSPE) and mercury coated carbon screen-printed electrodes. Selection of the experimental parameters was made using experimental design methodology. The detection limit found was 5.0 × 10-6 M and 2.0 × 10-6 M for the non modified and Hg modified CSPE, respectively. In terms of reproducibility, the precision of the above mentioned methods was calculated in %RSD values at 9.83% for CSPE and 2.73% for Hg-CSPE. The Hg-coated CSPEs developed in this work were successfully applied in the determination of lamotrigine in pharmaceutical preparations. PMID:27879931

  3. Determination of Lamotrigine in Pharmaceutical Preparations by Adsorptive Stripping Voltammetry Using Screen Printed Electrodes

    Directory of Open Access Journals (Sweden)

    M. Julia Arcos-Martínez

    2008-07-01

    Full Text Available This paper describes a procedure that has been optimized for the determination of lamotrigine by Differential Pulse Adsorptive Stripping Voltammetry (DPAdSV using carbon screen-printed electrodes (CSPE and mercury coated carbon screen-printed electrodes. Selection of the experimental parameters was made using experimental design methodology. The detection limit found was 5.0 x 10-6 M and 2.0 x 10-6 M for the non modified and Hg modified CSPE, respectively. In terms of reproducibility, the precision of the above mentioned methods was calculated in %RSD values at 9.83% for CSPE and 2.73% for Hg-CSPE. The Hg-coated CSPEs developed in this work were successfully applied in the determination of lamotrigine in pharmaceutical preparations.

  4. Esterification of pseudoephedrine hydrochloride by citric acid in a solid dose pharmaceutical preparation.

    Science.gov (United States)

    Goel, Alok; Zhao, Zhicheng; Sørensen, Dan; Zhou, Jay; Zhang, Fa

    2016-09-10

    Esterification of pseudoephedrine hydrochloride (PSE) by citric acid was observed in a solid dose pharmaceutical preparation at room temperature and accelerated stability condition (40°C/75% relative humidity). The esterification of PSE with citric acid was confirmed by a solid-state binary reaction in the presence of minor level of water at elevated temperature to generate three isomeric esters. The structures of the pseudoephedrine citric acid esters were elucidated using high-resolution mass spectrometry and nuclear magnetic resonance spectroscopy (NMR). Occurrence of esterification in solid state, instead of amidation which is generally more favorable than esterification, is likely due to remaining HCl salt form of solid pseudoephedrine hydrochloride to protect its amino group from amidation with citric acid. In contrast, the esterification was not observed from solution reaction between PSE and citric acid.

  5. Use of inductor agents GSE24.2 for producing pharmaceutical compositions for treating illnesses relating to cellular senescence

    OpenAIRE

    2010-01-01

    This invention relates to the use of an inductor or activator compound GSE24.2 for producing a medicament or a pharmaceutical composition for treating a preferably human illness or pathological situation caused by a senescence process. Said pharmaceutical composition can be useful for a treatment for regenerating tissues, for example of epithelial tissues or haematopoietic cells, and also for the immortalisation of eucaryotic cells in order to use of same in biotechnological investigation or ...

  6. Spectrophotometric and potentiometric determination of piroxicam and tenoxicam in pharmaceutical preparations.

    Science.gov (United States)

    El-Ries, Mohamed A; Mohamed, Gehad; Khalil, Shaeban; El-Shall, Manal

    2003-01-01

    Two simple and accurate methods are described for the determination of piroxicam and tenoxicam in their pharmaceutical preparations. The spectrophotometric method involves the oxidation of these drugs with potassium iodate in acid medium with the liberation of iodine and subsequent extraction with cyclohexane followed by measuring the absorbance at lambda=522 nm. Beer's law is obeyed in the concentration range of 0.05-1.1 and 0.05-0.6 mg x ml(-1) for piroxicam and tenoxicam, respectively. The apparent molar absorptivities of the resulting coloured products are found to be 2.7 x 10(3) and 2.5 x 10(3) l mol(-1) x cm(-1), whereas Sandell sensitivities are 0.012 and 0.013 g x cm(-2) for piroxicam and tenoxicam, respectively. The potentiometric method involves the direct titration of both drugs with N-bromosuccinimide in acid medium and the end point is determined potentiometrically using platinum indicator electrode. Piroxicam and tenoxicam can be determined quantitatively in the concentration range of 0.33-3.37 and 0.33-4.08 mg x ml(-1) for tenoxicam and piroxicam, respectively. The standard deviation and relative standard deviation values are found to be ranged from 0.05-0.07 and 0.37-0.98% and 0.025-0.078 and 0.25-1.2% for tenoxicam and piroxicam, respectively. The two methods are accurate within +/-1.0%. Optimum conditions affecting both methods are studied. The proposed methods are applied for the determination of the drugs in pure form and in commercial pharmaceutical preparations.

  7. Chemically modified carbon paste ion-selective electrodes for determination of atorvastatin calcium in pharmaceutical preparations

    Directory of Open Access Journals (Sweden)

    Salwa Fares Rassi

    2017-06-01

    Full Text Available A simple, rapid and sensitive method for the determination of atorvastatin calcium in pharmaceutical preparations using two modified carbon paste electrodes was developed. One electrode (sensor A is based on ion-pair of atorvastatin with 5,6-diaminouracil hydrochloride (ATS-DAUH and the other (sensor B is based on atorvastatin with picric acid (ATS-PC. Among three different solvent mediators tested, dioctylphthalate (DOPH exhibited a proper behavior including Nernstian slopes of the calibration curve at 58.76 ± 0.8 and 57.48±1 mV per decade for sensors A and B. The response times were 10 and 12 s, detection limits 1.3 × 10−6 and 2.2 × 10−6 M; the concentration range 2.5 × 10−6-7.9 × 10−2 M and 3.0 × 10−6 to 7.9 × 10−2 M respectively. The present electrodes show good discrimination of atorvastatin calcium from several inorganic, organic ions, sugars and some common excipients. The sensors were applied for the determination of atorvastatin calcium in pharmaceutical preparations using standard addition and the calibration curve methods. The results obtained were satisfactory with excellent percentage recovery comparable and sometimes better than those obtained by other routine methods for the assay. The proposed potentiometric methods offer the advantages of simplicity, accuracy, automation feasibility and applicability to turbid and colored sample solutions.

  8. Pharmaceutical approaches to preparing pelletized dosage forms using the extrusion-spheronization process.

    Science.gov (United States)

    Trivedi, Namrata R; Rajan, Maria Gerald; Johnson, James R; Shukla, Atul J

    2007-01-01

    Pelletized dosage forms date back to the 1950s, when the first product was introduced to the market. Since then, these dosage forms have gained considerable popularity because of their distinct advantages, such as ease of capsule filling because of better flow properties of the spherical pellets; enhancement of drug dissolution; ease of coating; sustained, controlled, or site-specific delivery of the drug from coated pellets; uniform packing; even distribution in the GI tract; and less GI irritation. Pelletized dosage forms can be prepared by a number of techniques, including drug layering on nonpareil sugar or microcrystalline cellulose beads, spray drying, spray congealing, rotogranulation, hot-melt extrusion, and spheronization of low melting materials or extrusion-spheronization of a wet mass. This review discusses recent developments in the pharmaceutical approaches that have been used to prepare pelletized dosage forms using the extrusion-spheronization process over the last decade. The review is divided into three parts: the first part discusses the extrusion-spheronization process, the second part discusses the effect of varying formulation and process parameters on the properties of the pellets, and the last part discusses the different approaches that have been used to prepare pelletized dosage forms using the extrusion-spheronization process.

  9. [Fecal microbiota transplantation in recurrent Clostridium difficile infections. Framework and pharmaceutical preparation aspects].

    Science.gov (United States)

    Batista, R; Kapel, N; Megerlin, F; Chaumeil, J-C; Barbut, F; Bourlioux, P; Chast, F

    2015-09-01

    The fecal microbiota transplantation consists in introducing a preparation constituted by a dilution of stools of a healthy donor in the digestive tract of a patient recipient, to restore his intestinal physiological balance. This therapeutic approach was the subject of numerous studies showing its efficiency in the treatment of the recurrent infections with Clostridium difficile. The fecal microbiota transplantation has now a high level of clinical evidence, which explains that it appears in various international recommendations. In France, the fecal microbiota transplantation responds to the definition of a medication and can be executed as a pharmaceutical preparation or as an experimental drug for clinical trials under the responsibility of a hospital pharmacy. The objective of this paper is to propose a definition of a framework and to describe the methods of preparation of the fecal microbiota transplantation in the treatment of the recurrent infections with C. difficile and the interactions to consider for hospital pharmacies that do not have technical means to operate this technique. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  10. Assessing manganese nanostructures based carbon nanotubes composite for the highly sensitive determination of vitamin C in pharmaceutical formulation.

    Science.gov (United States)

    Hameed, Sadaf; Munawar, Anam; Khan, Waheed S; Mujahid, Adnan; Ihsan, Ayesha; Rehman, Asma; Ahmed, Ishaq; Bajwa, Sadia Z

    2017-03-15

    This work is the first report describing the development of a novel three dimensional manganese nanostructures based carbon nanotubes (CNTs-Mn NPs) composite, for the determination of ascorbic acid (vitamin C) in pharmaceutical formulation. Carbon nanotubes (CNTs) were used as a conductive skeleton to anchor highly electrolytic manganese nanoparticles (Mn NPs), which were prepared by a hydrothermal method. Scanning electron microscopy and atomic force microscopy revealed the presence of Mn Nps of 20-25nm, anchored along the whole length of CNTs, in the form of patches having a diameter of 50-500nm. Fourier transform infrared spectroscopy confirmed the surface modification of CNTs by amine groups, whereas dynamic light scattering established the presence of positive charge on the prepared nanocomposite. The binding events were studied by monitoring cyclic voltammetry signals and the developed nanosensor exhibited highly sensitive response, demonstrating improved electrochemical activity towards ascorbic acid. Linear dependence of the peak current on the square root of scan rates (R(2)=0.9785), demonstrated that the oxidation of ascorbic acid by the designed nanostructures is a diffusion control mechanism. Furthermore, linear range was found to be 0.06-4.0×10(-3)M, and nanosensor displayed an excellent detection limit of 0.1µM (S/N=3). This developed nanosensor was successfully applied for the determination of vitamin C in pharmaceutical formulation. Besides, the results of the present study indicate that such a sensing platform may offer a different pathway to utilize manganese nanoparticles based CNTs composite for the determination of other bio-molecules as well.

  11. Application of Fluorescence Spectrometry With Multivariate Calibration to the Enantiomeric Recognition of Fluoxetine in Pharmaceutical Preparations.

    Science.gov (United States)

    Poláček, Roman; Májek, Pavel; Hroboňová, Katarína; Sádecká, Jana

    2016-04-01

    Fluoxetine is the most prescribed antidepressant chiral drug worldwide. Its enantiomers have a different duration of serotonin inhibition. A novel simple and rapid method for determination of the enantiomeric composition of fluoxetine in pharmaceutical pills is presented. Specifically, emission, excitation, and synchronous fluorescence techniques were employed to obtain the spectral data, which with multivariate calibration methods, namely, principal component regression (PCR) and partial least square (PLS), were investigated. The chiral recognition of fluoxetine enantiomers in the presence of β-cyclodextrin was based on diastereomeric complexes. The results of the multivariate calibration modeling indicated good prediction abilities. The obtained results for tablets were compared with those from chiral HPLC and no significant differences are shown by Fisher's (F) test and Student's t-test. The smallest residuals between reference or nominal values and predicted values were achieved by multivariate calibration of synchronous fluorescence spectral data. This conclusion is supported by calculated values of the figure of merit.

  12. Simultaneous determination of paracetamol, phenylephrine hydrochloride and chlorpheniramine maleate in pharmaceutical preparations using multivariate calibration 1

    Science.gov (United States)

    Samadi-Maybodi, Abdolraouf; Hassani Nejad-Darzi, Seyed Karim

    2010-04-01

    Resolution of binary mixtures of paracetamol, phenylephrine hydrochloride and chlorpheniramine maleate with minimum sample pre-treatment and without analyte separation has been successfully achieved by methods of partial least squares algorithm with one dependent variable, principal component regression and hybrid linear analysis. Data of analysis were obtained from UV-vis spectra of the above compounds. The method of central composite design was used in the ranges of 1-15 mg L -1 for both calibration and validation sets. The models refinement procedure and their validation were performed by cross-validation. Figures of merit such as selectivity, sensitivity, analytical sensitivity and limit of detection were determined for all three compounds. The procedure was successfully applied to simultaneous determination of the above compounds in pharmaceutical tablets.

  13. Pharmaceutical studies of levothyroxine sodium hydrate suppository provided as a hospital preparation.

    Science.gov (United States)

    Hamada, Yuhei; Masuda, Kazushi; Okubo, Masato; Nakasa, Hiromitsu; Sekine, Yuko; Ishii, Itsuko

    2015-01-01

    The levothyroxine sodium hydrate suppository (L-T4-suppository) is provided as a hospital preparation for the treatment of hypothyroid patients with dysphagia in Japan because only oral preparations of levothyroxine sodium (L-T4) are approved for the treatment of hypothyroidism. However, it has been found that serum thyroxine and triiodothyronine levels do not increase as expected with the hospital preparation, requiring a higher dosage of L-T4 in the L-T4-suppository than in the oral preparations. In this study, to determine an effective thyroid gland hormone-replacement therapy for patients with dysphagia, the pharmaceutical properties of the L-T4-suppository were investigated. Suppositories containing 300 µg L-T4 in a base of Witepsol H-15 and Witepsol E-75 (ratio of 1 : 1) were prepared according to Chiba University Hospital's protocol. Content uniformity, stability, and suppository release were tested. The L-T4-suppository had uniform weight and content. The content and release property were stable over 90 d when the L-T4-suppository was stored at 4 °C and protected from light. The release rate of L-T4 increased as pH increased. However, no L-T4 was released below pH 7.2. The release rate of L-T4 decreased as temperature decreased. These findings suggest that the low level of release of L-T4 in the rectum under physiological conditions may be the cause of the low serum thyroxine and triiodothyronine levels following L-T4-suppository administration.

  14. Composite perfluorohydrocarbon membranes, their preparation and use

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Yong; Bikson, Benjamin

    2017-04-04

    Composite porous hydrophobic membranes are prepared by forming a perfluorohydrocarbon layer on the surface of a preformed porous polymeric substrate. The substrate can be formed from poly (aryl ether ketone) and a perfluorohydrocarbon layer can be chemically grafted to the surface of the substrate. The membranes can be utilized for a broad range of fluid separations, such as microfiltration, nanofiltration, ultrafiltration as membrane contactors for membrane distillation and for degassing and dewatering of fluids. The membranes can further contain a dense ultra-thin perfluorohydrocarbon layer superimposed on the porous poly (aryl ether ketone) substrate and can be utilized as membrane contactors or as gas separation. membranes for natural gas treatment and gas dehydration.

  15. Fracture Resistance of Composite Veneers with Different Preparation Designs

    OpenAIRE

    Zlatanovska, Katerina; Guguvcevski, Ljuben; Popovski, Risto; Dimova, Cena; Minovska, Ana; Mijoska, Aneta

    2016-01-01

    Background: The aim of this in vitro study was to examine the fracture load of composite veneers using three different preparation designs. Material and methods: Fifteen extracted, intact, human maxillary central incisors were selected. Teeth were divided into three groups with different preparation design: 1) feather preparation, 2) bevel preparation, and 3) incisal overlap- palatal chamfer. Teeth were restored with composite veneers, and the specimens were loaded to failure. The localizatio...

  16. Negatively charged silver nanoparticles with potent antibacterial activity and reduced toxicity for pharmaceutical preparations

    Directory of Open Access Journals (Sweden)

    Salvioni L

    2017-03-01

    Full Text Available Lucia Salvioni,1 Elisabetta Galbiati,1 Veronica Collico,1 Giulia Alessio,1 Svetlana Avvakumova,1 Fabio Corsi,2,3 Paolo Tortora,1 Davide Prosperi,1 Miriam Colombo1 1Nanobiolab, Department of Biotechnology and Bioscience, University of Milano-Bicocca, 2Biological and Clinical Science Department, University of Milan, Milano, 3Surgery Department, Breast Unit, IRCCS S Maugeri Foundation, Pavia, Italy Background: The discovery of new solutions with antibacterial activity as efficient and safe alternatives to common preservatives (such as parabens and to combat emerging infections and drug-resistant bacterial pathogens is highly expected in cosmetics and pharmaceutics. Colloidal silver nanoparticles (NPs are attracting interest as novel effective antimicrobial agents for the prevention of several infectious diseases.Methods: Water-soluble, negatively charged silver nanoparticles (AgNPs were synthesized by reduction with citric and tannic acid and characterized by transmission electron microscopy, dynamic light scattering, zeta potential, differential centrifuge sedimentation, and ultraviolet–visible spectroscopy. AgNPs were tested with model Gram-negative and Gram-positive bacteria in comparison to two different kinds of commercially available AgNPs.Results: In this work, AgNPs with higher antibacterial activity compared to the commercially available colloidal silver solutions were prepared and investigated. Bacteria were plated and the antibacterial activity was tested at the same concentration of silver ions in all samples. The AgNPs did not show any significant reduction in the antibacterial activity for an acceptable time period. In addition, AgNPs were transferred to organic phase and retained their antibacterial efficacy in both aqueous and nonaqueous media and exhibited no toxicity in eukaryotic cells.Conclusion: We developed AgNPs with a 20 nm diameter and negative zeta potential with powerful antibacterial activity and low toxicity compared

  17. The impact of the salting-out technique on the preparation of colloidal particulate systems for pharmaceutical applications.

    Science.gov (United States)

    Mendoza-Muñoz, Néstor; Quintanar-Guerrero, David; Allémann, Eric

    2012-12-01

    The recent advances in nanotechnology and its application in medicine have merged into a new concept called nanomedicine. Colloidal drug delivery systems and specifically polymeric nanoparticles are one of the most promising novel drug carriers due to their capacity for passive or active targeting for therapeutic and diagnostic applications. The introduction of novel therapeutic nanoscaled agents requires simple, efficient and feasible industrial-scale production methods. Biodegradable polymeric nanoparticles are usually prepared from preformed polymers by five techniques: emulsification- solvent evaporation, solvent displacement, salting-out, emulsification-solvent diffusion and double emulsion solvent evaporation. This review discusses the use of the salting-out technique for the preparation of nanoparticles in the development of systems for drug delivery and other pharmaceutical applications. The relevant applications, formulations and release characteristics of novel colloidal drug delivery preparations from research literature and patents are summarized. This review is intended as a tool for the rational development of polymeric colloidal systems for pharmaceutical use.

  18. Validated spectrometric determination of penciclovir and entecavir in bulk and in pharmaceutical preparations

    Directory of Open Access Journals (Sweden)

    Asmaa A. Elzaher

    2016-12-01

    Full Text Available Simple, rapid and sensitive spectroscopic methods were developed and validated for the determination of antiviral agents, namely, penciclovir (PCV and entecavir (ETV. The first method is based on measuring the native fluorescence of each of the cited drugs at its optimum excitation and emission wavelengths. The fluorescence intensity was measured for PCV & ETV at 363 nm and 370 nm upon excitation at 260 nm and 254 nm, respectively. The calibration curves were linear over the concentration range 0.1–0.8, 0.025–0.4 μg ml−1 for PCV and ETV, respectively. The second method is based on measuring the amplitude of ETV in the fourth derivative with Δλ = 8 and scaling factor = 100 at 256.4 nm at which its acidic degradation showed zero reading over the concentration range 5–60 μg ml−1. The proposed methods were applied for the determination of the cited drugs in bulk and pharmaceutical preparations. ICH guidelines were used for method validation.

  19. Determination of Vitamin B1 in Pharmaceutical Preparations by Flow-injection Analysis with Biamperometric Detection

    Institute of Scientific and Technical Information of China (English)

    LI Li-jun; CHENG Hao; ZHAO Chuan; HU Xiao-ge

    2005-01-01

    A new electrochemical method for the on-line determination of vitamin B1 is presented. Based on dead-stop endpoint biamperometry by using two platinum foil electrodes with an applied potential difference of 150 mV, vitamin B1can be oxidized by hexacyanoferrate ( Ⅲ ) in a sodium hydroxide medium via a reversible indicating couple Fe( CN)64-/Fe(CN)63-. The cell current is linear with the concentration of vitamin B1 in the concentration range of 4.0×10-6-1.0 × 10-3 mol/L with a detection limit of 8.0×10-7 mol/L(0. 27 μg/mL). Most familiar excipients,ions and vitamins do not interfere with the determination of vitamin B1. The method displays the advantages of simplicity, high efficiency( 180 samples/h), and high selectivity, and is suitable for the determination of vitamin B1 in pharmaceutical preparations.

  20. Validated stability-indicating spectrofluorimetric methods for the determination of ebastine in pharmaceutical preparations

    Directory of Open Access Journals (Sweden)

    Eid Manal

    2011-03-01

    Full Text Available Abstract Two sensitive, selective, economic, and validated spectrofluorimetric methods were developed for the determination of ebastine (EBS in pharmaceutical preparations depending on reaction with its tertiary amino group. Method I involves condensation of the drug with mixed anhydrides (citric and acetic anhydrides producing a product with intense fluorescence, which was measured at 496 nm after excitation at 388 nm. Method (IIA describes quantitative fluorescence quenching of eosin upon addition of the studied drug where the decrease in the fluorescence intensity was directly proportional to the concentration of ebastine; the fluorescence quenching was measured at 553 nm after excitation at 457 nm. This method was extended to (Method IIB to apply first and second derivative synchronous spectrofluorimetric method (FDSFS & SDSFS for the simultaneous analysis of EBS in presence of its alkaline, acidic, and UV degradation products. The proposed methods were successfully applied for the determination of the studied compound in its dosage forms. The results obtained were in good agreement with those obtained by a comparison method. Both methods were utilized to investigate the kinetics of the degradation of the drug.

  1. [Methods of pharmaceutical technology in preparation of pellets for detection of acetylcholinesterase inhibitors].

    Science.gov (United States)

    Vetchý, David; Leštinová, Hana; Tušarová, Ivana

    2012-10-01

    A variety of methods and technical equipment are currently available for checking of air contaminants. Generally, all known and sophisticated methods are based on sampling of substances in the air using different collectors or their capture in a suitable medium. However, new detection methods particularly useful in outdoor conditions are still looking for. Detection systems must be transportable, fast acting, inexpensive, sensitive and selective, and their operation should not be complicated. Such an appropriate system for the detection of carbamates and highly toxic organophosphates is detection tubes with microcrystalline cellulose pellets containing immobilized acetylcholinesterase, by which analyzed air is sucked through. The detection is based on the colorimetric Ellman reaction. Experimental work deals with the use of pharmaceutical technology methods for preparation of new variants of pellets for the detection of acetylcholinesterase inhibitors with 20% and 50% content of inorganic fillers (aluminium oxide, kaolin, colloidal silica, nalsit) produced by extrusion / spheronization. Pellets were impregnated by acetylcholinesterase after evaluating quality parameters and were tested for their activity and inhibition with Ellmans reagent. Pellets without inorganic fillers, containing 50% of aluminium oxide and containing 20% of colloidal silica were evaluated as a suitable filling of detection tubes.

  2. Manganese(III Porphyrin-based Potentiometric Sensors for Diclofenac Assay in Pharmaceutical Preparations

    Directory of Open Access Journals (Sweden)

    Eugenia Fagadar-Cosma

    2010-09-01

    Full Text Available Two manganese(III porphyrins: manganese(III tetraphenylporphyrin chloride and manganese(III-tetrakis(3-hydroxyphenylporphyrin chloride were tested as ionophores for the construction of new diclofenac−selective electrodes. The electroactive material was incorporated either in PVC or a sol−gel matrix. The effect of different plasticizers and additives (anionic and cationic on the potentiometric response was studied. The best results were obtained for the PVC membrane plasticized with dioctylphtalate and having sodium tetraphenylborate as a lipophilic anionic additive incorporated. The sensor response was linear in the concentration range 3 × 10−6 – 1 × 10−2 M with a slope of −59.7 mV/dec diclofenac, a detection limit of 1.5 × 10−6 M and very good selectivity coefficients. It was used for the determination of diclofenac in pharmaceutical preparations, by direct potentiometry. The results were compared with those obtained by the HPLC reference method and a good agreement was found between the two methods.

  3. Manganese(III) porphyrin-based potentiometric sensors for diclofenac assay in pharmaceutical preparations.

    Science.gov (United States)

    Vlascici, Dana; Pruneanu, Stela; Olenic, Liliana; Pogacean, Florina; Ostafe, Vasile; Chiriac, Vlad; Pica, Elena Maria; Bolundut, Liviu Calin; Nica, Luminita; Fagadar-Cosma, Eugenia

    2010-01-01

    Two manganese(III) porphyrins: manganese(III) tetraphenylporphyrin chloride and manganese(III)-tetrakis(3-hydroxyphenyl)porphyrin chloride were tested as ionophores for the construction of new diclofenac-selective electrodes. The electroactive material was incorporated either in PVC or a sol-gel matrix. The effect of different plasticizers and additives (anionic and cationic) on the potentiometric response was studied. The best results were obtained for the PVC membrane plasticized with dioctylphtalate and having sodium tetraphenylborate as a lipophilic anionic additive incorporated. The sensor response was linear in the concentration range 3 × 10(-6) - 1 × 10(-2) M with a slope of -59.7 mV/dec diclofenac, a detection limit of 1.5 × 10(-6) M and very good selectivity coefficients. It was used for the determination of diclofenac in pharmaceutical preparations, by direct potentiometry. The results were compared with those obtained by the HPLC reference method and a good agreement was found between the two methods.

  4. Spectrophotometric determination of pipazethate HCl, dextromethorphan HBr and drotaverine HCl in their pharmaceutical preparations

    Science.gov (United States)

    Amin, Alaa S.; El-Sheikh, Ragaa; Zahran, Faten; Gouda, Ayman Abou El-fetouh

    2007-07-01

    A simple, accurate and highly sensitive spectrophotometric method is proposed for the rapid determination of pipazethate hydrochloride, dextromethorphan hydrobromide and drotaverine hydrochloride using chromotrope 2B (C2B) and chromotrope 2R (C2R). The method consists of extracting the formed ion-associates into chloroform in the case of pipazethate HCl and dextromethorphan HBr or into methylene chloride in the case of drotaverine HCl. The ion-associates exhibit absorption maxima at 528, 540 and 532 nm with C2B and at 526, 517 and 522 nm with C2R for pipazethate HCl, dextromethorphan HBr and drotaverine HCl, respectively. The calibration curves resulting from the measurements of absorbance-concentration relations (at the optimum reaction conditions) of the extracted ion-pairs are linear over the concentration range 4.36-52.32 μg mL -1 for pipazethate, 3.7-48.15 μg mL -1 for dextromethorphan and 4.34-60.76 μg mL -1 for drotaverine, respectively. The effect of acidity, reagent concentration, time, solvent and stoichiometric ratio of the ion-associates were estimated. The molar absorptivity and Sandell sensitivity of the reaction products were calculated. Statistical treatment of the results reflects that the procedure is precise, accurate and easily applied for the determination of the drugs under investigation in pure form and in their pharmaceutical preparations.

  5. Composition and production rate of pharmaceutical and chemical waste from Xanthi General Hospital in Greece.

    Science.gov (United States)

    Voudrias, Evangelos; Goudakou, Lambrini; Kermenidou, Marianthi; Softa, Aikaterini

    2012-07-01

    The objective of this work was to determine the composition and production rates of pharmaceutical and chemical waste produced by Xanthi General Hospital in Greece (XGH). This information is important to design and cost management systems for pharmaceutical and chemical waste, for safety and health considerations and for assessing environmental impact. A total of 233 kg pharmaceutical and 110 kg chemical waste was collected, manually separated and weighed over a period of five working weeks. The total production of pharmaceutical waste comprised 3.9% w/w of the total hazardous medical waste produced by the hospital. Total pharmaceutical waste was classified in three categories, vial waste comprising 51.1%, syringe waste with 11.4% and intravenous therapy (IV) waste with 37.5% w/w of the total. Vial pharmaceutical waste only was further classified in six major categories: antibiotics, digestive system drugs, analgesics, hormones, circulatory system drugs and "other". Production data below are presented as average (standard deviation in parenthesis). The unit production rates for total pharmaceutical waste for the hospital were 12.4 (3.90) g/patient/d and 24.6 (7.48) g/bed/d. The respective unit production rates were: (1) for vial waste 6.4 (1.6) g/patient/d and 13 (2.6) g/bed/d, (2) for syringe waste 1.4 (0.4) g/patient/d and 2.8 (0.8) g/bed/d and (3) for IV waste 4.6 (3.0) g/patient/d and 9.2 (5.9) g/bed/d. Total chemical waste was classified in four categories, chemical reagents comprising 18.2%, solvents with 52.3%, dyes and tracers with 18.2% and solid waste with 11.4% w/w of the total. The total production of chemical waste comprised 1.8% w/w of the total hazardous medical waste produced by the hospital. Thus, the sum of pharmaceutical and chemical waste was 5.7% w/w of the total hazardous medical waste produced by the hospital. The unit production rates for total chemical waste for the hospital were 5.8 (2.2) g/patient/d and 1.1 (0.4) g/exam/d. The respective

  6. Preparation and characteristics of CNT-metal composites

    CSIR Research Space (South Africa)

    Pityana, SL

    2006-01-01

    Full Text Available The success in keeping carbon nanotubes (CNT) bonded to stainless steel provides a possible method for the preparation of CNT-metal composites. Alternative methods for the preparation of CNT-metal composites include hot pressing, sintering, etc...

  7. 制药工艺用水制备流程分析%Pharmaceutical preparation process water process analysis

    Institute of Scientific and Technical Information of China (English)

    闫秀红

    2015-01-01

    Preparation process of pharmaceutical process water include purified water treatment and water purification. At present, China's pharmaceutical unit structure and function of the presence of water equipment defective design, device control parameters are not advanced, pharmaceutical water equipment design and manufacturing level and low. Should increase supportive technology and funds to update equipment and systems, establish a sound regulatory system to address the pharmaceutical preparation process water problems.%制药工艺用水的制备流程包括水的提纯处理和水的纯化。目前我国制药用水设备存在装置结构功能设计不完善、设备控制参数不先进、制药用水设备设计及制造水平低等问题。应加大技术和资金的支持力,及时更新设备和系统,建立健全监管制度,以解决制药用水制备过程中出现的问题。

  8. Preparation of Mordenite Composite Membranes with Seeding

    Institute of Scientific and Technical Information of China (English)

    Su Xiaohui; Li Gang; Lin Ruisen; Kikuchi Eiichi; Matsukata Masahiko

    2006-01-01

    Mordenite composite membranes were prepared by means of coating a porous α-alumina support with nanosized mordenite seeds followed by hydrothermal crystallization.A systematic investigation was performed on the influence of several factors such as ageing of the reaction mixture,alkalinity,salt addition and temperature on the formation of a mordenite membrane on the seeded support.The ageing of the reaction mixture reduces the growth rate of mordenite crystal along a-axis and b-axis but hardly influences the growth rate along c-axis.As a result,the boundaries between the surface crystals become a little larger with prolonging the period of ageing time.The growth rate of the mordenite crystal along individual axes increases first and then decreases with increasing concentration of sodium hydroxide.A higher alkalinity is unfavorable for the formation of a continuous mordenite membrane.The addition of salt in the reaction mixture has different effect on the growth rate of the mordenite crystal along each axis.With increasing the amount of salt,there was hardly influence on the growth rate along c-axis,whereas an obvious decline was observed in the growth rate along either a-axis or b-axis,which enlarges the boundaries between the surface crystals.The growth rate of the mordenite crystal increases more along c-axis than that along a-axis or b-axis with increasing temperature for hydrothermal crystallization.The use of a temperature as high as 473 K produces a membrane composed of bar-like crystals with larger boundaries.

  9. Review on preparation techniques of particle reinforced metal matrix composites

    Directory of Open Access Journals (Sweden)

    HAO Bin

    2006-02-01

    Full Text Available This paper reviews the investigation status of the techniques for preparation of metal matrix composites and the research outcomes achieved recently. The mechanisms, characteristics, application ranges and levels of development of these preparation techniques are analyzed. The advantages and the disadvantages of each technique are synthetically evaluated. Lastly, the future directions of research and the prospects for the preparation techniques of metal matrix composites are forecasted.

  10. Preparation and Properties of Graphene Straw Retardant Composites

    Directory of Open Access Journals (Sweden)

    Xiao Li-guang

    2016-01-01

    Full Text Available This article was prepared by spin-coating the evaporation process graphene oxide having a shell core structure GO/straw flame retardant composite materials, through the oxygen index apparatus and SEM measured the relationship between the flame retardant properties and the morphological structure of the flame retardant composite material, the experiment preparation process is simple, environmentally friendly non-toxic, and the resulting GO/straw flame retardant composite material having a high fire retardant properties.

  11. Spectrophotometric Simultaneous Determination of Zinc(Ⅱ),Manganese(Ⅱ) and Iron(Ⅱ) in Pharmaceutical Preparations Using OSC-PLS

    Institute of Scientific and Technical Information of China (English)

    Ali NIAZI; Azadeh YAZDANIPOUR; Mohammad GOODARZI; Hamidreza KAMKAR; Ali RAFINEJAD

    2006-01-01

    This work reports the spectrophotometric simultaneous determination of zinc(Ⅱ),manganese(Ⅱ) and iron(Ⅱ) in pharmaceutical preparation, using orthogonal signal correctionpartial least squares (OSC-PLS). All the factors affecting on the sensitivity were optimized and the linear dynamic range for determination of these metals was found. The PLS modeling was used for the multivariate calibration of the spectrophotometric data. The OSC was used for preprocessing of data matrices and the prediction results of model. The experimental calibration matrix was designed by measuring the absorbance over the range 450-570 nm for 21 samples of The RMSEP for zinc(Ⅱ), manganese(Ⅱ) and iron(Ⅱ) using OSC-PLS were 0.0164, 0.0132, 0.0146,respectively. The proposed method was successfully applied the determination of zinc(Ⅱ),manganese(Ⅱ) and iron(Ⅱ) in pharmaceutical preparations.

  12. Sample preparation composite and replicate strategy case studies for assay of solid oral drug products.

    Science.gov (United States)

    Nickerson, Beverly; Harrington, Brent; Li, Fasheng; Guo, Michele Xuemei

    2017-08-16

    Drug product assay is one of several tests required for new drug products to ensure the quality of the product at release and throughout the life cycle of the product. Drug product assay testing is typically performed by preparing a composite sample of multiple dosage units to obtain an assay value representative of the batch. In some cases replicate composite samples may be prepared and the reportable assay value is the average value of all the replicates. In previously published work by Harrington et al. (2014) [5], a sample preparation composite and replicate strategy for assay was developed to provide a systematic approach which accounts for variability due to the analytical method and dosage form with a standard error of the potency assay criteria based on compendia and regulatory requirements. In this work, this sample preparation composite and replicate strategy for assay is applied to several case studies to demonstrate the utility of this approach and its application at various stages of pharmaceutical drug product development. Copyright © 2017. Published by Elsevier B.V.

  13. Determination of the enantiomeric composition of some molecules of pharmaceutical interest by chemometric analysis of the UV spectra of guest-host complexes formed with modified cyclodextrins.

    Science.gov (United States)

    Fakayode, Sayo O; Swamidoss, Isabel M; Busch, Marianna A; Busch, Kenneth W

    2005-02-28

    Multivariate regression modeling techniques (PLS-1 regression modeling) were applied to ordinary UV spectral absorption data obtained on solutions containing inclusion complexes formed between homochiral modified cyclodextrins (methyl-beta-cyclodextrin, alpha-, beta-, and gamma-carboxymethyl cyclodextrins and alpha-, beta-, and gamma-hydroxypropyl cyclodextrins) and four guest molecules of pharmaceutical interest (ephedrine, norephedrine, norepinephrine-l-bitartrate, and tryptophan methyl ester). The PLS-1 regression models were developed by correlating the known enantiomeric composition of laboratory prepared samples with ordinary UV absorption spectral data. The regression models were subsequently validated with laboratory-prepared test sets. The rms percent relative error in the predicted mol fraction of (1S, 2R)-(+)-ephedrine, (1S, 2R)-(+)-norephedrine, (R)-(-)-norepinephrine-l-bitartrate, and d-tryptophan methyl ester obtained with the independently prepared test sets was heavily dependent on the host molecule used.

  14. Evaluation of non-isothermal methods in stability studies of human insulin pharmaceutical preparations.

    Science.gov (United States)

    Oliva, Alexis; Suárez, Marta; Hernández, Juan Ramón; Llabrés, Matías; Fariña, José B

    2009-05-01

    The purpose of this research was to study the thermal stability of a human insulin pharmaceutical preparation using non-isothermal conditions and comparison with classical isothermal experiments. The isothermal studies were performed in the temperature range 20-60 degrees C, whereas non-isothermal stability studies were performed using a linear increasing temperature program, heating rate 0.25 degrees C per hour and temperature interval 30-70 degrees C. Under isothermal conditions, an apparent first-order degradation process was observed at all temperatures. The linear Arrhenius plot suggested that the insulin degradation mechanism was the same within the studied temperature range, with quite large uncertainties due to the small number of degrees of freedom based only on the scatter in the plot, giving an estimated shelf-life at 25 degrees C of 199.1 days. In non-isothermal conditions, the integral approach was used to estimate the activation parameters. It provides results in good agreement with those of the traditional method, but with the advantage that the uncertainty in the final result directly reflects the goodness of fit of the experimental data, since it takes into account the scatter in the original data. The estimated shelf-life in non-isothermal conditions was quite close to the value derived from isothermal data, 191.4 days, although the 95% confidence interval estimated were slightly higher. This is due to the differences in the estimation method and the nature of the experimental errors. The bootstrap technique is also applied to estimating confidence limits for the Arrhenius parameters and shelf-life. This method is very useful when the underlying distribution function of the parameters is unknown. The results obtained indicate that the Arrhenius parameters follow a normal distribution, whereas the shelf-life follows a log-normal distribution. In any case, the results obtained show that there is no difference between the asymptotic and bootstrap

  15. Spectrophotometric and spectrofluorimetric methods for analysis of tramadol, acebutolol and dothiepin in pharmaceutical preparations

    Science.gov (United States)

    Abdellatef, Hisham E.; El-Henawee, Magda M.; El-Sayed, Heba M.; Ayad, Magda M.

    2006-12-01

    Sensitive spectrophotometric and spectrofluorimetric methods are described for the determination of tramadol, acebutolol and dothiepin (dosulepin) hydrochlorides. The two methods are based on the condensation of the cited drugs with the mixed anhydrides of malonic and acetic acids at 60 °C for 25-40 min. The coloured condensation products are suitable for the spectrophotometric and spectrofluorimetric determination at 329-333 and 431-434 nm (excitation at 389 nm), respectively. For the spectrophotometric method, Beer's law was obeyed from 0.5 to 2.5 μg ml -1 for tramadol, dothiepin and 5-25 μg ml -1 for acebutolol. Using the spectrofluorimetric method linearity ranged from 0.25 to 1.25 μg ml -1 for tramadol, dothiepin and 1-5 μg ml -1 for acebutolol. Mean percentage recoveries for the spectrophotometric method were 99.68 ± 1.00, 99.95 ± 1.11 and 99.72 ± 1.01 for tramadol, acebutolol and dothiepin, respectively and for the spectrofluorimetric method, recoveries were 99.5 ± 0.844, 100.32 ± 0.969 and 99.82 ± 1.15 for the three drugs, respectively. The optimum experimental parameters for the reaction has been studied. The validity of the described procedures was assessed. Statistical analysis of the results has been carried out revealing high accuracy and good precision. The proposed methods were successfully applied for the determination of the selected drugs in their pharmaceutical preparations with good recoveries. The procedures were accurate, simple and suitable for quality control application.

  16. 灯盏花素制剂研究进展%Research Progress on Pharmaceutical Preparation of Breviscapine

    Institute of Scientific and Technical Information of China (English)

    方睿; 杜树山

    2011-01-01

    Objective: To Summarize the research progress on pharmaceutical preparation of breviscapine,which could be useful for the further research. Method: Literatures about breviscapine in plenty of books, journals and patents were referred to, and the progress of the pharmaceutical preparation was summarized. Result: The structure of breviscapine is clearly known and searching new pharmaceutical preparation of breviscapine is helpful for clinical. Conclusion: Although so many breviscapine preparations existed, but few used in clinical. However,in order to better utilize the preparations, it is important to study on biopharmaceutics and pharmacokinetics about scutellarin.%目的:总结灯盏花素在制剂方面的研究进展,为合理开发灯盏花素提供参考.方法:通过阅读大量近几年灯盏花素在制剂方面的书籍、文献及专利,并结合本课题组的研究经验和研究现状.对该领域进行总结概述.结果:灯盏花素结构明确,新的制剂技术的发展能使其临床应用效果更加显著.结论:虽然灯盏花素新制剂品种众多,但是临床应用较少,对其主要有效成分灯盏乙素进行深入的生物药剂学和药动学研究,对于制剂的开发利用非常重要.

  17. 红景天制剂的研究进展%Research advance on pharmaceutical preparations of Hongjingtian

    Institute of Scientific and Technical Information of China (English)

    王桂玲; 马小琴; 郭小红; 刘利

    2014-01-01

    目的:总结红景天在制剂方面的研究进展,为合理开发红景天提供参考。方法通过查阅大量近几年红景天在制剂方面的书籍、文献及专利,并结合本课题组的研究经验和研究现状,进行总结概述。结果红景天有效成分明确,新的制剂技术的发展能使其临床应用效果更加显著。结论虽然红景天新制剂品种众多,但是临床应用较少,对其主要有效成分红景天苷及酪醇进行深入地生物药剂学和药动学研究,对制剂的开发利用非常重要。%Objective To summarize the research progress on pharmaceutical preparations of Hongjingtian ,which could be useful for the further research .Methods Literatures about Hongjingtian in books ,journals and patents were analyzed ,and the progress of the pharmaceutical preparations was summarized .Results The active ingredients of Hongjingtian are clearly known and searching for new pharmaceutical preparations of Hongjingtian is helpful for clinical .Conclusion Although so many Hongjingtian prepara-tions existed ,few was used in clinic .In order to better utilize the preparations ,it is necessary to study the biopharmaceutics and pharmacokinetics of salidroside and tyrosot .

  18. Coulometric differential FFT admittance voltammetry determination of Amlodipine in pharmaceutical formulation by nano-composite electrode.

    Science.gov (United States)

    Norouzi, Parviz; Gupta, Vinod Kumar; Larijani, Bagher; Rasoolipour, Solmaz; Faridbod, Farnoush; Ganjali, Mohammad R

    2015-01-01

    An electrochemical detection technique based on combination of was coulometric differential fast Fourier transformation admittance voltammetry (CDFFTAV) and nano-composite film modified glassy carbon electrode was successfully applied for sensitive determination of Amlodipine. The nano-composite film was made by a mixture of ionic liquid, 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIMBF4), multiwall carbon nanotube and Au nanoparticles as electrochemical mediators. Studies reveal that the irreversible oxidation of Amlodipine was highly facile on the electrode surface. The electrochemical response was established on calculation of the charge under the admittance peak, which was obtained by discrete integration of the admittance response in a selected potential range, obtained in a flow injection analysis. Once established the best operative optimum conditions, the resulting nano-composite film electrode showed a catalytic effect on the oxidation of the analyte. The response is linear in the Amlodipine concentration range of 1.0 × 10(-9) to 2.0 × 10(-7)M with a detection limit of 1.25 × 10(-10)M. Moreover, the proposed technique exhibited high sensitivity, fast response time (less than 6s) and long-term stability and reproducibility around 96%, and it was successfully used to the determination of Amlodipine content in the pharmaceutical formulation.

  19. Spectrophotometric Determination of N-Acetyl-L-Cysteine and N-(2-Mercaptopropionyl-Glycine in Pharmaceutical Preparations

    Directory of Open Access Journals (Sweden)

    Lea Kukoc-Modun

    2011-01-01

    Full Text Available A simple spectrophotometric method for the determination of N-acetyl-L-cysteine (NAC and N-(2-mercaptopropionylglycine (MPG in pharmaceutical preparations was developed, validated, and used. The proposed equilibrium method is based on a coupled two-step redox and complexation reaction. In the first step, Fe(III is reduced to Fe(II by NAC or MPG. Subsequently, Fe(II is complexed with 2,4,6-tripyridyl-s-triazine (TPTZ. Several analytical parameters of the method were optimized for NAC and MPG analysis in the concentration range from 1.0 μM to 100.0 μM. Regression analysis of the calibration data showed a good correlation coefficient (0.9999. The detection limit of the method was 0.14 μM for NAC and 0.13 μM for MPG. The method was successfully applied to quantify NAC and MPG in pharmaceutical preparations. No interferences were observed from common pharmaceutical excipients.

  20. Determination of Propranolol Hydrochloride in Pharmaceutical Preparations Using Near Infrared Spectrometry with Fiber Optic Probe and Multivariate Calibration Methods

    Directory of Open Access Journals (Sweden)

    Jucelino Medeiros Marques Junior

    2015-01-01

    Full Text Available A method for determination of propranolol hydrochloride in pharmaceutical preparation using near infrared spectrometry with fiber optic probe (FTNIR/PROBE and combined with chemometric methods was developed. Calibration models were developed using two variable selection models: interval partial least squares (iPLS and synergy interval partial least squares (siPLS. The treatments based on the mean centered data and multiplicative scatter correction (MSC were selected for models construction. A root mean square error of prediction (RMSEP of 8.2 mg g−1 was achieved using siPLS (s2i20PLS algorithm with spectra divided into 20 intervals and combination of 2 intervals (8501 to 8801 and 5201 to 5501 cm−1. Results obtained by the proposed method were compared with those using the pharmacopoeia reference method and significant difference was not observed. Therefore, proposed method allowed a fast, precise, and accurate determination of propranolol hydrochloride in pharmaceutical preparations. Furthermore, it is possible to carry out on-line analysis of this active principle in pharmaceutical formulations with use of fiber optic probe.

  1. Comparative artificial neural network and partial least squares models for analysis of Metronidazole, Diloxanide, Spiramycin and Cliquinol in pharmaceutical preparations.

    Science.gov (United States)

    Elkhoudary, Mahmoud M; Abdel Salam, Randa A; Hadad, Ghada M

    2014-09-15

    Metronidazole (MNZ) is a widely used antibacterial and amoebicide drug. Therefore, it is important to develop a rapid and specific analytical method for the determination of MNZ in mixture with Spiramycin (SPY), Diloxanide (DIX) and Cliquinol (CLQ) in pharmaceutical preparations. This work describes simple, sensitive and reliable six multivariate calibration methods, namely linear and nonlinear artificial neural networks preceded by genetic algorithm (GA-ANN) and principle component analysis (PCA-ANN) as well as partial least squares (PLS) either alone or preceded by genetic algorithm (GA-PLS) for UV spectrophotometric determination of MNZ, SPY, DIX and CLQ in pharmaceutical preparations with no interference of pharmaceutical additives. The results manifest the problem of nonlinearity and how models like ANN can handle it. Analytical performance of these methods was statistically validated with respect to linearity, accuracy, precision and specificity. The developed methods indicate the ability of the previously mentioned multivariate calibration models to handle and solve UV spectra of the four components' mixtures using easy and widely used UV spectrophotometer.

  2. Review on preparation techniques of particle reinforced metal matrix composites

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    This paper reviews the investigation status of the techniques for preparation of metal matrix composites and the research outcomes achieved recently. The mechanisms, characteristics, application ranges and levels of development of these preparatior techniques are analyzed. The advantages and the disadvantages of each technique are synthetically evaluated. Lastly, the future directions of research and the prospects for the preparation techniques of metal matrix composites are forecasted.

  3. Quantitative spot-test analysis of metformin in pharmaceutical preparations using ultraviolet-visible diffuse reflectance spectroscopy.

    Science.gov (United States)

    Tubino, Matthieu; Bianchessi, Luís Francisco; Vila, Marta M D C

    2010-01-01

    A quantitative spot-test for the determination of metformin in pharmaceutical preparations using diffuse UV-visible reflectance is reported. The procedure is quite simple, involving in the formation of a metformin-nickel(II) complex on a glass filter membrane with a later measurement of the reflectance in the spectrophotometer using an integration sphere. The analytical results obtained with commercial products were statistically compared with those resulting from a method recommended by JP and by USP, where complete agreement was observed. The average RSD is 2.5% and the detection (0.009 mol L(-1)) and the quantitation (0.03 mol L(-1)) limits are quite adequate for pharmaceutical analysis.

  4. Determination of nifuroxazide and drotaverine hydrochloride in pharmaceutical preparations by three independent analytical methods.

    Science.gov (United States)

    Metwally, Fadia H; Abdelkawy, Mohammed; Naguib, Ibrahim A

    2006-01-01

    Three new, different, simple, sensitive, and accurate methods were developed for quantitative determination of nifuroxazide (I) and drotaverine hydrochloride (II) in a binary mixture. The first method was spectrophotometry, which allowed determination of I in the presence of II using a zero-order spectrum with an analytically useful maximum at 364.5 nm that obeyed Beer's law over a concentration range of 2-10 microg/mL with mean percentage recovery of 100.08 +/- 0.61. Determination of II in presence of I was obtained by second derivative spectrophotometry at 243.6 nm, which obeyed Beer's law over a concentration range of 2-10 microg/mL with mean recovery of 99.82 +/- 1.46%. The second method was spectrodensitometry, with which both drugs were separated on a silica gel plate using chloroform-acetone-methanol-glacial acetic acid (6 + 3 + 0.9 + 0.1) as the mobile phase and ultraviolet (UV) detection at 365 nm over a concentration range of 0.2-1 microg/band for both drugs, with mean recoveries of 99.99 +/- 0.15 and 100.00 +/- 0.34% for I and II, respectively. The third method was reversed-phase liquid chromatography using acetonitrile-water (40 + 60, v/v; adjusted to pH 2.55 with orthophosphoric acid) as the mobile phase and pentoxifylline as the internal standard at a flow rate of 1 mU/min with UV detection at 285 nm at ambient temperature over a concentration range of 2-10 microg/mL for both drugs, with mean recoveries of 100.24 +/- 1.51 and 100.08 +/- 0.78% for I and II, respectively. The proposed methods were checked using laboratory-prepared mixtures and were successfully applied for the analysis of pharmaceutical formulations containing the above drugs with no interference from other dosage form additives. The validity of the suggested procedures was further assessed by applying the standard addition technique which was found to be satisfactory, and the percentage recoveries obtained were in accordance with those given by the EVA Pharma reference

  5. Ionic liquid-facilitated preparation of lignocellulosic composites

    Science.gov (United States)

    Lignocellulosic composites (LCs) were prepared by partially dissolving cotton along with steam exploded Aspen wood and burlap fabric reinforcements utilizing an ionic liquid (IL) solvent. Two methods of preparation were employed. In the first method, a controlled amount of IL was added to preassembl...

  6. Ion Association Methods for the Determination of Fexofenadine in Pharmaceutical Preparations

    Directory of Open Access Journals (Sweden)

    L. D. Srinivas

    2005-01-01

    Full Text Available Two simple and sensitive Visible spectrophotometric methods (A and B for the determination of Fexofenadine (FEX in bulk sample and pharmaceutical formulations are described. Methods A and B are based on the formation of ion-association complex involving carboxylic acid group of FEX and the basic dyes, Safranin-O (SFN-O, method A, methylene blue (MB, method B. The results obtained in the above two methods are reproducible and are statistically validated and found to be suitable for the assay of Fexofenadine in bulk and its pharmaceutical formulations.

  7. A sensitive determination of terbutaline in pharmaceuticals and urine samples using a composite electrode based on zirconium oxide nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Baytak, Aysegul Kutluay; Teker, Tugce; Duzmen, Sehriban; Aslanoglu, Mehmet, E-mail: maslanoglu@harran.edu.tr

    2016-10-01

    An accurate and precise determination of terbutaline has been carried out using a glassy carbon electrode (GCE) modified with a composite of multi-walled carbon nanotubes (MWCNTs) and nanoparticles of zirconium oxide (ZrO{sub 2}NPs). Energy dispersive X-ray and scanning electron microscopic techniques were utilized for the characterization of the composite layer. Terbutaline exhibited a broad oxidation peak at 770 mV on a GCE. However, MWCNTs/GCE presented an electrocatalytic effect toward the oxidation of terbutaline with a better anodic peak at 660 mV. Furthermore, the electrochemical behavior of terbutaline has greatly been improved at a GCE modified with a composite of MWCNTs and nanoparticles of ZrO{sub 2}. The ZrO{sub 2}NPs/MWCNTs/GCE exhibited a sharp anodic wave at 645 mV with a large enhancement of the current response for terbutaline. Square wave voltammetry (SWV) was performed for the determination of terbutaline at ZrO{sub 2}NPs/MWCNTs/GCE. A linear plot was obtained for the current responses of terbutaline against concentrations in the range of 10–160 nM yielding a detection limit of 2.25 nM (based on 3S{sub b}/m). Improved voltammetric behavior, long-time stability and good reproducibility were obtained for terbutaline at the proposed electrode. A mean recovery of 101.2% with an RSD% of 1.9 was obtained for the analysis of the drug formulation. The accurate and precise quantification of terbutaline makes the ZrO{sub 2}NPs/MWCNTs/GCE system of great interest for monitoring its therapeutic use. - Graphical abstract: A sensitive determination of terbutaline in pharmaceuticals and urine samples using a composite electrode based on zirconium oxide nanoparticles. Display Omitted - Highlights: • A composite electrode was prepared using nanoparticles of ZrO{sub 2} and MWCNTs. • The ZrO{sub 2}NPs/MWCNTs/GCE has greatly improved the voltammetry of terbutaline • The proposed electrode enabled a detection limit of 2.25 nM. • The proposed electrode

  8. Kinetics of oil saponification by lead salts in ancient preparations of pharmaceutical lead plasters and painting lead mediums.

    Science.gov (United States)

    Cotte, M; Checroun, E; Susini, J; Dumas, P; Tchoreloff, P; Besnard, M; Walter, Ph

    2006-12-15

    Lead soaps can be found in archaeological cosmetics as well as in oil paintings, as product of interactions of lead salts with oil. In this context, a better understanding of the formation of lead soaps allows a follow-up of the historical evolution of preparation recipes and provides new insights into conservation conditions. First, ancient recipes of both pharmaceutical lead plasters and painting lead mediums, mixtures of oil and lead salts, were reconstructed. The ester saponification by lead salts is determined by the preparation parameters which were quantified by FT-IR spectrometry. In particular, ATR/FT-IR spectrometer was calibrated by the standard addition method to quantitatively follow the kinetics of this reaction. The influence of different parameters such as temperature, presence of water and choice of lead salts was assessed: the saponification is clearly accelerated by water and heating. This analysis provides chemical explanations to the historical evolution of cosmetic and painting preparation recipes.

  9. Nano-structured polymer composites and process for preparing same

    Science.gov (United States)

    Hillmyer, Marc; Chen, Liang

    2013-04-16

    A process for preparing a polymer composite that includes reacting (a) a multi-functional monomer and (b) a block copolymer comprising (i) a first block and (ii) a second block that includes a functional group capable of reacting with the multi-functional monomer, to form a crosslinked, nano-structured, bi-continuous composite. The composite includes a continuous matrix phase and a second continuous phase comprising the first block of the block copolymer.

  10. Preparation of Porous Mullite Composite by Microwave Sintering

    Institute of Scientific and Technical Information of China (English)

    FAN Bingbing; ZHANG Rui; SUN Bing; LI Xuqin; LI Chunguang

    2012-01-01

    Microwave sintering method was carried out to prepare porous mullite composite.An insulation structure based on hybrid heating mode was well designed with the wall of mullite and the aided heaters of SiC.The obtained samples were characterized by XRD analysis,apparent porosity detection,and bending strength measurement.SEM was used to observe the microstructure of the sample.It is found that the porous mullite composite could be prepared through the microwave sintering within 2 h at relatively low temperatures around 1000 ℃.The lasted samples show comparatively superior properties to the products prepared by conventional processing.

  11. Preparation and characterization of rice husk/ferrite composites

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    A novel ferrite composite using rice husk as substrate has been prepared via high temperature treatment under nitrogen atmosphere.The rice husk substrate consists of porous activated carbon and silica,where spinel ferrite particles with average diameter of 59 nm are distributed.The surface area of the composite is greater than 170 m~2 g~(-1) and the bulk density is less than 0.6 g cm~(-3).Inert atmosphere is indispensable for the synthesis of pure ferrite composites,while different preparation temperatur...

  12. Potentiometric determination of antihistaminic diphenhydramine hydrochloride in pharmaceutical preparations and biological fluids using screen-printed electrode.

    Science.gov (United States)

    Frag, Eman Y Z; Mohamed, Gehad G; El-Sayed, Wael G

    2011-10-01

    The performance characteristic of sensitive screen-printed (SPE) and carbon paste (CPE) electrodes was investigated for the determination of diphenhydramine hydrochloride (DPH) drug in pure, pharmaceutical preparations and biological fluids. Different experimental conditions namely types of materials used to prepare the working electrode (plasticizer), titrant, pH, temperature and life time were studied. Under these conditions, the SPE shows the best performance than CPE with respect to total potential change and potential break at the end point. The SPE and CPE exhibit suitable response to DPH in a concentration range of 1.0.10(-2) to 1.0.10(-6) mol/L with a limit of detection 9.70.10(-7) and 9.80.10(-7) mol/L, respectively. The slope of the system was 55.2±1.0 and 54.7±1.0 mV/decade over pH range 3.0-8.0 and 3-7 for SPE and CPE, respectively. Selectivity coefficients for DPH relative to a numbers of potential interfering substances were investigated. The SPE and CPE show a fast response time of 10 and 16s and were used over a period of 2 months with a good reproducibility. The sensors were applied successfully to determine DPH in pharmaceutical preparations and biological fluids. The results are compared with the official method.

  13. Preparation of ultrafine magnetic biochar and activated carbon for pharmaceutical adsorption and subsequent degradation by ball milling

    Science.gov (United States)

    Shan, Danna; Deng, Shubo; Zhao, Tianning; Wang, Bin; Wang, Yujue; Huang, Jun; Yu, Gang; Winglee, Judy; Wiesner, Mark R.

    2017-01-01

    Ball milling was used to prepare two ultrafine magnetic biochar/Fe3O4 and activated carbon (AC)/Fe3O4 hybrid materials targeted for use in pharmaceutical removal by adsorption and mechanochemical degradation of pharmaceutical compounds. Both hybrid adsorbents prepared after 2 hours milling exhibited high removal of carbamazepine (CBZ), and were easily separated magnetically. These adsorbents exhibited fast adsorption of CBZ and tetracycline (TC) in the initial 1 hour. The biochar/Fe3O4 had a maximum adsorption capacity of 62.7 mg/g for CBZ and 94.2 mg/g for TC, while values obtained for AC/Fe3O4 were 135.1 mg/g for CBZ and 45.3 mg/g for TC respectively when data were fitted using the Langmuir expression. Solution pH values slightly affected the sorption of TC on the adsorbents, while CBZ sorption was almost pH-independent. The spent adsorbents with adsorbed CBZ and TC were milled to degrade the adsorbed pollutants. The adsorbed TC itself was over 97% degraded after 3 hours of milling, while about half of adsorbed CBZ were remained. The addition of quartz sand was found to improve the mechanochemical degradation of CBZ on biochar/Fe3O4, and its degradation percent was up to 98.4% at the dose of 0.3 g quarts sand/g adsorbent. This research provided an easy method to prepare ultrafine magnetic adsorbents for the effective removal of typical pharmaceuticals from water or wastewater and degrade them using ball milling. PMID:26685062

  14. Preparation of ultrafine magnetic biochar and activated carbon for pharmaceutical adsorption and subsequent degradation by ball milling.

    Science.gov (United States)

    Shan, Danna; Deng, Shubo; Zhao, Tianning; Wang, Bin; Wang, Yujue; Huang, Jun; Yu, Gang; Winglee, Judy; Wiesner, Mark R

    2016-03-15

    Ball milling was used to prepare two ultrafine magnetic biochar/Fe3O4 and activated carbon (AC)/Fe3O4 hybrid materials targeted for use in pharmaceutical removal by adsorption and mechanochemical degradation of pharmaceutical compounds. Both hybrid adsorbents prepared after 2h milling exhibited high removal of carbamazepine (CBZ), and were easily separated magnetically. These adsorbents exhibited fast adsorption of CBZ and tetracycline (TC) in the initial 1h. The biochar/Fe3O4 had a maximum adsorption capacity of 62.7mg/g for CBZ and 94.2mg/g for TC, while values obtained for AC/Fe3O4 were 135.1mg/g for CBZ and 45.3mg/g for TC respectively when data were fitted using the Langmuir expression. Solution pH values slightly affected the sorption of TC on the adsorbents, while CBZ sorption was almost pH-independent. The spent adsorbents with adsorbed CBZ and TC were milled to degrade the adsorbed pollutants. The adsorbed TC itself was over 97% degraded after 3h of milling, while about half of adsorbed CBZ were remained. The addition of quartz sand was found to improve the mechanochemical degradation of CBZ on biochar/Fe3O4, and its degradation percent was up to 98.4% at the dose of 0.3g quarts sand/g adsorbent. This research provided an easy method to prepare ultrafine magnetic adsorbents for the effective removal of typical pharmaceuticals from water or wastewater and degrade them using ball milling.

  15. PREPARATION, CHARACTERIZATION, AND PHARMACEUTICAL APPLICATION OF LINEAR DEXTRINS .1. PREPARATION AND CHARACTERIZATION OF AMYLODEXTRIN, METASTABLE AMYLODEXTRINS, AND METASTABLE AMYLOSE

    NARCIS (Netherlands)

    WIERIK, GHPT; EISSENS, AC; BESEMER, AC; LERK, CF

    The linear dextrin amylodextrin was prepared by enzymatic hydrolysis from waxy maize. Four metastable amylodextrins were prepared by complexation with different volatile organic compounds. All products showed partial dissolution into water at room temperature, because of dissolution of molecules

  16. A home-made hybrid system for the simultaneous determination of ergotamine, dipyrone and caffeine in pharmaceutical preparations

    OpenAIRE

    2007-01-01

    A novel home-made hybrid detection system was designed for simultaneous determination of caffeine (CAF), dipyrone (DIP) and ergotamine (ERG) in pharmaceutical preparations. Thus, ERG was determined by a fluorimetric signal and PLS-1 method for resolving DIP and CAF UV-Vis spectral data was used. The calibration curve for ERG was linear over the range 2.5-10 mg L-1. The calibration set consisted of 18 mixtures with 0.5 to 4 mg L-1 for CAF, 5 to 20 mg L-1 for DIP and 2.5 and 10 mg L-1 for ERG. ...

  17. Simultaneous spectrophotometric determination of overlapping spectra of paracetamol and caffeine in laboratory prepared mixtures and pharmaceutical preparations using continuous wavelet and derivative transform

    Directory of Open Access Journals (Sweden)

    Ahmed Ashour

    2015-03-01

    Full Text Available In the present paper, two spectrophotometric methods were used for the simultaneous analysis of paracetamol (PCT and caffeine (CAF in their laboratory prepared mixtures and pharmaceutical preparations. Simple spectrophotometric analysis of PCT and CAF is not possible due to their complete spectral overlap. The proposed methods are based on the application of continuous wavelet transform (CWT and derivative transform (using Savitsky–Golay filters on the ratio spectra to predict each of CAF and PCT. Several wavelet families were tested. Coif1 and Sym2 were found to give best results under optimum conditions. The transformed signals of ratio spectra were used to plot the calibration curves for both components. The predictability of the built calibrations was validated through their application on several synthetic mixtures of both drugs. The proposed methods were used for the prediction of CAF and PCT in pharmaceutical preparation. The obtained results were statistically compared to a reference HPLC method. No significant differences were found between the obtained results and those from the reference method. Being simple, rapid, cheap and sensitive, the proposed methods are recommended for the routine daily analysis of these two drugs in their mixtures in quality control laboratories.

  18. MAIN FACTORS IN PREPARATION OF ANTIBACTERIAL PARTICLES/PVC COMPOSITE

    Institute of Scientific and Technical Information of China (English)

    Xuehua Chen; Chunzhong Li; Ling Zhang; Shoufang Xu; Qiuling Zhou; Yihua Zhu; Xianzhang Qu

    2004-01-01

    Zirconium phosphate containing silver was chosen as antibacterial particles in preparing antibacterial particles/PVC composite. The effect of surface property of the antibacterial particles and of their filler content on the properties of antibacterial particles/PVC composite was studied. The effect of the interfacial compatibility on mechanical properties of the composite was also discussed. Experimental results showed that the antibacterial PVC composite had good antibacterial property, reaching almost 100% bacteriostatic level at an antibacterial powder filler content of 1.5 phr.

  19. Development of pharmaceutical heroin preparations for medical co-prescription to opioid dependent patients.

    Science.gov (United States)

    Klous, Marjolein G; Van den Brink, Wim; Van Ree, Jan M; Beijnen, Jos H

    2005-12-12

    Presently, there is a considerable interest in heroin-assisted treatment: co-prescription of heroin to certain subgroups of chronic, treatment-resistant, opioid dependent patients. In 2002, nine countries had planned (Australia, Belgium, Canada, France, Spain) or ongoing (Germany, The Netherlands, Switzerland, United Kingdom) clinical trials on this subject. These trials (and the routine heroin-assisted treatment programs that might result) will need pharmaceutical heroin (diacetylmorphine) to prescribe to the patients. Research into the development of pharmaceutical forms of heroin for prescription to addicts can benefit from the large amount of knowledge that already exists regarding this substance. Therefore, in this paper we review the physicochemical and pharmaceutical properties of diacetylmorphine and the clinically investigated routes of administration, as well as routes of administration utilised on the street in the context of developing pharmaceutical heroin formulations for prescription to addicts. Patient acceptability of the formulation is essential, because heroin-assisted treatment is aimed at treatment-resistant addicts, who often have to be encouraged to participate (or to maintain participation) in a treatment program. This means that the most suitable products would have pharmacokinetic profiles mimicking that of diacetylmorphine for injection, with rapid peak concentrations of diacetylmorphine and 6-acetylmorphine, ensuring the 'rush effect' and the sustained presence of morphine(-6-glucuronide) creating the prolonged euphoria. Diacetylmorphine for inhalation after volatilisation (via 'chasing the dragon') seems to be a suitable candidate, while intranasal and oral diacetylmorphine are currently thought to be unsuitable. However, oral and intranasal delivery systems might be improved and become suitable for use by heroin dependent patients.

  20. Spectrofluorimetric method for the determination of sulpiride in pharmaceutical preparations and human plasma through derivatization with 2-cyanoacetamide.

    Science.gov (United States)

    Shah, Jasmin; Jan, M Rasul; Khan, M Naeem; Shah, Sultan

    2013-01-01

    A sensitive and accurate spectrofluorimetric method has been developed for the determination of sulpiride in pharmaceutical preparations and human plasma. The developed method is based on the derivatization reaction of 2-cyanoacetamide with sulpiride in 30% ammonical solution. The fluorescent derivatized reaction product exhibited maximum fluorescence intensity at 379 nm after excitation at 330 nm. The optimum conditions for derivatization reactions were studied and the fluorescence intensity versus concentration plot was found to be linear over the concentration range 0.2-20.0 µg/mL with a correlation coefficient of 0.9985. The limit of detection (LOD) and limit of quantification (LOQ) were found to be 0.82 and 2.73 ng/mL, respectively. The proposed method was validated according to ICH guidelines. The effects of common excipients and co-administered drugs were also studied. The accuracy of the method was checked using the standard addition method and percent recoveries were found to be in the range of 99.00-101.25% for pharmaceutical preparations and 97.00-97.80% for spiked human plasma. The method was successfully applied to commercial formulations and the results obtained for the proposed method were compared with a high-performance liquid chromatography reference method and statistically evaluated using the Student's t-test for accuracy and the variance ratio F-test for precision. A reaction pathway was also proposed.

  1. Development and validation of an MEKC method for determination of nitrogen-containing drugs in pharmaceutical preparations.

    Science.gov (United States)

    Buiarelli, Francesca; Coccioli, Franco; Jasionowska, Renata; Terracciano, Alessandro

    2008-09-01

    A fast and accurate micellar electrokinetic capillary chromatography method was developed for quality control of pharmaceutical preparations containing cold remedies as acetaminophen, salicylamide, caffeine, phenylephrine, pseudoephedrine, norephedrine and chlorpheniramine. The method optimization was realized on a Beckman P/ACE System MDQ instrument. The baseline separation of seven analytes was performed in an uncoated fused silica capillary internal diameter (ID)=50 microm using tris-borate (20 mM, pH=8.5) containing sodium dodecyl sulphate 30 mM BGE. On line-UV detection at 214 nm was performed and the applied voltage was 10 kV. The operating temperature was 25 degrees C. After experimental conditions optimization, the proposed method was validated. The evaluated parameters were: precision of migration time and of corrected peak area ratio, linearity range, limit of detection, limit of quantification, accuracy (recovery), ruggedness and applicability. The method was then successfully applied for the analysis of three pharmaceutical preparations containing some of the analytes listed before.

  2. Preparation technique of SiCp reinforced Al matrix composite

    Institute of Scientific and Technical Information of China (English)

    HAO Bin; CUI Hua; YU Zhi-yong; TAO Kai; YANG Bin; ZHANG Ji-shan

    2006-01-01

    A new preparation technique-"block dispersal and cast" method is introduced, and three kinds of powd.er mixing methods, vertical, horizontal and inclining styles, are compared. The results demonstrate that the inclining style is the best way to mix powders. The Al and nano SiC powders are pressed into blocks, dipped into molten Al, stirred into mold so that SiC/Al matrix composites can be obtained at last. The microstructure of SiC particle reinforced Al matrix composite prepared by "block dispersal and cast" method have been studied using scanning electron microscopy (SEM). Phase analysis has also been conducted by means of X-ray diffraction (XRD). The results show that nano SiC particles can be dispersed uniformly in Al matrix. Thus, it is feasible to prepare SiC particle reinforced Al matrix composites by this method.

  3. Composite bone substitutes prepared by two methods

    Science.gov (United States)

    Lee, Hoe Y.

    A variety of ceramics and polymers exists that can be used as bone substitute materials with desirable properties such as biocompatibility and osteoconductivity. A key feature missing in these bone substitutes, or scaffolds, is the ability to bear loads. This work explored two methods for solving this problem. The first used cancellous bone taken from bovine femoral bone to create a natural scaffold through a heat treating process that eliminated the organic components and sintered the bone minerals, known as hydroxyapatite, together. The strength and Young's modulus of the natural scaffold were greatly improved after polymer infiltration with polymethylmethacrylate. Unfortunately, compression testing revealed that there was not a good interfacial bond between the mineral and polymer phases. The second method employed a freeze-casting technique to create synthetic hydroxyapatite scaffolds that have an aligned lamellar microstructure. By varying the amount of hydroxyapatite in the initial slurry mixture and the cooling rate, synthetic scaffolds with a range of porosities and strengths was produced. The highest solid loading and fastest cooling rate produced a scaffold with a strength and modulus approaching that of cortical bone. Further study is required to produce a two phase composite that is chemically bonded together for optimal performance. The synthetic scaffolds, with their tunable mechanical properties and ease of fabrication, make them a promising material for a load-bearing bone substitute.

  4. Preparation and Characterization Analysis of Hydroxyapatite/Gelatin Composite

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The hydroxyapatite (HAp)/gelatin composite was prepared by self-assembly method. X-ray diffraction confirmed that the inorganic phase in the composite was HAp. The Fourier transform infra-red spectrum(FT-IR) indicated the presence of amide and hydroxyl groups in the composite. The organic-inorganic ratio of the composite is similar to that of the human bone, which was determined by differential thermal analysis ( DTA )and thermogravimetric analysis ( TGA ). Transmission Electron Microscopy (TEM) showed that the composite is composed by spindly grains and the multilayer nanostructure can also be seen. Gelatin in the composite assembled orderly and directionally ; and the HAp crystals grew along the gelatin molecule at nearly the same direction. A model was established to explain the process of the interaction between gelatin and HAp.

  5. Preparation and characterization of bioglass/polyvinyl alcohol composite hydrogel

    Energy Technology Data Exchange (ETDEWEB)

    Xu Hong [College of Materials Science and Engineering, South China University of Technology, Guangzhou 510641 (China); Wang Yingjun [College of Materials Science and Engineering, South China University of Technology, Guangzhou 510641 (China); Zheng Yudong [College of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Chen Xiaofeng [College of Materials Science and Engineering, South China University of Technology, Guangzhou 510641 (China); Ren Li [College of Materials Science and Engineering, South China University of Technology, Guangzhou 510641 (China); Wu Gang [College of Materials Science and Engineering, South China University of Technology, Guangzhou 510641 (China); Huang Xiaoshan [College of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083 (China)

    2007-06-01

    In order to form firm active fixation with the adjacent bone, a new kind of bioactive composite hydrogel was prepared with polyvinyl alcohol (PVA) and bioglass (BG) through ultrasonic dispersion, heat-high-pressure and freeze/thawed technique. A digital speckle correlation method (DSCM) was utilized to characterize the mechanical properties of the series of BG/PVA composites. Results showed that at different load pressures, the composite hydrogel displayed different displacement and deformation in the V field. Results also showed that an increase of PVA percentage (15-30 wt%) or of bioglass percentage (2-10 wt%) in composite hydrogel could lead to an increase in the elastic compression modulus. Scanning electron microscope results indicated that bioglass was uniformly dispersed in the BG/PVA composite hydrogel. The BG/PVA composite hydrogel shows a promising prospect as a new bionic cartilage implantation material.

  6. Preparation and characterization of gold-decorated graphite nanosheet composites.

    Science.gov (United States)

    Kim, Jungsoo; Nam, Dae Geun; Oh, Weon Tae

    2013-05-01

    Some composites of gold nanoparticles and graphite nanosheets were prepared by electrostatic interaction, and structurally and electrochemically characterized using X-ray diffraction, X-ray photoelectron spectroscopy, UVNis spectroscopy, transmission electron microscopy, and cyclic-voltammetry. Pristine graphite was chemically treated using aqueous acid solution, and dispersed inpoly(diallyldimethylammonium) chloride aqueous solution to prepare positively charged graphite nanosheets. The gold nanoparticles (GNPs) in this work were stabilized by sodium dodecyl sulfate, poly(sodium 4-styrene sulfonate), or poly(vinylpyrrolidone). Gold nanoparticles and graphite nanosheet composites with gold nanoparticles showed the characteristic surface plasmon band at -530 nm. The electrochemical properties of the graphite nanosheet composites with gold nanoparticles were studied by cyclic voltammetry, in which reduction potential and reduction current of gold nanoparticles were strongly dependent on the gold-wrapped stabilizer in the composites.

  7. Preparation of Nano/Micron Composite Materials by Process Method

    Institute of Scientific and Technical Information of China (English)

    GAN Ai-feng; WEI Qi; JI; Yuan; HU Chuan-xin; YAO Jun-min

    2004-01-01

    This thesis put forward a method that controls the process of synthesizing nanomaterial to realize the composite of nanomaterial and micronmaterial. This thesis realizes the composite of nanomaterial and micronmaterial by adding micronmaterial during production of nanomaterial through sol-gel method, also introduces the technique and experiment's process preparation of nanocomposite material, and successfully prepared nanocomposite materials with nano-PbTiO3 covered on the surface of micron-Ni. According to the sample's SEM-pictures, the core-shell can be observed plate microstructure, and it is uniform, tight, full and good.

  8. Preparation and Characterization of Conducting Polybutadiene/ Polythiophene Composites

    OpenAIRE

    KIRALP, Senem; Küçükyavuz, Zuhal

    2003-01-01

    Conductive composite films of cis-1,4-polybutadiene (PBD) with polythiophene (PTh) were prepared electrochemically. Thiophene was polymerized on PBD-coated platinium electrodes. The composites with different PTh percentages showed conductivity in the order of 10-3 (W cm)-1. The characterization of the films was performed using FTIR, scanning electron microscope and differential scanning calorimetry techniques. In order to understand the dominant transport mechanism, the temperature...

  9. Composite polysaccharide fibers prepared by electrospinning and coating

    OpenAIRE

    2013-01-01

    Composite polysaccharide fibers composed two oppositely charged natural polysaccharides, chitosan and hyaluronic acid, were prepared by electrospinning and subsequent coating The fiber size distribution was characterized by scanning electron microscopy. Chitosan/hyaluronic acid composite fibers were stable in water but showed controlled release of hyaluronic acid into phosphate buffered saline, and the presence of 3-wt% hyaluronic acid coating improved the swelling ratio to 30%. The resulting...

  10. Polypropylene–clay composite prepared from Indian bentonite

    Indian Academy of Sciences (India)

    Madhuchhanda Sarkar; Kausik Dana; Sankar Ghatak; Amarnath Banerjee

    2008-02-01

    In the present work, a set of experimental polypropylene (PP) clay composites containing pristine bentonite clay of Indian origin has been prepared and then characterized. The polymer clay composites are processed by solution mixing of polypropylene with bentonite clay using a solvent xylene and high speed electric stirrer at a temperature around 130°C and then by compression molding at 170°C. The mechanical properties of PP–clay composites like tensile strength, hardness and impact resistance have been investigated. Microstructural studies were carried out using scanning electron microscope and transmission electron microscope and the thermal properties were studied using differential scanning calorimeter. Mechanical properties of the prepared composites showed highest reinforcing and toughening effects of the clay filler at a loading of only 5 mass % in PP matrix. Tensile strength was observed to be highest in case of 5 mass % of clay loading and it was more than 14% of that of the neat PP, while toughness increased by more than 80%. Bentonite clay–PP composite (5 mass %) also showed 60% increase in impact energy value. However, no significant change was observed in case of hardness and tensile modulus. Higher percentages of bentonite clay did not further improve the properties with respect to pristine polypropylene. The study of the microstructure of the prepared polymer layered silicate clay composites showed a mixed morphology with multiple stacks of clay layers and tactoids of different thicknesses.

  11. Preparation and thermal properties of chitosan/bentonite composite beads

    Directory of Open Access Journals (Sweden)

    Teofilović Vesna

    2014-01-01

    Full Text Available Due to their biodegradable and nontoxic nature, biopolymer composites are often used as remarkable adsorbents in treatment of wastewater. In this study chitosan/bentonite composite beads were obtained by addition of clay into the polymer using solution process. Before the composite preparation, bentonite was modified with surfactant cetyltrimethyl ammonium bromide (CTAB. The morphology of beads was examined by scanning electron microscopy (SEM. Thermal properties of the composite beads were studied by simultaneous thermogravimetry coupled with differential scanning calorimetry (SDT and differential scanning calorimetry (DSC. TG results showed that the complex decomposition mechanism of the composites depends on the preparation procedure. It was observed that the concentration of NaOH used for composites precipitation affects the final structure of beads. The influence of preparation procedure on the glass transition temperature Tg of chitosan/bentonite samples was not found (Tg values for all samples were about 144 °C. [Projekat Ministarstva nauke Republike Srbije, br. III45022 and ON172014 and Provincial Secretariat of Vojvodina for Science and Technological Development 114-451-2396/2011-01.

  12. Spectrophotometric determination of thioctic (a-Aipoic acid in water and pharmaceutical preparations

    Directory of Open Access Journals (Sweden)

    ZAGORKA KORICANAC

    2007-01-01

    Full Text Available A spectrophotometric method is described for the assay of thioctic acid. The method is based on the reaction between the drug and palladium(II chloride. In this reaction, a yellow-coloured, water soluble product with a 1:1 stoichiometric ratio and an absorption maximum at 365 nm was formed. The stability of the formed complex depends on various factors (pH, reaction time, concentration of reagents, ionic strength. Based on these findings, a new method is suggested for the spectrophotometric determination of thioctic acid in pharmaceutical formulations. This method is simple, sensitive and reproducible.

  13. Composite polysaccharide fibers prepared by electrospinning and coating.

    Science.gov (United States)

    Maeda, N; Miao, J; Simmons, T J; Dordick, J S; Linhardt, R J

    2014-02-15

    Composite polysaccharide fibers composed two oppositely charged natural polysaccharides, chitosan and hyaluronic acid, were prepared by electrospinning and subsequent coating. The fiber size distribution was characterized by scanning electron microscopy. Chitosan/hyaluronic acid composite fibers were stable in water but showed controlled release of hyaluronic acid into phosphate buffered saline, and the presence of 3-wt% hyaluronic acid coating improved the swelling ratio to 30%. The resulting composite polysaccharide fibers have a number of potential biomedical applications in wound healing applications and in drug delivery systems.

  14. Construction and evaluation of PVC conventional and tubular tripelennamine-selective electrodes: their application in pharmaceutical preparations.

    Science.gov (United States)

    Lima, J L; Montenegro, M C; Sales, M G

    1996-06-01

    The construction and evaluation of tripelennamine conventionally-shaped ion-selective electrodes and tubular detectors for the determination of this compound in pharmaceutical formulations are described. Electrodes with conventional configuration have been constructed without an internal reference solution, using several types of immobilized ionic sensors in PVC. The different electrode membranes were prepared by using tripelennamine tetraphenylborate as ionic-exchanger, dissolved in 2-nitrophenyl octyl ether (type A), dibutylphthalate (type B) and bis-(2-ethylhexyl)sebacate (type C) as plasticizer solvents. The general working characteristics of the different types of conventional electrodes were evaluated in tripelennamine solutions, with adjusted ionic strength, showing a linear response in the concentration range of about 4 x 10(-5) - 1 x 10(-1) M and a slope near the theoretical value. The electrodes presented a fast response (> 20 s) and a high reproducibility (> or = 0.2 mV per day). The electrode selectivity in the presence of some interferents, such as sodium, potassium, lithium, ammonium, chlorpheniramine, diphenydramine, promethazine, meclizine and pentazocine, was good, particularly for those whose sensor membrane was prepared with tripelennamine tetraphenylborate dissolved in 2-nitrophenyl octyl ether (type A). Tubular detectors were also prepared using the same sensor membrane and were evaluated in a low-dispersion flow-injection manifold. Under these conditions the detectors presented response characteristics similar to those of the corresponding conventionally-shaped electrodes. The analysis of different pharmaceutical forms (creams, syrups and gels) gave good results with mean recoveries of 99.8-100.6% when the experiments were conducted by direct potentiometry and 99.9-100.4% where the same determinations were conducted by flow-injection analysis with tubular detectors.

  15. Use of a compound of formula (I) to manufacture a medicament for treating gaucher's disease, pharmaceutical composition, a compound of formula (IB) and method for obtaining said compound

    OpenAIRE

    Alfonso Palacin, Pilar; Moya García, Aurelio; Sánchez-Jiménez, Francisca; Pocovi Mieras, Miguel; Giraldo, Pilar; Ortiz-Mellet, Carmen; García Fernández, José Manuel

    2013-01-01

    [EN] Use of a compound of formula (I) to manufacture a medicament for treating Gaucher's disease in a human subject, a pharmaceutical composition comprising a compound of formula (I), compounds of formula (Ib) and method for obtaining said compounds.

  16. Preparation, physicochemical and pharmaceutical characterization of chitosan from Catharsius molossus residue.

    Science.gov (United States)

    Ma, Jiahua; Xin, Chao; Tan, Chengjia

    2015-09-01

    Polypeptide from Catharsius molossus L. is an active ingredient in the treatment of benign prostatic hyperplasia. The residue after extraction is harmful to the environment and is also a waste of resources. Chitosan was extracted from C. molossus L. residue with chemical methods and with an improved intermittent heating method. Physicochemical and pharmaceutical characteristics of chitosan from C. molossus L. and shrimp were mainly measured by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermal gravimetric analysis (TGA), scanning electron microscopy (SEM). The results showed chitosan from C. molossus L. was superior to commercial medical-grade chitosan from shrimp in the aspects of degree of deacetylation, crystallinity, heavy metal content, viscosity, protein residue, ash content, and in vitro adhesion. In addition, properties of chitosan membrane were studied, including water vapor permeability, light transmittance, enzymatic hydrolysis, swelling behavior, mechanical properties, and SEM images. It was found that the membrane of chitosan from C. molossus L. had better performance. This preliminary result shows chitosan from C. molossus L. is more suitable than shrimp's as a pharmaceutical excipient in colonic adhesive drug delivery system.

  17. A simple spectrophotometric method for the determination of captopril in pharmaceutical preparations using ammonium molybdate

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro, P.R.S., E-mail: pauloufma@ufma.b [Universidade Federal do Maranhao (CCSST/UFMA), Imperatriz, MA (Brazil). Centro de Ciencias Sociais, Saude e Tecnologia; Pezza, L.; Pezza, H.R. [UNESP, Araraquara, SP (Brazil). Inst. de Quimica

    2010-09-15

    A simple, rapid and sensitive spectrophotometric method for the determination of captopril (CPT) in pharmaceutical formulations is proposed. This method is based on the reduction reaction of ammonium molybdate, in the presence of sulphuric acid, for the group thiol of CPT, producing a green compound ({lambda}{sub max} 407 nm). Beer's law is obeyed in a concentration range of 4.60 x 10{sup -4} - 1.84 x 10{sup -3} mol l{sup -1} of CPT with an excellent correlation coefficient (r = 0.9995). The limit of detection and limit of quantification were 7.31 x 10{sup -6} and 2.43 x 10{sup -5} mol l{sup -1} of CPT, respectively. The proposed method was successfully applied to the determination of CPT in commercial brands of pharmaceuticals. No interferences were observed from the common excipients in the formulations. The results obtained by the proposed method were favorably compared with those given by the official reported method at 95 % confidence level. (author)

  18. New Diazo Coupling Reactions for Visible Spectrophotometric Determination of Alfuzosin in Pharmaceutical Preparations

    Directory of Open Access Journals (Sweden)

    M. Vamsi Krishna

    2007-01-01

    Full Text Available Simple, rapid and sensitive spectrophotometric procedures were developed for the analysis of Alfuzosin hydrochloride (AFZ in pure form as well as in pharmaceutical formulations. The methods are based on the reaction of AFZ with nitrite in acid medium to form diazonium ion, which is coupled with ethoxyethylenemaleic ester (Method A or ethylcyanoacetate (Method B or acetyl acetone (method C in basic medium to form azo dyes, showing absorption maxima at 440, 465 and 490 nm respectively. Beer’s law is obeyed in the concentration of 4-20 μg/mL of AFZ for methods A, B and 3-15 μg/mL of AFZ for method C. The molar absorptivity and sandell’s sensitivity of AFZ- ethoxyethylenemaleic ester, AFZ- ethylcyanoacetate and AFZ-acetyl acetone are1.90 × 104, 0.022; 1.93 × 104, 0.021 and 2.67 × 104 L mole-1 cm-1, 0.015 μg cm-2 respectively. The optimum reaction conditions and other analytical parameters were evaluated. The methods were successfully applied to the determination of AFZ in pharmaceutical formulations.

  19. Electrostaticspray preparation and properties of RDX/DOS composites

    Directory of Open Access Journals (Sweden)

    Jian Yao

    2017-08-01

    Full Text Available A composite explosive based on 1, 3, 5-trinitro-1, 3, 5-triazinane (RDX was prepared by electrostaticspray method with dioctyl sebacate (DOS as desensitizer. After preparation, the particle size and crystal structure were characterized and chemical features, such as chemical bonds, functional groups, thermal decomposition parameters and mechanical sensitivity were investigated as well. In terms of the morphologies of the composites, the particle sizes were in the range of 1–3 μm. Compared with RDX, the crystal types, chemical bonds and functional groups of the RDX/DOS composites were unchanged. The activation energy of the composites was lower than that of raw RDX, and the 3wt % DOS composites had the lowest activation energy. The impact sensitivity and friction sensitivity of the RDX/DOS composites were lower than those of raw RDX, and the 10wt% DOS composites had the highest H50 (125.9 cm and the lowest friction sensitivity (8%.

  20. Utilization of a Green Brominating Agent for the Spectrophotometric Determination of Pipazethate HCl in Pure Form and Pharmaceutical Preparations

    Directory of Open Access Journals (Sweden)

    Ayman A. Gouda

    2013-01-01

    Full Text Available Five simple, accurate, and sensitive spectrophotometric methods (A–E have been described for the indirect assay of pipazethate HCl (PZT either in pure form or in pharmaceutical preparations. The proposed methods are based on the bromination of pipazethate HCl with a solution of excess bromate-bromide mixture in hydrochloric acid medium and subsequent estimation of the residual bromine by different reaction schemes. In the first three methods (A–C, the determination of the residual bromine is based on its ability to bleach the color of methyl orange, indigo carmine, or thymol blue dyes and measuring the absorbance at 520, 610, and 550 nm for methods A, B, and C, respectively. Methods D and E involves treating the unreacted bromine with a measured excess of iron(II, and the remaining iron(II is complexed with 1,10-phenanthroline, and the increase in absorbance is measured at 510 nm for method D and the resulting iron(III is complexed with thiocyanate and the absorbance is measured at 480 nm for method E. The different experimental parameters affecting the development and stability of the color are carefully studied and optimized. Regression analysis of the Beer-Lambert plots showed good correlation in the concentration ranges of 0.5–8.0 μg . The apparent molar absorptivity, Sandell's sensitivity, detection and quantitation limits were evaluated. The proposed methods have been applied and validated successfully for the analysis of the drug in its pure form and pharmaceutical formulations with mean recoveries of 99.94%–100.15% and relative standard deviation ≤1.53. No interference was observed from a common pharmaceutical adjuvant. Statistical comparison of the results with the reference method shows excellent agreement and indicates no significant difference in accuracy and precision.

  1. Squalane and isosqualane compositions and methods for preparing the same

    Science.gov (United States)

    Fisher, Karl; Schofer, Susan Jessica; Kanne, David B

    2013-11-19

    Provided herein are methods comprising catalytic dimerization of .beta.-farnesene to obtain squalane and/or isosqualane. Compositions comprising squalane and/or isosqualane are provided. In certain embodiments, squalane and isosqualane prepared by the methods provided herein can be useful for applications in cosmetic industry and/or in the lubricants industry.

  2. The Preparation and Properties of RDX-Composition A

    Science.gov (United States)

    1945-12-29

    accordingly RDX particles adhere to wax globules and re- tain them in the slurry. The RDX is neither capable of acting as an efficient powder- emulsifier for...prepared by the addition of extra wax and aluminum, plus lecithin , to a rollod Composition A. "ith a total of 12fr wax, such a mixture can be poured, but

  3. Squalane and isosqualane compositions and methods for preparing the same

    Energy Technology Data Exchange (ETDEWEB)

    Fisher, Karl; Schofer, Susan Jessica; Kanne, David B

    2013-11-19

    Provided herein are methods comprising catalytic dimerization of .beta.-farnesene to obtain squalane and/or isosqualane. Compositions comprising squalane and/or isosqualane are provided. In certain embodiments, squalane and isosqualane prepared by the methods provided herein can be useful for applications in cosmetic industry and/or in the lubricants industry.

  4. Application of the central composite design to optimize the preparation of novel micelles of harmine

    Directory of Open Access Journals (Sweden)

    Bei YY

    2013-05-01

    Full Text Available Yong-Yan Bei,1,* Xiao-Feng Zhou,2,3,* Ben-Gang You,1 Zhi-Qiang Yuan,1 Wei-Liang Chen,1 Peng Xia,1 Yang Liu,1 Yong Jin,4 Xiao-Juan Hu,1 Qiao-Ling Zhu,1 Chun-Ge Zhang,1 Xue-Nong Zhang,1 Liang Zhang5 1Department of Pharmaceutics, College of Pharmaceutical Sciences, Soochow University, Suzhou 215123, People’s Republic of China; 2College of Radiological Medicine and Protection, Soochow University, Suzhou, People’s Republic of China; 3Changshu Hospital of Traditional Chinese Medicine, Changshu, People’s Republic of China; 4Invasive Technology Department, The Second Affiliated Hospital of Soochow University, Suzhou, People’s Republic of China; 5Department of Biopharmaceutics, College of Pharmaceutical Sciences, Soochow University, Suzhou, People’s Republic of China*These authors contributed equally to the paperAbstract: Lactose–palmitoyl–trimethyl–chitosan (Lac-TPCS, a novel amphipathic self-assembled polymer, was synthesized for administration of insoluble drugs to reduce their adverse effects. The central composite design was used to study the preparation technique of harmine (HM-loaded self-assembled micelles based on Lac-TPCS (Lac-TPCS/HM. Three preparation methods and single factors were screened, including solvent type, HM amount, hydration volume, and temperature. The optimal preparation technique was identified after investigating the influence of two independent factors, namely, HM amount and hydration volume, on four indexes, ie, encapsulation efficiency (EE, drug-loading amount (LD, particle size, and polydispersity index (PDI. Analysis of variance showed a high coefficient of determination of 0.916 to 0.994, thus ensuring a satisfactory adjustment of the predicted prescription. The maximum predicted values of the optimal prescription were 91.62%, 14.20%, 183.3 nm, and 0.214 for EE, LD, size, and PDI, respectively, when HM amount was 1.8 mg and hydration volume was 9.6 mL. HM-loaded micelles were successfully characterized by

  5. Preparation and Characterization of Chitosan—Agarose Composite Films

    Directory of Open Access Journals (Sweden)

    Zhang Hu

    2016-09-01

    Full Text Available Nowadays, there is a growing interest to develop biodegradable functional composite materials for food packaging and biomedicine applications from renewable sources. Some composite films were prepared by the casting method using chitosan (CS and agarose (AG in different mass ratios. The composite films were analyzed for physical-chemical-mechanical properties including tensile strength (TS, elongation-at-break (EB, water vapor transmission rate (WVTR, swelling ratio, Fourier-transform infrared spectroscopy, and morphology observations. The antibacterial properties of the composite films were also evaluated. The obtained results reveal that an addition of AG in varied proportions to a CS solution leads to an enhancement of the composite film’s tensile strength, elongation-at-break, and water vapor transmission rate. The composite film with an agarose mass concentration of 60% was of the highest water uptake capacity. These improvements can be explained by the chemical structures of the new composite films, which contain hydrogen bonding interactions between the chitosan and agarose as shown by Fourier-transform infrared spectroscopy (FTIR analysis and the micro-pore structures as observed with optical microscopes and scanning electron microscopy (SEM. The antibacterial results demonstrated that the films with agarose mass concentrations ranging from 0% to 60% possessed antibacterial properties. These results indicate that these composite films, especially the composite film with an agarose mass concentration of 60%, exhibit excellent potential to be used in food packaging and biomedical materials.

  6. Preparation and Characterization of Chitosan-Agarose Composite Films.

    Science.gov (United States)

    Hu, Zhang; Hong, Pengzhi; Liao, Mingneng; Kong, Songzhi; Huang, Na; Ou, Chunyan; Li, Sidong

    2016-09-30

    Nowadays, there is a growing interest to develop biodegradable functional composite materials for food packaging and biomedicine applications from renewable sources. Some composite films were prepared by the casting method using chitosan (CS) and agarose (AG) in different mass ratios. The composite films were analyzed for physical-chemical-mechanical properties including tensile strength (TS), elongation-at-break (EB), water vapor transmission rate (WVTR), swelling ratio, Fourier-transform infrared spectroscopy, and morphology observations. The antibacterial properties of the composite films were also evaluated. The obtained results reveal that an addition of AG in varied proportions to a CS solution leads to an enhancement of the composite film's tensile strength, elongation-at-break, and water vapor transmission rate. The composite film with an agarose mass concentration of 60% was of the highest water uptake capacity. These improvements can be explained by the chemical structures of the new composite films, which contain hydrogen bonding interactions between the chitosan and agarose as shown by Fourier-transform infrared spectroscopy (FTIR) analysis and the micro-pore structures as observed with optical microscopes and scanning electron microscopy (SEM). The antibacterial results demonstrated that the films with agarose mass concentrations ranging from 0% to 60% possessed antibacterial properties. These results indicate that these composite films, especially the composite film with an agarose mass concentration of 60%, exhibit excellent potential to be used in food packaging and biomedical materials.

  7. PREPARATION AND PROPERTIES OF CHITOSAN/LIGNIN COMPOSITE FILMS

    Institute of Scientific and Technical Information of China (English)

    Long Chen; Chang-yu Tang; Nan-ying Ning; Chao-yu Wang; Qiang Fu; Qin Zhang

    2009-01-01

    Biodegradable composite films based on chitosan and lignin with various composition were prepared via the solution-casting technique.FT-IR results indicate the existence of hydrogen bonding between chitosan and lignin,and SEM images show that lignin could be well dispersed in chitosan when the content of lignin is below 20 wt% due to the strong interfacial interaction.As a result of strong interaction and good dispersion,the tensile strength,storage modulus,thermal degradation temperature and glass transition temperature of chitosan have been largely improved by adding lignin.Our work provides a simple and cheap way to prepare fully biodegradable chitosan/lignin composites,which could be used as packaging films or wound dressings.

  8. Sterile Preparation Workshop Reconstruction of New Pharmaceutical GMP%新版药品GMP无菌制剂车间改造

    Institute of Scientific and Technical Information of China (English)

    李颖君

    2011-01-01

    Taking the reconstruction of sterile preparation workshop of pharmaceutical factory as an example, the production requirement of the sterile preparation in new pharmaceutical GMP was discussed, and the process design of reconstruction was made to be suita%以一个无菌制剂车间的改造为例,对新版药品GMP中无菌药品附录的生产要求进行讨论,从工艺设计的角度分析,使改造设计满足新规范要求。

  9. Development and Validation of High Performance Liquid Chromatographic Method for Determination of Lamivudine from Pharmaceutical Preparation

    Directory of Open Access Journals (Sweden)

    S. K. Patro

    2010-01-01

    Full Text Available A new, simple, specific, accurate and precise RP-HPLC method was developed for determination of lamivudine in pure and tablet formulations. A Thermo BDS C18 column in isocratic mode, with a mobile phase consisting of 0.01 M ammonium dihydrogen orthophosphate buffer adjusted to pH 2.48 by using formic acid and methanol in the ratio of 50:50 was used. The flow rate was set at 0.6 mL/min and UV detection was carried out at 264 nm. The retention time of lamivudine and nevirapine were 2.825 min and 4.958 min respectively. The method was validated for linearity, precision, robustness and recovery. Linearity for lamivudine was found in the range of 50-175 μg/mL. Hence, it can be applied for routine quality control of lamivudine in bulk and pharmaceutical formulations.

  10. DEVELOPMENT AND VALIDATION OF HPLC METHOD FOR SOME AZOLES IN PHARMACEUTICAL PREPARATION

    Directory of Open Access Journals (Sweden)

    Wael Abu Dayyih et al

    2012-10-01

    Full Text Available A new, simple and rapid reversed-phase high-performance liquid chromatography (HPLC method was developed and validated for the determination of some azoles drug (Ketoconazole, Isoconazole and Miconazole in pharmaceutical dosage forms in Jordan market. The HPLC separation was achieved on a C18 BDS column (100 mm × 4.6 mm using a mobile phase of acetonitrile and 0.05 M Ammonium Acetate buffer (70:30, v/v that adjusted to pH 6 using phosphoric acid at a flow rate of 1 mL min−1 and using UV absorbance detection at 254 nm. The method was validated for specificity, linearity, precision, accuracy, robustness. The separation was completed within 11.77 minutes and the assay was linear over the concentration range of 50% to 150% (r2 = 0.9999, the percent recovery for test and reference formulation was (98.14%-101.12%.

  11. Recent developments in micro- and nanofabrication techniques for the preparation of amorphous pharmaceutical dosage forms.

    Science.gov (United States)

    Qi, Sheng; Craig, Duncan

    2016-05-01

    Nano- and microfabrication techniques have been widely explored in the textile, polymer and biomedical arenas, although more recently these systems have attracted considerable interest as drug delivery vehicles with concomitant considerations of physical characterization, scalability, stability and drug release. In this review, the current thinking with regards to the manufacture of solid amorphous pharmaceutical materials using electrohydrodynamic and gyration-based approaches, melt-spinning approaches, thermal moulding, inkjet printing and 3D printing will be examined in the context of their potential and actual viability as dosage forms. A series of practical examples will be discussed as to how these approaches have been used as means of producing drug delivery systems for a range of delivery systems and treatments.

  12. Development and Validation of RP-HPLC Method for Simultaneous Estimation of Ramipril, Aspirin and Atorvastatin in Pharmaceutical Preparations

    Directory of Open Access Journals (Sweden)

    Rajesh Sharma

    2012-01-01

    Full Text Available A simple, sensitive, accurate and rapid reverse phase high performance liquid chromatographic method is developed for the simultaneous estimation of ramipril, aspirin and atorvastatin in pharmaceutical preparations. Chromatography was performed on a 25cm×4.6 mm i.d, 5µm particle, C18 column with Mixture of (A acetonitrile methanol (65:35 and (B 10 mM sodium dihydrogen phosphate monohydrate (NaH2PO4.H2O buffer and mixture of A:B (60:40 v/v adjusted to pH 3.0 with o-phosphoric acid (5%v/v was used as a mobile phase at a flow rate of 1.5 ml min-1. UV detection was performed at 230 nm. Total run time was less then 12 min; retention time for Ramipril, aspirin and Atorvastatin were 3.620, 4.920 min and 11.710 min respectively. The method was validated for accuracy, precision, linearity, specificity and sensitivity in accordance with ICH guidelines. Validation revealed that the method is specific, rapid, accurate, precise, reliable, and reproducible. Calibration plots were linear over the concentration ranges 05-50 µg mL-1 for Ramipril, 05-100 µgmL-1 for aspirin and 02-20 µg mL-1 for atorvastatin. Limits of detection were 0.014, 0.10 and 0.0095 ng mL-1 limits of quantification were 0.043, 0.329 and 0.029 ng mL-1 for ramipril aspirin and atorvastatin respectively. The high recovery and low coefficients of variation confirm the suitability of the method for simultaneous analysis of the all three drugs in the dosage forms. The validated method was successfully used for quantitative analysis of marketed pharmaceutical preparations.

  13. High Performance Liquid Chromatography for the Determina- tion of Metoclopramide in Pharmaceutical Preparations Using Pre-column Derivatization with Fluorescamine

    Institute of Scientific and Technical Information of China (English)

    Tatar Ulu, Sevgi

    2012-01-01

    A simple, rapid and sensitive high performance liquid chromatography (HPLC) method was developed for the determination of metoclopramide in pharmaceutical preparation. The method is based on the derivatization of metoclopramide with fluorescamine. The separation was achieved on a C18 column using methanol-water (70 : 30, V/V) mobile phase. Fluorescence detector was used at the excitation and emission of 403 and 485 nm, respectively. The method was validated for linearity, limit of detection, limit of quantification, precision, accuracy, recovery, robust- ness and system suitability. The assay was linear over the concentration range of 100-2000 ng/mL. The mean recovery was 100.37%. The proposed method was successfully applied to the assay of metoclopramide in tablet preparation. The preparation was also analyzed with an official method and statistical comparison by t- and F-tests revealed that there was no significant difference between the results of the two methods with respect to mean values and standard deviations at the 95% confidence level.

  14. Preparation and characterization of organic polymer modified composite polyaluminum chloride

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Compared with traditional aluminum salts, polyaluminum chloride (PACl) has better coagulation-flocculation performance in turbidity removal. However, it is still inferior to organic polymers in terms of bridging function. In order to improve the aggregating property of PACl, different composite PACl flocculants were prepared with various organic polymers. The effect of organic polymer on the distribution of Al (Ⅲ) species in composite flocculants was studied using 27Al NMR and Al-ferron complexation methods. The charge neutralization and surface adsorption characteristics of composite flocculants were also investigated. Jar tests were conducted to evaluate the turbidity removal efficacy of organic polymer modified composite flocculants. The study shows that cationic polymer and anionic polymer have significant influences on the coagulation-flocculation behaviors of PACl. Both cationic and anionic polymers can improve the turbidity removal performance of PACl but the mechanisms are much different: cationic organic polymer mainly increases the charge neutralization ability, but anionic polymer mainly enhances the bridging function.

  15. Preparation and performance of novel thermal stable composite nanofiltration membrane

    Institute of Scientific and Technical Information of China (English)

    Chunrui WU; Shouhai ZHANG; Fajie YANG; Chun YAN; Xigao JIAN

    2008-01-01

    The novel thermal stable composite nanofiltra-tion membranes were prepared through the interfacial polymerization of piperazine and trimesoyl chloride on the poly (phthalazinone ether) ultrafiltration substrate. The effects of polymerization and testing conditions on membrane performance were studied. The surface morphologies of the substrate and the composite mem-branes were observed by means of scanning electron microscopy (SEM) and atomic force microscopy (AFM). The separation properties of membranes for dyes and salts were tested. The composite membranes show good ther-mal stability. The rejection for Na2SO4 was kept over 96%, 1.0 MPa and 80℃. When tested at 1.0 MPa and 60℃, the rejection of the composite membrane for dyes was kept at the rejection for NaCl was lower than 20%.

  16. Preparation and Properties of Orthogonal Piezoelectric Composite Materials

    Institute of Scientific and Technical Information of China (English)

    Liu Jun; Lu Ying; Zhang Xingguo; Shen Yi; Chen Chun

    2004-01-01

    . PZT piezoelectric ceramic with La2O3, SrCO3, BaO and Sb2O5 was prepared. It has high value of the piezoelectric strain constant d33 ( -681 PC/N) and high value of-d33/d31 (2.65). Orthogonal piezoelectric composite materials was designed and prepared by PZT, DAD- 40 electric conductive adhesive and E51 epoxy resin. The OPCM shows obvious orthogonal anisotropy. The matching property of the interface between piezoelectric ceramic and polymer of OPCM relies on the defects of interface. The proper conductive mid-layer could improve the matching property of the interface.

  17. Preparation and characterization of PEGylated chitosan nanocapsules as a carrier for pharmaceutical application

    Science.gov (United States)

    Najafabadi, Alireza Hassani; Abdouss, Majid; Faghihi, Shahab

    2014-03-01

    A new method to conjugate methoxy polyethylene glycol (mPEG) to C6 position of chitosan under the mild condition is introduced that improves the biocompatibility and water solubility of chitosan. Harsh deprotecting step and several purification cycles are two major disadvantages of the current methods for preparing PEGylated chitosan. In this study, the amine groups at C2 position of chitosan are protected using SDS followed by grafting the PEG. The protecting group of chitosan is simply removed by dialyzing against Tris solution. The chemical structure of the prepared polymer is characterized by FTIR and 1H NMR spectroscopy. Fourier transformed-infrared (FT-IR) and 1H NMR spectra confirmed that the mPEG is successfully grafted to C6 position of chitosan. Prepared methoxy polyethylene glycol (mPEG) is then employed to prepare the nanocapsules for the encapsulation of poor water-soluble drug, propofol. The TEM, AFM, and DLS techniques are used to characterize the prepared nanocapsules size and morphology. The results show a size of about 80 nm with spherical shape for nanocapsules. In vitro drug release is carried out to evaluate the potential of nanocarriers for the intravenous delivery of drugs. The profile of release from formulated nanocapsules is similar to those of commercial lipid emulsion (CLE). In vivo animal sleep-recovery test on rats shows a close similarity between the time of unconsciousness and recovery of righting reflex between nanoparticles and CLE. This study provides an efficient, novel, and easy method for preparing a carrier system that requires less intensive reaction conditions, fewer reaction steps, and less purification steps. In addition, the nanocapsules introduced here could be a promising nano carrier for the delivery of poor water-soluble drugs.

  18. Preparation and properties of gluten/calcium carbonate composites

    Institute of Scientific and Technical Information of China (English)

    Min Zuo; Zheng Zheng Lai; Yi Hu Song; Qiang Zheng

    2008-01-01

    Environment friendly thermosetting composites were prepared by blending wheat gluten (WG) as matrix, calcium carbonate (CaCO3) as filler and glycerol as plasticizer followed by compression molding the mixture at 120 ℃ to crosslink the WG matrix. Morphology observation showed that the CaCO3 particles were finely dispersed in matrix. Incorporation of CaCO3 up to 10 wt% into the composites caused Young's modulus and tensile strength to increase markedly. On the other hand, the moisture absorption and elongation at break decreased slightly.

  19. Preparation of Silver-Coated Polystyrene Composite Particles

    Institute of Scientific and Technical Information of China (English)

    陈卓; 詹鹏; 章建辉; 王振林; 章维益; 闵乃本

    2003-01-01

    We report a feasible approach to the preparation of monodispersed metal-shell composite microspheres based on a combination of surface reaction and surface seeding techniques. The method was implemented for coating polystyrene (PS) spheres with silver shell having a variable thickness by controlling the amount of reagents in the reaction procedure. These composite spherical particles in dimensions of the submicrometer range may become attractive building blocks for the creation of metallo-dielectric photonic band gap materials when they are organized into crystals.

  20. Differential pulse voltammetric determination of acyclovir in pharmaceutical preparations using a pencil graphite electrode.

    Science.gov (United States)

    Dilgin, Didem Giray; Karakaya, Serkan

    2016-06-01

    In this study, a new selective and sensitive voltammetric procedure for determination of acyclovir (ACV) was proposed using a disposable electrode, pencil graphite electrode (PGE). Cyclic and differential pulse voltammograms of ACV were recorded in Britton-Robinson buffer solution containing 0.10 M KCl with pH of 4.0 at PGE. The PGE displayed a very good electrochemical behavior with significant enhancement of the peak current compared to a glassy carbon electrode (GCE). Under experimental conditions, the PGE had a linear response range from 1.0 μM to 100.0 μM ACV with a detection limit of 0.3 μM (based on 3 Sb). Relative standard deviations of 4.8 and 3.6% were obtained for five successive determinations of 10.0 and 50.0 μM ACV, respectively, which indicate acceptable repeatability. This voltammetric method was successfully applied to the direct determination of ACV in real pharmaceutical samples. The effect of various interfering compounds on the ACV peak current was studied.

  1. Development and validation of a GC-FID assay for determination of fluvastatin in pharmaceutical preparations

    Directory of Open Access Journals (Sweden)

    Serap Saglik Aslan

    2009-01-01

    Full Text Available A gas chromatographic method has been developed for the assay of fluvastatin sodium (FLU. FLU was silylated with N,O-bis(trimethylsilyltrifluoroacetamide-1% trimethylchlorosilane at 90 ºC for 30 min and analysed in a DB-1 column by capillary gas chromatograph with a flame ionization detector. The method was validated. The assay was linear over the concentration range at 10.0 to 50.0 µg mL-1. The limit of detection and the limit of quantitation were 1.0 and 3.0 µg mL-1, respectively. The recoveries of FLU derivatives were in the range of 99.25-99.80%. In inter-day and intra-day analysis, the values of relative standard deviation (% and the relative mean error (% were found between 0.20-0.80% and -0.20-0.75%, respectively. The developed method was succesfully applied to analyze the FLU content in tablet formulation. The results were statistically compared with those obtained by the official method, and no significant difference was found between the two methods. Therefore, it can be recommended for the quality control assay of FLU in pharmaceutical industry.

  2. Simultaneous determination of Nifuroxazide and Drotaverine hydrochloride in pharmaceutical preparations by bivariate and multivariate spectral analysis

    Science.gov (United States)

    Metwally, Fadia H.

    2008-02-01

    The quantitative predictive abilities of the new and simple bivariate spectrophotometric method are compared with the results obtained by the use of multivariate calibration methods [the classical least squares (CLS), principle component regression (PCR) and partial least squares (PLS)], using the information contained in the absorption spectra of the appropriate solutions. Mixtures of the two drugs Nifuroxazide (NIF) and Drotaverine hydrochloride (DRO) were resolved by application of the bivariate method. The different chemometric approaches were applied also with previous optimization of the calibration matrix, as they are useful in simultaneous inclusion of many spectral wavelengths. The results found by application of the bivariate, CLS, PCR and PLS methods for the simultaneous determinations of mixtures of both components containing 2-12 μg ml -1 of NIF and 2-8 μg ml -1 of DRO are reported. Both approaches were satisfactorily applied to the simultaneous determination of NIF and DRO in pure form and in pharmaceutical formulation. The results were in accordance with those given by the EVA Pharma reference spectrophotometric method.

  3. Pharmaceutical microparticle engineering with electrospraying

    DEFF Research Database (Denmark)

    Bohr, Adam; Wan, Feng; Kristensen, Jakob

    2015-01-01

    , acetone, and an anti-solvent, methanol, for PLGA were studied in different ratios. Properties of the spraying solutions were examined and the resulting microparticles were characterized with regard to size, morphology, porosity, solid state form, surface chemistry and drug release. Particle formation...... demonstrated by the increasingly higher drug release rates. The results demonstrate the importance of solvent composition in particle preparation and indicate potential for exploiting this dependence to improve pharmaceutical particle design and performance....

  4. An elective pharmaceutical care course to prepare students for an advanced pharmacy practice experience in Kenya.

    Science.gov (United States)

    Schellhase, Ellen M; Miller, Monica L; Ogallo, William; Pastakia, Sonak D

    2013-04-12

    OBJECTIVE. To develop a prerequisite elective course to prepare students for an advanced pharmacy practice experience (APPE) in Kenya. DESIGN. The course addressed Kenyan culture, travel preparation, patient care, and disease-state management. Instructional formats used were small-group discussions and lectures, including some Web-based presentations by Kenyan pharmacists on disease states commonly treated in Kenya. Cultural activities include instruction in conversational and medical Kiswahili and reading of a novel related to global health programs. ASSESSMENT. Student performance was assessed using written care plans, quizzes, reflection papers, a formulary management exercise, and pre- and post-course assessments. Student feedback on course evaluations indicated that the course was well received and students felt prepared for the APPE. CONCLUSION. This course offered a unique opportunity for students to learn about pharmacy practice in global health and to apply previously acquired skills in a resource-constrained international setting. It prepares students to actively participate in clinical care activities during an international APPE.

  5. Pharmacokinetics and pharmacodynamics of high doses of pharmaceutically prepared heroin, by intravenous or by inhalation route in opioid-dependent patients

    NARCIS (Netherlands)

    E.J. Rook; J.M. van Ree; W. van den Brink; M.J.X. Hillebrand; A.D.R. Huitema; V.M. Hendriks; J.H. Beijnen

    2006-01-01

    A pharmacokinetic-pharmacodynamic study was performed in opioid-dependent patients in the Netherlands, who were currently treated with high doses of pharmaceutically prepared heroin on medical prescription. Besides intravenous heroin, heroin was prescribed for inhalation by "chasing the dragon" meth

  6. A new generation of starch products as excipient in pharmaceutical tablets .1. Preparation and binding properties of high surface area potato starch products

    NARCIS (Netherlands)

    Wierik, GHPT; ArendsScholte, AW; Eissens, AC; Lerk, CF

    1996-01-01

    A new pharmaceutical excipient with a high binding capacity was prepared from potato starch by enzymatic degradation, followed by suitable dehydration of the precipitated and filtered retrograded starch to produce high specific surface area products. Thermal dehydration methods like drying at room o

  7. Retention of composite resin restorations in class IV preparations.

    Science.gov (United States)

    Eid, Hani

    2002-01-01

    Clinicians often utilized composite resin restorations in combination with different types of preparation to restore class IV fractures on anterior incisors. A new preparation technique called (stair-step chamfer technique) is investigated in this study to detect bond strength to tooth structure. Eighty-eight bovine teeth were divided into 4 groups. Group I had twenty-three samples with a 45 degree bevel that extended 2 millimeters beyond the fracture line. Group II had twenty-three samples with a circumferential chamfer, which extended 2 mm beyond the fracture line and half the enamel thickness in depth. Group III had twenty-three samples with a facial stair-step chamfer, which followed the anatomical contour and extended 2 mm beyond the fracture line with a lingual plain chamfer. Group IV had eighteen samples as controls, which were untreated teeth. The first three groups were prepared and restored with hybrid composite resin in conjunction with a single step bonding agent and as surface penetrating sealer, then tested for shear-bond strength on the Instron machine. The results were that there was no significant difference found between the treated teeth when tested for shear-bond strength. However, according to the site of the fracture, the stair-step chamfer technique gave significantly better results. It can be concluded that, the stir-step chamfer technique provides the clinician better environment to place a composite resin restoration resulting in good shear-bond strength and better esthetics.

  8. Study on Pharmaceutical Excipients of Nasal Preparation%鼻用制剂药用辅料研究

    Institute of Scientific and Technical Information of China (English)

    邬伟魁; 张海燕; 宋伟; 贺娅; 李芳; 杨明

    2011-01-01

    Literatures about study on pharmaceutical excipients of nasal preparations have been analyzed. Thirty-two literatures at home and abroad were sieved. This paper reviews basic physicochemical properties, functionality and security of common nasal excipients ( absorption enhancer, bio-adhesion, preservative). It wasdemonstrated that based on manufacture, package, quality, storage and application of domestic nasal excipients, researchers have recognized the closing relation between nasal excipients and nasal preparation. To push forward the development and clinic application of nasal preparation, and quality standard of pharmaceutical excipient, strengthen organic combination of production, study and research, promote new excipients, new technology and new drug deliver system is important.%对鼻用制剂药用辅料研究进行文献整理和分析.经检索、筛选得国内外文献32篇,主要综述了常用鼻用辅料如吸收促进剂(环糊精及其衍生物、表面活性剂、冰片和月桂氮酮等)、生物黏附剂(如壳聚糖)、防腐剂等的基本物化性质、功能性和安全性研究.分析表明,基于当前国内鼻用制剂药用辅料生产、包装、质量、贮存、使用等环节的现状,业内人士日益认识到鼻用辅料质量及合理应用与鼻用制剂质量的紧密关系,但我国辅料生产和研究仍很大程度落后于西方发达国家,加强产学研有机结合,促进新辅料、新技术和新型载药系统的研发,将有利于国产鼻用制剂的研发和临床应用及其药用辅料的质量标准提高.

  9. BULK AND SURFACE PROPERTIES OF TIN BASED HERBAL DRUG DURING ITS PREPARATION: FINGERPRINTING OF THE ACTIVE PHARMACEUTICAL CONSTITUENT

    Directory of Open Access Journals (Sweden)

    Asit Baran Mandal et al.

    2012-04-01

    Full Text Available The Tin based herbal drug (Vangaparpam - a Siddha system of Medicine has been widely used for the treatment of urinogenital infection and Arthritis. It was prepared by ten sequential stages of calcinations of the medicinally purified tin along with Aloe vera extract. In this study we analysed samples from various stages of preparation using analytical techniques viz., Fourier Transformed Infrared spectroscopy, Powder X ray Diffraction, X ray Photoelectron Spectroscopy, Energy Dispersive X- ray spectroscopy , Scanning Electron Microscopy, to create fingerprints required for the optimisation of the process parameters, detection of toxic impurities and crystal morphology of the Active Pharmaceutical ingredient during the formulation of drug for which reports are not available. Upon analysis of the samples of various stages of calcinations, we found that there was a programmed heating the medicinally purified tin metal was converted to crystalline tin oxide in the tetragonal phase at the first stage of calcinations itself along with a small percentage of therapeutically important elements of Calcium, Iron, and Potassium. Further calcinations steps brought interplay of nano and sub-micro sized particles for optimum bioavailability of the drug.

  10. Laser Surface Preparation and Bonding of Aerospace Structural Composites

    Science.gov (United States)

    Belcher, M. A.; Wohl, C. J.; Hopkins, J. W.; Connell, J. W.

    2010-01-01

    Adhesive bonds are critical to the integrity of built-up structures. Disbonds can often be detected but the strength of adhesion between surfaces in contact is not obtainable without destructive testing. Typically the number one problem in a bonded structure is surface contamination, and by extension, surface preparation. Standard surface preparation techniques, including grit blasting, manual abrasion, and peel ply, are not ideal because of variations in their application. Etching of carbon fiber reinforced plastic (CFRP) panels using a neodymium-doped yttrium aluminum garnet (Nd:YAG) laser appears to be a highly precise and promising way to both clean a composite surface prior to bonding and provide a bond-promoting patterned surface akin to peel ply without the inherent drawbacks from the same (i.e., debris and curvature). CFRP surfaces prepared using laser patterns conducive to adhesive bonding were compared to typical prebonding surface treatments through optical microscopy, contact angle goniometry, and post-bonding mechanical testing.

  11. Solid dispersion application in pharmaceutical technology: Methods of preparation and characterization

    OpenAIRE

    Medarević, Đorđe; Ibrić, Svetlana; Đuriš, Jelena; Đurić, Zorica

    2013-01-01

    A growing number of newly synthesized drugs exhibit low aqueous solubility, leading to poor bioavailability. Therefore, improving drug solubility and dissolution rate became one of the greatest challenges during formulation development. Solid dispersions formulation is one of the commonly investigated techniques for improving solubility of poorly soluble drugs. Solid dispersions are dispersions of one or more drugs in an inert carrier (matrix) in the solid state prepared by melting, solvent, ...

  12. Sponge Gourd (Luffa Cylindrica Reinforced Polyester Composites: Preparation and Properties

    Directory of Open Access Journals (Sweden)

    Valcineide O.A. Tanobe

    2014-05-01

    Full Text Available Increasing environmental concern along with the drive to find substitutes for synthetic fibers and value added applications for low cost and renewable plant fibers have led to the development of composites based on biomaterials. One of the drawbacks encountered in such exercise is the lack of adhesion between the incorporated plant fibers and synthetic polymeric matrices. Such drawback can be reduced by appropriate treatment of fibers. This paper describes the chemical treatments used on sponge gourd (Luffa cylindrica fibers of Brazil to prepare their composites with polyester resin. Production of short fiber-polymer composite as well as mat-polyester composites is presented here. Characterization of the composites in respect of evaluation of density, water absorption, thermalstability, tensile properties and impact strength were made and the results are discussed. Observed impact strengthand tensile properties are discussed based on the fractographic studies of the composites.Defence Science Journal, Vol. 64, No. 3, May 2014, pp. 273-280, DOI:http://dx.doi.org/ 10.14429/dsj.64.7327

  13. Different compositions of pharmaceuticals in Dutch and Belgian rivers explained by consumption patterns and treatment efficiency

    NARCIS (Netherlands)

    Laak, ter T.L.; Kooij, P.J.F.; Tolkamp, H.; Hofman, J.

    2014-01-01

    In the current study, 43 pharmaceuticals and 18 transformation products were studied in the river Meuse at the Belgian-Dutch border and four tributaries of the river Meuse in the southern part of the Netherlands. The tributaries originate from Belgian, Dutch and mixed Dutch and Belgian catchments.

  14. Different compositions of pharmaceuticals in Dutch and Belgian rivers explained by consumption patterns and treatment efficiency

    NARCIS (Netherlands)

    Laak, ter T.L.; Kooij, P.J.F.; Tolkamp, H.; Hofman, J.

    2014-01-01

    In the current study, 43 pharmaceuticals and 18 transformation products were studied in the river Meuse at the Belgian-Dutch border and four tributaries of the river Meuse in the southern part of the Netherlands. The tributaries originate from Belgian, Dutch and mixed Dutch and Belgian catchments. I

  15. Pharmaceutical preparation of Saubhagya Shunthi Churna: A herbal remedy for puerperal women

    Science.gov (United States)

    Shukla, Khushbu; Dwivedi, Manjari; Kumar, Neeraj

    2010-01-01

    Background: In the last few decades, there has been exponential growth in the field of herbal remedies. Pharmacopoeial preparations like avleha or paka (semi-solid), swarasa (expressed juice), kalka (mass), him (cold infusion) and phanta (hot infusion), kwatha (decoction) and churna (powder) form the backbone of Ayurvedic formulations. Newer guidelines for standardization, manufacture, and quality control, and scientifically rigorous research will be necessary for traditional treatments. This traditional knowledge can serve as powerful search engine that will greatly facilitate drug discovery. Purpose: The aim of the present study is to standardize Saubhagya Shunthi Paka in churna (powder) form. The powder form makes this traditional drug more stable for long-term storage and hence, easier to preserve. Materials and Methods: Saubhagya Shunthi Paka is an ayurvedic formulation containing Shunthi (Zingiber officinalis) as one of its chief ingredients. The basic preparation of this drug is a semisolid. We checked the microbial load and nutrient values (using International Standard IS and Association of Official Analytical chemists AOAC methods) Results: The powdered form of Saubhagya Shunthi Churna yielded a weight loss of approximately 17.64% of the total weight of ingredients. The total energy of Churna (calculated based on nutrient content) was found higher over Paka. Conclusion: Saubhagya Shunthi Churna may be a good therapeutic and dietary medicine for Indian women, which may be easily prepared at home. PMID:20532094

  16. Preparation and Electrical Property of Polypyrrole-Polyethylene Composite

    Science.gov (United States)

    Yoshino, Katsumi; Yin, Xiao Hong; Morita, Shigenori; Nakanishi, Yutaka; Nakagawa, Shinichi; Yamamoto, Hideo; Watanuki, Toshiro; Isa, Isao

    1993-02-01

    Polypyrrole-polyethylene composites have been prepared by pressing the mixture of polypyrrole coated and non-coated polyethylene spheres. Electrical conductivity is enhanced by more than 16 orders of magnitude and its activation energy decreases remarkably at concentration of polypyrrole coated polyethylene above around 10-20%, which corresponds to effective polypyrrole concentration of 0.1-0.2%. These characteristics can be explained by a percolation model. That is, at this concentration electrodes are bridged by conducting channel of doped polypyrrole. Thermoelectric power increases in proportion to absolute temperature and is independent on concentration of polypyrrole coated polyethylene sphere above 30%, which support the percolation model. The electrical property of this polypyrrole-polyethylene composite is found to be stable up to 160°C. The application of this composite to the semiconducting layer of a cable has been proposed.

  17. Spectrophotometric determination of meclizine hydrochloride and pyridoxine hydrochloride in laboratory prepared mixtures and in their pharmaceutical preparation

    Science.gov (United States)

    Ibrahim, Maha M.; Elzanfaly, Eman S.; El-Zeiny, Mohamed B.; Ramadan, Nesreen K.; Kelani, Khadiga M.

    2017-05-01

    In this paper, three rapid, simple, accurate and precise spectrophotometric methods were developed for the determination of meclizine hydrochloride in the presence of pyridoxine hydrochloride without previous separation. The methods under study are dual wavelength (DWL), ratio difference (RD) and continuous wavelet transform (CWT). On the other hand, pyridoxine hydrochloride (PYH) was determined directly at 291 nm. The methods obey Beer's law in the range of (5-50 μg/mL) for both compounds. All the methods were validated according to the ICH guidelines where the accuracy was found to be 98.29, 99.59, 100.42 and 100.62% for DWL, RD, CWT and PYH; respectively. Moreover the precision of the methods were calculated in terms of %RSD and it was found to be 0.545, 0.372, 1.287 and 0.759 for DWL, RD,CWT and PYH; respectively. The selectivity of the proposed methods was tested using laboratory prepared mixtures and assessed by applying the standard addition technique. So, they can be used for the routine analysis of pyridoxine hydrochloride and meclizine hydrochloride in quality-control laboratories.

  18. Novel preparation of carbon-TiO{sub 2} composites

    Energy Technology Data Exchange (ETDEWEB)

    Elizalde-González, María P., E-mail: maria.elizalde.uap.mx@gmail.com; García-Díaz, Esmeralda; Sabinas-Hernández, Sergio A.

    2013-12-15

    Highlights: • Glycerol and TiOSO{sub 4}·xH{sub 2}O produced a carbon-anatase precursor in a one-step sol–gel reaction. • Ultrasound irradiation led to the formation of crystalline TiO{sub 2} prior to thermal treatment. • Carbon and TiO{sub 2} nanocrystals developed larger specific surface in composites. • Large band gap (3.6 eV) in TiO{sub 2} was obtained. • Benzenesulfonic acid identified by LC–MS among decomposition reaction intermediates of the dye Acid Orange 7. -- Abstract: Carbon-TiO{sub 2} sulfated composites were obtained from TiOSO{sub 4}·xH{sub 2}O and glycerol as the TiO{sub 2} and carbon sources, respectively. The precursor xerogels were prepared in a one-step ultrasonic-assisted sol–gel reaction, followed by thermal treatment at 400 °C under a nitrogen atmosphere to produce carbon-TiO{sub 2} sulfated composites. XRD, micro-Raman, SEM, and TEM studies showed that the composites consisted of nanocrystalline clusters of TiO{sub 2} and carbon. Ultrasonication in glycerol promoted the crystallinity of the xerogel precursors prior to thermal treatment. X-ray powder diffraction and Raman spectroscopy studies confirmed that glycerol also facilitated the formation of small crystallites. The band gaps of carbon-TiO{sub 2} composites with two different carbon loadings were found to be 3.06 eV and 2.69 eV. By contrast, the band gap of TiO{sub 2} prepared by our method was 3.53 eV. Calcination of the precursors led to an unusual increase in the specific surface and porosity of the composites compared to TiO{sub 2}. The photocatalytic activities of the prepared composites were tested in a decomposition assay of Acid Orange 7. The reaction was monitored by UV–vis spectrophotometry and by LC-ESI-(Qq)-TOF-MS-DAD. Some intermediate species were identified by LC-ESI-QTOF-MS.

  19. Preparation and properties of lignin-epoxy resin composite

    Directory of Open Access Journals (Sweden)

    Quanfu Yin

    2012-11-01

    Full Text Available A cross-linked biomass-polymer composite with a lignin content of up to 60% was prepared by blending lignin with an epoxy resin and polyamine using a hot press molding process. The characteristics of the curing reaction of lignin with epoxy resin were studied using DSC and FTIR analysis. The effect of molding temperature and molding pressure on the mechanical properties and microstructure of the lignin/epoxy resin composite was also studied by SEM, DMA, and TG analyses. The results showed that the epoxy resin can be cured by lignin, and the curing temperature for the blends can be reduced by the introduction of a polyamine cure agent. The properties of the composite, such as bending strength, impact strength, glass-transition temperature, and thermal stability, were evidently influenced by the molding process. A good interfacial combination was formed between lignin and epoxy resin. Increasing the molding temperature and pressure proved beneficial to achieve a better interfacial combination for the composite, and the degree of ductile fracture was increased in the fracture surface of the composite.

  20. Bioactive carbon-PEEK composites prepared by chemical surface treatment.

    Science.gov (United States)

    Miyazaki, Toshiki; Matsunami, Chisato; Shirosaki, Yuki

    2017-01-01

    Polyetheretherketone (PEEK) has attracted much attention as an artificial intervertebral spacer for spinal reconstruction. Furthermore, PEEK plastic reinforced with carbon fiber has twice the bending strength of pure PEEK. However, the PEEK-based materials do not show ability for direct bone bonding, i.e., bioactivity. Although several trials have been conducted for enabling PEEK with bioactivity, few studies have reported on bioactive surface modification of carbon-PEEK composites. In the present study, we attempted the preparation of bioactive carbon-PEEK composites by chemical treatments with H2SO4 and CaCl2. Bioactivity was evaluated by in vitro apatite formation in simulated body fluid (SBF). The apatite formation on the carbon-PEEK composite was compared with that of pure PEEK. Both pure PEEK and carbon-PEEK composite formed the apatite in SBF when they were treated with H2SO4 and CaCl2; the latter showed higher apatite-forming ability than the former. It is conjectured that many functional groups able to induce the apatite nucleation, such as sulfo and carboxyl groups, are incorporated into the dispersed carbon phase in the carbon-PEEK composites.

  1. Preparation of SiC Fiber Reinforced Nickel Matrix Composite

    Institute of Scientific and Technical Information of China (English)

    Lu Zhang; Nanlin Shi; Jun Gong; Chao Sunt

    2012-01-01

    A method of preparing continuous(Al+Al2O3)-coated SiC fiber reinforced nickel matrix composite was presented,in which the diffusion between SiC fiber and nickel matrix could be prevented.Magnetron sputtering is used to deposit Ni coating on the surface of the(Al+Al2O3)-coated SiC fiber in preparation of the precursor wires.It is shown that the deposited Ni coating combines well with the(Al+Al2O3) coating and has little negative effect on the tensile strength of(Al+Al2O3)-coated SiC fiber.Solid-state diffusion bonding process is employed to prepare the(Al+Al2O3)-coated SiC fiber reinforced nickel matrix with 37% fibers in volume.The solid-state diffusion bonding process is optimized and the optimum parameters are temperature of 870,pressure of 50 MPa and holding time of 2 h.Under this condition,the precursor wires can diffuse well,composite of full density can be formed and the(Al+Al2O3) coating is effective to restrict the reaction between SiC fiber and nickel matrix.

  2. A simple and sensitive method for determination of Norfloxacin in pharmaceutical preparations

    Directory of Open Access Journals (Sweden)

    Zhuo Ye

    2015-06-01

    Full Text Available In this approach, a new voltammetric method for determination of norfloxacin was proposed with high sensitivity and wider detection linear range. The used voltammetric sensor was fabricated simply by coating a layer of graphene oxide (GO and Nafion composited film on glassy carbon electrode. The advantage of proposed method was sensitive electrochemical response for norfloxacin, which was attributed to the excellent electrical conductivity of GO and the accumulating function of Nafion under optimum experimental conditions, the present method revealed a good linear response for determination of norfloxacin in the range of 1×10-8mol/L-7×10-6 mol/L with a detection limit of 5×10-9 mol/L. The proposed method was successfully applied in the determination of norfloxacin in capsules with satisfactory results.

  3. Preparation, characterization, and potential application of chitosan, chitosan derivatives, and chitosan metal nanoparticles in pharmaceutical drug delivery

    OpenAIRE

    Ahmed TA; Aljaeid BM

    2016-01-01

    Tarek A Ahmed1,2 Bader M Aljaeid11Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, King Abdulaziz University, Jeddah, Kingdom of Saudi Arabia; 2Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, Al-Azhar University, Cairo, EgyptAbstract: Naturally occurring polymers, particularly of the polysaccharide type, have been used pharmaceutically for the delivery of a wide variety of therapeutic agents. Chitosan, the second abundant naturally o...

  4. Preparation and pharmaceutical characterization of amorphous cefdinir using spray-drying and SAS-process.

    Science.gov (United States)

    Park, Junsung; Park, Hee Jun; Cho, Wonkyung; Cha, Kwang-Ho; Kang, Young-Shin; Hwang, Sung-Joo

    2010-08-30

    The aim of this study was to investigate the effects of micronization and amorphorization of cefdinir on solubility and dissolution rate. The amorphous samples were prepared by spray-drying (SD) and supercritical anti-solvent (SAS) process, respectively and their amorphous natures were confirmed by DSC, PXRD and FT-IR. Thermal gravimetric analysis was performed by TGA. SEM was used to investigate the morphology of particles and the processed particle had a spherical shape, while the unprocessed crystalline particle had a needle-like shape. The mean particle size and specific surface area were measured by dynamic light scattering (DLS) and BET, respectively. The DLS result showed that the SAS-processed particle was the smallest, followed by SD and the unprocessed cefdinir. The BET result was the same as DLS result in that the SAS-processed particle had the largest surface area. Therefore, the processed cefdinir, especially the SAS-processed particle, appeared to have enhanced apparent solubility, improved intrinsic dissolution rate and better drug release when compared with SD-processed and unprocessed crystalline cefdinir due not only to its amorphous nature, but also its reduced particle size. Conclusions were that the solubility and dissolution rate of crystalline cefdinir could be improved by physically modifying the particles using SD and SAS-process. Furthermore, SAS-process was a powerful methodology for improving the solubility and dissolution rate of cefdinir.

  5. Preparation and properties of polymer and quantum dot composites

    Institute of Scientific and Technical Information of China (English)

    Tian Hongye; Shao Jun; He Rong; Gao Feng; Cui Daxiang; Gu Hongchen

    2006-01-01

    Quantum dots (QDs) were prepared in an organic system through a simple and low-cost wet chemistry method.Polymer beads with a diameter of 60-70 nm and specific functional groups were synthesized by a particular seeded emulsion polymerization technique.QDs were embedded in the polymer beads with the specific functional groups through dissolving and swelling method,which provided the condition for the conjunction of biomolecules and QDs as fluorescent probes.The prepared composites were characterized with UV-Vis,PL,TEM,FTIR,CLSM and conductance titration etc.The results show that QDs are successfully embedded in polymer beads,which breaks the limitation that the conjunction of biomolecules and QDs can be achieved only for those synthesized in aqueous system.

  6. Preparation of Lanthanide-Polymer Composite Material via Click Chemistry.

    Science.gov (United States)

    Chen, Bin; Wen, Guian; Wu, Jiajie; Feng, Jiachun

    2015-10-01

    Covalently attaching lanthanide complexes to the polymer backbone can effectively reduce the clustering of lanthanides and thus become an important strategy to fully unleash their potential. In this Communication, a metal-free click reaction is used for the first time to link a lanthanide complex to the polymer matrix. A diene-bearing copolymer with anthracenylmethyl methacrylate as a monomer and a dienophile-bearing lanthanide complex with 5-maleimido-1,10-phenanthroline as the second ligand are synthesized and coupled together through a Diels-Alder cycloaddition (DA). A comparative investigation demonstrates that the composite material prepared by DA click reaction shows the highest quantum yields in the same lanthanide concentration as compared to materials prepared by widely used "directly doping" and "in situ coordinating lanthanide ions with macromolecular ligand" approaches. This work suggests that the "metal-free" DA click reaction can be a promising tool in the synthesis of high efficient lanthanide functionalized polymeric materials.

  7. Development of a Method for a Sensitive Simultaneous Determination of Dopamine and Paracetamol in Biological Samples and Pharmaceutical Preparations

    Directory of Open Access Journals (Sweden)

    Ali Babaei

    2011-01-01

    Full Text Available A chemically modified electrode is constructed based on multiwalled carbon nanotube—modified glassy carbon electrode (MWCNTs/GCE. The measurements were carried out by application of differential pulse voltammetry (DPV, cyclic voltammetry (CV, and chronoamperometry (CA methods. Application of DPV method showed wide linear range of DA from 1 μM to 540 μM and a detection limit of 0.098 μM (S/N=3. The linear range of PAR of 3 μM to 300 μM and a detection limit of 0.15 μM, were obtained. The modified electrode showed electrochemical responses with high sensitivity, high selectivity, and excellent stability for DA and PAR determination at optimal conditions, which makes it a suitable sensor for simultaneous submicromolar detection of DA and PAR in solutions. The analytical performance of this sensor has been evaluated for detection of DA and PAR in human serum, human urine, and pharmaceutical preparation with satisfactory results.

  8. Simultaneous determination of loratadine and desloratadine in pharmaceutical preparations using liquid chromatography with a microemulsion as eluent.

    Science.gov (United States)

    El-Sherbiny, Dina T; El-Enany, Nahed; Belal, Fathalla F; Hansen, Steen H

    2007-03-12

    A rapid HPLC procedure for analytical quality control of pharmaceutical preparations containing the antihistaminic drug substance loratadine and/or its analog desloratadine (which is also an active metabolite of loratadine) was developed using a microemulsion as the eluent. The separation was performed on a column packed with cyanopropyl bonded stationary phase adopting UV detection at 247 nm using a flow rate of 1 ml/min. The optimized microemulsion mobile phase consisted of 0.1M sodium dodecyl sulphate, 1% octanol, 10% n-propanol and 0.3% triethylamine in 0.02 M phosphoric acid, pH 3.0. The developed method was validated in terms of specificity, linearity, lower limit of quantification, lower limit of detection, precision and accuracy. With the proposed method satisfactory resolution between loratadine and desloratadine (resolution factor=3.85). The method requires a minimum of sample handling and is rapid (10 min), and reproducible (R.S.D.drug substance, did not interference with the assay and was successfully separated using the developed HPLC method.

  9. Application of CZE Method in Routine Analysis for Determination of B-Complex Vitamins in Pharmaceutical and Veterinary Preparations

    Directory of Open Access Journals (Sweden)

    Marina Franco

    2012-01-01

    Full Text Available A competitive CZE method for quality control analysis of multivitamin preparations and veterinary products containing B-group vitamins was developed. Vitamins of interest are thiamine hydrochloride (B1, thiamine monophosphate chloride (B1a, riboflavine (B2, riboflavine-5′monophosphate (B2a, nicotinamide (B3, d-pantothenic acid calcium salt (B5, pyridoxine hydrochloride (B6, folic acid (B9, and 4-aminobenzoic acid (B10. These analytes were separated optimizing the experimental conditions in 20 mM tetraborate buffer pH=9.2 as a BGE (background electrolyte, on a Beckman P/ACE System MDQ instrument, using uncoated fused silica capillary. The effective capillary length was of 49.5 cm, I.D.=50 μm, the applied voltage 20 kV and the temperature 25∘C. Detection was performed by a diode array detector at 214 nm for all vitamins except B5 (190 nm and B2a (260 nm. Separation time was about 9 min. After experimental conditions optimization, the proposed method was validated. Precision of migration time and corrected peak area, linearity range, LOD and LOQ, accuracy (recovery, robustness, and ruggedness were evaluated for each analyte demonstrating the good reliability of the method. Analyses of the pharmaceutical real samples were performed and confirmed the versatility of this method.

  10. Simultaneous determination of EDTA, sorbic acid, and diclofenac sodium in pharmaceutical preparations using high-performance liquid chromatography.

    Science.gov (United States)

    Heydari, Rouhollah; Shamsipur, Mojtaba; Naleini, Nasim

    2013-06-01

    A simple high-performance liquid chromatographic method for simultaneous determination of ethylenediaminetetraacetic acid (EDTA), sorbic acid, and diclofenac sodium was developed and validated. Separation was achieved on a C(18) column (10 cm×4.6 mm) using gradient elution. The mobile phase consisted of acetonitrile-ammonium dihydrogen phosphate buffer solution (0.01 M, pH=2.5, containing 0.8% tetra-n-butyl ammonium hydroxide). The detector wavelength was set at 254 nm. Under these conditions, separation of three compounds was achieved in less than 10 min. The effect of two metal salts and metal concentration on peak area of EDTA was investigated. The pH effect on retention of EDTA and sorbic acid was studied. The method showed linearity for EDTA, sorbic acid, and diclofenac in the ranges of 2.5-100.0, 5.0-200.0, and 20.0-120.0 μg/mL, respectively. The within- and between-day relative standard deviations ranged from 0.52 to 1.94%, 0.50 to 1.34%, and 0.78 to 1.67% for EDTA, sorbic acid, and diclofenac, respectively. The recovery of EDTA, sorbic acid, and diclofenac from pharmaceutical preparation ranged from 96.0-102.0%, 99.7-101.5%, to 97.0-102.5%, respectively. To the best of our knowledge, this is the first report about simultaneous determination of EDTA, sorbic acid, and diclofenac.

  11. Simultaneous determination of artificial sweeteners, preservatives, caffeine, theobromine and theophylline in food and pharmaceutical preparations by ion chromatography.

    Science.gov (United States)

    Chen, Q C; Wang, J

    2001-12-07

    A novel ion chromatographic method was proposed for the simultaneous determination of artificial sweeteners (sodium saccharin, aspartame, acesulfame-K), preservatives (benzoic acid, sorbic acid), caffeine, theobromine and theophylline. The separation was performed on an anion-exchange analytical column operated at 40 degrees C within 45 min by an isocratic elution with 5 mM aqueous NaH2PO4 (pH 8.20) solution containing 4% (v/v) acetonitrile as eluent, and the determination by wavelength-switching ultraviolet absorbance detection. The detection limits (signal-to-noise ratio 3:1) for all analytes were below the sub-microg/ml level. Under the experimental conditions, several organic acids, including citric acid, malic acid, tartaric acid and ascorbic acid, did not interfere with the determination. The method has been successfully applied to the analysis of various food and pharmaceutical preparations, and the average recoveries for real samples ranged from 85 to 104%. The levels of all analytes determined by this method were in good agreement with those obtained by the high-performance liquid chromatographic procedure. The results also indicated that ion chromatography would be possibly a beneficial alternative to conventional high-performance liquid chromatography for the separation and determination of these compounds.

  12. Determination of losartan potassium, quinapril hydrochloride and hydrochlorothiazide in pharmaceutical preparations using derivative spectrophotometry and chromatographic-densitometric method.

    Science.gov (United States)

    Stolarczyk, Mariusz; Maślanka, Anna; Apola, Anna; Krzek, Jan

    2013-01-01

    Two methods, spectrophotometric and chromatographic-densitometric ones, were developed for determination of losartan potassium, quinapril hydrochloride and hydrochlorothiazide in pharmaceutical preparations. Spectrophotometric method involved derivative spectrophotometry and zero order spectrophotometry. The measurements were carried out at lambda = 224.0 nm for quinapril, lambda = 261.0 nm for hydrochlorothiazide and lambda = 270.0 nm for losartan when the derivative spectrophotometry was applied and lambda = 317.0 nm when zero order spectrophotometry was applied for the determination of hydrochlorothiazide. In chromatographic-densitometric studies high performance thin layer chromatography (HPTLC) plates were used as stationary phase and a mixture of solvents n-butanol : acetic acid : water (15 : 5 : 1, v/v/v) as mobile phase. Under the established conditions good resolution of examined constituents was obtained. Retardation factor for quinapril hydrochloride was R(f) - 0.70, for losartan potassium R(f) - 0.85 and for hydrochlorothiazide R(f) - 0.78. The developed methods are characterized by high sensitivity and accuracy. For quantitative analysis, densitometric measurements were carried out at lambda = 218.0 nm for quinapril, lambda = 275.0 nm for hydrochlorothiazide and = 232.0 nm for losartan.

  13. Preparation and characterisation of compositionally graded SmCo films

    Science.gov (United States)

    Dias, Andre; Gomez, Gabriel; Givord, Dominique; Bonfim, Marlio; Dempsey, Nora M.

    2017-05-01

    A compositionally graded SmCo film has been prepared by magnetron sputtering using a Co target partially covered by a Sm foil. The film was deposited onto a 100 mm thermally oxidised Si substrate and then annealed ex-situ. The SmCo film has been used as a test sample to validate an in-house developed scanning MOKE (Magneto-Optic Kerr effect) system incorporating a pulsed magnetic field source capable of producing fields as high as 10 T. A 2D array of hysteresis loops was measured across the entire wafer. The evolution in coercivity measured along a selected 1D strip of the sample is correlated with changes in composition and crystallographic structures measured using Energy Dispersive Spectroscopy and X-ray diffraction. The high field Scanning MOKE system holds much potential for optimizing the extrinsic properties of known hard magnetic phases as well as in the search for new hard magnetic phases.

  14. Compositions, antibodies, asthma diagnosis methods, and methods for preparing antibodies

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Hongjun; Zangar, Richard C.

    2017-01-17

    Methods for preparing an antibody are provided with the method including incorporating 3-bromo-4-hydroxy-benzoic acid into a protein to form an antigen, immunizing a mammalian host with the antigen, and recovering an antibody having an affinity for the antigen from the host. Antibodies having a binding affinity for a monohalotyrosine are provided as well as composition comprising an antibody bound with monohalotyrosine. Compositions comprising a protein having a 3-bromo-4-hydroxy-benzoic acid moiety are also provided. Methods for evaluating the severity of asthma are provide with the methods including analyzing sputum of a patient using an antibody having a binding affinity for monohalotyrosine, and measuring the amount of antibody bound to protein. Methods for determining eosinophil activity in bodily fluid are also provided with the methods including exposing bodily fluid to an antibody having a binding affinity for monohalotyrosine, and measuring the amount of bound antibody to determine the eosinophil activity.

  15. Preparation and properties of wheat gluten/silica composites

    Institute of Scientific and Technical Information of China (English)

    SONG Yi-Hu; ZHENG Qiang; ZHOU Wen-Ce

    2009-01-01

    Wheat gluten (WG)/silica (SiO2) hybrids were prepared through in-situ synthesis of SiO2 in WG disper-sion of aqueous ammonia. The hybrids with different SiO2 contents were mixed with glycerol plasticizer to form cohesive dough and the dough was compressively molded to form cross-linked sheets. Mor-phology, moisture absorption, protein solubility in water, tensile mechanical properties and dynamic rheological behavior of the WG/SiO2 composites were investigated in relation to SiO2 contents.

  16. Preparation and properties of wheat gluten/silica composites

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Wheat gluten (WG)/silica (SiO2) hybrids were prepared through in-situ synthesis of SiO2 in WG disper-sion of aqueous ammonia. The hybrids with different SiO2 contents were mixed with glycerol plasticizer to form cohesive dough and the dough was compressively molded to form cross-linked sheets. Morphology, moisture absorption, protein solubility in water, tensile mechanical properties and dynamic rheological behavior of the WG/SiO2 composites were investigated in relation to SiO2 contents.

  17. Validation of a Thin-Layer Chromatography for the Determination of Hydrocortisone Acetate and Lidocaine in a Pharmaceutical Preparation

    Science.gov (United States)

    Dołowy, Małgorzata; Kulpińska-Kucia, Katarzyna; Pyka, Alina

    2014-01-01

    A new specific, precise, accurate, and robust TLC-densitometry has been developed for the simultaneous determination of hydrocortisone acetate and lidocaine hydrochloride in combined pharmaceutical formulation. The chromatographic analysis was carried out using a mobile phase consisting of chloroform + acetone + ammonia (25%) in volume composition 8 : 2 : 0.1 and silica gel 60F254 plates. Densitometric detection was performed in UV at wavelengths 200 nm and 250 nm, respectively, for lidocaine hydrochloride and hydrocortisone acetate. The validation of the proposed method was performed in terms of specificity, linearity, limit of detection (LOD), limit of quantification (LOQ), precision, accuracy, and robustness. The applied TLC procedure is linear in hydrocortisone acetate concentration range of 3.75 ÷ 12.50 μg·spot−1, and from 1.00 ÷ 2.50 μg·spot−1 for lidocaine hydrochloride. The developed method was found to be accurate (the value of the coefficient of variation CV [%] is less than 3%), precise (CV [%] is less than 2%), specific, and robust. LOQ of hydrocortisone acetate is 0.198 μg·spot−1 and LOD is 0.066 μg·spot−1. LOQ and LOD values for lidocaine hydrochloride are 0.270 and 0.090 μg·spot−1, respectively. The assay value of both bioactive substances is consistent with the limits recommended by Pharmacopoeia. PMID:24526880

  18. Preparation and Characterization of Novel PVC/Silica–Lignin Composites

    Directory of Open Access Journals (Sweden)

    Łukasz Klapiszewski

    2015-09-01

    Full Text Available An advanced SiO2–lignin hybrid material was obtained and tested as a novel poly(vinyl chloride (PVC filler. The processing of compounds of poly(vinyl chloride in the form of a dry blend with silica–lignin hybrid material and, separately, with the two components from which that material was prepared, was performed in a Brabender mixing chamber. An analysis was made of processing (mass melt flow rate, MFR, thermal (thermogravimetric analysis, Congo red and Vicat softening temperature test and tensile properties of the final PVC composites with fillers in a range of concentrations between 2.5 wt % and 10 wt %. Additionally, the effects of filler content on the fusion characteristics of PVC composites were investigated. The homogeneity of dispersion of the silica–lignin hybrid material in the PVC matrix was determined by optical microscopy and SEM. Finally, it should be noted that it is possible to obtain a PVC composite containing up to 10 wt % of silica–lignin filler using a melt processing method. The introduction of hybrid filler into the PVC matrix results in a homogeneous structure of the composites and positive processing and functional properties, especially thermal stability and Vicat softening temperature.

  19. Prolastin, a pharmaceutical preparation of purified human α1-antitrypsin, blocks endotoxin-mediated cytokine release

    Directory of Open Access Journals (Sweden)

    Westin Ulla

    2005-01-01

    Full Text Available Abstract Background α1-antitrypsin (AAT serves primarily as an inhibitor of the elastin degrading proteases, neutrophil elastase and proteinase 3. There is ample clinical evidence that inherited severe AAT deficiency predisposes to chronic obstructive pulmonary disease. Augmentation therapy for AAT deficiency has been available for many years, but to date no sufficient data exist to demonstrate its efficacy. There is increasing evidence that AAT is able to exert effects other than protease inhibition. We investigated whether Prolastin, a preparation of purified pooled human AAT used for augmentation therapy, exhibits anti-bacterial effects. Methods Human monocytes and neutrophils were isolated from buffy coats or whole peripheral blood by the Ficoll-Hypaque procedure. Cells were stimulated with lipopolysaccharide (LPS or zymosan, either alone or in combination with Prolastin, native AAT or polymerised AAT for 18 h, and analysed to determine the release of TNFα, IL-1β and IL-8. At 2-week intervals, seven subjects were submitted to a nasal challenge with sterile saline, LPS (25 μg and LPS-Prolastin combination. The concentration of IL-8 was analysed in nasal lavages performed before, and 2, 6 and 24 h after the challenge. Results In vitro, Prolastin showed a concentration-dependent (0.5 to 16 mg/ml inhibition of endotoxin-stimulated TNFα and IL-1β release from monocytes and IL-8 release from neutrophils. At 8 and 16 mg/ml the inhibitory effects of Prolastin appeared to be maximal for neutrophil IL-8 release (5.3-fold, p Conclusion Our data demonstrate for the first time that Prolastin inhibits bacterial endotoxin-induced pro-inflammatory responses in vitro and in vivo, and provide scientific bases to explore new Prolastin-based therapies for individuals with inherited AAT deficiency, but also for other clinical conditions.

  20. Quality analysis of salmon calcitonin in a polymeric bioadhesive pharmaceutical formulation: sample preparation optimization by DOE.

    Science.gov (United States)

    D'Hondt, Matthias; Van Dorpe, Sylvia; Mehuys, Els; Deforce, Dieter; DeSpiegeleer, Bart

    2010-12-01

    A sensitive and selective HPLC method for the assay and degradation of salmon calcitonin, a 32-amino acid peptide drug, formulated at low concentrations (400 ppm m/m) in a bioadhesive nasal powder containing polymers, was developed and validated. The sample preparation step was optimized using Plackett-Burman and Onion experimental designs. The response functions evaluated were calcitonin recovery and analytical stability. The best results were obtained by treating the sample with 0.45% (v/v) trifluoroacetic acid at 60 degrees C for 40 min. These extraction conditions did not yield any observable degradation, while a maximum recovery for salmon calcitonin of 99.6% was obtained. The HPLC-UV/MS methods used a reversed-phase C(18) Vydac Everest column, with a gradient system based on aqueous acid and acetonitrile. UV detection, using trifluoroacetic acid in the mobile phase, was used for the assay of calcitonin and related degradants. Electrospray ionization (ESI) ion trap mass spectrometry, using formic acid in the mobile phase, was implemented for the confirmatory identification of degradation products. Validation results showed that the methodology was fit for the intended use, with accuracy of 97.4+/-4.3% for the assay and detection limits for degradants ranging between 0.5 and 2.4%. Pilot stability tests of the bioadhesive powder under different storage conditions showed a temperature-dependent decrease in salmon calcitonin assay value, with no equivalent increase in degradation products, explained by the chemical interaction between salmon calcitonin and the carbomer polymer.

  1. Pharmaceutical wastewater being composite mixture of environmental pollutants may be associated with mutagenicity and genotoxicity.

    Science.gov (United States)

    Sharif, Ali; Ashraf, Muhammad; Anjum, Aftab Ahmed; Javeed, Aqeel; Altaf, Imran; Akhtar, Muhammad Furqan; Abbas, Mateen; Akhtar, Bushra; Saleem, Ammara

    2016-02-01

    Pharmaceutical industries are amongst the foremost contributor to industrial waste. Ecological well-being is endangered owing to its facile discharge. In the present study, heavy metals and organic contaminants in waste water were characterized using atomic absorption spectrophotometer and GC-MS, respectively. Mutagenicity and genotoxic potential of pharmaceutical waste water were investigated through bacterial reverse mutation assay and in vitro comet assay, respectively. Ames test and comet assay of first sample were carried out at concentrations of 100, 50, 25, 12.5, 6.25 % v/v effluent with distilled water. Chromium (Cr), lead (Pb), arsenic (As), and cadmium (Cd) were found in high concentrations as compared to WHO- and EPA-recommended maximum limits. Arsenic was found to be the most abundant metal and its maximum concentration was 0.8 mg.L(-1). GC-MS revealed the presence of lignocaine, digitoxin, trimethoprim, caffeine, and vitamin E in waste water. Dose-dependent decrease in mutagenic index was observed in both strains. Substantial increase in mutagenicity was observed for TA-100, when assay was done by incorporating an enzyme activation system, whereas a slight increase was detected for TA-102. In vitro comet assay of waste water exhibited decrease in damage index and percentage fragmentation with the increase in dilution of waste water. Tail length also decreased with an increase in the dilution factor of waste water. These findings suggest that pharmaceutical waste water being a mix of different heavy metals and organic contaminants may have a potent mutagenic and genotoxic effect on exposed living organisms.

  2. Effect of Heat Treatment on Mechanical Properties and Phase Composition of Magnesium-Aluminum Composite Prepared by Explosive Welding

    Science.gov (United States)

    Arisova, V. N.; Trykov, Yu. P.; Slautin, O. V.; Ponomareva, I. A.; Kondakov, A. E.

    2015-09-01

    Results are given for a study of the effect of heat treatment regimes on the nature of change in micromechanical properties and phase composition of magnesium-aluminum composite material AD1-MA2-1 prepared by explosive welding.

  3. Antioxidant Activities, Metabolic Profiling, Proximate Analysis, Mineral Nutrient Composition of Salvadora persica Fruit Unravel a Potential Functional Food and a Natural Source of Pharmaceuticals

    Science.gov (United States)

    Kumari, Asha; Parida, Asish K.; Rangani, Jaykumar; Panda, Ashok

    2017-01-01

    Salvadora persica is a medicinally important plant mainly used in oral hygiene. However, little attention has been given towards the nutritional prominence of this plant. This study encloses the proximate and mineral nutrient contents, amino acid composition, metabolite profiling and antioxidant potential of S. persica fruit. The ripen fruit contained substantial amount of sugars, mineral nutrients, carotenoids, polyphenols and flavonoids. The metabolic profiling of the fruit extract by GC-MS revealed a total of 22 metabolites comprising of sugars, sugar alcohols, organic acids, organic base, and aromatic silica compound. The identified metabolites have been previously reported to have potential antioxidant, antimicrobial, anti-hyperglycemic, and antitumor properties. The GC-MS analysis indicated high glucose and glucopyranose (247.62 and 42.90 mg g-1 FW respectively) contents in fruit of S. persica. The fruit extract demonstrated a significantly higher antioxidant and ROS scavenging properties along with high contents of mineral nutrients and essential amino acids. HPLC analysis revealed presence of essential and non-essential amino acid required for healthy body metabolism. The cysteine was found to be in highest amount (733.69 mg 100 g-1 DW) among all amino acids quantified. Specifically, compared to similar medicinal plants, previously reported as a source of non-conventional food and with some of the commercially important fruits, S. persica fruit appears to be a potential source of essential mineral nutrients, amino acids, vitamins (ascorbic acid and carotenoid) and pharmaceutically important metabolites contributing towards fulfilling the recommended daily requirement of these for a healthy human being. This is the first report establishing importance of S. persica fruit as nutraceuticals. The data presented here proposed that fruit of S. persica may be used as functional food or reinvigorating ingredient for processed food to reduce deficiency of nutrients

  4. Self-healing epoxy composites: preparation, characterization and healing performance

    Directory of Open Access Journals (Sweden)

    Reaz A. Chowdhury

    2015-01-01

    Full Text Available Low velocity impact damage is common in fiber reinforced composites, which leads to micro-crack and interfacial debonding, where damage is microscopic and invisible. The concept of self-healing composites can be a way of overcoming this limitation and extending the life expectancy while expanding their usage in structural applications. In the current study, extrinsic self-healing concept was adopted using urea-formaldehyde microcapsules containing room temperature curing epoxy resin system (SC-15 as the healing agent prepared by in situ polymerization. Microcapsules were characterized using Fourier transform infrared spectroscopy (FTIR for structural analysis. Size and shape of microcapsules were studied using optical microscopy and scanning electron microscopy (SEM. Size of the microcapsules was between 30 and 100 μm. Thermal characterization was carried out using thermogravimetric analysis. Microcapsules were thermally stable till 210 °C without any significant decomposition. Fiber reinforced composite fabrication was carried out in three different steps. In the first step, epoxy resin was encapsulated in urea-formaldehyde shell material, which was confirmed by FTIR analysis. In the next step, encapsulation of amine hardener was achieved by vacuum infiltration method. These two different microcapsules were added with epoxy at 10:3 ratio and composite fabrication was done with hand layup method. Finally, healing performance was measured in terms of low velocity impact test and thermoscopy analysis. Low velocity impact test with 30 J and 45 J impact loads confirmed the delamination and micro-crack in composite materials and subsequent healing recovery observed in terms of damaged area reduction and restoration of mechanical properties.

  5. Quality by design approach of a pharmaceutical gel manufacturing process, part 2: near infrared monitoring of composition and physical parameters.

    Science.gov (United States)

    Rosas, Juan G; Blanco, Marcel; González, Josep M; Alcalá, Manel

    2011-10-01

    We applied the principles of quality by design to the production process of a pharmaceutical gel by using the near infrared spectroscopy (NIRS) technique in combination with multivariate chemometric tools. For this purpose, we constructed a D-optimal experimental design having normal operational condition (NOC) batches as central point. The primary aim here was to develop an expeditious NIRS method for determining the composition of a pharmaceutical gel and assess the temporal changes in major physical factors affecting the quality of the product (specifically, viscosity and pH). Gel components were quantified by using partial least squares (PLS) calibration models of the PLS1 type. The study was completed by using the batch statistical process control method to compare product batches included in the experimental design with NOC batches. Similarities and differences between the two types of batches were identified by using control charts for residuals (Q-statistic) and Hotteling's T2 (D-statistic). The ensuing models, which were subject to errors less than 5%, allowed the gel production process to be effectively monitored. As shown in this work, the NIRS technique is a highly suitable tool for process analytical technology.

  6. Laser Surface Preparation for Adhesive Bonding of Aerospace Structural Composites

    Science.gov (United States)

    Belcher, M. A.; Wohl, C. J.; Hopkins, J. W.; Connell, J. W.

    2010-01-01

    Adhesive bonds are critical to the integrity of built-up structures. Disbonds can often be detected but the strength of adhesion between surfaces in contact is not obtainable without destructive testing. Typically the number one problem in a bonded structure is surface contamination, and by extension, surface preparation. Standard surface preparation techniques, including grit blasting, manual abrasion, and peel ply, are not ideal because of variations in their application. Etching of carbon fiber reinforced plastic (CFRP) panels using a neodymium-doped yttrium aluminum garnet (Nd:YAG) laser appears to be a highly precise and promising way to both clean a composite surface prior to bonding and provide a bond-promoting patterned surface akin to peel ply without the inherent drawbacks from the same (i.e., debris and curvature). CFRP surfaces prepared using laser patterns conducive to adhesive bonding were compared to typical pre-bonding surface treatments through optical microscopy, contact angle goniometry, and post-bonding mechanical testing.

  7. Preparation and properties of cellulose nanocrystals reinforced collagen composite films.

    Science.gov (United States)

    Li, Weichang; Guo, Rui; Lan, Yong; Zhang, Yi; Xue, Wei; Zhang, Yuanming

    2014-04-01

    Collagen films have been widely used in the field of biomedical engineering. However, the poor mechanical properties of collagen have limited its application. Here, rod-like cellulose nanocrystals (CNCs) were fabricated and used to reinforce collagen films. A series of collagen/CNCs films were prepared by collagen solution with CNCs suspensions homogeneously dispersed at CNCs: collagen weight ratios of 1, 3, 5, 7, and 10. The morphology of the resulting films was analyzed by scanning electron microscopy (SEM), the enhancement of the thermomechanical properties of the collagen/CNCs composites were demonstrated by thermal gravimetric analysis (TGA) and mechanical testing. Among the CNCs contents used, a loading of 7 wt % led to the maximum mechanical properties for the collagen/CNCs composite films. In addition, in vitro cell culture studies revealed that the CNCs have no negative effect on the cell morphology, viability, and proliferation and possess good biocompatibility. We conclude that the incorporation of CNCs is a simple and promising way to reinforce collagen films without impairing biocompatibility. This study demonstrates that the composite films show good potential for use in the field of skin tissue engineering.

  8. The Current Status and Perspectives of Research on Pharmaceut ical Preparations%药物制剂研究概况及展望

    Institute of Scientific and Technical Information of China (English)

    王英; 彭志芬; 王海辉

    2001-01-01

    Objective: To improve on the theories of pharm aceutics. Methods: Explore the research methodology, pers pectives and direction of the pharmaceutical preparations. Results: The DDS has many advantages and great potential for development. Conclusion: Numerous new pharmaceutical preparations will be developed in the near future. The potential of the modern pharmaceutical prepar ations is immeasurable.%目的:促进药物制剂理论的不断提高与完善 。方法:探讨药物制剂的研究方法、前景及方向性。结 果:药物传递系统制剂有许多优点,且有广阔的发展前景。结论: 在不久的将来,会有许多新的制剂不断出现,现代药物制剂的发展必定具有广 阔的前景。

  9. Determination of piroxicam in pharmaceutical preparations by ultraviolet direct spectrophotometry, ultraviolet difference spectrophotometry and high performance liquid chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Hackmann, E.R.M.; Santos Gianotto, E.A. dos; Miritello Santoro, M.I.R. (Universidade de Sao Paulo (Brazil))

    1993-02-01

    Piroxicam in pharmaceutical preparations (capsules (C), tablets (T), oral drops (OD), suppositories (S) and simulated sample (SS)) was determined by UV direct spectrophotometry (UVS) at 333 nm, by UV difference spectrophotometry (UVDS) at 327 nm, and in C and T, by high performance liquid chromatography (HPLC). For UVS, Beer's law was obeyed in the range 3.0-8.5 [mu]g/mL. The coefficient of correlation (CC), absolute precision (AP) and relative precision (RP) were 0.9999, 0.02 and 0.33%, respectively. The coefficient of variation (CV) for C, T, OD, S and SS were 0.48%, 0.35%, 0.48% and 0.19%, respectively. The recovery average (RA) was 100.22%. For UVDS, Beer's law was obeyed in the range 5.0-15.0 [mu]g/mL. The CC, AP and RP were respectively 0.9999, 0.05 and 0.47%. The CV for C, T, OD, S and SS were 0.64%, 0.84%, 0.62%, 0.54% and 0.15%, respectively. The RA was 99.02%. In HPLC determination, a LiChrospher[reg sign] 100 RP-18 (5 [mu]m) in LiChroCART[reg sign] 125-4 column at ambient temperature with a mobile phase consisting of methanol: (buffer solution citric acid-dibasic sodium phosphate pH 3.0) (55:45) and UV detection at 254 nm enabled the determination of piroxicam in C and T. The response peak area versus concentration presented linearity in the range 10.0-100.0 [mu]g/mL. The CC, AP and RP were 0.9997, 0.45 and 0.90%, respectively. The CV was 0.51%-0.82% and the RA, 97.13%. 14 refs., 1 fig., 5 tabs.

  10. Pharmaceutical development, composition and quantitative analysis of phthalocyanine as the photosensitizer for cancer photodynamic therapy.

    Science.gov (United States)

    Jiang, Zhou; Shao, Jingwei; Yang, Tingting; Wang, Jian; Jia, Lee

    2014-01-01

    Phthalocyanine (Pc) and its related derivatives are a class of functional materials that are easily activated by the light at a special wavelength. As such photosensitizer, Pc has been applied to photodynamic therapy (PDT), in addition to its broad applications in many fields, for both malignant and benign diseases. One of our long-term research focuses is to develop Pc for cancer therapy. Herein we briefly review mechanisms of action of Pc used for photodynamic therapy, its pharmaceutical development and molecular modification to enhance its drugability and improve its intracellular localization. We also describe the current status of the Pc derivatives under clinical investigation, and analyze the methods used for quantitative analysis of those Pc derivatives. Copyright © 2013 Elsevier B.V. All rights reserved.

  11. Preparation and characterization of carbon nanofiber-polymide composites

    Science.gov (United States)

    Li, Xiaobing

    interact with polymer. However, XPS indicated that approximately one percent of the carbon atoms on the CNF surface reacted with diamine, which was derivatized from scarce reactive oxygen groups available on the OCNFs. Polyimide based composites were produced using either blending CNFs assisted by sonication or in-situ polymerization. Pristine fibers, oxidized fibers and fibers functionalized with PDA and polyimide oligomer were incorporated into the polyimide matrix, respectively. The goal was to investigate the effect of surface functional groups and the approach to form composite on the dispersion of fibers in the matrix and on the tensile strength and thermal mechanical properties. Scanning electron microscope (SEM) images showed that pristine fibers had poor dispersion in which agglomerations and a bottom-settled layer of fibers were observed, while there were few agglomerations of any other type of fibers formed in the matrix. Blending in hot DMAc and in-situ polymerization were found to disperse fibers well in the polyimide matrix. Functionalized fiber-PI composites exhibited improvement in glass transition temperature (Tg), modulus and tensile strength. In addition, the impact of fiber loadings from 0.5% to 5.0% by weight in composite was investigated. There was about a 10°C increase in Tg even at very low fiber concentration of 0.5 wt%. The modulus of the composites prepared in this study was as high as 130% of that of base PI. While functionalized fibers effectively enhanced the modulus and tensile strength of composites, pristine fibers exhibited little reinforcement to the host PI at low concentration (0.5 wt% and 1.5 wt%) and adversely affected the properties of composite at high loading of 5.0 wt%, indicating better compatibility and interfacial interaction in the case of functionalized fibers embedded.

  12. Pharmaceutical composition to protect an animal against a disorder arising from an infection with a bacterium that belongs to the group of nocardioform actinomycetes

    NARCIS (Netherlands)

    Arnoldus, Christiaan Jacobs; van der Geize, Robert; Dijkhuizen, Lubbert

    2011-01-01

    The invention pertains to a pharmaceutical composition to protect an animal against a disorder arising from an infection with a bacterium that belongs to the group of nocardioform actinomycetes having the ability to survive within macrophages of the animal, comprising live bacteria of a nocardioform

  13. Pharmaceutical composition to protect an animal against a disorder arising from an infection with a bacterium that belongs to the group of nocardioform actinomycetes

    NARCIS (Netherlands)

    Arnoldus, Christiaan Jacobs; van der Geize, Robert; Dijkhuizen, Lubbert

    2011-01-01

    The invention pertains to a pharmaceutical composition to protect an animal against a disorder arising from an infection with a bacterium that belongs to the group of nocardioform actinomycetes having the ability to survive within macrophages of the animal, comprising live bacteria of a nocardioform

  14. Preparation of Calcined Zirconia-Carbon Composite from Metal Organic Frameworks and Its Application to Adsorption of Crystal Violet and Salicylic Acid

    Directory of Open Access Journals (Sweden)

    Zubair Hasan

    2016-03-01

    Full Text Available Zirconia-carbon (ZC composites were prepared via calcination of Zr-based metal organic frameworks, UiO-66 and amino-functionalized UiO-66, under N2 atmosphere. The prepared composites were characterized using a series of instrumental analyses. The surface area of the ZC composites increased with the increase of calcination temperature, with the formation of a graphite oxide phase observed at 900 °C. The composites were used for adsorptive removal of a dye (crystal violet, CV and a pharmaceutical and personal care product (salicylic acid, SA. The increase of the calcination temperature resulted in enhanced adsorption capability of the composites toward CV. The composite calcined at 900 °C exhibited a maximum uptake of 243 mg·g−1, which was much greater than that by a commercial activated carbon. The composite was also effective in SA adsorption (102 mg·g−1, and N-functionalization of the composite further enhanced its adsorption capability (109 mg·g−1. CV adsorption was weakly influenced by solution pH, but was more dependent on the surface area and pore volume of the ZC composite. Meanwhile, SA adsorption showed strong pH dependence, which implies an active role of electrostatic interactions in the adsorption process. Base-base repulsion and hydrogen bonding are also suggested to influence the adsorption of CV and SA, especially for the N-functionalized composite.

  15. Metal-Matrix Composites Prepared by Paper-Manufacturing Technology

    Science.gov (United States)

    Wenzel, Claudia; Aneziris, Christos G.; Pranke, Katja

    2016-01-01

    In this work, metal-matrix composites were prepared via paper-manufacturing technology using metastable austenitic steel powder of type 16-7-3 (Cr-Mn-Ni in wt pct) and magnesia partially stabilized zirconia reinforcing particles. The influence of the process parameters on the paper web formation and the resulting properties of the MMCs were studied and solids retention of >90 wt pct was achieved. During filtration of the aqueous fiber-filler suspension, the steel particles were incorporated in the fiber network, and steel clusters were formed. Calendering had a positive influence on the porosity, bulk density, and tensile strength of the green paper sheets. Within this contribution, the debinding process for the metal-matrix paper sheets was in focus. A debinding rate of 0.5 K/min to 733 K (460 °C) with a dwell time of 90 minutes was sufficient to completely remove cellulose fibers. The sintered composites attained a tensile strength of up to 177 N/mm2 at a total porosity of 66 pct.

  16. In situ preparation of Nanoparticles/polymer composites

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Nanoparticle (NP) is the matter between molecule and bulk material. It has attracted much attention in catalysis, optoelectronics and biology due to its unique physical and chemical properties. Incorporation of these NPs into the polymer matrix is one of the best methods to display their special functions, which not only stabilize the NPs but also realize the functional assembly of NPs and polymers. However, reali- zation of this idea depends largely on the compatibility of NPs and polymers as well as the interaction between them. Therefore, many methods have been developed to prepare the composites of NPs and polymers in order to obtain the function ex- pected. In this review, we mainly focus on the combination of in situ method with other methods to synthesize different functional one-dimension, two-dimension as well as bulk composites, which has been recently developed by our group. The most striking character of our method is the excellent compatibility between NPs and polymers which ensures a homogeneous distribution of NPs in the polymer matrix. The existence of the polymer network makes the NPs more stable, and is significant for displaying their functions.

  17. In situ preparation of Nanoparticles/polymer composites

    Institute of Scientific and Technical Information of China (English)

    SUN HaiZhu; YANG Bai

    2008-01-01

    Nanoparticle (NP) is the matter between molecule and bulk material. It has attracted much attention in catalysis, optoelectronics and biology due to its unique physical and chemical properties. Incorporation of these NPs into the polymer matrix is one of the best methods to display their special functions, which not only stabilize the NPs but also realize the functional assembly of NPs and polymers. However, reali-zation of this idea depends largely on the compatibility of NPs and polymers as well as the interaction between them. Therefore, many methods have been developed to prepare the composites of NPs and polymers in order to obtain the function ex-pected. In this review, we mainly focus on the combination of in situ method with other methods to synthesize different functional one-dimension, two-dimension as well as bulk composites, which has been recently developed by our group. The most striking character of our method is the excellent compatibility between NPs and polymers which ensures a homogeneous distribution of NPs in the polymer matrix. The existence of the polymer network makes the NPs more stable, and is significant for displaying their functions.

  18. Preparation and Characterization of InAs/Si Composite Film

    Institute of Scientific and Technical Information of China (English)

    YANG Lin; LI Guang-Hai; ZHENG Mao-Jun; ZHANG Li-De

    2000-01-01

    Composite thin films consisting of nanosized InAs particles embedded in amorphous Si matrices were prepared by radio frequency co-sputtering of InAs and Si. X-ray diffraction spectra show that the particle size of InAs increases with the increasing annealing temperature, while the particle sizes of In and As reach their maximum values at the temperature of 200℃, and decrease with the further increase of the annealing temperature. In and As can not exist in the 500℃ sample due to the sublimation of In and As and the reaction In+As→InAs. The composition of the film in different levels was analyzed. We found that only in the deep level, the mole contents of As and In conform to the stoichiometric ratio and the oxidation occurs only a few nanometers from the surface. We believe that the scarcity of In and As near the surface is due to the sublimation of In and the oxide of As.

  19. Preparation and corrosion behavior evaluation of amalgam/titania nano composite

    Directory of Open Access Journals (Sweden)

    Neda Bahremandi Tolou

    2011-01-01

    Conclusion: By adding nano particles of titania and preparing amalgam/titania nano composite as a dental amalgam, corrosion behavior and mercury release during the 2 st h after preparation could be improved.

  20. Methods for Preparing Nanoparticle-Containing Thermoplastic Composite Laminates

    Science.gov (United States)

    Gruber, Mark B. (Inventor); Jensen, Brian J. (Inventor); Cano, Roberto J. (Inventor)

    2016-01-01

    High quality thermoplastic composites and composite laminates containing nanoparticles and/or nanofibers, and methods of producing such composites and laminates are disclosed. The composites comprise a thermoplastic polymer and a plurality of nanoparticles, and may include a fibrous structural reinforcement. The composite laminates are formed from a plurality of nanoparticle-containing composite layers and may be fused to one another via an automated process.

  1. Composite wheat-plantain starch salted noodles. preparation, proximal composition and in vitro starch digestibility

    OpenAIRE

    Rodolfo Rendón-Villalobos; Perla Osorio-Díaz; Edith Agama-Acevedo; Juscelino Tovar; Luis A. Bello-Pérez

    2008-01-01

    Salted noodles were prepared with different contents of wheat grits and plantain starch (PS). The blends were hydrated with 2% NaCl (w/v), homogenized, and the resulting doughs were sheeted through a pasta machine, cut into strips ~30cm in length, cooked, and their composition and in vitro starch digestibility was assessed. Moisture (6.43-7.60%) and ash contents (2.08-3.12%) increased by the addition of PS. Fat level decreased from 0.41 to 0.31% as the substitution of wheat grits increased. R...

  2. Preparation of composite membrane microcapsules. Fukugomaku microcapsul no chosei

    Energy Technology Data Exchange (ETDEWEB)

    Hatate, Y.; Uemura, Y. (Kagoshima University, Kagoshima (Japan). Faculty of Engineering)

    1991-12-01

    The ternd for the composite membrane microcapsules(CMMC) which have the capsule wall consisting of multiple phases or materials was presented. The purpose to make any capsules CMMC is to make them intelligent so that a microcapsule(MC) recognizes any stimulus from an external environment to change the characteristics. The manufacturing method of CMMC is divided into the membrane bulk property improvement method and the surface property improvement method. The former has the property to control the permebility by the double membrane of lipid and further has the possibility to recognize any light, ultrasonic wave, pH and electric field. There is a MC containig ferrite with which some carcinostatic agents are concentrated to a tumor by a magnet. The MC of nylon/ polystyrene could also be developed by using the interfacial polymerization and the subumerged drying methods. In the case of the surface property improvement, MC containing carcinostatic agents is prepared with ethylene cellulose by the coacervation method and then the dispersibility into water could be improved by treating MC in a hexane solution of lecithin to enable the reduction of releasing rate of the core materials. In addition, a surface treated MC of high compatibility to some biological tissues has been developed. 15 refs., 8 figs.

  3. Application of Nanotechnology in the Development of Pharmaceutical Preparations%纳米技术在药物制剂研究中的应用

    Institute of Scientific and Technical Information of China (English)

    高洁; 连潇嫣; 魏振平; 王博; 李洪起; 任晓文

    2012-01-01

    The lower bioavailability caused by poor water solubility is one of the important factors that hurdled the development and reasonable use of the pharmaceutical APIs. However, with the application of the nanotechnology in the development of pharmaceutical preparations, the bioavailability for some of the poorly water-soluble drugs had been greatly improved. In this article, applications of nanotechnology were introduced in pharmaceutical preparations as dosage-forms of microemulsion, solid lipid nanoparticles, nanogel, polymeric nanoparticle and nanocrystals. The possible problems resulted from the use of nano-preparations were discussed together with their advantages over the traditional dosage-forms with the purpose of expanding the application of nanotechnology in the R&D of novel pharmaceutical preparations.%药物的水难溶性以及由此导致的低生物利用度是阻碍药学发展的主要原因之一,随着纳米技术的发展以及在药物制剂研究的应用,有些水难溶药物生物利用度低的问题已经得到了较好的解决.本论文在对纳米技术进行简介的基础上,重点介绍了该技术在微乳液、固体脂质纳米粒、纳米凝胶、聚合物纳米粒及纳米结晶等新型给药系统中的应用.在介绍纳米药物相对于传统药物的主要优势时,也对纳米技术在药物制剂研究中潜在的问题也进行了提示,以使纳米技术在新型药物制剂的研究中发挥更好作用.

  4. Properties of natural rubber/attapulgite composites prepared by latex compounding method: Effect of filler loading

    Energy Technology Data Exchange (ETDEWEB)

    Muttalib, Siti Nadzirah Abdul, E-mail: sitinadzirah.amn@gmail.com; Othman, Nadras, E-mail: srnadras@usm.my; Ismail, Hanafi, E-mail: ihanafi@usm.my [School of Materials and Mineral Resources Engineering, Engineering Campus, Universiti Sains Malaysia, Seri Ampangan, 14300 Nibong Tebal, Pulau Pinang (Malaysia)

    2015-07-22

    This paper reports on the effect of filler loading on properties of natural rubber (NR)/attapulgite (ATP) composites. The NR/ATP composites were prepared by latex compounding method. It is called as masterbatch. The masterbatch was subsequently added to the NR through melt mixing process. The vulcanized NR/ATP composites were subjected to mechanical, swelling and morphological tests. All the results were compared with NR/ATP composites prepared by conventional system. The composites from masterbatch method showed better results compared to composites prepared by conventional method. They have higher tensile properties, elongation at break and tear strength. The images captured through scanning electron microscopy test revealed the improvement of tensile strength in masterbatch NR/ATP composites. It can be seen clearly that masterbatch NR/ATP have better filler dispersion compared to conventional method NR/ATP composites.

  5. Polymer composites prepared from heat-treated starch and styrene-butadiene latex

    Science.gov (United States)

    Thermoplastic starch/latex polymer composites were prepared using styrene–butadiene (SB) latex and heat-treated cornstarch. The composites were prepared in a compression mold at 130 °C, with starch content 20%. An amylose-free cornstarch, waxy maize, was used for this research and the heat treatment...

  6. Optimization of a spectrofluorimetric method based on a central composite design for the determination of potassium losartan in pharmaceutical products

    Directory of Open Access Journals (Sweden)

    Fatma Demirkaya-Miloglu

    2014-09-01

    Full Text Available Here, a spectrofluorimetric method for the determination of potassium losartan (PL in pharmaceutical products is described. The effects of critical parameters, pH, acid molarity, and temperature, on the fluorescence intensity of PL were analyzed, and these parameters were optimized using a central composite design (CCD. The highest fluorescent intensity at excitation (λex and emission (λem wavelengths of 248 nm and 410 nm, respectively, was achieved using 0.01 M sulfurous acid (pH 2 at 21.6 °C. Under optimum conditions, the method was linear from 0.025-0.5 µg/mL, with a reasonably high correlation coefficient (0.9993. Furthermore, the method was very sensitive (LOQ, 0.006, accurate (RE, ≤7.06, and precise (%RSD, ≤6.51. After development and validation of the method, samples containing PL were analyzed with this method, and the obtained data were statistically compared with those obtained with a previously published reference method using a two one-sided equivalence test (TOST. According to the data, the results from the proposed and reference assays were equivalent.

  7. Preparation and application of pharmaceutical wastewater treatment by praseodymium doped SnO2/Ti electrocatalytic electrode

    Institute of Scientific and Technical Information of China (English)

    HAN Guocheng; LIU Zheng; WANG Yongliao

    2008-01-01

    Praseodymium was selected as a promoter for SnO2/Ti electrode to improve the electrocatalytic performance by electrodeposition in pharmaceutical wastewater treatment;the micrograph and the structure were characterized by SEM and XRD. Mixture uniform design was used in the optimization of the electrolytic conditions;mathematical model was established according to the rate of wiping COD off, which revealed the relationship between the current intensity, time of electrolysis, the amount of doped Pr, and the ratio of area (SnO2/Ti:Al). On the basis of the analysis of the empirical model, the optimized parameters had been obtained;the rate of wiping COD off was up to 94.9%, it decreased from 392 to 20 mg/L. Experimental results showed that the electrocatalytic performance of the electrode doped with Pr was superior for the treatment of pharmaceutical wastewater.

  8. Preparation of a concentrated organophyllosilicate and nanocomposite composition

    Science.gov (United States)

    Chaiko, David J.; Niyogi, Suhas G.

    2007-01-16

    The present invention provide methods for producing a low moisture organophyllosilicate composition using monomers, oligomers, or polymers to displace water associated with the organophyllosilicates in an aqueous organophyllosilicate slurry or filter cake. The invention additionally provides methods for producing organophyllosilicate nanocomposites from the concentrated organophyllosilicate compositions by dispersing the compositions in a polymer matrix.

  9. High-performance liquid chromatographic method for the determination of nicardipine in pure, pharmaceutical preparations and plasma and its application to pharmacokinetics in humans

    Directory of Open Access Journals (Sweden)

    Sheikha M. Al-Ghannam

    2009-01-01

    Full Text Available A simple, sensitive and reproducible reversed-phase liquid chromatographic method has been developed and validated for the determination of nicardipine hydrochloride (NC in pure, pharmaceutical preparations, human plasma and the study of the pharmacokinetics of the drug in human body. Nicardipine in plasma were extracted with hexane-butanol (12:1,v/v after addition of borate buffer (0.5 M, pH=9.0, and then measured by HPLC-UV using a Waters Symmetry C18 column as stationary phase and methanol– triethylamine buffer (0.01M pH 4 with acetic acid (70:30 as mobile phase. Nicardipine was quantified by ultraviolet absorbance at 353 nm. The method proved to be linear in the pure drug in the ranges of 15-200 ng/mL (r=0.9989 and 5-40 ?g/mL (r=0.9995, and for the pharmaceutical preparations and plasma for drug concentrations in the range of 5-40 ?g/mL (r =0.9992 and 25-150 ng/mL (r=0.9991, respectively. The lower limit of detection and the lower quantitation limit of NC in plasma were 11.74 and 35.57 ng/mL, respectively. The method is sensitive and reliable for harmacokineticstudies of nicardipine in humans after the oral administration of immediate-release capsules to healthy subjects.

  10. Research Progress of Preparation and Characterization methods of Pharmaceutical Cocrystal%药物共晶制备及表征方法研究进展

    Institute of Scientific and Technical Information of China (English)

    张晓明; 卢晓娥; 李静

    2013-01-01

      药物共晶是一种新的药物晶型,对于一个给定的活性药物成分,通过形成共晶一方面可以改善药物的理化性质,提高临床药效,另一方面可以增加药物的结晶形式,这在新药研发中具有很大的应用潜力。文章综述性地介绍药物共晶近年来的主要制备方法和表征方法,为制备新的药物共晶提供参考。%Drug eutectic is a kind of new drug polymorphs, for a given active pharmaceutical ingredients, through the formation of eutectic hand can improve the physicochemical properties of the drug, to improve the clinical efficacy, on the one hand can increase the drug to the crystalline form, which in the new drug research and development has great potential application. The paper introduced drug eutectic in recent years the main preparation methods and analyzed methods, for the preparation of new pharmaceutical reference.

  11. Thermophysical properties of starch and whey protein composite prepared in presence of organic acid and esters

    Science.gov (United States)

    Previously, we prepared starch and protein composite by reactive mixing in presence of various organic acids and found that use of these acid esters resulted in composites with good mechanical properties. In this study, concentration (% w/w) of acid citrates in the starch-protein composites were var...

  12. TECHNOLOGICAL BASIS FOR THE CREATION OF IMPLANTS WITH A PHARMACEUTICAL COMPOSITION OF CIPROFLOXACIN AND THEIR ANTIMICROBIAL ACTIVITY IN EXPERIMENTS IN VITRO

    Directory of Open Access Journals (Sweden)

    V. V. Sheykin

    2016-01-01

    Full Text Available The article is devoted to the investigation of the possibility of immobilized on the surface of the titanium implantable devices (model plates, “U-shaped” brackets antimicrobial substances.Material and methods. The object of research were modeling titanium plates and titanium “U-shaped” brackets for implantation. Ciprofloxacin, hydroxypropylmethylcellulose and methylcellulose has been proposed as materials for the creation of antimicrobial pharmaceutical composition to immobilization. The antimicrobial properties of titanium implantable “U-shaped” brackets with ciprofloxacin was evaluated for potential antimicrobial activity against medically important bacterial (S. aureus, P. aeruginosa, E. coli, E. faecalis and S. pyogenes using method of diffusion in agar. Results. The results showed the possibility of putting and holding а ciprofloxacin in grooves on the modified surface of titanium implants. In the course of the study was developed a pharmaceutical composition, comprising ciprofloxacin and hydroxypropylmethylcellulose. The results showed high antimicrobial activity of pharmaceutical composition with ciprofloxacin against the test organisms (S. aureus, P. aeruginosa, E. coli, E. faecalis and S. pyogenes.

  13. Enantioselective nano liquid chromatographic separation of racemic pharmaceuticals: a facile one-pot in situ preparation of lipase-based polymer monoliths in capillary format.

    Science.gov (United States)

    Ahmed, Marwa; Ghanem, Ashraf

    2014-11-01

    New affinity monolithic capillary columns of 150 µm internal diameter were prepared in situ fused glass capillary via either immobilization or encapsulation of Candida antarctica lipase B (CALB) on or within polymer monoliths, respectively. The immobilized lipase-based monoliths were prepared via copolymerization of 19.1% monomers (8.9% MMA and 10.2% GMA), 19.8% EDMA, and 61.1% porogens (54.2% formamide and 6.9% 1-propanol) w/w or 20% GMA, 20% EDMA, and 60% porogens (51.6% cyclohexanol and 8.4% 1-dodecanol) in the presence of AIBN (1%) as a radical initiator. This was followed by pumping a solution of lipase through the capillaries and rinsing with potassium phosphate buffer. On the other hand, the encapsulated lipase-based monoliths were prepared via copolymerization of 20% monomers (GMA), 20% EDMA, and 60% porogens (48% 1-propanol, 6% 1,4-butanediol) or 16.4% monomers (16% BuMA, 0.4% SPMA), 23.6% EDMA, and 60% porogens (36% 1-propanol, 18% 1,4-butanediol along with 6% lipase aqueous solution in potassium phosphate buffer. The prepared capillary columns were investigated for the enantioselective nano liquid chromatographic separation of a set of different classes of racemic pharmaceuticals, namely, α- and β-blockers, antiinflammatory drugs, antifungal drugs, dopamine antagonists, norepinephrine-dopamine reuptake inhibitors, catecholamines, sedative hypnotics, diuretics, antihistaminics, anticancer drugs, and antiarrhythmic drugs. Run-to-run repeatability was quite satisfactory. The encapsulated lipase-based capillary monolith showed better enantioselective separations of most of the investigated compounds. Baseline separation was achieved for alprenolol, atenolol, bromoglutithimide, carbuterol, chloropheneramine, cizolertine carbinol, 4-hydroxy-3-methoxymandelic acid, desmethylcizolertine, nomifensine, normetanephrine, and sulconazole under reversed phase chromatographic conditions. A speculation about the understanding of the chiral recognition mechanism of

  14. RESEARCH OF THE PREPARATION «AMINALON-FARMAK» ON THE PHARMACEUTICAL MARKET OF THE UKRAINE: INFORMATION REVIEW

    Directory of Open Access Journals (Sweden)

    V. A. Kuchmistov

    2014-01-01

    Full Text Available Among the contemporary medicinal remedies the derivatives of -aminobutyric acid have a special place. The present work is devoted to the remedy «Aminalon» which has a dignity of a combination of nootropic and neuroprotective actions and it has special value for the geriatric and pediatric practices. The task of the authors was a holding of a market review with the purpose to generalize the information about the place of the given remedy as a segment of the pharmaceutical market.

  15. Assessing the Factors Associated With Iran's Intra-Industry Trade in Pharmaceuticals.

    Science.gov (United States)

    Yusefzadeh, Hassan; Hadian, Mohammad; Abolghasem Gorji, Hassan; Ghaderi, Hossein

    2015-03-30

    Pharmaceutical industry is a sensitive and profitable industry. If this industry wants to survive, it should be able to compete well in international markets. So, study of Iran's intra-industry trade (IIT) in pharmaceuticals is essential in order to identify competitiveness potential of country and boost export capability in the global arena. This study assessed the factors associated with Iran's intra-industry trade in pharmaceuticals with the rest of the world during the 2001-2012 periods using seasonal time series data at the four-digit SITC level. The data was collected from Iran's pharmaceutical Statistics, World Bank and International Trade Center. Finally, we discussed a number of important policy recommendations to increase Iran's IIT in pharmaceuticals. The findings indicated that economies of scale, market structure and degree of economic development had a significantly positive impact on Iran's intra-industry trade in pharmaceuticals and tariff trade barriers were negatively related to IIT. Product differentiation and technological advancement didn't have the expected signs. In addition, we found that Iran's IIT in pharmaceuticals have shown an increasing trend during the study period. Thus, the composition of Iran trade in pharmaceuticals has changed from inter-industry trade to intra-industry trade. In order to get more prepared for integration into the global economy, the development of Iran's IIT in pharmaceuticals should be given priority. Therefore, paying attention to IIT could have an important role in serving pharmaceutical companies in relation to pharmaceutical trade.

  16. Preparation of Dysprosium Ferrite/Polyacrylamide Magnetic Composite Microsphere and Its Characterization

    Institute of Scientific and Technical Information of China (English)

    Hidehiro Kumazawa; Wang Zhifeng; Zhou Lanxiang; Zhang Hong; Li Yourong; Zhang Ming

    2005-01-01

    Using the technique of microemulsion polymerization with nano-reactor, dysprosium ferrite/polyacrylamide magnetic composite microsphere was prepared by one-step method in a single inverse microemulsion. The structure, average particle size, morphology of composite microsphere were characterized by FTIR, XRD, TEM and TGA. The magnetic responsibility of composite microsphere was also investigated. The results indicate that the magnetic composite microsphere possess high magnetic responsibility and suspension stability.

  17. Biodegradable and magnetic core-shell composite particle prepared by emulsion solvent diffusion method

    Science.gov (United States)

    Oka, Chiemi; Ushimaru, Kazunori; Horiishi, Nanao; Tsuge, Takeharu; Kitamoto, Yoshitaka

    2016-02-01

    The present paper describes optimization of preparation conditions of a core-shell composite particle, and its heat generation by alternating magnetic fields. The composite particles are prepared with a modified emulsion solvent diffusion method, which is combined with Pickering emulsion stabilized by magnetic nanoparticles. In this method, the magnetic nanoparticles act as an emulsifier, and its amount and size are crucial to morphology of the composite particles. The magnetic nanoparticles of 8-9 nm would be strongly adsorbed at a liquid-liquid interface rather than the larger nanoparticles. At the optimized concentration of the magnetic nanoparticle’s suspension for the preparation, small and uniform composite particles are obtained since the amount of the nanoparticles is enough to prevent coalescence of droplets during the formation of the composites. The heat generation by alternating magnetic fields emerged certainly. This result suggests the composite particles have a property as a heat-generating carrier for hyperthermia treatment.

  18. Preparation and properties of PAn/ATTP/PE conductive composites

    Institute of Scientific and Technical Information of China (English)

    QIU Jian-hui; FENG Hui-xia

    2006-01-01

    Polyaniline/Attapugite/ PE(PAn-ATTP/PE)composites containing particles with core-shell structure were obtained via the two-step blending processs. The experimental condition is as follows: Organo-attapulgite and PAn was obtained by modifying attapulgite with laury benzenesulfonic acid sodium salt and,then added to PE. The electrical conductivity,structure and properties of the composites were studied. Under the function of shear stress,core-shell structure particles with ATTP as the core and PAn as the shell were formed in the composites. The structure of PAn-ATTP/PE composites were characterized by FTIR,XRD,SEM,etc,respectively. The effects of concentration of doping agent on the conductivity and mechanical property of the composites were investigated. The mechanical properties and impact fracture surface of the ternary composites were studied by means of the tensile tester,SEM,etc. The results show that polyaniline encapsulated ATTP enhances the strength of the PE. And the conductivity of PAn-ATTP/PE composites of is improved effectively when polyaniline encapsulated ATTP is added. The composite have good conductivity when 10% polyaniline encapsulated ATTP is added.

  19. Effect of particle shape of active pharmaceutical ingredients prepared by fluidized-bed jet-milling on cohesiveness.

    Science.gov (United States)

    Fukunaka, Tadashi; Sawaguchi, Kohta; Golman, Boris; Shinohara, Kunio

    2005-05-01

    Milling is a common procedure to improve bioavailability of many active pharmaceutical ingredients (APIs), which typically have low solubility in water. But such micronization can yield an increase in the cohesiveness of particles. Although particle cohesiveness is desirable for tablet strength in the subsequent formulation process, increased particle cohesiveness can lead to operational difficulties in a milling equipment due to compaction of particles inside. In this article, the impact of milling via a fluidized-bed jet-mill on the cohesive strength and interparticle force was studied using Ethenzamide as a pharmaceutical model compound. As a result, the particle shape was found to affect both the tensile strength of powder bed and the interparticle cohesive force. A powder bed, having relatively high void fraction by direct tensile test, shows a positive correlation between the cohesive force and the particle sphericity, while powders with low void fraction by diametral compression test show a positive correlation between the cohesive force and the angularity of the particle.

  20. Development of an HPLC-UV Method for the Analysis of Drugs Used for Combined Hypertension Therapy in Pharmaceutical Preparations and Human Plasma

    Directory of Open Access Journals (Sweden)

    Serife Evrim Kepekci Tekkeli

    2013-01-01

    Full Text Available A simple, rapid, and selective HPLC-UV method was developed for the determination of antihypertensive drug substances: amlodipine besilat (AML, olmesartan medoxomil (OLM, valsartan (VAL, and hydrochlorothiazide (HCT in pharmaceuticals and plasma. These substances are mostly used as combinations. The combinations are found in various forms, especially in current pharmaceuticals as threesome components: OLM, AML, and HCT (combination I and AML, VAL, and HCT (combination II. The separation was achieved by using an RP-CN column, and acetonitrile-methanol-10 mmol orthophosphoric acid pH 2.5 (7 : 13 : 80, v/v/v was used as a mobile phase; the detector wavelength was set at 235 nm. The linear ranges were found as 0.1–18.5 μg/mL, 0.4–25.6 μg/mL, 0.3–15.5 μg/mL, and 0.3–22 μg/mL for AML, OLM, VAL, and HCT, respectively. In order to check the selectivity of the method for pharmaceutical preparations, forced degradation studies were carried out. According to the validation studies, the developed method was found to be reproducible and accurate as shown by RSD ≤6.1%, 5.7%, 6.9%, and 4.6% and relative mean error (RME ≤10.6%, 5.8%, 6.5%, and 6.8% for AML, OLM, VAL, and HCT, respectively. Consequently, the method was applied to the analysis of tablets and plasma of the patients using drugs including those substances.

  1. Development of an HPLC-UV Method for the Analysis of Drugs Used for Combined Hypertension Therapy in Pharmaceutical Preparations and Human Plasma.

    Science.gov (United States)

    Kepekci Tekkeli, Serife Evrim

    2013-01-01

    A simple, rapid, and selective HPLC-UV method was developed for the determination of antihypertensive drug substances: amlodipine besilat (AML), olmesartan medoxomil (OLM), valsartan (VAL), and hydrochlorothiazide (HCT) in pharmaceuticals and plasma. These substances are mostly used as combinations. The combinations are found in various forms, especially in current pharmaceuticals as threesome components: OLM, AML, and HCT (combination I) and AML, VAL, and HCT (combination II). The separation was achieved by using an RP-CN column, and acetonitrile-methanol-10 mmol orthophosphoric acid pH 2.5 (7 : 13 : 80, v/v/v) was used as a mobile phase; the detector wavelength was set at 235 nm. The linear ranges were found as 0.1-18.5  μ g/mL, 0.4-25.6  μ g/mL, 0.3-15.5  μ g/mL, and 0.3-22  μ g/mL for AML, OLM, VAL, and HCT, respectively. In order to check the selectivity of the method for pharmaceutical preparations, forced degradation studies were carried out. According to the validation studies, the developed method was found to be reproducible and accurate as shown by RSD ≤6.1%, 5.7%, 6.9%, and 4.6% and relative mean error (RME) ≤10.6%, 5.8%, 6.5%, and 6.8% for AML, OLM, VAL, and HCT, respectively. Consequently, the method was applied to the analysis of tablets and plasma of the patients using drugs including those substances.

  2. Preparation of electrodes on cfrp composites with low contact resistance comprising laser-based surface pre-treatment

    KAUST Repository

    Almuhammadi, Khaled Hamdan

    2016-12-29

    Various examples are provided related to the preparation of electrodes on carbon fiber reinforced polymer (CFRP) composites with low contact resistance. Laser-based surface preparation can be used for bonding to CFRP composites. In one example, a method includes preparing a pretreated target area on a CFRP composite surface using laser pulsed irradiation and bonding an electrode to exposed fibers in the pretreated target area. The surface preparation can allow the electrode to have a low contact resistance with the CFRP composite.

  3. Effect of Composition on Mechanical Properties of Mullite-WC Nano Composites Prepared by Spark Plasma Sintering

    Directory of Open Access Journals (Sweden)

    H. Rajaei

    2016-12-01

    Full Text Available Mullite-WC composites were prepared from Mullite and WC powders by spark plasma sintering at 1400 °C for a holding time of 180 s under 30 MPa. Microstructure, strength, and hardness of the mullite-WC composites were studied. The mullite-WC composite containing 5-20 wt% WC reached over 94 % theoretical density. The strength and Vickers hardness of mullite-(10 wt% WC sintered composite reached maximum values of 298 MPa, and 1589 HV, respectively demonstrating that the introduction of WC significantly enhances the mechanical properties of the mullite matrix.

  4. Preparation of Antibacterial Nanofibre/Nanoparticle Covered Composite Yarns

    Directory of Open Access Journals (Sweden)

    Fatma Yalcinkaya

    2016-01-01

    Full Text Available The antibacterial efficiency of nanofibre composite yarns with an immobilized antibacterial agent was tested. This novel type of nanofibrous composite material combines the good mechanical properties of the core yarn with the high specific surface of the nanofibre shell to gain specific targeted qualities. The main advantages of nanofibre covered composite yarns over the standard planar nanofibre membranes include high tensile strength, a high production rate, and their ability to be processed by standard textile techniques. The presented paper describes a study of the immobilization of an antibacterial agent and its interaction with two types of bacterial colonies. The aim of the study is to assess the applicability of the new composite nanomaterial in antibacterial filtration. During the experimental tests copper(II oxide particles were immobilized in the polyurethane and polyvinyl butyral nanofibre components of a composite yarn. The antibacterial efficiency was evaluated by using both Gram-negative Escherichia coli and Gram-positive Staphylococcus gallinarum bacteria. The results showed that the composite yarn with polyvinyl butyral nanofibres incorporating copper(II oxide nanoparticles exhibited better antibacterial efficiency compared to the yarn containing the polyurethane nanofibres. The nanofibre/nanoparticle covered composite yarns displayed good antibacterial activity against a number of bacteria.

  5. Preparation of Cu-based Bulk Metallic Glass Matrix Composites

    Institute of Scientific and Technical Information of China (English)

    Yufeng SUN; Yuren WANG; Bingchen WEI; Weihuo LI

    2006-01-01

    Cu47Ti34Zr11Ni8 bulk metallic glass (BMG) matrix composites containing in situ formed TiC particles and δ-TiCu dendrite phase were developed by copper mold cast. The thermal stability and microstructure of the composites are investigated. Room temperature compression tests reveal that the composite samples exhibit higher fracture strength and distinct plastic strain of 0.2%~0.5%, comparing with that of the corresponding Cu47Ti34Zr11 Ni8 monolithic BMG.

  6. Extractive spectrophotometric determination of five selected drugs by ion-pair complex formation with bromothymol blue in pure form and pharmaceutical preparations

    Directory of Open Access Journals (Sweden)

    Sneha G. Nair

    2015-12-01

    Full Text Available Simple, precise, selective, and expeditious spectrophotometric methods have been developed for the determination of itopride (ITO, midodrine (MID, diclofenac (DIC, mesalamine (MES, and sumatriptan (SUM in their pure form as well as in pharmaceutical preparations. The method was based on ion-pair complex formation between the drugs and anionic dye, bromothymol blue in an acidic medium (pH 2.0–4.0. The yellow colored complexes formed were quantitatively extracted into chloroform and measured at 411, 410, 413, 412, and 414 nm wavelength for ITO, MID, DIC, MES, and SUM, respectively. Beer’s law was obeyed in the concentration range of 3.0–30 µg/mL for ITO, 1.0–20 µg/mL for MID, 1.5–40 µg/mL for DIC, 1.2–12 µg/mL for MES, and 0.5–15 µg/mL for SUM. The stoichiometry of the complexes formed between the drugs and the dye was 1:1 as determined by Job’s method of continuous variation. The association constant (KIP of the ion-pair complexes formed was evaluated using Benesi–Hildebrand equation. Limit of detection, limit of quantification, and Sandell’s sensitivity of the methods were also estimated. The proposed methods were successfully employed for the determination of these drugs in their pharmaceutical dosage forms.

  7. Preparation of methacrylic acid copolymer S nano-fibers using a solvent-based electrospinning method and their application in pharmaceutical formulations.

    Science.gov (United States)

    Hamori, Mami; Shimizu, Yuki; Yoshida, Kaori; Fukushima, Keizo; Sugioka, Nobuyuki; Nishimura, Asako; Naruhashi, Kazumasa; Shibata, Nobuhito

    2015-01-01

    In this study, we applied an electrospinning (ES) method, which is mainly employed in the textile industry, to the field of pharmaceuticals. We developed and modified an ES instrument and then utilized it to produce methacrylic acid copolymer S (MAC) nano-fibers to prepare tablets. By attaching a conductor rod made from stainless steel to the central part of the nano-fiber-collection plate of the ES apparatus, a MAC nano-fiber sheet could be produced effectively. In addition, we studied various operating conditions for this new ES method, including needle gauge, voltage between the electrodes, distance between the needle and nano-fiber-collection plate and the flow rate of MAC polymer solution, but these had no significant effect on the diameter of MAC nano-fibers. On the other hand, the viscosity (concentration) of MAC polymer solution and permittivity of solvent used to dilute MAC were closely related to the mean diameter of the nano-fibers. Tableting of MAC nano-fibers was performed using a tableting machine without lubricants, and addition of Tween 20 to the tablets enabled regulation of the release profile of a water-soluble drug. The modified ES method reported here is a useful technique for the controlled-release of drugs and has wide-ranging potential for pharmaceutical applications.

  8. Physicochemical and structural properties of composite gels prepared with myofibrillar protein and lard diacylglycerols.

    Science.gov (United States)

    Diao, Xiaoqin; Guan, Haining; Zhao, Xinxin; Diao, Xinping; Kong, Baohua

    2016-11-01

    The objective of this study was to investigate the physicochemical and structural properties of composite gels prepared with porcine myofibrillar protein (MP) and lard, glycerolized lard (GL) or purified glycerolized lard (PGL). The gels prepared with MP and GL or PGL had significantly higher penetration force and water-holding capacity (WHC) than the gel with lard (Pgel, T21 and T22 of the gels that were prepared with GL or PGL moved in the direction of slower relaxation time, which suggests that the water mobility in the gel system was restricted. The presence of lard, GL and PGL did not affect the participating proteins in composite gels. The presence of GL and PGL altered the secondary and tertiary structures of MP in composite gels, which changed the gel properties. In general, the composite gels that were prepared with MP and GL or PGL showed improved gel quality.

  9. Preparation and characterization of antimicrobial nano-hydroxyapatite composites

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Juhong [The Key Laboratory of Advanced Textile Materials and Manufacturing Technology of Ministry of Education, College of Materials and Textiles, Zhejiang Sci-Tech University, Hangzhou 310018 (China); Chu, Xiaobing [The First Affiliated Hospital, Zhejiang Chinese Medicine University, Hangzhou 310006 (China); Cai, Yurong [The Key Laboratory of Advanced Textile Materials and Manufacturing Technology of Ministry of Education, College of Materials and Textiles, Zhejiang Sci-Tech University, Hangzhou 310018 (China); Tong, Peijian [The First Affiliated Hospital, Zhejiang Chinese Medicine University, Hangzhou 310006 (China); Yao, Juming, E-mail: yaoj@zstu.edu.cn [The Key Laboratory of Advanced Textile Materials and Manufacturing Technology of Ministry of Education, College of Materials and Textiles, Zhejiang Sci-Tech University, Hangzhou 310018 (China)

    2014-04-01

    Deep infection of prosthesis is one of the most frequent complications after joint replacement. One of the most effective ways is to introduce directly some antibiotics in the local site of the surgery. In the present study, an antimicrobial composite has been fabricated using nano-hydroxyapatite particles as carriers for the antimicrobial drug of vancomycin hydrochloride (VAN) and the mixture of oxidation sodium alginate (OSA) and gelatin (GT) as a sticky matrix. Samples have been characterized using X-ray diffraction instrument (XRD), field emission scanning electron microscope (FE-SEM), transmission electron microscope (TEM) and Fourier transform infrared (FTIR) spectra, Brunauer–Emmett–Teller (BET) methods, the rotational rheometer and the texture analyzer. The release of VAN from nano-hydroxyapatite (nHAP) particles was detected by the ultraviolet–visible (UV–vis) spectrophotometer and then bactericidal property of the composite was evaluated using the Staphylococcus aureus (S. aureus) as a bacterial model. Experimental results showed that the composite possessed an adhesive property derived from the gel of OSA and GT, which implied that the composite could bond directly to the fracture surface of bones in surgery. Furthermore, VAN was loaded efficiently on the surface of nHAP particles and could be released slowly from these particles, which endowed the composite with an obvious and continuous antimicrobial performance. The sticky and antimicrobial composite may has a potential application in arthroplasty to overcome deep infection in a simple and direct manner. - Highlights: • A sticky and antimicrobial composite has been designed to overcome deep infection. • The composite was composed of antibiotic, antibiotic carrier and a viscous matrix. • The sticky matrix was obtained by blending of oxidation sodium alginate and gelatin. • Hydroxyapatite nanoparticle could be used as carrier to control release of antibiotic.

  10. Glass matrix composite material prepared with waste foundry sand

    Directory of Open Access Journals (Sweden)

    ZHANG Zhao-shu

    2006-11-01

    Full Text Available The technology of glass matrix of the composite material manufactured through a sintering process and using waste foundry sand and waste glass as the main raw materials was studied. The effects of technological factors on the performance of this material were studied. The results showed that this composite material is formed with glass as matrix, core particulate as strengthening material, it has the performance of glass and ceramics, and could be used to substitute for stone.

  11. Glass matrix composite material prepared with waste foundry sand

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhao-shu; XIA Ju-pei; ZHU Xiao-qin; LIU Fan; HE Mao-yun

    2006-01-01

    The technology of glass matrix of the composite material manufactured through a sintering process and using waste foundry sand and waste glass as the main raw materials was studied. The effects of technological factors on the performance of this material were studied. The results showed that this composite material is formed with glass as matrix, core particulate as strengthening material, it has the performance of glass and ceramics, and could be used to substitute for stone.

  12. Determination of guaiphenesin in anti-tussive pharmaceutical preparations containing dextromethorphan by first- and second-derivative ultraviolet spectrophotometry.

    Science.gov (United States)

    Lee, A R; Hu, T M

    1994-06-01

    Rapid, simple and direct assay procedures based on selective first (D1)- and second (D2)-derivative spectrophotometry, using a zero-crossing technique of measurement at 279.2 and 280.0 nm, respectively, have been developed for the specific determination of guaiphenesin in the presence of dextromethorphan, drugs with closely overlapping absorption spectra, in synthetic admixtures and in pharmaceutical dosage forms (tablets and syrups). The methods do not require extraction with organic solvents and are easier to perform than their conventional counterparts. Calibration graphs were linear (r = 0.99999 for D1 and 0.99969 for D2, respectively). Good selectivity, accuracy and precision were found. However, the performance of the analysis of guaiphenesin by the second-derivative mode deteriorated when the ratio of dextromethorphan to guaiphenesin was greater than one. Thus, the first-derivative spectrophotometry is the method of choice for the assay of tablets and syrups containing the two drugs.

  13. Validated HPLC method for simultaneous estimation of khellol glucoside, khellin and visnagin in Ammi visnaga L. fruits and pharmaceutical preparations.

    Science.gov (United States)

    Badr, Jihan M; Hadad, Ghada M; Nahriry, Khaled; Hassanean, Hashem A

    2015-01-01

    Tea bags including fruits of Ammi visnaga L. are used in Egypt as remedy for the treatment of kidney stones. Our study focuses on developing simple and rapid method utilising HPLC for quantitative estimation of khellol glucoside (KG), khellin (KH) and visnagin (VS) simultaneously. Their concentrations were determined in A. visnaga L. fruits at different developmental stages and in pharmaceutical formulations together with following up them during shelf life. Separation was accomplished using HPLC. Perfect resolution between KG, KH and VS was possible through using a mobile phase consisting of water:methanol:tetrahydrofuran (50:45:5, v/v/v). Peaks were detected at 245 nm. The suggested method for the determination of KG, KH and VS was successful in determining the analytes of interest without any interference of other compounds and matrix. All validation parameters were satisfactory and the procedure was relatively easy and fast as extracts are evaluated without previous steps of purification.

  14. Preparation of novel functional Mg/O/PCL/ZnO composite biomaterials and their corrosion resistance

    Energy Technology Data Exchange (ETDEWEB)

    Xi, Zhongxian; Tan, Cui; Xu, Lan; Yang, Na; Li, Qing, E-mail: liqingdswu@163.com

    2015-10-01

    Highlights: • Novel functional Mg/O/PCL/ZnO composite biomaterials were prepared. • The biomaterials were prepared by anodization treatment and dip-coating technique. • The composite biomaterials were smooth and with low porosity. • The prepared biomaterials have good corrosion resistance in SBF. • The composite biomaterials can release zinc ion to promote bone formation. - Abstract: In this study, novel and functional Mg/O/PCL/ZnO (magnesium/anodic film/poly(ε-caprolactone)/zinc oxide) composite biomaterials for enhancing the bioactivity and biocompatibility of the implant was prepared by using anodization treatment and dip-coating technique. The surface morphology, microstructure, adhesion strength and corrosion resistance of the composite biomaterials were investigated using scanning electron microscopy (SEM), adhesion measurements, electrochemical tests and immersion tests respectively. In addition, the biocompatible properties of Mg (magnesium), Mg/PCL (magnesium/poly(ε-caprolactone)) and Mg/O/PCL (magnesium/anodic film/poly(ε-caprolactone)) samples were also investigated. The results show that the Mg/O/PCL/ZnO composite biomaterials were with low porosity and with the ZnO powders dispersed in PCL uniformly. The adhesion tests suggested that Mg/O/PCL/ZnO composite biomaterials had better adhesion strength than that of Mg/PCL composite biomaterials obviously. Besides, an in vitro test for corrosion demonstrated that the Mg/O/PCL/ZnO composite biomaterials had good corrosion resistance and zinc ion was released obviously in SBF.

  15. Multicomponent kinetic spectrophotometric determination of pefloxacin and norfloxacin in pharmaceutical preparations and human plasma samples with the aid of chemometrics

    Science.gov (United States)

    Ni, Yongnian; Wang, Yong; Kokot, Serge

    2008-10-01

    A spectrophotometric method for the simultaneous determination of the important pharmaceuticals, pefloxacin and its structurally similar metabolite, norfloxacin, is described for the first time. The analysis is based on the monitoring of a kinetic spectrophotometric reaction of the two analytes with potassium permanganate as the oxidant. The measurement of the reaction process followed the absorbance decrease of potassium permanganate at 526 nm, and the accompanying increase of the product, potassium manganate, at 608 nm. It was essential to use multivariate calibrations to overcome severe spectral overlaps and similarities in reaction kinetics. Calibration curves for the individual analytes showed linear relationships over the concentration ranges of 1.0-11.5 mg L -1 at 526 and 608 nm for pefloxacin, and 0.15-1.8 mg L -1 at 526 and 608 nm for norfloxacin. Various multivariate calibration models were applied, at the two analytical wavelengths, for the simultaneous prediction of the two analytes including classical least squares (CLS), principal component regression (PCR), partial least squares (PLS), radial basis function-artificial neural network (RBF-ANN) and principal component-radial basis function-artificial neural network (PC-RBF-ANN). PLS and PC-RBF-ANN calibrations with the data collected at 526 nm, were the preferred methods—%RPE T ˜ 5, and LODs for pefloxacin and norfloxacin of 0.36 and 0.06 mg L -1, respectively. Then, the proposed method was applied successfully for the simultaneous determination of pefloxacin and norfloxacin present in pharmaceutical and human plasma samples. The results compared well with those from the alternative analysis by HPLC.

  16. Preparation of Al-SiC{sub p} composite coating by plasma thermal spray

    Energy Technology Data Exchange (ETDEWEB)

    Min, J.W. [Chungnam National University, Taejeon (Korea); Yoo, S.E. [Korea Automotive Technology Institute, Chonan (Korea); Kim, Y.J. [Sunmoon University, Asan (Korea); Kim, J.S.; Suhr, D.S. [Chungnam National University, Taejeon (Korea)

    2003-03-01

    Al-SiC{sub p} composite layer was prepared by plasma thermal spray on aluminum substrate using composite powder prepared by mechanical alloying. Mechanically alloyed powder was achieved after 24 h milling, which was used for thermal spray coating. The correlations between process conditions and thickness/porosity were analyzed, and increase of hardness was confirmed. The presence of Al-Si-C-O compound was detected by TEM analysis. (author). 16 refs., 6 tabs., 11 figs.

  17. Determinação espectrofotométrica de hexametilenotetramina (HMT em medicamentos, utilizando ácido cromotrópico e forno de micro-ondas Spectrophotometric determination of hexamethylenetetramine (HMT in pharmaceutical preparations using chromotropic acid and microwave oven

    Directory of Open Access Journals (Sweden)

    Enelton Fagnani

    2009-01-01

    Full Text Available This paper proposes a methodology for spectrophotometric determination of hexamethylenetetramine (HMT by using chromotropic acid in a phosphoric acid media employing a domestic microwave oven as a source of heating. The reddish-purple soluble product is quantitatively formed after 30 s of irradiation and obeys the Beer´s law in the range between 0.1-1.2 mg L-1 HMT (r = 0.99925. The method was applied successfully in commercial pharmaceutical preparations containing dyes in their composition. The results showed that the method proposed is feasible for simplicity, speed, low cost, precision and accuracy when compared with United States Pharmacopeia official method.

  18. PREPARATION OF PUZZOLANA ACTIVE TWO COMPONENT COMPOSITE FOR LATENT HEAT STORAGE

    Directory of Open Access Journals (Sweden)

    Jan Fort

    2016-10-01

    Full Text Available Application of Phase Change Materials (PCMs represents promising way for an increase of energy efficiency of industrial devices, reduction of energy demands for heating and cooling, waste heat recovery, solar energy storage and smart control of buildings interior climate. In this paper, the potential of diatomite as the bearer for the shape stable PCM was studied in order to develop material applicable in the mix composition of composite materials. Considering availability, endurance and compatibility of diatomite with the cement and lime based materials, preparation of diatomite/wax composite brings pozzolana active PCM with great promises at a reasonable cost. Prepared composite was analysed in detail using laser diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy and differential scanning calorimetry. Also the pozzolanic activity was measured. The prepared two components composite exhibits high latent heat storage and particle size distribution compatible with cement and hydrated lime.

  19. International Conference on Harmonisation; guidance on Q4B Evaluation and Recommendation of Pharmacopoeial Texts for use in the International Conference on Harmonisation Regions; Annex 4C on Microbiological Examination of Nonsterile Products: Acceptance Criteria for Pharmaceutical Preparations and Substances for Pharmaceutical Use General Chapter; availability. Notice.

    Science.gov (United States)

    2009-04-08

    The Food and Drug Administration (FDA) is announcing the availability of a guidance entitled "Q4B Evaluation and Recommendation of Pharmacopoeial Texts for Use in the ICH Regions; Annex 4C: Microbiological Examination of Nonsterile Products: Acceptance Criteria for Pharmaceutical Preparations and Substances for Pharmaceutical Use General Chapter." The guidance was prepared under the auspices of the International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH). The guidance provides the results of the ICH Q4B evaluation of the Microbiological Examination of Nonsterile Products: Acceptance Criteria for Pharmaceutical Preparations and Substances for Pharmaceutical Use General Chapter harmonized text from each of the three pharmacopoeias (United States, European, and Japanese) represented by the Pharmacopoeial Discussion Group (PDG). The guidance conveys recognition of the three pharmacopoeial methods by the three ICH regulatory regions and provides specific information regarding the recognition. The guidance is intended to recognize the interchangeability between the local regional pharmacopoeias, thus avoiding redundant testing in favor of a common testing strategy in each regulatory region. In the Federal Register of February 21, 2008 (73 FR 9575), FDA made available a guidance on the Q4B process entitled "Q4B Evaluation and Recommendation of Pharmacopoeial Texts for Use in the ICH Regions."

  20. Sealing of silorane-based composite in laser-prepared primary teeth: effect of acid etching.

    Science.gov (United States)

    Shafiei, Fereshteh; Memarpour, Mahtab; Fekrazad, Reza

    2014-01-01

    The purpose of this study was to evaluate the influence of prior etching on the sealing of silorane composite restorations in Class V cavity preparations prepared with an Er,Cr:YSGG laser compared to bur preparation in primary teeth. Standard Class V cavity preparations were prepared on the buccal surfaces of 56 extracted primary canines and randomly divided into four groups of 14 teeth each, according to laser or bur preparation and the use of prior acid etching in the preparation. All cavity preparations were restored with silorane adhesive and silorane composite. After water storage and thermocycling, the specimens were placed in 0.5 percent basic fuchsin dye solution. Dye penetration was evaluated with a stereomicroscope. The data were analyzed with nonparametric tests (P=.05). Laser preparation and prior etching in bur-prepared cavity preparation had no significant effect on enamel sealing (P>.05), but significantly increased microleakage at the dentin margin (Pacid etching may be necessary to ensure good marginal sealing when laser preparation is used. However, this step is not required when bur cutting is used in primary teeth.

  1. Determination of neomycin and related substances in pharmaceutical preparations by reversed-phase high performance liquid chromatography with mass spectrometry and charged aerosol detection.

    Science.gov (United States)

    Stypulkowska, K; Blazewicz, A; Fijalek, Z; Warowna-Grzeskiewicz, M; Srebrzynska, K

    2013-03-25

    A new, simple and repeatable liquid chromatographic method with charged aerosol detection (LC-CAD) for determination of neomycin and related substances has been developed. Analysis of neomycin or other aminoglycosides is problematic due to a lack of chromophores. Universal response of CAD enables direct quantification of neomycin and related substances, for which no reference standard are available. Separation was performed on C18 Hypersil(®) Gold aQ column using water, methanol and heptaflurobutyric acid as mobile phase. Under developed chromatographic conditions all impurities were well separated from neomycin B. Peaks identification was evaluated by electrospray ionization mass spectrometry. The proposed method was validated according to ICH guidelines and applied to the content determination of neomycin and related substances in pharmaceutical preparations.

  2. Full spectrum and selected spectrum based chemometric methods for the simultaneous determination of Cinnarizine and Dimenhydrinate in laboratory prepared mixtures and pharmaceutical dosage form

    Science.gov (United States)

    Tawakkol, Shereen M.; El-Zeiny, Mohamed B.; Hemdan, A.

    2017-02-01

    Three chemometric methods namely, concentration residual augmented classical least squares (CRACLS), spectral residual augmented classical least squares (SRACLS) and partial least squares (PLS) were applied for the simultaneous quantitative determination of Cinnarizine and Dimenhydrinate in their binary mixtures. All techniques were applied with and without variable selection using genetic algorithm (GA) resulting in six models (CRACLS, GA-CRACLS, SRACLS, GA-SRACLS, PLS, GA-PLS). These models were applied for the simultaneous determination of the drugs in their laboratory prepared mixtures and pharmaceutical dosage form via handling their UV spectral data. It was found that GA based models are simpler and more robust than those built with the full spectral data. The proposed models were found to be simple, fast and require no preliminary separation steps; so they can be used for the routine analysis of this binary mixture in quality control laboratories.

  3. Development and validation of a near infrared method for the analytical control of a pharmaceutical preparation in three steps of the manufacturing process.

    Science.gov (United States)

    Blanco, M; Coello, J; Iturriaga, H; Maspoch, S; Pou, N

    2000-11-01

    A near infrared diffuse reflectance spectroscopy (NIRS) procedure for the quantitative control analysis of the active compound (otilonium bromide) in a pharmaceutical preparation in three steps of the production process (blended product, cores and coated tablets) and a methodology for its validation are proposed. The analytical procedure is composed by two consecutive steps. First, the sample is identified by comparing its spectrum with a second derivative spectral library. If the sample is positively identified, the active compound is quantified by using a previously established partial least squares (PLS) calibration model. The procedure was validated by studying repeatability, intermediate precision, accuracy and linearity. To this end, an adaptation of ICH (International Conference on Harmonisation) validation methodology to an NIR multivariate calibration procedure is proposed. The relative standard error of prediction (RSEP) was < or = 1% and the suitability of the procedure for control analysis was confirmed by the results obtained analysing new production samples produced over a three-month period.

  4. Progress on the Application of Xanthan Gum in Pharmaceutical Preparations%黄原胶在药物制剂中的应用研究进展

    Institute of Scientific and Technical Information of China (English)

    邵华荣; 凌沛学

    2011-01-01

    Xanthan gum is a kind of biomacromolecule with chemical stability and non-toxicity.Research advances in pharmaceutical preparations of xanthan gum were reviewed in this paper, including oral controlled release system,mucosal drug delivery system,transdermal drug delivery system, and so on.%黄原胶是一种生物高分子多精,其化学性质稳定、无毒,广泛心用于药物制剂.本文对近年来黄原胶在口服缓控释制剂、黏膜给药制剂、经皮给药制剂及其它制剂中的应用研究作一综述.

  5. Iron-based adsorbent prepared from Litchi peel biomass via pyrolysis process for the removal of pharmaceutical pollutant from synthetic aqueous solution.

    Science.gov (United States)

    Foletto, Vitória Segabinazzi; Ferreira, Ananda Bulegon; da Cruz Severo, Eric; Collazzo, Gabriela Carvalho; Foletto, Edson Luiz; Dotto, Guilherme Luiz

    2017-03-10

    A porous iron-based adsorbent obtained from litchi peel via pyrolysis process was prepared in this work, in order to evaluate its adsorptive potential for the removal of a pharmaceutical dye (amaranth) from aqueous solution. The material was characterized by X-ray diffraction, nitrogen adsorption-desorption isotherms, and scanning electron microscopy. Several isotherm and kinetic models were tested aiming to represent the amaranth dye adsorption. The prepared sample presented magnetic property, and a mesoporous texture constituted of graphite and three iron-based phases. The adsorption kinetics of amaranth on the adsorbent followed the pseudo-second-order model, whereas the equilibrium data were in good agreement with the BET isotherm, being represented by a sigmoid-shaped adsorption isotherm. The maximum adsorption capacity for the amaranth dye was found to be 44.87 mg g(-1), demonstrating that the material prepared in this work showed to be a promising adsorbent for the removal of amaranth from aqueous solution.

  6. Pharmaceutical and pharmacokinetic characteristics of different types of fenofibrate nanocrystals prepared by different bottom-up approaches.

    Science.gov (United States)

    Zhang, Hua; Meng, Yuan; Wang, Xueqing; Dai, Wenbing; Wang, Xinglin; Zhang, Qiang

    2014-12-01

    Low dissolution rate of a poorly water soluble drug often leads to low and variable oral bioavailability. Formulating drugs as nanocrystals can help to overcome these problems by increasing the solubility and dissolution velocity. But different preparation approaches may result in different nanocrystals with different characteristics. In this study, three types of fenofibrate nanocrystals (FNT-NCs) were prepared by bottom-up methods, antisolvent and thermal precipitation under different conditions. These FNT-NCs were characterized by scanning electron micrography, dissolution testing, differential scanning calorimetry and powder X-ray diffractometry. A significant increase of dissolution rate was observed in the drug nanocrystals compared to the crude FNT powder (from 20% to 80% in 5 min). The crystallinity of the FNT-NCs prepared by antisolvent precipitation increased slightly, while that by thermal precipitation decreased. The oral bioavailability of two types of FNT-NCs prepared by antisolvent precipitation in rats increased notably compared to that of the crude powder (5.5-folds and 5.0-folds, respectively). However, the oral absorption of FNT-NCs prepared by thermal precipitation did not increase, although its dissolution rate was higher than that of the crude powder. In conclusion, different bottom-up methods produce different FNT-NCs with different crystallinity, which results in different oral bioavailability. Namely, a careful study and rational choice on preparation approaches are significant for the nanocrystal techniques.

  7. Preparation and characterization of GA/RDX nanostructured energetic composites

    Indian Academy of Sciences (India)

    YUANFEI LAN; XUEBAO WANG; YUNJUN LUO

    2016-12-01

    Graphene aerogel (GA) with nano-porous structure was assembled through the formation of physical cross-links between graphene sheets by a facile sol–gel method and supercritical CO$_2$ drying process. Thenhexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) was added and trapped in the nano-porous three-dimensional networks of GA to obtain a novel GA/RDX nanostructured energetic composite. The composition, morphology andstructure of the obtained GA/RDX nanostructured energetic composite were characterized by elemental analysis, scanning electron microscopy, nitrogen sorption tests and X-ray diffraction. Moreover, the thermal decompositioncharacteristic was investigated by thermogravimetry and differential scanning calorimetry. The results showed that GA could be a perfect aerogel matrix for the fabrication of GA/RDX nanostructured energetic composite due to itsunique nano-porous structure and attributes. It was also demonstrated that RDX homogeneously disperses in the asprepared GA/RDX nanostructured energetic composite at nanometric scale. GA showed promising catalytic effects for the thermal decomposition of RDX. After incorporating with GA, the decomposition of RDX was obviously accelerated.

  8. Electrochemical slurry compositions and methods for preparing the same

    Energy Technology Data Exchange (ETDEWEB)

    Doherty, Tristan; Limthongkul, Pimpa; Butros, Asli; Duduta, Mihai; Cross, III, James C.

    2016-11-01

    Embodiments described herein generally relate to semi-solid suspensions, and more particularly to systems and methods for preparing semi-solid suspensions for use as electrodes in electrochemical devices such as, for example batteries. In some embodiments, a method for preparing a semi-solid electrode includes combining a quantity of an active material with a quantity of an electrolyte to form an intermediate material. The intermediate material is then combined with a conductive additive to form an electrode material. The electrode material is mixed to form a suspension having a mixing index of at least about 0.80 and is then formed into a semi-solid electrode.

  9. Field emission characteristics of SnO2/CNT composite prepared by microwave assisted wet impregnation

    CSIR Research Space (South Africa)

    Kesavan Pillai, Sreejarani

    2012-01-01

    Full Text Available nanoparticles on CNTs, which was consistent with the results from X-ray diffraction. Enhanced field emission performance was observed for SnO2/CNT composite prepared by a microwave method when compared to pure CNTs and SnO2/CNT prepared by conventional wet...

  10. Preparation of bioactive porous HA/PCL composite scaffolds

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, J.; Guo, L.Y.; Yang, X.B. [Key Laboratory of Advanced Technologies of Materials (Ministry of Education), School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 610031 (China); Weng, J. [Key Laboratory of Advanced Technologies of Materials (Ministry of Education), School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 610031 (China)], E-mail: jweng@swjtu.cn

    2008-12-30

    Porous hydroxyapatite (HA) bioceramic scaffold has been widely attracted the attention to act as a three-dimensional (3D) template for cell adhesion, proliferation, differentiation and thus promoting bone and cartilage regeneration because of its osteoinduction. However, the porous bioceramic scaffold is fragile so that it is not suitable to be applied in clinic for bone repair or replacement. Therefore, it is significant to improve the mechanical property of porous HA bioceramics while the interconnected structure is maintained for tissue ingrowth in vivo. In the present research, a porous composite scaffold composed of HA scaffold and polycaprolactone (PCL) lining was fabricated by the method of polymer impregnating to produce HA scaffold coated with PCL lining. Subsequently, the composite scaffolds were deposited with biomimetic coating for improving the bioactivity. The HA/PCL composite scaffolds with improved mechanical property and bioactivity is expected to be a promising bone substitute in tissue engineering applications.

  11. Preparation of bioactive porous HA/PCL composite scaffolds

    Science.gov (United States)

    Zhao, J.; Guo, L. Y.; Yang, X. B.; Weng, J.

    2008-12-01

    Porous hydroxyapatite (HA) bioceramic scaffold has been widely attracted the attention to act as a three-dimensional (3D) template for cell adhesion, proliferation, differentiation and thus promoting bone and cartilage regeneration because of its osteoinduction. However, the porous bioceramic scaffold is fragile so that it is not suitable to be applied in clinic for bone repair or replacement. Therefore, it is significant to improve the mechanical property of porous HA bioceramics while the interconnected structure is maintained for tissue ingrowth in vivo. In the present research, a porous composite scaffold composed of HA scaffold and polycaprolactone (PCL) lining was fabricated by the method of polymer impregnating to produce HA scaffold coated with PCL lining. Subsequently, the composite scaffolds were deposited with biomimetic coating for improving the bioactivity. The HA/PCL composite scaffolds with improved mechanical property and bioactivity is expected to be a promising bone substitute in tissue engineering applications.

  12. Screening pharmaceutical preparations containing extracts of turmeric rhizome, artichoke leaf, devil's claw root and garlic or salmon oil for antioxidant capacity.

    Science.gov (United States)

    Betancor-Fernández, Alejandro; Pérez-Gálvez, Antonio; Sies, Helmut; Stahl, Wilhelm

    2003-07-01

    Pharmaceutical preparations derived from natural sources such as vegetables often contain compounds that contribute to the antioxidant defence system and apparently play a role in the protection against degenerative diseases. In the present study, commercial preparations containing extracts of turmeric, artichoke, devil's claw and garlic or salmon oil were investigated. The products were divided into fractions of different polarity, and their antioxidant activity was determined using the Trolox equivalent antioxidant capacity (TEAC) assay. This test is based on the efficacy of the test material to scavenge 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) derived radicals. Total phenols were determined in all fractions as well as specific carotenoids in the most lipophilic fraction to assess their contribution to the antioxidant activity. For comparison, the radical scavenging effect of selected constituents of the extracts such as curcumin, luteolin, kaempferol, chlorogenic acid, harpagoside, beta-carotene and alpha-tocopherol was investigated and compared with that of Trolox. Curcumin, luteolin, kaempferol, chlorogenic acid and beta-carotene showed an antioxidant activity superior to Trolox in the TEAC assay; harpagoside was barely active. All fractions of the turmeric extract preparation exhibited pronounced antioxidant activity, which was assigned to the presence of curcumin and other polyphenols. The antioxidant activity corresponding to the artichoke leaf extract was higher in the aqueous fractions than in the lipophilic fractions. Similarly, devil's claw extract was particularly rich in water-soluble antioxidants. Harpagoside, a major compound in devil's claw, did not contribute significantly to its antioxidant activity. The antioxidant capacity of the garlic preparation was poor in the TEAC assay. That of salmon oil was mainly attributed to vitamin E, which is added to the product for stabilization. In all test preparations, the antioxidant

  13. A Novel Method for Preparing Polyurethane Based Conductive Composites with Low Percolation Threshold

    Institute of Scientific and Technical Information of China (English)

    Ji Wen HU; Ming Wei LI; Ming Qiu ZHANG; Gen Shui CHENG; Min Zhi RONG

    2004-01-01

    A novel method for preparing conductive carbon black filled polymer composites with low percolation threshold from polyurethane emulsion are reported in this paper.The experimental results indicate that with a rise in carbon black concentration the insulator-conductor transition in the emulsion blended composites occurs at 0.8-1.4vol%.In contrast, the solution blended composites exhibit drastic increase in conductivity at conducting filler fraction as high as 12.3-13.3vol%.It is demonstrated that the composites microstructure rather than chemical structure of the matrix polymer predominantly determines the electrical conduction performance of the composites.

  14. Modelling and analysis of CVD processes in porous media for ceramic composite preparation

    NARCIS (Netherlands)

    Lin, Y.S.; Burggraaf, A.J.

    1991-01-01

    A continuum phenomenological model is presented to describe chemical vapour deposition (CVD) of solid product inside porous substrate media for the preparation of reinforced ceramic-matrix composites [by the chemical vapour infiltration (CVI) process] and ceramic membrane composites (by a modified C

  15. Carbon-based Composite Electrodes: Preparation, Characterization and Application in Electroanalysis

    NARCIS (Netherlands)

    Corb, I.; Manea, F.; Radovan, C.; Pop, A.; Burtica, G.; Malchev, P.G.; Picken, S.J.; Schoonman, J.

    2007-01-01

    Electrodes based on carbon, i.e., expanded graphite (20%, wt.)-epoxy composite (20EG-Epoxy) and expanded graphite (20%, wt.)-polystyrene composite (20EG-PS) have been prepared, characterized using scanning electron microscopy (SEM) and cyclic voltammetry (CV), and tested as anodic sensors. The elect

  16. Preparation and thermal behaviour of a series of liquid wood-polypropylene composites

    Science.gov (United States)

    Blanco, Ignazio; Cicala, Gianluca; Latteri, Alberta; Saccullo, Giuseppe

    2016-05-01

    Liquid Wood (a mixture of cellulose, hemp, fax and lignin) was used to prepare, by mechanical mixing followed by thermal extrusion, blends of various Polypropylene (PP)/Liquid Wood ratios. To verify if and how much the composition of the obtained composites affects their thermal properties Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA) experiments were carried out.

  17. Systematic approach to preparing ceramic-glass composites with high translucency for dental restorations.

    Science.gov (United States)

    Yoshimura, Humberto N; Chimanski, Afonso; Cesar, Paulo F

    2015-10-01

    Ceramic composites are promising materials for dental restorations. However, it is difficult to prepare highly translucent composites due to the light scattering that occurs in multiphase ceramics. The objective of this work was to verify the effectiveness of a systematic approach in designing specific glass compositions with target properties in order to prepare glass infiltrated ceramic composites with high translucency. First it was necessary to calculate from literature data the viscosity of glass at the infiltration temperature using the SciGlass software. Then, a glass composition was designed for targeted viscosity and refractive index. The glass of the system SiO2-B2O3-Al2O3-La2O3-TiO2 prepared by melting the oxide raw materials was spontaneously infiltrated into porous alumina preforms at 1200°C. The optical properties were evaluated using a refractometer and a spectrophotometer. The absorption and scattering coefficients were calculated using the Kubelka-Munk model. The light transmittance of prepared composite was significantly higher than a commercial ceramic-glass composite, due to the matching of glass and preform refractive indexes which decreased the scattering, and also to the decrease in absorption coefficient. The proposed systematic approach was efficient for development of glass infiltrated ceramic composites with high translucency, which benefits include the better aesthetic performance of the final prosthesis. Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  18. Preparation and characterization of bio-composite PEEK/nHA

    Science.gov (United States)

    Jin, Y. S.; Bian, C. C.; Zhang, Z. Q.; Zhao, Y.; Yang, L.

    2017-01-01

    PEEK/nHA composite material, with excellent mechanical property as polyetheretherketone (PEEK) and biological activity as hydroxyapatite (HA), has attracted wide attention of medical experts and materials science experts. The addition of hydroxyapatite was the decisive factor for biological activity in PEEK/nHA composite. In this paper, acicular nanohydroxyapatite was prepared by chemical precipitation method with Ca(NO3)2, (NH4)2HPO4 as raw material; PEEK/nHA composite was prepared by solution blending and vacuum sintering method. The composite was characterized with FT-IR, XRD, DSC, TG and mechanical property test. Results showed that the composite has good thermal stability and compressive property when the mass ratio of PEEK to nHA is 10:3; and high nHA content can improve the biological activity of the composite, which can meet the basic requirements for bone tissue engineering scaffold.

  19. Influence of surface preparation on fusion bonding of thermoplastic composites

    NARCIS (Netherlands)

    Sacchetti, F.; Grouve, W.J.B.; Warnet, L.L.; Fernandez Villegas, I.

    2015-01-01

    Carbon fibre-reinforced thermoplastic composites laminates (CFRP) meant for fusion bonding have been moulded using different release media. The potential contamination of the laminate surface by the release media and its effect on the mechanical performance of fusion bonded joints was studied. The p

  20. Microwave Irradiation Assisted Preparation of Chitosan Composite Microsphere for Dye Adsorption

    OpenAIRE

    Xiaoyu Chen; Lindun He

    2017-01-01

    Chitosan-activated carbon composite microspheres were prepared by emulsion cross-linking method and its adsorption properties for methyl orange were studied. Chitosan solution was mixed with activated carbon powder and then chitosan was cross-linked by epichlorohydrin under microwave irradiation. SEM photos show that the composite microspheres have diameters of 200–400 μm and activated carbon powder dispersed on the surface of composite microsphere. FTIR spectrum indicates chitosan is success...

  1. NUMERICAL SIMULATION OF EXTRUSION OF COMPOSITE POWDERS PREPARED BY HIGH ENERGY MILLING

    Institute of Scientific and Technical Information of China (English)

    X.Q. Li; W.P. Chen; W. Xia; Q.L. Zhu; Y.Y. Li; E.D. Wang

    2004-01-01

    Based on the characteristic of high energy milling and the micromechanics of composite material, a plastic constitutive equation is implemented for milled composite powders. To check the equation, the extrusion of Ti/Al composite powders prepared by high energy milling was simulated. It was from the numerical analysis that the predicted extrusion pressure mounted up with milling time and extrusion ratio increasing,which was perfect agreement with experimental results.

  2. Preparation of Desirable Porous Cell Structure Polylactide/Wood Flour Composite Foams Assisted by Chain Extender

    Directory of Open Access Journals (Sweden)

    Youyong Wang

    2017-08-01

    Full Text Available Polylactide (PLA/wood flour composite foam were prepared through a batch foaming process. The effect of the chain extender on the crystallization behavior and dynamic rheological properties of the PLA/wood flour composites were investigated as well as the crystal structure and cell morphology of the composite foams. The incorporation of the chain extender enhanced the complex viscosity and storage modulus of PLA/wood flour composites, indicating the improved melt elasticity. The chain extender also led to a decreased crystallization rate and final crystallinity of PLA/wood flour composites. With an increasing chain extender content, a finer and more uniform cell structure was formed, and the expansion ratio of PLA/wood flour composite foams was much higher than without the chain extender. Compared to the unfoamed composites, the crystallinity of the foamed PLA/wood flour composites was improved and the crystal was loosely packed. However, the new crystalline form was not evident.

  3. Simultaneous determination of aliskiren and hydrochlorothiazide from their pharmaceutical preparations using a validated stability-indicating MEKC method.

    Science.gov (United States)

    Sangoi, Maximiliano S; Wrasse-Sangoi, Micheli; Oliveira, Paulo R; Rolim, Clarice M B; Steppe, Martin

    2011-08-01

    A stability-indicating MEKC method was developed and validated for the simultaneous determination of aliskiren (ALI) and hydrochlorothiazide (HCTZ) in pharmaceutical formulations using ranitidine as an internal standard (IS). Optimal conditions for the separation of ALI, HCTZ and its major impurity chlorothiazide (CTZ), IS and degradation products were investigated. The method employed 47 mM Tris buffer and 47 mM anionic detergent SDS solution at pH 10.2 as the background electrolyte. MEKC method was performed on a fused-silica capillary (40 cm) at 28°C. Applied voltage was 26 kV (positive polarity) and photodiode array (PDA) detector was set at 217 nm. The method was validated in accordance with the ICH requirements. The method was linear over the concentration range of 5-100 and 60-1200 μg/mL for HCTZ and ALI, respectively (r(2) >0.9997). The stability-indicating capability of the method was established by enforced degradation studies combined with peak purity assessment using the PDA detection. Precision and accuracy evaluated by RSD were lower than 2%. The method proved to be robust by a fractional factorial design evaluation. The proposed MEKC method was successfully applied for the quantitative analysis of ALI and HCTZ both individually and in a combined dosage tablet formulation to support the quality control.

  4. Patients' appropriateness, acceptability, usability and preferences for pharmaceutical preparations: Results from a literature review on clinical evidence.

    Science.gov (United States)

    Drumond, Nélio; van Riet-Nales, Diana A; Karapinar-Çarkit, Fatma; Stegemann, Sven

    2017-04-15

    Patients play an important role in achieving the desired therapeutic outcomes, as they are frequently responsible for their own medication management. To facilitate drug administration and overcome medication issues, the patients' needs and preferences should be considered in the pharmaceutical drug product design. With the aim to evaluate the current state of evidence for patient appropriateness, acceptability, usability and preference for aspects of this design, a literature search was performed. Comparative clinical studies that assessed such endpoints for different patient populations were included and summarized descriptively. The search identified 45 publications that met the inclusion criteria. A detailed analysis of the studies identified two main areas investigating either packaging design (n=10) or dosage form design (n=35). Studies on packaging design showed preferences for wing top and screw cap openings, push-through blisters and suppositories with slide system. Additionally, child-resistant containers should be avoided concerning specific patient populations. Regarding dosage form design, sprinkles and minitablets were the most preferred in studies involving young patients, while preferences varied considerably depending on route of administration and geographical region in studies with adult patients. Review of the methodology used in the studies revealed that ten studies had used well-defined protocols and observational endpoints to investigate patient appropriateness. Studies focusing on methodology for testing the appropriateness and usability of drug products by patients were not found. In conclusion, more interdisciplinary scientific efforts are required to develop and increase research in understanding patient needs and preferences.

  5. A New Spectrophotometric Method for Determination of Selenium in Cosmetic and Pharmaceutical Preparations after Preconcentration with Cloud Point Extraction

    Directory of Open Access Journals (Sweden)

    Mohammad Hosein Soruraddin

    2011-01-01

    Full Text Available A simple, rapid, and sensitive spectrophotometric method for the determination of trace amounts of selenium (IV was described. In this method, all selenium spices reduced to selenium (IV using 6 M HCl. Cloud point extraction was applied as a preconcentration method for spectrophotometric determination of selenium (IV in aqueous solution. The proposed method is based on the complexation of Selenium (IV with dithizone at pH < 1 in micellar medium (Triton X-100. After complexation with dithizone, the analyte was quantitatively extracted to the surfactant-rich phase by centrifugation and diluted to 5 mL with methanol. Since the absorption maxima of the complex (424 nm and dithizone (434 nm overlap, hence, the corrected absorbance, Acorr, was used to overcome the problem. With regard to the preconcentration, the tested parameters were the pH of the extraction, the concentration of the surfactant, the concentration of dithizone, and equilibration temperature and time. The detection limit is 4.4 ng mL-1; the relative standard deviation for six replicate measurements is 2.18% for 50 ng mL-1 of selenium. The procedure was applied successfully to the determination of selenium in two kinds of pharmaceutical samples.

  6. A rapid and sensitive resonance Rayleigh scattering spectra method for the determination of quinolones in human urine and pharmaceutical preparation.

    Science.gov (United States)

    Qiao, Man; Wang, Yaqiong; Liu, Shaopu; Liu, Zhongfang; Yang, Jidong; Zhu, Jinghui; Hu, Xiaoli

    2015-03-01

    A new method based on resonance Rayleigh scattering (RRS) was proposed for the determination of quinolones (QNS) at the nanogram level. In pH 3.3-4.4 Britton-Robinson buffer medium, quinolones such as ciprofloxacin, pipemidic acid (PIP), lomefloxacin (LOM), norfloxacin (NOR) and sarafloxacin (SAR) were protonated and reacted with methyl orange (MO) to form an ion-pair complex, which then further formed a six-membered ring chelate with Pd(II). As a result, new RRS spectra appeared and the RRS intensities were enhanced greatly. RRS spectral characteristics of the MO-QNS-Pd(II) systems, the optimum conditions for the reaction, and the influencing factors were investigated. Under optimum conditions, the scattering intensity (∆I) increments were directly proportional to the concentration of QNS with in certain ranges. The method had high sensitivity, and the detection limits (3σ) ranged from 6.8 to 12.6 ng/mL. The proposed method had been successfully applied for the determination of QNS in pharmaceutical formulations and human urine samples. In addition, the mechanism of the reaction system was discussed based on IR, absorption and fluorescence spectral studies. The reasons for the enhancement of scattering spectra were discussed in terms of fluorescence-scattering resonance energy transfer, hydrophobicity and molecular size.

  7. Nanosilica reinforced epoxy floor coating composites: preparation and thermophysical characterization

    Directory of Open Access Journals (Sweden)

    Mir Mohammad Alavi Nikje

    2012-01-01

    Full Text Available In this study, flooring grade epoxy/nanoSiO2 nanocomposites were prepared by in-situ polymerization method. Nano silica was treated by coupling agent in order to surface treating and introducing of reactive functional groups to achieving adequate bonding between polar inorganic nano particles and epoxy organic polymer. γ-Aminopropyltriethoxysilane (Amino A-100 was used as an effective and commercially available coupling agent and nano silica treated in acetone media. SEM observations of cured samples revealed that the nano silica was completely dispersed into polymer matrix into nanoscale particles. Thermal and physical properties of prepared samples were investigated and data showed improvements in physical and mechanical properties of the flooring samples in comparison with unfilled resin.

  8. Preparation and characterization of photoactive composite kaolinite/TiO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Mamulova Kutlakova, K., E-mail: katerina.mamulova.kutlakova@vsb.cz [Nanotechnology Centre, VSB-Technical University of Ostrava, 17. listopadu 15/2172, 708 33 Ostrava-Poruba (Czech Republic); Tokarsky, J. [Nanotechnology Centre, VSB-Technical University of Ostrava, 17. listopadu 15/2172, 708 33 Ostrava-Poruba (Czech Republic); Kovar, P. [Czech Technological Centre for Inorganic Pigments a.s., Prerov (Czech Republic); Vojteskova, S. [Nanotechnology Centre, VSB-Technical University of Ostrava, 17. listopadu 15/2172, 708 33 Ostrava-Poruba (Czech Republic); Kovarova, A. [Czech Technological Centre for Inorganic Pigments a.s., Prerov (Czech Republic); Smetana, B. [Department of Physical Chemistry and the Theory of Technological Processes, VSB-Technical University of Ostrava, 17. listopadu 15/2172, 708 33 Ostrava-Poruba (Czech Republic); Kukutschova, J.; Capkova, P.; Matejka, V. [Nanotechnology Centre, VSB-Technical University of Ostrava, 17. listopadu 15/2172, 708 33 Ostrava-Poruba (Czech Republic)

    2011-04-15

    Preparation of nanocomposite kaolinite/TiO{sub 2}, using hydrolysis of titanyl sulfate in the presence of kaolin was addressed. A variable (kaolin)/(titanyl sulfate) ratio has been used in order to achieve the desired TiO{sub 2} content in prepared nanocomposites. Calcination of the composites at 600 deg, C led to the transformation of the kaolinite to metakaolinite and to origination of metakaolinite/TiO{sub 2} composites. The prepared samples were investigated using X-ray fluorescence spectroscopy, X-ray powder diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, thermogravimetry and diffuse reflectance spectroscopy in the UV-VIS region. Structural ordering of TiO{sub 2} on the kaolinite particle surface was modeled using empirical force field atomistic simulations in the Material Studio modeling environment. Photodegradation activity of the composites prepared was evaluated by the discoloration of Acid Orange 7 aqueous solution.

  9. The preparation of dental glass-ceramic composites with controlled fraction of leucite crystals

    Directory of Open Access Journals (Sweden)

    Martina Mrázová

    2008-06-01

    Full Text Available This work is dealing with synthesis of leucite powder, which can be used for the preparation of dental glassceramic composites by subsequent thermal treatment. Newly developed procedure is based on preparation of dental raw material as a mixture of two separate compounds: the crystalline leucite powder prepared at relatively low temperature and a commercial matrix powder.Hydrothermal synthesis of tetragonal leucite particles (KAlSi2O6 with the average size of about 3 μm was developed in our laboratory. The leucite dental raw material was prepared by mixing of 20 wt.% of synthetic tetragonal leucite with commercial matrix. Dental composites were prepared from the dental raw material by uniaxial pressing and firing up to 960°C. Dilatometric measurements confirmed that the coefficient of thermal expansion increased by 32% when 20 wt.% of the tetragonal leucite was added into the basic matrix. In addition, it was showed that the synthesized leucite powder was suitable for the preparation of leucite composites with controlled coefficient of thermal expansion. High value of the thermal expansion coefficient enables application of prepared composite in metal-ceramics restorations.

  10. Continuous Preparation of Copper/Carbon Nanotube Composite Films and Application in Solar Cells.

    Science.gov (United States)

    Luo, Xiao Gang; Le Wu, Min; Wang, Xiao Xia; Zhong, Xin Hua; Zhao, Ke; Wang, Jian Nong

    2016-02-08

    Realizing the continuous and large scale preparation of particle/carbon nanotube (CNT) composites with enhanced functionalities, and broad applications in energy conversion, harvesting, and storage systems, remains as a big challenge. Here, we report a scalable strategy to continuously prepare particle/CNT composite films in which particles are confined by CNT films. This is achieved by the continuous condensation and deposition of a cylindrical assembly of CNTs on a paper strip and the in situ incorporation of particles during the layer-by-layer deposition process. A Cu/CNT composite film is prepared as an example; such a film exhibits very high power conversion efficiency when it is used as a counter electrode in a solar cell, compared with previous materials under otherwise identical conditions. The proposed method can be extended to other CNT-based composite films with excellent functionalities for wide applications.

  11. Preparation of cast aluminum alloy-mica particle composites

    Science.gov (United States)

    Deonath, MR.; Bhat, R. T.; Rohatgi, P. K.

    1980-01-01

    A method for making aluminum-mica particle composites is presented in which mica particles are stirred in molten aluminum alloys followed by casting in permanent molds. Magnesium is added either as an alloying element or in the form of pieces to the surface of the alloy melts to disperse up to 3 wt% mica powders in the melts and to obtain high recoveries of mica in the castings. The mechanical properties of the aluminum alloy-mica composite decrease with increasing mica content; however, even at 2.2% it has a tensile strength of 14.22 kg/sq mm with 1.1% elongation, a compression strength of 42.61 kg/sq mm, and an impact strength of 0.30 kgm/sq cm. Cryogenic and self-lubricating bearing are mentioned applications.

  12. Composite oxygen electrode and method for preparing same

    DEFF Research Database (Denmark)

    2010-01-01

    The present invention provides a composite oxygen electrode, comprising - a porous backbone structure comprising two separate but percolating phases, the first phase being an electronic conducting phase, the second phase being an oxide ion conducting phase; and - an electrocatalytic layer...... on the surface of said backbone structure, wherein said electrocatalytic layer comprises first and second nanoparticles, wherein the first and second particles are randomly distributed throughout said layer. The present invention further comprises a method of producing the above composite electrode, comprising...... the steps of: - forming a porous backbone structure comprising two separate but percolating phases, the first phase being an electronic conducting phase, the second phase being an oxide ion conducting phase; and - applying an electrocatalytic layer on the surface of said backbone structure, wherein said...

  13. Preparation of cast aluminum alloy-mica particle composites

    Science.gov (United States)

    Deonath, MR.; Bhat, R. T.; Rohatgi, P. K.

    1980-01-01

    A method for making aluminum-mica particle composites is presented in which mica particles are stirred in molten aluminum alloys followed by casting in permanent molds. Magnesium is added either as an alloying element or in the form of pieces to the surface of the alloy melts to disperse up to 3 wt% mica powders in the melts and to obtain high recoveries of mica in the castings. The mechanical properties of the aluminum alloy-mica composite decrease with increasing mica content; however, even at 2.2% it has a tensile strength of 14.22 kg/sq mm with 1.1% elongation, a compression strength of 42.61 kg/sq mm, and an impact strength of 0.30 kgm/sq cm. Cryogenic and self-lubricating bearing are mentioned applications.

  14. Nanostructured Sulfide Composite Coating Prepared by Atmospheric Plasma Spraying

    Institute of Scientific and Technical Information of China (English)

    关耀辉

    2006-01-01

    Nanostructured FeS-SiC coating was deposited by atmospheric plasma spraying (APS). The microstructure and phase composition of the coating were characterized with SEM and XRD, respectively. In addition, the size distribution of the reconstituted powders and the porosity of the coating have been measured. It was found that the reconstitiuted powers with sizes in the range of 20 to 80 μm had excellent flowability and were suitable for plasma spraying process. The assprayed FeS-SiC composite coating exhibited a bimodal distribution with small grains (30~80nm) and large grains (100~200nm). The coating was mainly composed of FeS and SiC, a small quantity of Fe1-x S and oxide were also found. The porosity of the coating was approximately 19 %.

  15. Preparation and pharmaceutical evaluation of acetaminophen nano-fiber tablets: Application of a solvent-based electrospinning method for tableting.

    Science.gov (United States)

    Hamori, Mami; Nagano, Kana; Kakimoto, Sayaka; Naruhashi, Kazumasa; Kiriyama, Akiko; Nishimura, Asako; Shibata, Nobuhito

    2016-03-01

    In this study, we developed nano-fiber-based tablets with acetaminophen (AAP; LogPow=0.51) for controlled-release delivery systems and evaluated in vitro drug dissolution and in vivo pharmacokinetics in rats. Nano-fibers made from methacrylic acid copolymer S (MAC; EUDRAGIT S100) and containing AAP were prepared using a solvent-based electrospinning (ES) method. In vitro dissolution rate profiles of AAP showed tableting pressure-dependent decreases and pH-dependent increases. The results of tablet tracking by X-ray irradiation showed tablets based on MAC nano-fibers did not disintegrate in the upper intestinal lumen and had the properties of a long-term-acting tablet. In addition, the in vitro release profiles of AAP from nano-fiber tablets prepared by dissolving MAC with AAP (NFT), nano-fiber tablets prepared by adsorbing AAP to drug-free MAC nano-fibers (NFTadso), and tablets prepared by adsorbing half the amount of AAP to MAC nano-fibers containing the remaining amount of AAP (NFThalf) showed independent controlled-release aspects of AAP compared with physical mixture tablets (PMT). In vivo pharmacokinetic studies in rats after intraduodenal administration of 14 mg/rat AAP in NFT, NFTadso, and NFThalf demonstrated that all these tablets based on MAC nano-fibers showed sustained-release profiles compared with PMT, and showed ultra-sustained release properties for AAP. These new tablets based on MAC nano-fibers did not disintegrate in the intestine in the lower pH region, and the tablets could regulate the release of AAP in a pH-dependent manner. The ES method is a useful technique to prepare nano-fibers and showed promising results as an oral delivery system for sustained-release regulation. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  16. Preparation of Rare-Earth Composite Ferrite Magnetic Fluid

    Institute of Scientific and Technical Information of China (English)

    蒋荣立; 刘永超; 刘守坤; 鞠明礼

    2004-01-01

    Water-based rare-earth ferrite (RexFe3-xO4)magnetic fluids were prepared by chemical co-precipitation method. The result shows that saturation magnetic intensity of ferrite magnetic fluids can be improved by adding Dy3+ and the saturation magnetic intensity will reach the highest if n(Fe)∶n(Dy3+)=30∶1. The modification and formation mechanism of RexFe3-xO4 particles is discussed in detail. The physicochemical properties are investigated by the Gouy magnetic balance, IR, TEM, XRD, and EDX, etc.

  17. Preparation research of Nano-SiC/Ni-P composite coating under a compound field

    Science.gov (United States)

    Zhou, H. Z.; Wang, W. H.; Gu, Y. Q.; Liu, R.; Zhao, M. L.

    2016-07-01

    In this paper, the preparation process of Ni-P-SiC composite coatings on 45 steel surfaces with the assistance of magnetic and ultrasound fields was researched. The influence of external field on the surface morphology and performance of the composite layer is also discussed. Experimental results showed that when prepared under magnetic and ultrasonic fields, composite layers are significantly more dense and uniform than coatings made without external fields. Nano-SiC particles, dispersed uniformly in the layer, significantly improve the hardness of the composite layer, and the composite layer under the external field had the highest hardness at 680 HV The external fields can also accelerate deposition and increase the thickness of the layer. Compared to layers processed without the assistance of external fields, the thickness of the layers increased by nearly ten µm.

  18. Photoactive composite films prepared from mixtures of polystyrene microgel dispersions and poly(3-hexylthiophene) solutions.

    Science.gov (United States)

    Chen, Mu; Cui, Zhengxing; Edmondson, Steve; Hodson, Nigel; Zhou, Mi; Yan, Junfeng; O'Brien, Paul; Saunders, Brian R

    2015-11-14

    Whilst polystyrene microgels belong to the oldest family of microgel particles, their behaviours when deposited onto substrates or prepared as composites have received little attention. Because polystyrene microgels are solvent-swellable, and inherently colloidally stable, they are well suited to form composites with conjugated polymers. Here, we investigate the morphology and light absorption properties of spin coated composite films prepared from mixed dispersions of polystyrene microgels and poly(3-hexylthiophene) (P3HT) for the first time. We compare the morphologies of the composite films to spin coated microgel films. The films were studied using optical microscopy, SEM, AFM, wide-angle X-ray diffraction and UV-visible spectroscopy. The films contained flattened microgel particles with an aspect ratio of ∼10. Microgel islands containing hexagonally close packed particles were evident for both the pure microgel and microgel/P3HT composite films. The latter were electrically conducting. The composite film morphology was dependent on the microgel and P3HT concentration used for film preparation and a morphology phase diagram was constructed. The P3HT phase acted as an electrically conducting cement and increased the robustness of the films to solvent washing. The composite films were photoactive due to the P3HT component. The absorbance for the films was tuneable and increased linearly with both microgel and P3HT concentration. The results of the study should apply to other organic swellable microgel/conjugated polymer combinations and may lead to new colloidal composites for future optoelectronic applications.

  19. Use of multiresponse statistical techniques to optimize the separation of diosmin, hesperidin, diosmetin and hesperitin in different pharmaceutical preparations by high performance liquid chromatography with UV-DAD.

    Science.gov (United States)

    Sammani, Mohamad Subhi; Clavijo, Sabrina; Portugal, Lindomar; Suárez, Ruth; Seddik, Hassan; Cerdà, Víctor

    2017-05-15

    A new method for the separation and determination of four flavonoids: hesperidin (HES), diosmin (DIO), hesperitin (HTIN), and diosmetin (DTIN) in pure form and pharmaceutical formulations has been developed by using high performance liquid chromatography (HPLC) with UV-DAD detection. Multivariate statistics (2(k) full factorial and Box Behnken Designs) has been used for the multiresponse optimization of the chromatographic separation, which was completed in 22min, and carried out on a symmetry® C18 column (250×3mm; 5µm) as stationary phase. Separation was conducted by gradient elution mode using a mixture of methanol, acetonitrile and water pH: 2.5 (CH3COOH), as mobile phase. Analytes were separated setting the column at 22°C, with a flow rate of 0.58mLmin(-1) and detected at 285nm. Under the optimized conditions, the flavonoids showed retention times of: 8.62, 11.53, 18.55 and 19.94min for HES, DIO, HTIN and DTIN, respectively. Limits of detection and quantification were <0.0156µgmL(-1) and <0.100µgmL(-1), respectively. Linearity was achieved with good correlation coefficients values (r(2)=0.999; n=5). Intra-day and inter-day precision were found to be less than 3.44% (n=7). Finally, the proposed method was successfully applied to determine the target flavonoids in pharmaceutical preparations with satisfactory recoveries (between 95.2% and 107.9%), demonstrating that should also find application in the quality control, as well as in the pharmacokinetic studies of these drugs.

  20. Mechanical, dielectric and optical assessment of glass composites prepared using milling technique

    Indian Academy of Sciences (India)

    Gurbinder Kaur; G Pickrell; V Kumar; O P Pandey; K Singh; S K Arya

    2015-08-01

    In the present investigation, mechanical and spectroscopic properties of glass composites have been investigated. The glass composites have been prepared by the milling technique instead of using any filler particle. Due to the presence of different alkaline earth modifiers in composites, marked difference in their strength and optical properties is observed. The band gap, Urbach energy and the extinction coefficient of the glass composites have been calculated using UV–visible spectroscopy. Moreover, the real and imaginary dielectric constants have also been calculated for all the composites in addition to the Weibull statistics and cumulative probability of failure. The results have been discussed in light of comparison between the glass composites and the individual glasses. The mechanical and optical properties indicate marked effect on the mechanical strength, band gap and Urbach energy for glass composites as compared with the individual glasses.

  1. Preparation, tribological properties and biocompatibility of fluorinated graphene/ultrahigh molecular weight polyethylene composite materials

    Science.gov (United States)

    Xu, L.; Zheng, Y.; Yan, Z.; Zhang, W.; Shi, J.; Zhou, F.; Zhang, X.; Wang, J.; Zhang, J.; Liu, B.

    2016-05-01

    Fluorinated graphene (FG)/ultra-high molecular weight polyethylene (UHMWPE) composites were successfully prepared by ultrasonic dispersion and liquid thermoforming method. The mechanical and tribological properties of pure UHMWPE and FG/UHMWPE composites were investigated using micro-hardness tester and high-speed reciprocating friction tester. The results showed that: adding FG could not only increase the micro-hardness of the composites, but also decrease the wear volume of the composite significantly. The friction coefficients of the composites were also reduced with the increasing of FG content. In addition, the MC3T3-E1 cells adhered and grew well on the surface of the FG/UHMWPE composites as observed by SEM and fluorescence microscope, indicating the addition of FG did not affect the morphology and activity of the cells. The FG/UHMWPE composites exhibited excellent mechanical properties, tribological properties and biocompatibility, which could be used as the potential artificial joint replacement material.

  2. Preparation of silver-carbon nanotubes composites with plasma electrochemistry

    Science.gov (United States)

    Hoefft, Oliver; Lohmann, Lara; Olschewski, Mark; Endres, Frank

    2016-09-01

    Plasma electrochemistry is a powerful tool to generate free nanoparticles in aqueous solutions and especially in ionic liquids (ILs). Due to their very low vapour pressure, ionic liquids can be employed under vacuum conditions as fluid substrates or solvents. Thus, ionic liquids are well suitable electrolytes for plasma electrochemical processes delivering stable and homogeneous plasmas. We have shown that free copper and germanium nanoparticles can be obtained in ILs by applying a plasma as a mechanically contact-free electrode. Here we present our results using an argon plasma for the electrochemical synthesis of silver on pure and pre-treated multiwall carbon nanotubes (MWCNTs) in 1-ethyl-3-methylimidazolium dicyanamide. For the pre-treatment of the MWCNTS we have used a dielectric barrier discharge plasma (DBD) at atmospheric pressure. For the untreated MWCNTs we have found a formation of free silver nanoparticles between, on and in the vicinity of the carbon nanotubes. In case of the plasma treated MWCNTs a silver-carbon nanotubes composite is formed. Thus, the treatment of the MWCNTs obviously has a great influence on the deposit. Therefore we additionally have investigated the influence of the DBD on the chemical composition of the MWCNTs surface with X-Ray Photoelectron Spectroscopy.

  3. Preparation, processing and properties of lignosulfonate-flax composite boards.

    Science.gov (United States)

    Privas, Edwige; Navard, Patrick

    2013-03-01

    Hemp, hay, straw for animal litters, raffia and sisal stems, abaca and jute bleached pulp fibres, miscanthus stems and flax fibres were mixed to lignosulfonate at 70% filler concentration and compressed in the form of 5 cm-thick boards. Flax was found to give the best mechanical properties measured in bending mode and used for all tests. Several methods able to improve adhesion between matrix and flax fibres were studied. A treatment of flax fibres with NaOH-water was found to decrease the mechanical properties of composites. Ethanol or dichloromethane solvents that are known to dewax flax fibre surfaces improve the mechanical properties of final board. The addition of pectin to the lignosulfonate matrix was found to improve the mechanical properties in the same order of magnitude as with the ethanol treatment. Both methods improve the flexural strength by 60% while keeping the elastic modulus constant. Mechanical improvement shows that these two methods are increasing the lignosulfonate/flax fibre interfacial adhesion. The best compositions have mechanical properties above the normalized minimum required for wood-based boards.

  4. Preparation and Characterization of Rare Earth Composite Materials Radiating Far Infrared for Activating Liquefied Petroleum Gas

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Rare earth composite materials radiating far-infrared rays were prepared according to far infrared absorption spectrum of main component in liquefied petroleum gas (LPG). The composite materials were characterized by scanning electron microscope (SEM), X-ray diffraction (XRD), and Fourier transformed infrared spectra(FTIR). The results show that after the composite materials were calcined at 873 K for 4 h, FTIR spectra of rare earth composite materials display two new peaks at 1336 and 2926 cm-1 available for activating LPG.

  5. Novel titanium particles reinforced Zr-based bulk metallic glass composites prepared by infiltration casting

    Institute of Scientific and Technical Information of China (English)

    Cuimei Zhang; Xidong Hui; Meiling Wang; Guoliang Chen

    2008-01-01

    A novel Ti/Zr41.2Ti13.8Cu12.5Ni10.0Be22.5 composite was successfully prepared by infiltrating the melt into sintered Ti preform. It shows that the introduction of Ti particles into the composite results in an increase in elastic strain to 3% and an enhancement of the strength up to 2.1 GPa. High specific strength has been obtained because of the decrease in density of the composite. It is suggested that an improvement in the mechanical properties of the composite may be attributed to the generation of multiple shear bands and some deformation in the Ti particles.

  6. The Preparation of Soft Magnetic Composites Based on FeSi and Ferrite Fibers

    Science.gov (United States)

    Strečková, Magdaléna; Fáberová, Mária; Bureš, Radovan; Kurek, Pavel

    2016-12-01

    The fields of soft magnetic composites and powder metallurgy technologies have a powerful potential to redesign the way of electric motor preparation, and will continue to grow for years to come. A design of the novel soft microcomposite material composed of spherical FeSi particles and Ni0.3Zn0.7Fe2O4 ferrite nanofibers is reported together with a characterization of basic mechanical and electrical properties. The needle-less electrospinning method was used for a preparation of Ni0.3Zn0.7Fe2O4 ferrite nanofibers, which has a spinel-type crystal structure as verified by XRD and TEM analysis. The dielectric coating was prepared by mixing of nanofibers with glycerol and ethanol because of safe manipulation with fumed fibers and homogeneous distribution of the coating around the FeSi particle surface. The final microcomposite samples were prepared by a combination of the traditional PM compaction technique supplemented with a conventional sintering process of the prepared green compacts. The composition and distribution of the secondary phase formed by the spinel ferrite fibers were examined by SEM. It is demonstrated that the prepared composite material has a tight arrangement without any significant porosity, which manifest itself through superior mechanical properties (high mechanical hardness, Young modulus, and transverse rupture strength) and specific electric resistivity compared to the related composite materials including resin as the organic binder.

  7. Characterization and behavior of composite hydrogel prepared from bamboo shoot cellulose and β-cyclodextrin.

    Science.gov (United States)

    Liu, Shumin; Luo, Wenchao; Huang, Huihua

    2016-08-01

    Carboxymethyl cellulose was derived from bamboo shoot cellulose via chemical modification and was prepared into composite hydrogels by cross-linkage with β-cyclodextrin using epichlorohydrin as crossing agent. The structure of the prepared hydrogel was characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis and scanning electron microscopy. The results showed that the prepared composite hydrogel was sensitive to surrounding changes in pH value, temperature and ionic strength. Under the surroundings of low temperatures and high pH values, the prepared hydrogel had significant high swelling ratios (23338±988% at 15°C and 6937±112% at pH 8.0, respectively). In the solution of 0.1mol/L NaCl, the hydrogel showed the maximum water retention rate (48.73%). Sodium salicylate was used as the model drug to study the behaviors of hydrogel adsorption and release in simulated intestinal (at pH 7.4) and gastric liquid (at pH 1.8) surroundings. The prepared composite hydrogel exhibited higher drug release ratio in simulated intestinal liquid (63.09% after 380min) than in gastric liquid (22.09% after 400min). These pH responses of the prepared composite hydrogel showed its potential applications, especially as the drug carrier to attain control release of drugs under different surrounding conditions or organs in human body.

  8. Preparation and characterization of polyimide/silica/silver composite films

    Institute of Scientific and Technical Information of China (English)

    Ning LUO; Zhanpeng WU; Nanxiang MOU; Lizhong JIANG; Dezhen WU

    2008-01-01

    Polyimide/silica/silver hybrid films were pre-pared by the sol-gel method combined with in situ single-stage self-metallization technique.The structure of polyi-mide films in the thermal curing process and the influence of silica content on the migration and aggregation of silver particles to the surface of hybrid films were investigated.The hybrid films were characterized by transmission elec-tron microscopy,dynamic mechanical thermal analysis,Fourier transform infrared spectroscopy,ultraviolet visible spectroscopy and mechanical measurements.The results indicated that there was no degradation of the polyimide matrix after the formation of silica and silver particles.Silica acted as the nucleus for the silver particles.With increasing silica content,more and more silver particles were kept in the hybrid films instead of being migrated onto the surface of the hybrid films and the reflections of hybrid films decreased gradually.

  9. Nutritional composition of ginger powder prepared using various drying methods.

    Science.gov (United States)

    Sangwan, A; Kawatra, A; Sehgal, S

    2014-09-01

    A study was undertaken to prepare ginger powder using various drying methods and their nutritional evaluation was carried out. Ginger (Zingiber officinale) was dried using shade, solar, oven and microwave drying methods. All the samples were ground in grinder to make fine powder. Sensory analysis indicated that acceptability of all types of ginger powders were in the range of 'liked very much' to 'liked moderately' by the panelists. The mean score obtained for colour was higher in shade dried ginger powder i.e., 8.20 as compared to oven dried (7.60), solar dried (7.70) and microwave dried ginger powder (7.80). Moisture content ranged from 3.55 % in solar dried ginger powder to 3.78 % in shade dried ginger powder. Slightly higher moisture content was found in shade dried ginger powder. Protein, crude fiber, fat and ash contents ranged from 5.02 to 5.82, 4.97 to 5.61, 0.76 to 0.90 and 3.38 to 3.66 %, respectively. β-carotene and ascorbic acid content was found maximum in shade dried ginger powder i.e., 0.81 mg/100 g and 3.83 mg/100 g, respectively. Polyphenol content was almost similar in all the samples whereas calcium was slightly higher in the shade dried ginger powder i.e., 69.21 mg/100 g. Results have shown that ginger powder prepared from various drying methods had good sensory and nutritional profile.

  10. Preparation of graphene/polymer composite photocathode for QDSSC

    Science.gov (United States)

    Wang, Qiandi; Shen, Yue; Tan, Jie; Xu, Kai; Shen, Tan; Cao, Meng; Gu, Feng; Wang, Linjun

    2013-12-01

    Graphene (rGO) was fabricated by modified Hummers method and a reducing process. Conductive polymer/graphene films were obtained by scalpel technology and used as photocathode in CdS quantum dot-sensitized solar cell (QDSSC). Polymers used in this paper were ethyl cellulose (EC), polyphenyl vinyl (PPV) and polyvinyl butyral (PVB), respectively. The obtained composite films were investigated by X-ray diffraction, Raman spectroscopy technology and scanning electron microscope (SEM). The photoelectric properties of QDSSCs were tested under AM 1.5 irradiation. Test results show that the film performance of the EC/rGO and PPV/rGO photocathode have been improved effectively. Power conversion efficiency (PCE) of the relative QDSSCs under AM 1.5 irradiation were 0.81% and 0.86%, respectively.

  11. Mapping Chemical and Structural Composition of Pharmaceutical and Biological Samples by Raman, Surface-Enhanced Raman and Fluorescence Spectral Imaging

    Science.gov (United States)

    Chourpa, Igor; Cohen-Jonathan, Simone; Dubois, Pierre

    Raman spectroscopy is an analytical technique recognised for its structural and conformational specificity. The efficient discrimination of molecular species by Raman is particularly potent for multidimensional microscopic imaging of complex biological environment, as demonstrated in the present book. The commonly admitted problem of Raman, low sensitivity, can often be circumvented due to high output instruments and via approaches like RRS (resonance Raman scattering), SERS (surface-enhanced Raman scattering), TERS (tip-enhanced Raman scattering) or CARS (coherent anti-Stokes Raman scattering). In contrast to the latter, RRS and SERS are realizable with less sophisticated set-up based on common Raman systems. Although more invasive than RRS, SERS provides better sensitivity and quenching of fluorescence. SERRS (surface-enhanced resonance Raman scattering) spectroscopy can be used in coupling with fluorescence and competes in selectivity and sensitivity with spectrofluorimetry. In the chapter below, we use recent applications made in our group to illustrate the use of Raman and SERRS spectral imaging for characterization of biological samples (animal subcutaneous tissue, human cancer cells) and pharmaceutical samples (microparticles for drug delivery, fibres for wound dressing). After a brief description of experimental details on spectral imaging, the chapter will focus on results concerning (i) biocompatible pharmaceutical materials made of alginates and (ii) anticancer drugs in pharmaceutical forms and in biological systems.

  12. Preparation, characterization, and in vitro release of gentamicin from coralline hydroxyapatite-alginate composite microspheres.

    Science.gov (United States)

    Sivakumar, M; Rao, K Panduranga

    2003-05-01

    In this work, composite microspheres were prepared from bioactive ceramics such as coralline hydroxyapatite [Ca(10)(PO(4))(6)(OH)(2)] granules, a biodegradable polymer, sodium alginate, and an antibiotic, gentamicin. Previously, we have shown a gentamicin release from coralline hydroxyapatite granules-chitosan composite microspheres. In the present investigation, we attempted to prepare composite microspheres containing coralline hydroxyapatite granules and sodium alginate by the dispersion polymerization technique with gentamicin incorporated by absorption method. The crystal structure of the composite microspheres was analyzed using X-ray powder diffractometer. Fourier transform infrared spectra clearly indicated the presence of per-acid of sodium alginate, phosphate, and hydroxyl groups in the composite microspheres. Scanning electron micrographs and optical micrographs showed that the composite microspheres were spherical in shape and porous in nature. The particle size of composite microspheres was analyzed, and the average size was found to be 15 microns. The thermal behavior of composite microspheres was studied using thermogravimetric analysis and differential scanning calorimetric analysis. The cumulative in vitro release profile of gentamicin from composite microspheres showed near zero order patterns.

  13. Preparation and Properties of Nano-Hydroxyapatite/Gelatin/Poly(vinyl alcohol) Composite Membrane.

    Science.gov (United States)

    Liao, Haotian; Shi, Kun; Peng, Jinrong; Qu, Ying; Liao, Jinfeng; Qian, Zhiyong

    2015-06-01

    In this study, the bone-like composite membrane based on blends of gelatin (Gel), nano-hydroxyapatite (n-HA) and poly(vinyl alcohol) (PVA) was fabricated by solvent casting and evaporation methods. The effect of n-HA content and the ratio of Gel/PVA on the properties of the composite was investigated. The Gel/PVA and n-HA/Gel/PVA composite membranes were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), water contact angle measurement and scanning electron microscopy (SEM). The mechanical properties of the composites were determined by tensile tests. The as prepared composite membranes exhibited hydrophobility, the water contact angle of composite membrane was 126.6 when its mass ratio of n-HA/Gel/PVA was 10/50/40. The tensile strength of composite membranes was greatly increased due to the introduction of n-HA, and the tensile strength was increased to 74.92 MPa when the mass ratio of n-HA/Gel/PVA was 10/50/40. SEM observation indicated that n-HA was dispersed in the membranes and a sea-island structure was formed in the n-HA/Gel/PVA composite membranes, resulting in a significant increase in tensile strength. The as-prepared n-HA/Gel/PVA composite membranes may be applied in the field of bone tissue engineering.

  14. Preparation and Characterization of Bi2Te3/Graphite/Polythiophene Thermoelectric Composites

    Science.gov (United States)

    Lai, Chunhua; Li, Junjie; Pan, Chengjun; Wang, Lei; Bai, Xiaojun

    2016-10-01

    The Bi2Te3/graphite/polythiophene composites were prepared by solution mixing, mechanical ball milling, cold pressing and spark plasma sintering (SPS) in order to utilize and integrate the high Seebeck coefficient of Bi2Te3, high electrical conductivity of graphite (G) and low thermal conductivity of polythiophene (PTh). The structures and properties of the composites were characterized by scanning electron microscope, thermo gravimetric analyzer, x-ray diffraction and ULVAC ZEM-2 Seebeck coefficient measurement. The results showed that the related components were uniformly dispersed in the composites, and the electrical conductivity of the composites increased significantly with increasing G content. A small addition of Bi2Te3 to the matrix contributed to an increase in Seebeck coefficient and the thermal conductivity of the composites stayed at a low level owing to the low thermal conductivity of PTh. These composites prepared by SPS show an increase in Seebeck coefficient but a decrease in electrical conductivity as compared to corresponding composites prepared by cold pressing.

  15. Study on preparation and performances of CDPVC/Ag3PO4 composite photocatalyst

    Directory of Open Access Journals (Sweden)

    Peng WANG

    2016-04-01

    Full Text Available PVC/Ag3PO4 composites are prepared by solution-dipping method, and the as-prepared composites are heat-treated to release HCl from PVC molecules to obtain conjugated derivative of PVC/Ag3PO4(CDPVC/Ag3PO4 composites. The CDPVC/Ag3PO4 composites are characterized by XRD, SEM, UV-vis DRS, PL and XPS. The effects of preparation conditions on the visible-light photocatalytic performances of CDPVC/Ag3PO4 composites are investigated by evaluating the decomposition of methyl orange under visible light irradiation. The results reveal that the modification of CDPVC is beneficial to the dispersion of Ag3PO4 particles, and it can obviously improve the absorbance of the CDPVC/Ag3PO4 composites in the range of visible light and the charge separation efficiency. The CDPVC/Ag3PO4 composites exhibit excellent visible-light photocatalytic acitivity and stability when the mass percentage of PVC to Ag3PO4, heat-treatment temperature and time are 0.03%, 130 ℃, and 2 h, respectively.

  16. Feasibility of antibody-poly(glutamic acid) complexes: preparation of high-concentration antibody formulations and their pharmaceutical properties.

    Science.gov (United States)

    Izaki, Shunsuke; Kurinomaru, Takaaki; Maruyama, Takuya; Uchida, Takayuki; Handa, Kenji; Kimoto, Tomoaki; Shiraki, Kentaro

    2015-06-01

    Development of high-concentration antibody formulations for subcutaneous administration remains challenging. Recently, a precipitation-redissolution method was proposed to prepare suspensions or precipitates of salt-dissociable protein-poly(amino acid) complexes. To elucidate the utility of this method for protein therapy, we investigated the feasibility of a precipitation-redissolution method using poly(amino acid) for high-concentration antibody formulation. Omalizumab and adalimumab formulations of 150 mg/mL could be prepared using poly-l-glutamic acid (polyE) from low-concentration stock solutions. Enzyme-linked immunosorbent assay, circular dichroism, and size-exclusion chromatography revealed that the formation of antibody-polyE complex and precipitation-redissolution process did not significantly affect the immunoreactivity or secondary structure of the antibodies. The precipitation-redissolution method was less time-consuming and more effective than lyophilization-redissolution, evaporation-redissolution, and ultrafiltration from the viewpoint of final yield. Scalability was confirmed from 400 μL to 1.0 L. The general toxicity and pharmacokinetic profiles of the antibody-polyE complex formulations were similar to those of conventional antibody formulations. These results suggested that the precipitation-redissolution method using poly(amino acid) has great potential as a concentration method for antibody formulation and medicinal use.

  17. Preparation and performance of ZnO/Polyaniline nano-composite for supercapacitor

    Energy Technology Data Exchange (ETDEWEB)

    Yu, S.P.; Chang, X.C.; Wang, Z.M.; Han, K.F.; Zhu, H. [Beijing Univ. of Chemical Technology, Beijing (China). School of Science

    2010-07-01

    Supercapacitors combine the advantages of traditional capacitors and batteries. In this study, a zinc oxide (ZnO-PANI) nano-composite material was fabricated in order to investigate its behaviour in a supercapacitor application. The ZnO nano-powder was synthesized using the sol-gel method. An inverted emulsion polymerization method was then used to prepare the ZnO/PANI nanocomposite. X-ray diffraction (XRD) analyses demonstrated that the prepared ZnO had a hexagonal structure. The ZnO/PANI composite electrode was prepared. Electrochemical impedance spectroscopy (EIS) analyses indicated that the nano-composite material functioned well as an electrode. The highest capacitance rating achieved by the electrode was 31.82 F per g. 6 refs., 4 figs.

  18. Titanium carbide/carbon composite nanofibers prepared by a plasma process

    Energy Technology Data Exchange (ETDEWEB)

    El Mel, A A; Gautron, E; Angleraud, B; Granier, A; Tessier, P Y [Universite de Nantes, CNRS, Institut des Materiaux Jean Rouxel, UMR 6502, 2 rue de la Houssiniere BP 32229-44322 Nantes cedex 3 (France); Choi, C H [Department of Mechanical Engineering, Stevens Institute of Technology, Hoboken, NJ 07030 (United States)

    2010-10-29

    The incorporation of metal or metal carbide nanoparticles into carbon nanofibers modifies their properties and enlarges their field of application. The purpose of this work is to report a new non-catalytic and easy method to prepare organized metal carbide-carbon composite nanofibers on nanopatterned silicon substrates prepared by laser interference lithography coupled with deep reactive ion etching. Titanium carbide-carbon composite nanofibers were grown on the top of the silicon lines parallel to the substrate by a hybrid plasma process combining physical vapor deposition and plasma enhanced chemical vapor deposition. The prepared nanofibers were analyzed by scanning electron microscopy, x-ray photoelectron spectroscopy, Raman spectroscopy and transmission electron microscopy. We demonstrate that the shape, microstructure and the chemical composition of the as-grown nanofibers can be tuned by changing the plasma conditions.

  19. Titanium carbide/carbon composite nanofibers prepared by a plasma process.

    Science.gov (United States)

    El Mel, A A; Gautron, E; Choi, C H; Angleraud, B; Granier, A; Tessier, P Y

    2010-10-29

    The incorporation of metal or metal carbide nanoparticles into carbon nanofibers modifies their properties and enlarges their field of application. The purpose of this work is to report a new non-catalytic and easy method to prepare organized metal carbide-carbon composite nanofibers on nanopatterned silicon substrates prepared by laser interference lithography coupled with deep reactive ion etching. Titanium carbide-carbon composite nanofibers were grown on the top of the silicon lines parallel to the substrate by a hybrid plasma process combining physical vapor deposition and plasma enhanced chemical vapor deposition. The prepared nanofibers were analyzed by scanning electron microscopy, x-ray photoelectron spectroscopy, Raman spectroscopy and transmission electron microscopy. We demonstrate that the shape, microstructure and the chemical composition of the as-grown nanofibers can be tuned by changing the plasma conditions.

  20. Wear Behavior of Aluminium Metal Matrix Composite Prepared from Industrial Waste

    Directory of Open Access Journals (Sweden)

    L. Francis Xavier

    2016-01-01

    Full Text Available With an increase in the population and industrialization, a lot of valuable natural resources are depleted to prepare and manufacture products. However industrialization on the other hand has waste disposal issues, causing dust and environmental pollution. In this work, Aluminium Metal Matrix Composite is prepared by reinforcing 10 wt% and 20 wt% of wet grinder stone dust particles an industrial waste obtained during processing of quarry rocks which are available in nature. In the composite materials design wear is a very important criterion requiring consideration which ensures the materials reliability in applications where they come in contact with the environment and other surfaces. Dry sliding wear test was carried out using pin-on-disc apparatus on the prepared composites. The results reveal that increasing the reinforcement content from 10 wt% to 20 wt% increases the resistance to wear rate.

  1. Copper-containing polyvinyl alcohol composite systems: Preparation, characterization and biological activity

    Science.gov (United States)

    Reza Hajipour, Abdol; Mohammadsaleh, Fatemeh; Reza Sabzalian, Mohammad

    2015-08-01

    The present investigation reports, the complex formation of Cu(II) with polyvinyl alcohol (PVA) and the synthesis of PVA-stabilized Cu2O particles. This PVA-Cu2O composite has been prepared via chemical reduction method using PVA-Cu(II) complex as precursor. At first, Cu(II) ions were stabilized in PVA matrix via complex formation with OH groups; subsequently, this PVA-Cu(II) macromolecular complex as precursor reacted with ascorbic acid as reducing agent at pH=12 to prepare PVA-Cu2O composite. The products were characterized by FTIR, XRD, FE-SEM, HRTEM, Visible Spectroscopy and atomic absorption. In the following, the antibacterial properties of as-prepared composites were examined against Gram-positive (Bacillus thuringiensis) and Gram-negative bacteria (Escherichia coli), and the results showed excellent antibacterial activity of these materials.

  2. Preparation of Methylene Blue-Silica Composite Microcapsules

    Energy Technology Data Exchange (ETDEWEB)

    Ono, Hideo. [Nihon Millipore Corp., Yamagata (Japan); Takahashi, Koji. [Yamagata University, Yamagata (Japan). Department of Materials Science and Engineering

    1999-06-01

    Silica microcapsules comprising methylene blue (MB-SiO{sub 2}) of mean diameter 4.0 {mu}m were prepared by solgel and water-in-oil emulsion techniques where water pools are use as microreactors in which methylene blue is dissolved at a high water to surfactant molar ratio. It is confirmed that the cationic methylene blue is incorporated in the silica microcapsule wall during hydrolysis and condensation of tetraethoxysilane. Fixation of methylene blue in the silica wall is examined by passing water or acetic acid aq. soln. (pH 2-4) through a cartridge in which MB-SiO{sub 2} is packed and then measuring the fractions using UV-VIS analysis. The elution behavior is affected drastically by the pH value of the eluent. Methylene blue tends to stay in the wall when the pH value of eluent is above the isoelectric point (IEP) of the silica microcapsules. However, release of methylene blue cation occurs when it is below the IEP. These results reveal that coulomb interaction has an important role to fix methylene blue in the silica microcapsule. (author)

  3. A Facile Electrochemical Preparation of Reduced Graphene Oxide@Polydopamine Composite: A Novel Electrochemical Sensing Platform for Amperometric Detection of Chlorpromazine

    Science.gov (United States)

    Palanisamy, Selvakumar; Thirumalraj, Balamurugan; Chen, Shen-Ming; Wang, Yi-Ting; Velusamy, Vijayalakshmi; Ramaraj, Sayee Kannan

    2016-09-01

    We report a novel and sensitive amperometric sensor for chlorpromazine (CPZ) based on reduced graphene oxide (RGO) and polydopamine (PDA) composite modified glassy carbon electrode. The RGO@PDA composite was prepared by electrochemical reduction of graphene oxide (GO) with PDA. The RGO@PDA composite modified electrode shows an excellent electro-oxidation behavior to CPZ when compared with other modified electrodes such as GO, RGO and GO@PDA. Amperometric i-t method was used for the determination of CPZ. Amperometry result shows that the RGO@PDA composite detects CPZ in a linear range from 0.03 to 967.6 μM. The sensor exhibits a low detection limit of 0.0018 μM with the analytical sensitivity of 3.63 ± 0.3 μAμM-1 cm-2. The RGO@PDA composite shows its high selectivity towards CPZ in the presence of potentially interfering drugs such as metronidazole, phenobarbital, chlorpheniramine maleate, pyridoxine and riboflavin. In addition, the fabricated RGO@PDA modified electrode showed an appropriate recovery towards CPZ in the pharmaceutical tablets.

  4. A Facile Electrochemical Preparation of Reduced Graphene Oxide@Polydopamine Composite: A Novel Electrochemical Sensing Platform for Amperometric Detection of Chlorpromazine

    Science.gov (United States)

    Palanisamy, Selvakumar; Thirumalraj, Balamurugan; Chen, Shen-Ming; Wang, Yi-Ting; Velusamy, Vijayalakshmi; Ramaraj, Sayee Kannan

    2016-01-01

    We report a novel and sensitive amperometric sensor for chlorpromazine (CPZ) based on reduced graphene oxide (RGO) and polydopamine (PDA) composite modified glassy carbon electrode. The RGO@PDA composite was prepared by electrochemical reduction of graphene oxide (GO) with PDA. The RGO@PDA composite modified electrode shows an excellent electro-oxidation behavior to CPZ when compared with other modified electrodes such as GO, RGO and GO@PDA. Amperometric i-t method was used for the determination of CPZ. Amperometry result shows that the RGO@PDA composite detects CPZ in a linear range from 0.03 to 967.6 μM. The sensor exhibits a low detection limit of 0.0018 μM with the analytical sensitivity of 3.63 ± 0.3 μAμM–1 cm–2. The RGO@PDA composite shows its high selectivity towards CPZ in the presence of potentially interfering drugs such as metronidazole, phenobarbital, chlorpheniramine maleate, pyridoxine and riboflavin. In addition, the fabricated RGO@PDA modified electrode showed an appropriate recovery towards CPZ in the pharmaceutical tablets. PMID:27650697

  5. Study on Preparation and Property of Poly-Aminosilicone-Rare Earth Composite

    Institute of Scientific and Technical Information of China (English)

    Zhang Ming(张明); Qiu Guanming(邱关明); Chen Haiyan(陈海燕); Zhou Lanxiang(周兰香); Inoue Shinich; Okamoto Hiroshi

    2003-01-01

    The poly-aminosilicone-rare earth composite was prepared by poly-aminosilicone cross-linked with rare earth and active silanol. The thermal stability of the composites was studied by thermogravimetric analysis (TG). Force condition of the composites in electric field was analyzed and relative polarizability was derived. It is found that the composites containing different rare earth ions have different relative polarizability. The experiment results reveal that organosilicon materials with different electrical performance can be obtained by this way. Meanwhile, the absorption and flourescene spectrum of composites were also investigated. Compared to rare earth chloride, the spectrum properties of the composite are changed obviously. The possible reasons for these phenomena were discussed.

  6. Simultaneous quantitative resolution of atorvastatin calcium and fenofibrate in pharmaceutical preparation by using derivative ratio spectrophotometry and chemometric calibrations.

    Science.gov (United States)

    Nagaraj; Vipul, Kalamkar; Rajshree, Mashru

    2007-04-01

    In the present work, five different spectrophotometric techniques for simultaneous determination of formulations containing atorvastatin calcium (ATOR) and fenofibrate (FENO) in various combinations are described. In ratio spectra derivative spectrophotometry, analytical signals were measured at wavelengths corresponding to either maximums or minimums for both drugs in first derivative spectra of ratio spectra obtained by using either spectrum as divisor. For the remaining four methods using chemometric techniques, namely, classical least squares (CLS), inverse least squares (ILS), principal component regression (PCR) and partial least squares (PLS), the calibrations were constructed by using the absorption data matrix corresponding to the concentration data matrix, with measurements in the range of 231 - 310 nm (Deltalambda = 1 nm) in their zero-order spectra. The linearity range was found to be 4 - 22 and 2 - 20 microg/ml for ATOR and FENO, respectively. The validity of the proposed methods was successfully assessed for analyses of both drugs in laboratory-prepared mixtures and in commercial tablet formulations.

  7. Preparation of magnetic photocatalyst nanohybrid decorated by polyoxometalate for the degradation of a pharmaceutical pollutant under solar light.

    Science.gov (United States)

    Bastami, Tahereh Rohani; Ahmadpour, Ali

    2016-05-01

    Magnetic polyoxometalate nanohybrid was prepared by the surface modification of γ-Fe2O3/SrCO3 nanoparticles with PW 12 O 40 (3 -) polyoxometalate (POM) anions. The results of Fourier transform infrared (FTIR) and energy-dispersive X-ray (EDX) confirm the presence of POM on the surface of γ-Fe2O3/SrCO3 nanoparticles. TEM results revealed the ellipsoid-like structure of nanohybrid which was 23 nm in length and 6 nm in width. The activity of the photocatalyst was investigated by the photocatalytic degradation of ibuprofen (IBP) in an aqueous solution under solar light. It was found that in comparison with the γ-Fe2O3/SrCO3, the degradation of IBP after 2-h exposure to the solar light irradiation was significantly higher for POM-γ-Fe2O3/SrCO3 nanohybrids. The degradation of IBP was enhanced by the addition of H2O2 to the air saturated solution, while the addition of NaHCO3 and isopropanol restricted the degradation process. In the presence of H2O2, the Fenton photocatalyst degradation under solar light irradiation led to relatively complete degradation of IBP. Furthermore, the photocatalytic activity and magnetization properties of this magnetic photocatalyst nanohybrid provide a promising solution for the degradation of water pollutants and photocatalyst recovery. Graphical Abstract Schematic illustration for preparation of POM-γ-Fe2O3/SrCO3 nanohybrid and photocatalytic reaction of IBP on POM-γ-Fe2O3/SrCO3 nanohybrid.

  8. Durable hydrophobic coating composition for metallic surfaces and method for the preparation of the composition

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Jiong

    2017-02-14

    A durable hydrophobic coating composition containing fluorinated silanes for metallic surfaces, such as stainless steel surfaces. The composition includes at least one fluorine-containing silane compound, at least one phosphorus-containing silane compound, and at least one hydrolysable compound. This coating is suitable for condenser tubes, among other applications, to promote dropwise condensation.

  9. Preparation of 6066/SiCp composites by multilayer spray deposition

    Institute of Scientific and Technical Information of China (English)

    康智涛; 陈振华

    2001-01-01

    SiC particulate reinforced 6066 aluminium alloy metal matrix composites (MMCs) were prepared by multi-layer spray forming. The preparation technology and process parameters were discussed. It is shown that SiC particulate can be continuously and evenly fed and co-deposited in the spray forming process. The reciprocally scanning movement of spraying system can make the SiC particulates distribute homogeneously in the composite. The ratio of SiC particulates captured by the metal matrix is influenced by process parameters, especially the metal flow rate. 6066/SiCp composite preforms of d300  mm×540  mm and tubes with a size of up to d650/d300  mm×1  000  mm were made by the same process. After extrusion and T6 heat treatment, the multi-layer spray deposited 6066/SiCp composites can achieve improved properties.

  10. Innovative Fly Ash Geopolymer-Epoxy Composites: Preparation, Microstructure and Mechanical Properties

    Directory of Open Access Journals (Sweden)

    Giuseppina Roviello

    2016-06-01

    Full Text Available The preparation and characterization of composite materials based on geopolymers obtained from fly ash and epoxy resins are reported for the first time. These materials have been prepared through a synthetic method based on the concurrent reticulation of the organic and inorganic components that allows the formation of hydrogen bonding between the phases, ensuring a very high compatibility between them. These new composites show significantly improved mechanical properties if compared to neat geopolymers with the same composition and comparable performances in respect to analogous geopolymer-based composites obtained starting from more expensive raw material such as metakaolin. The positive combination of an easy synthetic approach with the use of industrial by-products has allowed producing novel low cost aluminosilicate binders that, thanks to their thixotropicity and good adhesion against materials commonly used in building constructions, could be used within the field of sustainable building.

  11. Preparation and corrosion resistance of MAO/Ni-P composite coat on Mg alloy

    Science.gov (United States)

    Fan, Xizhi; Wang, Ying; Zou, Binglin; Gu, Lijian; Huang, Wenzhi; Cao, Xueqiang

    2013-07-01

    Microarc oxidation (MAO) coat was designed as an intermediate layer for the electroless plated Ni-P top coat, providing inert surface and necessary hardness for Mg alloy substrate. The composite coat was successfully prepared to improve the corrosion resistance of Mg alloy. The preparation and the characterization of the composite coat were investigated. The results show that the pre-treatment of MAO before electroless plating plays an important role in the deposition of compact composite coat. The activation (by HF solution) makes the MAO coat dense with uniform cracks which supply excellent bonding interface for Ni-P coat. Compared with monolithic MAO or Ni-P coat, the composite coat has excellent corrosion resistance and stable bonding interface. There is main pit corrosion at substrate after the corrosive medium penetrating through the whole coat. With the inert MAO interlayer, the electrochemical corrosion between the Ni-P and substrate is effectively inhibited.

  12. Preparation of QTi4.3-4Graghite Composite by Semi-solid Casting Technology

    Institute of Scientific and Technical Information of China (English)

    ZHANG Peng; DU Yunhui; LIU Hanwu; ZENG Daben; BA Limin

    2005-01-01

    The electromagnetic-mechanical stirring technology was employed for preparing QTi4.3-4 graghite composite slurry, and QTi4.3-4 graghite composite with uniform distribution of graphite particles was prepared using the semi-solid casting technology successfully. The structure of this QTi4.3-4 graghite composite was studied and the condition for uniform distribution of graphite particles was got. The experimental results show that there exists a linear relationship between the solid fraction aud the stirring temperature of QTi4.3-4 graphite slurry. With the decreasing of stirring temperature, the solid fraction of QTi4.3-4 graghite slurry increases constantly. In casting, with the iucreasing of solid fraction of QTi4.3-4graghite slurry, the agglomeration of graphite particles is removed gradually. When the solid fraction is higher than 40% , graphite particles can distribute evenly in QTi4.3-4 graghite composite.

  13. Facile Preparation and Characterization of Poly (3-hexylthiophene)/Multiwalled Carbon Nanotube Thermoelectric Composite Films

    Science.gov (United States)

    Du, Y.; Shen, S. Z.; Yang, W. D.; Chen, S.; Qin, Z.; Cai, K. F.; Casey, P. S.

    2012-06-01

    This paper reports a novel, cost-effective, scalable, and simple method for preparing poly(3-hexylthiophene)/multiwalled carbon nanotube (P3HT/MWCNT) nanocomposite films. The P3HT/MWCNT films were prepared by oxidative polymerization of 3-hexylthiophene in chloroform solution containing dispersed MWCNT. The phase composition and microstructure of the composite films were analyzed by x-ray diffraction (XRD), Fourier-transform infrared spectroscopy, Raman spectroscopy, thermogravimetric analysis, and field-emission scanning electron microscopy. The composite films were smooth, dense, and uniform. The thermoelectric properties of the composite films were measured at room temperature. The electrical conductivity and Seebeck coefficient of the films with MWCNT content of 5 wt.% were ~1.3 × 10-3 S/cm and 131.0 μV/K, respectively.

  14. Innovative Fly Ash Geopolymer-Epoxy Composites: Preparation, Microstructure and Mechanical Properties.

    Science.gov (United States)

    Roviello, Giuseppina; Ricciotti, Laura; Tarallo, Oreste; Ferone, Claudio; Colangelo, Francesco; Roviello, Valentina; Cioffi, Raffaele

    2016-06-09

    The preparation and characterization of composite materials based on geopolymers obtained from fly ash and epoxy resins are reported for the first time. These materials have been prepared through a synthetic method based on the concurrent reticulation of the organic and inorganic components that allows the formation of hydrogen bonding between the phases, ensuring a very high compatibility between them. These new composites show significantly improved mechanical properties if compared to neat geopolymers with the same composition and comparable performances in respect to analogous geopolymer-based composites obtained starting from more expensive raw material such as metakaolin. The positive combination of an easy synthetic approach with the use of industrial by-products has allowed producing novel low cost aluminosilicate binders that, thanks to their thixotropicity and good adhesion against materials commonly used in building constructions, could be used within the field of sustainable building.

  15. Innovative Fly Ash Geopolymer-Epoxy Composites: Preparation, Microstructure and Mechanical Properties

    Science.gov (United States)

    Roviello, Giuseppina; Ricciotti, Laura; Tarallo, Oreste; Ferone, Claudio; Colangelo, Francesco; Roviello, Valentina; Cioffi, Raffaele

    2016-01-01

    The preparation and characterization of composite materials based on geopolymers obtained from fly ash and epoxy resins are reported for the first time. These materials have been prepared through a synthetic method based on the concurrent reticulation of the organic and inorganic components that allows the formation of hydrogen bonding between the phases, ensuring a very high compatibility between them. These new composites show significantly improved mechanical properties if compared to neat geopolymers with the same composition and comparable performances in respect to analogous geopolymer-based composites obtained starting from more expensive raw material such as metakaolin. The positive combination of an easy synthetic approach with the use of industrial by-products has allowed producing novel low cost aluminosilicate binders that, thanks to their thixotropicity and good adhesion against materials commonly used in building constructions, could be used within the field of sustainable building. PMID:28773582

  16. Preparation of AlB sub 4 C composites for image analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kelly, A.M.; Reiswig, R.D.; Hill, M.A.; Blumenthal, W.R.

    1990-01-01

    Composites made by infiltrating B{sub 4}C networks with aluminium, or its alloys are of interest for lightweight armor applications. Image analysis plays an important part in correlating the microstructures of such composites with their mechanical properties. Accurate image analysis requires a high degree of perfection in the metallographic preparation, which is particularly difficult where the phases present have such disparate hardness and reactivities. Two preparation procedures have been developed that produce adequate contrast and definition for analysis of key microstructural features. 8 refs., 5 figs., 1 tab.

  17. Composition, XRD and morphology study of laser prepared LiNbO3 films

    Science.gov (United States)

    Jelínek, M.; Havránek, V.; Remsa, J.; Kocourek, T.; Vincze, A.; Bruncko, J.; Studnička, V.; Rubešová, K.

    2013-03-01

    LiNbO3 films were deposited by PLD from LiNbO3 crystalline or from three different stoichiometric or Li-enriched LiNbO3 targets. Polycrystalline films were prepared on SiO2/Si or sapphire substrates at temperatures T S ˜650-750 °C. Main attention was paid to the influence of targets preparation and the deposition conditions on films composition, morphology and crystallinity. The thin-film morphology was determined by SEM microscopy. The composition was measured by SIMS, RBS, PIXE and PIGE methods. Highly oriented, smooth and stoichiometric LiNbO3 films were synthesized.

  18. Deposition and Characterization of Sisal Fiber Composite Prepare By Iron Oxide Synthesis.

    Directory of Open Access Journals (Sweden)

    Asif Jehan

    2015-02-01

    Full Text Available Iron oxide synthesized through sintering route. The present research work deals with ferrite composite prepared using chemical reactions. Ferric nitrates and ammonium chloride doped with sisal fiber has been prepared. The comparative studies of ferric oxide were examined through few characterizations. The structural behavior of iron oxide was studied in XRD, FT/IR, TEM and SEM. This behavior showed ferrite nature of the sample.

  19. Preparation of Composite Charge-mosaic Hollow Fiber Membrane by Interfacial Polymerization

    Institute of Scientific and Technical Information of China (English)

    Hao Qin ZHANG; Jin Dun LIU

    2004-01-01

    The preparation of composite charge-mosaic membrane included spinning of hollow fiber as the supporting membrane, preparing a selective layer on the inside surface of the fiber by interfacial polymerization. The charge-mosaic membranes show a high salt permeability while retaining sucrose. The charge-mosaic membrane can be effectively used to separate multivalent salts with organic matter of molecular weight great than 300 g/mol in industry.

  20. Preparation and Properties of OMMT/PU Composites

    Directory of Open Access Journals (Sweden)

    Chen Yufei

    2015-01-01

    Full Text Available Prepolymer of polyurethane (PU was prepared by toluene diisocyanate (TDI and polyether diol through polymerization, organically modified montmorillonite (OMMT gained by montmorillonite (MMT that was modified by octadecyl trimethyl ammonium chloride (OTAC, and the OMMT was used as intercalator; alcohol-based OMMT/PU adhesive was synthesized. The micromorphology of OMMT/PU adhesives was observed by XRD, SEM, and AFM, and the shear strength, elongation at break, peel strength, and water resistance were tested and the relationship between structure and properties of the adhesives was observed and analyzed. XRD suggested that OMMT has been completely peeled in the polyurethane matrix and the spacing of layers has increased. SEM and AFM indicated that the OMMT dispersed evenly in the PU matrix and had a good transition with PU matrix, and the interface effects between two phases were strong. The results of the mechanical properties showed that OMMT could significantly help to improve properties of OMMT/PU adhesive, and the shearing strength, fracture tensile strength, and peel strength of 4 wt% OMMT/PU adhesive were 7.24 MPa, 2.14 MPa, and 451.2 N/m, respectively; the water absorption quantity was 2.82%. Compared with the unmodified PU, the shearing strength, tensile strength, and elongation at break of 4 wt% OMMT/PU adhesive were increased by 36.75%, 134.90%, and 76.80%, respectively. The peel strength decreased by 30.76%, and the water absorption decreased by 17.54%, in the meanwhile.

  1. Preparation of Chitosan-collagen-alginate Composite Dressing and Its Promoting Effects on Wound Healing.

    Science.gov (United States)

    Xie, Haixia; Chen, Xiuli; Shen, Xianrong; He, Ying; Chen, Wei; Luo, Qun; Ge, Weihong; Yuan, Weihong; Tang, Xue; Hou, Dengyong; Jiang, Dingwen; Wang, Qingrong; Liu, Yuming; Liu, Qiong; Li, Kexian

    2017-08-28

    The present study aimed to prepare a composite dressing composed of collagen, chitosan, and alginate, which may promote wound healing and prevent from seawater immersion. Chitosan-collagen-alginate (CCA) cushion was prepared by paintcoat and freeze-drying, and it was attached to a polyurethane to compose CCA composite dressing. The swelling, porosity, degradation, and mechanical properties of CCA cushion were evaluated. The effects on wound healing and seawater prevention of CCA composite dressing were tested by rat wound model. Preliminary biosecurity was tested by cytotoxicity and hemocompatibility. The results revealed that CCA cushion had good water absorption and mechanical properties. A higher wound healing ratio was observed in CCA composite dressing treated rats than in gauze or chitosan treated ones. On the fifth day, the healing rates of CCA composite dressing, gauze, and chitosan were 48.49%±1.07%, 28.02%±6.4%, and 38.97%±8.53%, respectively. More fibroblast and intact re-epithelialization were observed in histological images of CCA composite dressing treated rats, and the expressions of EGF, bFGF, TGF-β, and CD31 increased significantly. CCA composite dressing showed no significant cytotoxicity, and favorable hemocompatibility. These results suggested that CCA composite dressing could prevent against seawater immersion and promote wound healing while having a good biosecurity. Copyright © 2017. Published by Elsevier B.V.

  2. Preparation and properties of metal-PVA composite hydrophilic ultrafiltration membranes

    Institute of Scientific and Technical Information of China (English)

    邱运仁; 张启修

    2003-01-01

    Metal-polyvinyl alcohol(PVA) composite ultrafiltration membranes were prepared by coating a certain concentration of PVA solution on metallic fiber sintered membranes. The effects of preparation conditions, such as the coating solution concentration, sequence and times of coating, and heat-treatment on the properties of the composite membranes were studied. The results show that the hole diameter of the composite membrane decreases with the increase of the concentration of PVA, the hole diameter of composite membrane is different when the sequence of coating is different. When the higher concentration of PVA solution is used to coat the metallic membrane for the first time and the other smaller one for the second time, the hole diameter of the composite membrane is relatively small, compared with that of the composite membrane made by the smaller concentration of PVA solution for the first time and the other higher one for the second time. The holes of the composite membrane contract and the stability of the membrane is improved by heat treatment. When metal-PVA composite hydrophilic membranes are used to treat the oil/water emulsion with the concentration of 1 000 mg@ L -1, the retention is from 80% to 90%, and the permeate flux is from 15 L @ m-2 @ h-1 to 40 L @ m-2 @ h-1 at pressure of 0.2 to 0.3 MPa.

  3. Electrospinning preparation and luminescence properties of Eu(TTA)_3phen/polystyrene composite nanofibers

    Institute of Scientific and Technical Information of China (English)

    张小萍; 温世鹏; 胡水; 张立群; 刘力

    2010-01-01

    Efficient luminescent composite nanofibers,composed of polystyrene(PS,Mw=250000) and europium complex Eu(TTA)3phen(TTA=2-thenoyltrifluoroacetone,phen=1,10-phenanthroline) with diameters ranging from 350 nm to 700 nm,were prepared by electrospinning and characterized by scanning electron microscope(SEM),Fourier transform infrared spectroscopy(FT-IR),fluorescence spectroscopy,and thermogravimetric analysis(TG).The room-temperature fluorescence spectra of the composite nanofibers were composed of the typical E...

  4. THE PREPARATION AND COMPOSITION ANALYSIS OF ALITE-YE'ELIMITE WITH INDUSTRIAL WASTES

    OpenAIRE

    Yueyang Hu; Suhua Ma; Li Weifeng; Shen Xiaodong

    2016-01-01

    Alite-ye'elimite clinker is a high cementing clinker that is prepared by introducing calcium sulfoaluminate, a non-silicate mineral, into cement clinker. The industrial residue was used to produce cement clinker. The relationship of the aluminate modulus (IM) and the mineral composition and mechanics of tricalcium silicate-rich sulfur aluminate cement is reported. The effects of the aluminate modulus on the phase compositions, morphology and compressive strength were investigated. The phase m...

  5. Preparation and Properties of Functional Graphene/Thermoplastic Polyurethane Composite Film

    OpenAIRE

    ZHENG Hui-dong; OU Zhong-xing; ZHENG Yu-ying; XIAO Dong-sheng; CAO Ning-ning

    2016-01-01

    The modified graphene oxide(DD-GO) was reacted by the Didodecyldimethylammonium bromide (DDAB) and graphene oxide,and then reduced via L-ascorbic acid to obtain functional graphene(DD-RGO). Functional graphene (DD-RGO)/thermoplastic polyurethane (TPU) composite films were prepared by solution on the coating machine. The morphology and properties of DD-RGO/TPU composite films were investigated by FTIR, XRD, FE-SEM, oxygen transmission rate tester and high resistance meter. The results show tha...

  6. PREPARATION OF ZINC OXIDE AND POLY-ETHYLENE OXIDE COMPOSITE MEMBRANES AND THEIR PHASE RELATIONSHIP

    OpenAIRE

    JESÚS FABIAN JURADO; CARLOS VARGAS HERNÁNDEZ; RUBÉN ANTONIO VARGAS

    2012-01-01

    Zinc oxide and organic polymer (poly-ethylene oxide) based nanocomposite membranes were prepared and their phase relationship investigated. The composites were characterized by XRD, Raman scattering, DSC, and impedance spectroscopy analysis. It was found that embedding inorganic nanoparticles of ZnO into the polymer matrix of PEO allowed for some crystallinity formation, and cross-linking of the polymer composites during annealing or synthesis. The XRD and Raman scattering results show more d...

  7. Supersonic Retropulsion Surface Preparation of Carbon Fiber Reinforced Epoxy Composites for Adhesive Bonding

    Science.gov (United States)

    Palmieri, Frank L.; Belcher, Marcus A.; Wohl, Christopher J.; Blohowiak, Kay Y.; Connell, John W.

    2013-01-01

    Surface preparation is widely recognized as a key step to producing robust and predictable bonds in a precise and reproducible manner. Standard surface preparation techniques, including grit blasting, manual abrasion, and peel ply, can lack precision and reproducibility, which can lead to variation in surface properties and subsequent bonding performance. The use of a laser to ablate composite surface resin can provide an efficient, precise, and reproducible means of preparing composite surfaces for adhesive bonding. Advantages include elimination of physical waste (i.e., grit media and sacrificial peel ply layers that ultimately require disposal), reduction in process variability due to increased precision (e.g. increased reproducibility), and automation of surface preparation, all of which improve reliability and process control. This paper describes a Nd:YAG laser surface preparation technique for composite substrates and the mechanical performance and failure modes of bonded laminates thus prepared. Additionally, bonded specimens were aged in a hot, wet environment for approximately one year and subsequently mechanically tested. The results of a one year hygrothermal aging study will be presented.

  8. Preparation and characterization of rubbery epoxy/multiwall carbon nanotubes composites using amino acid salt assisted dispersion technique

    OpenAIRE

    2013-01-01

    Epoxy/multiwall carbon nanotubes (MWCNT) composites were prepared using sodium salt of 6-aminohexanoic acid (SAHA) modified MWCNT and its effect properties of related composites were investigated. The composite prepared using a polar solvent, tetrahydrofuran exhibits better mechanical properties compared to those prepared using less polar solvent and without using solvent. The tensile properties and dynamic storage modulus was found to be increased as a result of modification of MWCNT with SA...

  9. Electrochemical properties of tungsten sulfide-carbon composite microspheres prepared by spray pyrolysis.

    Science.gov (United States)

    Choi, Seung Ho; Boo, Sung Jin; Lee, Jong-Heun; Kang, Yun Chan

    2014-01-01

    Tungsten sulfide (WS2)-carbon composite powders with superior electrochemical properties are prepared by a two-step process. WO3-carbon composite powders were first prepared by conventional spray pyrolysis, and they were then sulfidated to form WS2-carbon powders. Bare WS2 powders are also prepared by sulfidation of bare WO3 powders obtained by spray pyrolysis. Stacked graphitic layers could not be found in the bare WS2 and WS2-carbon composite powders. The amorphous bare WS2 and WS2-carbon composite powders have Brunauer-Emmett-Teller (BET) surface areas of 2.8 and 4 m(2) g(-1), respectively. The initial discharge and charge capacities of the WS2-carbon composite powders at a current density of 100 mA g(-1) are 1055 and 714 mA h g(-1), respectively, and the corresponding initial Coulombic efficiency is 68%. On the other hand, the initial discharge and charge capacities of the bare WS2 powders are 514 and 346 mA h g(-1), respectively. The discharge capacities of the WS2-carbon composite powders for the 2(nd) and 50(th) cycles are 716 and 555 mA h g(-1), respectively, and the corresponding capacity retention measured after first cycle is 78%.

  10. Preparation and characterization of nano hydroxyapatite/polymeric composites materials. Part I

    Energy Technology Data Exchange (ETDEWEB)

    Mohamed, Khaled R., E-mail: kh_rezk1966@yahoo.com [Biomaterials Dept., National Research Centre, Dokki, Cairo (Egypt); El-Rashidy, Zenab M. [Biomaterials Dept., National Research Centre, Dokki, Cairo (Egypt); Salama, Aida A. [Biophysics Dept., Faulty of Science, El-Azhar Univ., Cairo (Egypt)

    2011-10-17

    Highlights: {yields} The formation and coating of CHA increased by increasing polymer content. {yields} The size of the prepared CHA was within nano-range scale. {yields} The composites had homogeneity and CHA formed within the polymeric matrix. - Abstract: The present study is focused on preparation of nano composite materials and the effect of citric acid on their different properties. The formation of nano HA and its interaction with chitosan (C), gelatin (G) polymers and citric acid (CA) materials were studied. The Fourier Transformed Infrared Spectroscopy (FT-IR), X-ray diffraction (XRD), thermo-gravimetric analysis (TGA), transmission electron microscope (TEM), and scanning electron microscope (SEM) were used to characterize these composite materials. The compressive strength (CS) was also measured to know the reinforcement of the prepared composites. The results show that carboxylic and amino groups play crucial role for HA formation on chitosan-gelatin polymeric matrix in the presence of citric acid (CA). The formation of nano HA particles and its average size of crystallite is increased with increase of CG content and decreased with addition of CA. Also, the HA formation and binding strength between its particles are improved into the composites especially with CA. The nano-composites containing the best ratio of nHA (70%) with CA (0.2 M) are promising for medical applications in the future.

  11. Xanthoceraside hollow gold nanoparticles, green pharmaceutics preparation for poorly water-soluble natural anti-AD medicine.

    Science.gov (United States)

    Meng, Da-Li; Shang, Lei; Feng, Xiao-He; Huang, Xing-Fei; Che, Xin

    2016-06-15

    In order to increase the solubility of poorly water-soluble natural product, xanthoceraside, an effective anti-AD compound from Xanthoceras sorbifolia Bunge, and maintain its natural property, the xanthoceraside hollow gold nanoparticles were successively prepared by green ultrasonic method with silica spheres as templates and HF solution as selective etching solvent. Hollow gold nanoparticles and drug-loaded hollow gold nanoparticles were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and differential scanning calorimetry (DSC). The solubilities of xanthoceraside loaded on hollow gold nanoparticles were increased obviously from 3.0μg/ml and 2.5μg/ml to 12.7μg/ml and 10.7μg/ml at 25°C and 37°C, respectively. The results of XRD and DSC indicated that the reason for this increase was mainly due to the amorphous state of xanthoceraside loaded on the hollow gold nanoparticles. In summary, the method of loading xanthoceraside onto hollow gold nanoparticles was a green and useful strategy to improve the solubility and dissolution of poorly water-soluble natural products and worth to applying to other natural products. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Determination of β-lactam Antibiotics in Pharmaceutical Preparations by Uv-visible Spectrophotometry Atomic Absorption and High Performance Liquid Chromatography

    Directory of Open Access Journals (Sweden)

    *A. J. Abdulghani

    2012-09-01

    Full Text Available The determination amoxicillin, ampicillin and cephalexin was studied by complexation of the antibiotics with Au(III and Hg(II ions in bulk and pharmaceutical preparations using uv-visible spectrophotometry, atomic absorption, and HPLC techniques. Optimum conditions for complex formation were fixed at pH 4 and (2-4 for Au(III and Hg(IIcomplexes respectively, heating temperature at (60 °C and heating time for (10 minute. All complexes were extracted from aqueous solution with benzyl alcohol prior to measurements except in the case of HPLC. The L:M ratios for all complexes were determined and stability constants were calculated using mole ratio method. The Beer's law was obeyed over the concentration range (5-60 and 5-50 µg/ml of antibiotics for Au(III and Hg(II complexes using colorimetric method and (1-25 µg/ml of Au(III for FAAS. The linearity for HPLC method was (10-110 and 10-120 µg/ml respectively. The correlation coefficients (r were (0.9981-0.9997. Generally, the highest sensitivity was recorded by FAAS.

  13. Development and validation of a reversed-phase column liquid chromatographic method for the determination of five cephalosporins in pharmaceutical preparations.

    Science.gov (United States)

    Elkady, Ehab F; Abbas, Samah S

    2011-01-01

    A new, simple, rapid, and precise RP-HPLC method has been developed and validated for the determination of five cephalosporins, namely, cefalexin, cefoperazone, ceftriaxone, ceftazidime, and cefepime. The method has been applied successfully for simultaneous determination of cefalexin in a binary mixture with sodium benzoate in a suspension, and cefoperazone in a binary mixture with sulbactam in vials. Chromatographic separation was achieved on a Waters microBondapak C18 column (250 x 4.6 mm id, 10 pm particle size) using the mobile phase monobasic potassium phosphate (50 mM, pH 4.6)-acetonitrile (80 + 20, v/v) with UV detection. A flow rate of 1 mL/min was applied. Linearity, accuracy, and precision were found to be acceptable over the concentration range of 30-300, 3-30, and 15-120 microg/mL for the studied cephalosporins, sodium benzoate, and sulbactam, respectively. The optimized method proved to be specific, robust, and accurate for QC of the cited drugs in their pharmaceutical preparations.

  14. Application of TLC- Densitometry, First Derivative and Ratio Derivative Spectrophotometry for the Determination of Eprosartan Mesylate and Hydrochlorothiazide in Pharmaceutical Preparation

    Directory of Open Access Journals (Sweden)

    Emad M Hussien

    2011-12-01

    Full Text Available Three sensitive and accurate methods are described for the direct determination of eprosartan mesylate (EPM and hydrochlorothiazide (HCT in bulk powder and combined dosage form without prior separation. The first method is a first derivative spectrophotometry (1D using a zerocrossing technique of measurement at 240.7 nm for EPM and at 233.4 nm for HCT. The second method is the first derivative of ratio spectrophotometry (1DD where the amplitudes were measured at 237.0 nm for EPM and at 277.0 nm for HCT. The third method is based on TLC separation of the two drugs followed by densitometric measurements of their spots at 290 and 270 nm for EPM and HCT, respectively. The separation was carried out on silica gel 60 F254 using n-butyl acetate-ethanol-waterammonia 33% (40:40:10:1, v/v/v/v as mobile phase. The calibration curves were linear in the range 1.0-18.0, 2.0- 18.0 μg mL-1 and 2.0-20.0 μg/spot for EPM and 1.0-9.0, 1.0-9.0 μg mL-1 and 2.0-9.0 μg/ spot for HCT using 1D, 1DD and TLC methods, respectively. The suggested methods were tested using laboratory-prepared mixtures and were successfully applied for the analysis of pharmaceutical preparations. The methods retained their accuracy and precision when the standard addition technique was applied. The results obtained by applying the proposed methods were statistically analyzed and compared with those obtained by the manufacturer’s and USP methods for EPM and HCT, respectively.

  15. Pharmaceutical Frenzy

    Institute of Scientific and Technical Information of China (English)

    LAN XINZHEN

    2010-01-01

    @@ When shares of Shanghai Pharmaceutical(Group)Co.Ltd.(Shanghai Pharma)resumed normal transactions on March9,2010,the biggest listed pharmaceutical company on China's stock market was born.By the time the closing bell rang at the end of the trading day,the market value of Shanghai Pharma had reached 32.28 billion yuan($4.73 billion).

  16. Preparation and Characterization of Composite Drug Membranes of Gelatin/Chitosan to Ocular

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Composite drug membranes of gelatin/chitosan for therapy of glaucoma by trabeculectomy were prepared through solvent volatilization, using triamcinolone acetonide as a model drug. The membranes were characterized by FT- IR, X-RD and SEM. Their degradability and swelling ability and biocompatibility were studied. The results showed that biocompatibility , flexibility, swelling ability and degradability of the composite films were better than pure film of chitosan . The composite membrane containing 25% (w/w) of gelatin was best. The drug was loaded in film in crystallite. The rabbit eyes experiment after 8 weeks showed that the form of follicle was all right, and ophthalmototus maintain in the perfect level.

  17. Preparation of Polyaniline/Filter-paper Composite for Removal of Coomassie Brilliant Blue

    DEFF Research Database (Denmark)

    Liu, Wanwan; Li, Xiaoqiang; Li, Mengjuan

    2015-01-01

    Polyaniline/filter-paper (PANI/FP) composite was prepared by in-situ polymerization of polyaniline onto filter-paper and subsequently evaluated for the removal of Coomassie brilliant blue (CBB) from aqueous solution. Scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and Fourier......-transform infrared (FTIR) spectroscopy were used to investigate the morphology and physicochemical properties of PANI/FP composite. Batch experimental results showed that the pH value and temperature could affect the removal capability of the PANUFP composite. Langmuir and Freundlich models were used to analyse...

  18. Preparation of Composite Films of a Conjugated Polymer and C60NWs and Their Photovoltaic Application

    OpenAIRE

    Takatsugu Wakahara; Kun’ichi Miyazawa; Osamu Ito; Nobutaka Tanigaki

    2016-01-01

    Composite films of conjugated polymers, such as poly[2-methoxy-5-(3′,7′-dimethyloctyloxy)-1,4-phenylenevinylene] (MDMO-PPV) and poly(3-hexylthiophene) (P3HT), with C60 nanowhiskers (C60NWs) were prepared. The photoluminescence originating from the conjugated MDMO-PPV polymers was effectively quenched in the composite film, indicating a strong interaction between the conjugated polymer and C60NWs. The photovoltaic devices were fabricated using C60NW (conjugated polymer) composite films, result...

  19. Preparation of Composite Films of a Conjugated Polymer and C60NWs and Their Photovoltaic Application

    OpenAIRE

    Takatsugu Wakahara; Kun’ichi Miyazawa; Osamu Ito; Nobutaka Tanigaki

    2016-01-01

    Composite films of conjugated polymers, such as poly[2-methoxy-5-(3′,7′-dimethyloctyloxy)-1,4-phenylenevinylene] (MDMO-PPV) and poly(3-hexylthiophene) (P3HT), with C60 nanowhiskers (C60NWs) were prepared. The photoluminescence originating from the conjugated MDMO-PPV polymers was effectively quenched in the composite film, indicating a strong interaction between the conjugated polymer and C60NWs. The photovoltaic devices were fabricated using C60NW (conjugated polymer) composite films, result...

  20. Optical properties and residual stress in Nb-Si composite films prepared by magnetron cosputtering.

    Science.gov (United States)

    Tang, Chien-Jen; Porter, Glen Andrew; Jaing, Cheng-Chung; Tsai, Fang-Ming

    2015-02-01

    This paper investigates Nb-Si metal composite films with various proportions of niobium in comparison to pure Nb films. Films were prepared by two-target RF-DC magnetron cosputtering deposition. The optical properties and residual stress were analyzed. A composition of Nb(0.74)Si(0.26) was chosen toward the design and fabrication of solar absorbing coatings having a high absorption in a broad wavelength range, a low residual stress, and suitable optical constants. The layer thicknesses and absorption characteristics of the Nb-Si composite films adhere more closely to the design than other coatings made of dielectric film materials.

  1. Preparation of CdTe nanocrystal-polymer composite microspheres in aqueous solution by dispersing method

    Institute of Scientific and Technical Information of China (English)

    LI Minjie; WANG Chunlei; HAN Kun; YANG Bai

    2005-01-01

    Highly fluorescent CdTe nanocrystals were synthesized in aqueous solution, and then processible CdTe nanocrystal-polymer composites were fabricated by coating the aqueous nanocrystals with copolymers of styrene and octadecyl-p-vinyl-benzyldimethylammonium chloride (SOV- DAC) directly. A dichloromethane solution of CdTe nano- crystal-polymer composites was dispersed in the aqueous solution of poly (vinyl alcohol) (PVA) generating highly fluorescent microspheres. Experimental parameters such as the concentration of nanocrystal-polymer composites, the concentration of PVA, and stirring speed which had important effect on the preparation of the microspheres were investigated in detail with fluorescent microscope characterization.

  2. Preparation and Characterization of Palm Leaf Incorporated Polyvinyl Alcohol Bio Composites

    Science.gov (United States)

    Patel, Arunendra Kumar; Bajpai, Rakesh; Keller, J. M.; Saha, Abhijit

    2011-12-01

    The Bio Composites of palm leaf (PL) incorporated polyvinyl alcohol (PVA) has been prepared using solution cast technique. Structural and microhardness properties of pure PVA and PL filled PVA Bio Composites has been determined by using FTIR and Vicker's indentation techniquque respectively. The FTIR analysis reveals the presence of PL moieties in PVA, which indicates the good compatibility between PL and PVA. The values of microhardness increases in all composition of PL incorporated PVA films as compared to the pure PVA. This increment in the microhardness is attributed to the excellent binding of PL into PVA.

  3. Preparation of zeolite-A/chitosan hybrid composites and their bioactivities and antimicrobial activities

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Liang; Gong, Jie [State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemistry and Chemical Engineering, Nanjing University of Technology, Nanjing 210009 (China); Zeng, Changfeng [College of Mechanic and Power Engineering, Nanjing University of Technology, Nanjing 210009 (China); Zhang, Lixiong, E-mail: lixiongzhang@yahoo.com [State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemistry and Chemical Engineering, Nanjing University of Technology, Nanjing 210009 (China)

    2013-10-15

    Zeolite-A/chitosan hybrid composites with zeolite contents of 20–55 wt.% were prepared by in situ transformation of silica/chitosan mixtures in a sodium aluminate alkaline solution through impregnation–gelation–hydrothermal synthesis. The products were characterized by X-ray diffraction, diffuse reflectance infrared Fourier transform spectroscopy, scanning electron microscopy, thermogravimetric analysis, and mercury penetration porosimetry. Their in vitro bioactivities were examined using as-synthesized and Ca{sup 2+}-exchanged hybrid composites in simulated body fluid (SBF) for hydroxyapatite (HAP) growth. Their antimicrobial activities for Escherichia coli (E. coli) in trypticase soy broth (TSB) were evaluated using Ag{sup +}-exchanged hybrid composites. The zeolite-A/chitosan hybrid composites could be prepared as various shapes, including cylinders, plates and thin films. They possessed macropores with pore sizes ranging from 100 to 300 μm and showed compressive mechanical strength as high as 3.2 MPa when the zeolite content was 35 wt.%. Fast growth on the Ca{sup 2+}-exchanged hybrid composites was observed with the highest weight gain of 51.4% in 30 days. The 35 wt.% Ag{sup +}-exchanged hybrid composite showed the highest antimicrobial activity, which could reduce the 9 × 10{sup 6} CFU mL{sup −1}E. coli concentration to zero within 4 h of incubation time with the Ag{sup +}-exchanged hybrid composite amount of 0.4 g L{sup −1}. The bioactivity and antimicrobial activity could be combined by ion-exchanging the composites first with Ca{sup 2+} and then with Ag{sup +}. These zeolite-A/chitosan hybrid composites have potential applications on tissue engineering and antimicrobial food packaging. - Graphical abstract: Zeolite A/chitosan hybrid composites were prepared by in situ transformation of precursors in the chitosan matrix, which possess macroporous structures and exhibit superior bioactivity and antimicrobial activity and potential biomedical

  4. Preparation, Characterization and Application of Mg(OH)2-PAM Inorganic-Organic Composite Polymer in Removing Reactive Dye

    OpenAIRE

    Khai Ern Lee; Norhashimah Morad; Tjoon Tow Teng; Beng Teik Poh

    2012-01-01

    In this study, a series of inorganic-organic composite polymer was prepared. Magnesium hydroxide and polyacrylamide was composed in a composite matrix to prepare Mg(OH)2-PAM (MHPAM) inorganic-organic composite polymer. The characteristics of MHPAM inorganic-organic composite polymer was investigated in terms of chemical, physical, physical, thermal and morphological properties through FT-IR, conductivity, intrinsic viscosity, TGA and TEM, respectively. Results showed that the properties of MH...

  5. 云南省医疗机构制剂注册申报现状浅析%Analysis on Status Quo of Registration and Declaration of Pharmaceutical Preparations in Medical Institutions of Yunnan Province

    Institute of Scientific and Technical Information of China (English)

    万玫; 杨继红

    2013-01-01

    OBJECTIVE: To provide reference for the registration and declaration for pharmaceutical preparations in medical institutions. METHODS: The status quo of the registration and declaration for pharmaceutical preparations were analyzed in medical institutions of Yunnan province during 2005 -2011. The common problems of registration dossier were summarized. RESULTS & CONCLUSIONS: The basic test data is not standardized in the declaration for pharmaceutical preparations in medical institutions, such as insufficient prescription and technology research, quality risk of preparation, neglected stability test, deficiency of pharma-codynamics study, toxicity and safety evaluation, etc. It is suggested to develop the registration and declaration for new pharmaceutical preparations by strengthening research collaboration and abiding by technical guidelines.%目的:为医疗机构制剂新品种注册申报提供参考.方法:对2005年至2011年云南省医疗机构制剂申报情况及注册审评工作现状进行分析,总结申报资料中普遍存在的问题.结果与结论:目前医院制剂申报中普遍存在基础性试验资料不规范如处方及工艺研究不足,制剂质量控制存在隐患,不重视稳定性试验考察,缺乏药效学研究、毒性和安全性评价等情况.建议申报人通过加强科研协作、并按相关技术指导原则进行新品种注册申报工作.

  6. Preparation of ibuprofen/lipid composite microparticles by supercritical fluid technique

    Institute of Scientific and Technical Information of China (English)

    Xia WANG; Hui CHEN; Yanni GUO; Yuzhong SU; Hongtao WANG; Jun LI

    2008-01-01

    Using the CO2-and N2-assisted atomization processes, the production of ibuprofen/lipid composite microparticles is investigated, in which the lipid includes myristic acid and tripalmitin. The produced composite particles show similar morphology to that of the pure lipids obtained by the same process. In the case of the N2-assisted process, the average size of composite part-icles is slightly larger than that of the pure lipid particles due to the difficulty of solidification when using N2. In the case of the CO2-assisted process, the average size of com-posite particles is slightly smaller than that of the pure myr-istic acid particles, but slightly larger than that of the pure tripalmitin particles. The dissolution study reveals that the drug release from the ibuprofen/myristic acid particles is enhanced in comparison with that of the unprocessed ibu-profen. For the particles produced by the N2-assisted pro-cess, the X-ray diffraction (XRD) patterns clearly indicate the encapsulation of ibuprofen into myristic acid. The obtained ibuprofen/tripalmitin composite particles with 5% or 20% of ibuprofen (in mass) evidently show the con-trolled drug release: only about 20% of the drug is released in 500 min from the ibuprofen/tripalmitin composite part-icles consisting of 20% ibuprofen prepared by the CO2-assisted process, and the same release is obtained from the ibuprofen/tripalmitin composite particles containing 5% ibuprofen prepared by the N2-assisted process.

  7. Research on the preparation, biocompatibility and bioactivity of magnesium matrix hydroxyapatite composite material.

    Science.gov (United States)

    Linsheng, Li; Guoxiang, Lin; Lihui, Li

    2016-08-12

    In this paper, magnesium matrix hydroxyapatite composite material was prepared by electrophoretic deposition method. The optimal process parameters of electrophoretic deposition were HA suspension concentration of 0.02 kg/L, aging time of 10 days and voltage of 60 V. Animal experiment and SBF immersion experiment were used to test the biocompatibility and bioactivity of this material respectively. The SD rats were divided into control group and implant group. The implant surrounding tissue was taken to do tissue biopsy, HE dyed and organizational analysis after a certain amount of time in the SD rat body. The biological composite material was soaked in SBF solution under homeothermic condition. After 40 days, the bioactivity of the biological composite material was evaluated by testing the growth ability of apatite on composite material. The experiment results showed that magnesium matrix hydroxyapatite biological composite material was successfully prepared by electrophoretic deposition method. Tissue hyperplasia, connective tissue and new blood vessels appeared in the implant surrounding soft tissue. No infiltration of inflammatory cells of lymphocytes and megakaryocytes around the implant was found. After soaked in SBF solution, a layer bone-like apatite was found on the surface of magnesium matrix hydroxyapatite biological composite material. The magnesium matrix hydroxyapatite biological composite material could promot calcium deposition and induce bone-like apatite formation with no cytotoxicity and good biocompatibility and bioactivity.

  8. Preparation of Silica/Reduced Graphene Oxide Nanosheet Composites for Removal of Organic Contaminants from Water.

    Science.gov (United States)

    Li, Wen; Liu, Wei; Wang, Haifei; Lu, Wensheng

    2016-06-01

    Graphene-based composites open up new opportunities as effective adsorbents for the removal of organic contaminants from water. In this article, we report a novel and facile process to synthesize well-dispersed silica/reduced graphene oxide (SiO2/RGO) nanosheet composites. The SiO2/RGO nanosheet composites are prepared through a modified sol-gel process with in situ hydrolysis of tetraethoxysilane (TEOS) on graphene oxide (GO) nanosheet, followed by reduction of GO to graphene. In comparison with the RGO nanosheets, the as-prepared SiO2/RGO nanosheet composites have a larger surface area and good aqueous disperse ability. In addition, the application of SiO2/RGO nanosheet composites was demonstrated on removing organic dyes from water. The SiO2/RGO nanosheet composites show rapid and stable adsorption performance on removal of Methylene Blue (MB) and thionine (TH) from water. It is indicated that the resulting SiO2/RGO composites can be utilized as efficient adsorbents for the removal of organic contaminants from water.

  9. Preparation of Laminin-apatite-polymer Composites Using Metastable Calcium Phosphate Solutions

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    A synthetic polymer with a laminin-apatite composite layer on its surface would be useful as a percutaneous device. The preparation of such a composite was attempted in the present study using poly ( ethylene terephthalate ) (PET) and polyethylene ( PE ) as the synthetic polymer. PET and PE plates and those pretreated with an oxygen plasma were alternately dipped in calcium and phosphate ion solutions, and then immersed in a metastable ealcium phosphate solution supplemented with laminin ( LCP solution ). The PET and PE plates pretreated with an oxygen plasma formed a uniform and continuous layer of a laminin- apatite composite on their surfaces. In contrast, the PET and PE plates that had not been pretreated with an oxygen plasma did not form a continuous layer of a laminin-apatite composite on their surfaces. The hydrophilic functional groups on the PET and PE surfaces introduced by the plasma treatment were responsible for the successful laminin-apatite composite coating.

  10. Copper/bamboo fabric composite prepared via a silver catalytic electroless deposition process for electromagnetic shielding

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Qian; Lu, Yinxiang [Fudan Univ., Shanghai (China). Dept. of Materials Science

    2013-09-15

    Copper/bamboo fabric composite prepared via a silver catalytic electroless plating process is reported. The microstructure of the composite was analyzed by means of scanning electron microscopy, which illustrated that the copper coating was composed of spherical particles and clusters. The composition and chemical state of the metal layer were measured using X-ray diffraction and energy-dispersive X-ray analysis spectra; copper and a small amount of nickel were detected. Mechanical properties were measured based on a standard (ISO 13934-1:1999) for the fabrics with and without copper coating. The breaking force for the composite was improved by about 16.8% compared to uncoated bamboo fabric. The electromagnetic interference shielding effectiveness of the composite was more than 40 dB at frequencies ranging from 0.2 to 1000MHz. The copper coating on bamboo fabric passed the Scotch {sup registered} -tape test. (orig.)

  11. Preparation and Tribological Properties of Ni-P Electroless Composite Coating Containing Potassium Titanate Whisker

    Institute of Scientific and Technical Information of China (English)

    Yaxu JIN; Lin HUA

    2007-01-01

    Nickel-phosphorus (Ni-P) composite coatings containing potassium titanate (K2Ti6O13) whiskers (PTWs) were prepared by electroless plating. The surface morphology and component of coatings were investigated by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX), respectively before and after wear test. The tribological performance was evaluated using a pin-on-disk wear tester under dry conditions. It is found that the Ni-P-PTWs composite coatings exhibit higher wear resistance than Ni-P and Ni-P-SiC electroless coatings. The favorable effects of PTWs on the tribological properties of the composite coatings are attributed to the super-strong mechanical properties and the specific tunneling structures of PTWs. The PTWs greatly reinforce the structure of the Ni-P-based composite coatings and thereby greatly reduce the adhesive and plough wear of Ni-P-PTWs composite coatings.

  12. Preparation and Easy-Cleaning Property of Rare Earth Composite Ceramic

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Rare earth and far-infrared mineral composite materials were added to ceramic glazes to prepare easy-cleaning ceramic. The morphology of easy-cleaning ceramic was observed by SEM. The influence of easy-cleaning ceramic on water surface tension and contact angles of water were investigated. Through calculation of ceramic surface free energy and observation of oil drop on ceramic surface in water, the easy-cleaning mechanism of rare earth composite ceramic was studied. It is found that the rare earth composite ceramic can make water surface tension decrease. The surface free energy and the polar component of rare earth composite ceramic are increased. The rare earth composite ceramics have the easy-cleaning property.

  13. Preparation and Properties of Paraffin/TiO2/Active-carbon Composite Phase Change Materials

    Directory of Open Access Journals (Sweden)

    HAO Yong-gan

    2016-11-01

    Full Text Available A novel composite phase change materials (PCMs of paraffin/TiO2/active-carbon was prepared by a microemulsion method, where paraffin acted as a PCM and titanium dioxide (TiO2 as matrix material, and a small amount of active carbon was added to improve the thermal conductivity. The compositions, morphology and thermal properties of the paraffin/TiO2/active-carbon composite PCMs were characterized by XRD, SEM, TGA and DSC respectively. The shape stability during phase change process of this composite was also tested. The results show that paraffin is well encapsulated by TiO2 matrix, and thus exhibiting excellent shape-stabilized phase change feature. Besides, this composite PCM also presents superhydrophobic property. Therefore, these multifunctional features will endow PCMs with important application potential in energy efficient buildings.

  14. Preparation and properties of Cu matrix composite reinforced by carbon nanotubes

    Institute of Scientific and Technical Information of China (English)

    CHEN Xiao-hua; LI Wen-hua; CHEN Chuan-sheng; XU Long-shan; YANG Zhi; HU Jing

    2005-01-01

    Cu matrix composites reinforced by carbon nanotubes(CNTs) were prepared. The effect of carbon nanotubes on mechanical and tribological properties of the Cu matrix composites were investigated. The chemical method for coating CNTs was reported. The morphology of the fracture surfaces and worn surface were examined by SEM.The results show that Cu/coated-CNTs composites have higher hardness, much better wear resistance and antifriction properties than those of the reference Cu alloy (Cu-10Sn) and Cu/uncoated-CNTs composite sintered under the same conditions. The optimal mechanical properties of the composites occurred at 2. 25% (mass fraction) of CNTs. The excellent wear resistance and anti-friction properties are attributed to the fiber strengthening effect of CNTs and the effect of the spherical wear debris containing carbon nanotubes on the tribo-surface.

  15. Preparation and characterization of tungsten/epoxy composites for γ-rays radiation shielding

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Le [Key Laboratory of Specially Functional Polymeric Materials and Related Technology, Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237 (China); Zhang, Yan, E-mail: yzhang@ecust.edu.cn [Key Laboratory of Specially Functional Polymeric Materials and Related Technology, Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237 (China); Liu, Yujian; Fang, Jun [Key Laboratory of Specially Functional Polymeric Materials and Related Technology, Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237 (China); Luan, Weilin [Key Laboratory of Pressure and Safety (MOE), School of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai 200237 (China); Yang, Xiangmin; Zhang, Weidong [Institute of Nuclear Technology Application, School of Science, East China University of Science and Technology, Shanghai 200237 (China)

    2015-08-01

    Tungsten/epoxy composites were prepared by blending epoxy resin with different weight percent of tungsten powder. The effect of filler loading on shielding and mechanical properties of composites was investigated by using two different activities of Co-60 source. And radiation degradation mechanism was studied according to the changes of free radicals concentrations, mechanical properties and thermal properties of composites. The results show that with the increment of tungsten loading, shielding property of composites increases. However, with the increase of irradiation dose, thermal stability and mechanical properties of composites decrease firstly, then increase slightly, and decline sharply at the end due to competition reaction between chain scission and cross-linking originated from γ-rays radiation.

  16. [Adhesive cutaneous pharmaceutical forms].

    Science.gov (United States)

    Gafiţanu, E; Matei, I; Mungiu, O C; Pavelescu, M; Mîndreci, I; Apostol, I; Ionescu, G

    1989-01-01

    The adhesive cutaneous pharmaceutical forms aimed to local action release the drug substance in view of a dermatological, traumatological, antirheumatic, cosmetic action. Two such preparations were obtained and their stability, consistency and pH were determined. The "in vitro" tests of their bioavailability revealed the dynamics of calcium ions release according to the associations of each preparation. The bioavailability determined by evaluating the pharmacological response demonstrated the antiinflammatory action obtained by the association of calcium ions with the components extracted from poplar muds. The therapeutical efficiency of the studied preparations has proved in the treatment of some sport injuries.

  17. Laser Surface Preparation of Epoxy Composites for Secondary Bonding: Optimization of Ablation Depth

    Science.gov (United States)

    Palmieri, Frank L.; Hopkins, John; Wohl, Christopher J.; Lin, Yi; Connell, John W.; Belcher, Marcus A.; Blohowiak, Kay Y.

    2015-01-01

    Surface preparation has been identified as one of the most critical aspects of attaining predictable and reliable adhesive bonds. Energetic processes such as laser ablation or plasma treatment are amenable to automation and are easily monitored and adjusted for controlled surface preparation. A laser ablation process was developed to accurately remove a targeted depth of resin, approximately 0.1 to 20 micrometers, from a carbon fiber reinforced epoxy composite surface while simultaneously changing surface chemistry and creating micro-roughness. This work demonstrates the application of this process to prepare composite surfaces for bonding without exposing or damaging fibers on the surface. Composite panels were prepared in an autoclave and had a resin layer approximately 10 micrometers thick above the fiber reinforcement. These composite panels were laser surface treated using several conditions, fabricated into bonded panels and hygrothermally aged. Bond performance of aged, experimental specimens was compared with grit blast surface treated specimens using a modified double cantilever beam test that enabled accelerated saturation of the specimen with water. Comparison of bonded specimens will be used to determine how ablation depth may affect average fracture energies and failure modes.

  18. Preparation and characterization of nano-hydroxyapatite/chitosan/konjac glucomannan composite

    NARCIS (Netherlands)

    Zhou, G.; Li, Yubao; Zhang, L.; Zuo, Y.; Jansen, J.A.

    2007-01-01

    Nano-hydroxyapatite (n-HA)/chitosan (CS)/konjac glucomannan (KGM) composite was prepared by coprecipitation method and investigated by thermal gravitivity/differentiate thermal analysis, Fourier transform infrared spectroscopy, X-ray diffraction, inductively coupled plasma emission spectroscopy, sca

  19. Properties of dry film lubricants prepared by spray application of aqueous starch-oil composites

    Science.gov (United States)

    Aqueous dispersions of starch-soybean oil (SBO) and starch-jojoba oil (JO) composites, prepared by excess steam jet cooking, form effective dry film lubricants when applied as thick coatings to metal surfaces by doctor blade. This application method necessitates long drying times, is wasteful, requ...

  20. Preparation of designed poly(D,L-lactide)/nanosized hydroxyapatite composite structures by stereolithography.

    Science.gov (United States)

    Ronca, A; Ambrosio, L; Grijpma, D W

    2013-04-01

    The preparation of scaffolds to facilitate the replacement of damaged tissues and organs by means of tissue engineering has been much investigated. The key properties of the biomaterials used to prepare such scaffolds include biodegradability, biocompatibility and a well-defined three-dimensional 3-Dpore network structure. In this study a poly(D,L-lactide)/nanosized hydroxyapatite (PDLLA/nano-Hap) composite resin was prepared and used to fabricate composite films and computer designed porous scaffolds by micro-stereolithography, mixing varying quantities of nano-Hap powder and a liquid photoinitiator into a photo-crosslinkable PDLLA-diacrylate resin. The influence of nano-Hap on the rheological and photochemical properties of the resins was investigated, the materials being characterized with respect to their mechanical, thermal and morphological properties after post-preparation curing. In the cured composites stiffness was observed to increase with increasing concentration of nanoparticles. A computer designed construct with a pore network based on the Schwarz architecture was fabricated by stereolithography using PDLLA/nano-Hap composite resins.

  1. Sliding wear resistance of metal matrix composite layers prepared by high power laser

    NARCIS (Netherlands)

    Ocelik, Vaclav; Matthews, D; de Hosson, Jeff

    2005-01-01

    Two laser surface engineering techniques, Laser Cladding and Laser Melt Injection (LMI), were used to prepare three different metal matrix composite layers with a thickness of about 1 mm and approximately 25-30% volume fraction of ceramic particles. SiC/Al-8Si, WC/Ti-6Al-4V and TiB2/Ti-6Al-4V layers

  2. Chitosan-cellulose composite materials: Preparation, Characterization and application for removal of microcystin

    Energy Technology Data Exchange (ETDEWEB)

    Tran, Chieu D., E-mail: chieu.tran@marquette.edu [Department of Chemistry, Marquette University, P.O. Box 1881, Milwaukee, WI 53201 (United States); Duri, Simon [Department of Chemistry, Marquette University, P.O. Box 1881, Milwaukee, WI 53201 (United States); Delneri, Ambra; Franko, Mladen [Laboratory for Environmental Research, University of Nova Gorica, Vipavska 13, 5001 Nova Gorica (Slovenia)

    2013-05-15

    Highlights: •A novel and recyclable synthetic method using an ionic liquid, a Green Solvent. •Ecocomposite materials were synthesized from cellulose (CEL) and chitosan (CS). •Adding CEL into CS substantially increases tensile strength of the composite. •The composite is much better adsorbent for cyanotoxins than other materials. •The composite can be reused because adsorbed microcystin can be desorbed. -- Abstract: We developed a simple and one-step method to prepare biocompatible composites from cellulose (CEL) and chitosan (CS). [BMIm{sup +}Cl{sup −}], an ionic liquid (IL), was used as a green solvent to dissolve and prepare the [CEL + CS] composites. Since majority (>88%) of IL used was recovered for reuse by distilling the aqueous washings of [CEL + CS], the method is recyclable. XRD, FTIR, NIR, {sup 13}C CP-MAS-NMR and SEM were used to monitor the dissolution and to characterize the composites. The composite was found to have combined advantages of their components: superior mechanical strength (from CEL) and excellent adsorption capability for microcystin-LR, a deadly toxin produced by cyanobacteria (from CS). Specifically, the mechanical strength of the composites increased with CEL loading; e.g., up to 5× increase in tensile strength was achieved by adding 80% of CEL into CS. Kinetic results of adsorption confirm that unique properties of CS remain intact in the composite, i.e., it is not only a very good adsorbent for microcystin but also is better than all other available adsorbents. For example, it can adsorb 4× times more microcystin than the best reported adsorbent. Importantly, the microcystin adsorbed can be quantitatively desorbed to enable the composite to be reused with similar adsorption efficiency.

  3. Preparation and characterization of phosphorylated Zr-doped hybrid silica/PSF composite membrane.

    Science.gov (United States)

    Zhang, Yuqing; Jin, Zhenhua; Shan, Xing; Sunarso, Jaka; Cui, Ping

    2011-02-15

    Polysulfone (PSF) membranes are broadly applied in many fields owing to good physicochemical stability, resistance to oxidation and chlorine. But when treated with wastewater containing oil, PSF membranes are easy to be contaminated for its hydrophobicity, which can result in the declining of flux and lifespan of the membrane and limit their application in large scale. To enhance the capability of PSF membrane in the above circumstances, phosphorylated Zr-doped hybrid silica particles (SZP particles) were firstly prepared. SZP particles have various point defects inside their structure and lots of hydroxide radicals on their surface. SZP particles were added to the porous matrix of PSF to prepare a novel composite membrane (SZP/PSF) through a phase inversion process. Finally, the optimum preparation conditions of SZP/PSF composite membranes were determined. The optimum conditions are: the mass ratio of PSF, PEG400 and SZP is 12:10:10; ultrasound 10 min inside each 30 min; the pre-evaporating time is 10s. Optimized SZP/PSF composite membrane was characterized by scanning electron microscope (SEM) and ultrafiltration experiment. The results indicate that SZP particles can be uniformly dispersed in SZP/PSF composite membranes with excellent hydrophilic property, antifouling capability and tensile strength. Therefore, it can be concluded that the optimized SZP/PSF composite membrane is desirable in the treatment of wastewater containing oil and wastewater.

  4. Preparation and characterization of the PVDF-based composite membrane for direct methanol fuel cells

    Directory of Open Access Journals (Sweden)

    Qian Liu, Laizhou Song, Zhihui Zhang, Xiaowei Liu

    2010-07-01

    Full Text Available The polyvinylidene fluoride-sulfonated polystyrene composite membrane with proton exchange performance, denoted as PVDF-SPS, was prepared using a thermally induced polymerization technique. The thermal stability of the PVDF-SPS composite membrane was investigated using thermogravimetric (TG analysis. The complex formation of the composite membrane was ascertained by Fourier transform infrared spectroscopy (FTIR. The surface compositions of the PVDF-SPS membrane were analyzed using X-ray photoelectron spectroscopy (XPS. The morphology of the composite membrane was characterized by environmental scanning electron microscopy (ESEM. The proton conductivity of the PVDF-SPS membrane was measured using impedance spectroscopy in the hydrated condition. The PVDF-SPS membrane has a stronger hydrophilic character than the pristine PVDF membrane and the polyvinylidene fluoride-polystyrene composite membrane (PVDF-PS, which is caused by the incorporation of sulfonic acid groups. The proton conductivity and the methanol permeability of the PVDF-SPS membrane measured at 298 K are 29.3 mS.cm-1 and 8.6×10-8 cm2.s-1, respectively. Although PVDF-SPS composite membrane possesses the lower oxidative stability than Nafion-117 membrane, the composite membrane displays lower methanol permeability than the Nafion-117 membrane, and the selectivity (the ratio of proton conductivity and methanol permeability of the composite membrane is almost 20 times than that of Nafion-117.

  5. PREPARATION AND MECHANICAL PROPERTIES OF T-ZnOw/PS COMPOSITES

    Institute of Scientific and Technical Information of China (English)

    Yong Wang; Jing Shi; Zheng-bao He; Hong-wei Bai

    2009-01-01

    The main subject of this work is about the preparation of T-ZnOw/PS composites through different methods and the evaluation of mechanical properties of the composites.Different surface modification methods of T-ZnOw whiskers,the so called wet-type modification and dry-type modification,and different molding processing methods of T-ZnOw/PS composites,namely compression molding and injection molding,have been employed.Two different coupling agents,titanate coupling agent (NDZ105) and silane coupling agent (KH560),have been used to treat T-ZnOw.Both the interface structure between T-ZnOw whiskers and PS and the distribution of integrated T-ZnOw whiskers in composites have been studied by SEM.The mechanical properties of T-ZnOw/PS composites obtained through the above different methods have been studied comparatively.Although the tensile strength of the composites decreases slightly,the impact strength and tensile modulus increase with increasing the content of T-ZnOw in the composites.Both coupling agents and molding methods have great influence on the mechanical properties of the composites.The study of the impact-fractured surface shows that craze formation in PS matrix during the impact process is the main reason for the improvement of the composite toughness.

  6. Preparation and characterization of the PVDF-based composite membrane for direct methanol fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Liu Qian; Song Laizhou; Zhang Zhihui; Liu Xiaowei [Department of Environmental and Chemical Engineering, Yanshan University, Qinhuangdao 066004 (China)

    2010-07-01

    The polyvinylidene fluoride-sulfonated polystyrene composite membrane with proton exchange performance, denoted as PVDF-SPS, was prepared using a thermally induced polymerization technique. The thermal stability of the PVDF-SPS composite membrane was investigated using thermogravimetric (TG) analysis. The complex formation of the composite membrane was ascertained by Fourier transform infrared spectroscopy (FTIR). The surface compositions of the PVDF-SPS membrane were analyzed using X-ray photoelectron spectroscopy (XPS). The morphology of the composite membrane was characterized by environmental scanning electron microscopy (ESEM). The proton conductivity of the PVDF-SPS membrane was measured using impedance spectroscopy in the hydrated condition. The PVDF-SPS membrane has a stronger hydrophilic character than the pristine PVDF membrane and the polyvinylidene fluoride-polystyrene composite membrane (PVDF-PS), which is caused by the incorporation of sulfonic acid groups. The proton conductivity and the methanol permeability of the PVDF-SPS membrane measured at 298 K are 29.3 mS.cm-1 and 8.6x10-8 cm2.s-1, respectively. Although PVDF-SPS composite membrane possesses the lower oxidative stability than Nafion-117 membrane, the composite membrane displays lower methanol permeability than the Nafion-117 membrane, and the selectivity (the ratio of proton conductivity and methanol permeability) of the composite membrane is almost 20 times than that of Nafion-117.

  7. Preparation of SnO 2 /Carbon Composite Hollow Spheres and Their Lithium Storage Properties

    KAUST Repository

    Lou, Xiong Wen

    2008-10-28

    In this work, we present a novel concept of structural design for preparing functional composite hollow spheres and derived double-shelled hollow spheres. The approach involves two main steps: preparation of porous hollow spheres of one component and deposition of the other component onto both the interior and exterior surfaces of the shell as well as in the pores. We demonstrate the concept by preparing SnO2/carbon composite hollow spheres and evaluate them as potential anode materials for lithium-ion batteries. These SnO2/carbon hollow spheres are able to deliver a reversible Li storage capacity of 473 mA h g-1 after 50 cycles. Unusual double-shelled carbon hollow spheres are obtained by selective removal of the sandwiched porous SnO2 shells. © 2008 American Chemical Society.

  8. Plasma preparation and low-temperature sintering of spherical TiC-Fe composite powder

    Institute of Scientific and Technical Information of China (English)

    Jian-jun Wang; Jun-jie Hao; Zhi-meng Guo; Song Wang

    2015-01-01

    A spherical Fe matrix composite powder containing a high volume fraction (82vol%) of fine TiC reinforcement was produced us-ing a novel process combining in situ synthesis and plasma techniques. The composite powder exhibited good sphericity and a dense struc-ture, and the fine sub-micron TiC particles were homogeneously distributed in theα-Fe matrix. A TiC–Fe cermet was prepared from the as-prepared spherical composite powder using powder metallurgy at a low sintering temperature;the product exhibited a hardness of HRA 88.5 and a flexural strength of 1360 MPa. The grain size of the fine-grained TiC and special surface structure of the spherical powder played the key roles in the fabrication process.

  9. Preparation of bismuth titanate/calcium alginate composite bead and its photocatalytic degradation of dye pollutants

    Science.gov (United States)

    Gan, Huihui; Dong, Nanyang; Lu, Linxiao; Fu, Yan; Zhang, Huining; Qian, Yongxin; Zhang, Kefeng; Jin, Huixia

    2017-08-01

    In this study, the bismuth titanate/calcium alginate composite bead was synthesized by immobilizing bismuth titanate Bi4Ti3O12 particles into 1.5% sodium alginate (SA) matrix. The Bi4Ti3O12 particles were characterized by X-ray diffraction (XRD). The photocatalytic activity for the degradation of dye Rhodamine B in solution by as-prepared bismuth titanate/calcium alginate composite bead was investigated. The as-prepared composite beads CA/BTO-700 exhibited best photocatalytic efficiency for the degradation of RhB compared with CA/BTO-800 and CA/BTO-900 under simulated solar light. After 4 cycles in photocatalytic degradation of RhB, the degradation rate of the CA/BTO-700 nearly remained unchanged.

  10. Preparation and application of sodium borohydride composites for portable hydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Y. [School of Materials Science and Engineering, Tianjin Polytechnic University, Tianjin 300160 (China); Department of Environmental Engineering and Biotechnology, Myongji University, Yongin, Kyonggi-Do 449728 (Korea); Kim, H. [Department of Environmental Engineering and Biotechnology, Myongji University, Yongin, Kyonggi-Do 449728 (Korea)

    2010-02-15

    Novel composites consisting of cobalt-boron (CoB) catalyst and sodium borohydride (NaBH{sub 4}) implantation in polymers (polyethylene glycol (PEG) or sodium alginate) were prepared for portable hydrogen production. The CoB catalyst was synthesized by the reduction of cobalt salt in NaBH{sub 4} solution followed by heat treatment in nitrogen atmosphere. The catalyst was embedded in PEG gel or alginate beads and NaBH{sub 4} was directly added in PEG-dimethylformamide (DMF) gel and adsorbed in alginate beads. It is noted that the composites prepared are stable in dry air and can be easily used for hydrogen production. A rate of hydrogen production of 750 ml min{sup -1} g{sup -1} was reached when simply putting the composites into pure water. The humidified pure hydrogen can be used conveniently for fuel cells. (author)

  11. Preparation and characterization of a novel composite microporous polymer electrolyte for Li-ion batteries

    Institute of Scientific and Technical Information of China (English)

    CHEN Zuofeng; JIANG Yanxia; ZHUANG Quanchao; DONG Quanfeng; WANG Ye; SUN Shigang

    2005-01-01

    A novel composite microporous polymer electrolyte composed of poly(vinylidene fluoride-co-hexafluorop- ropylene) (PVdF-HFP) and mesoporous SBA-15 was prepared. The composite solid polymer electrolyte (CSPE) exhibits ionic conductivity as high as 0.30 mS·cm-1 with a composition of SBA-15:PVdF-HFP=3:8 at room temperature. Infrared transmission spectroscopic results suggested that the mechanism of micropore formation is similar to that of the phase inversion. X-ray diffraction (XRD) results demonstrated that the addition of SBA-15 inhibits the crystallization of PVdF-HFP, while the SBA-15 preserves well its ordered mesoporous structure during the course of preparation. The Li/CSPE/MCF of half-cell was assembled, and it showed a good electrochemical and cyclability performance during charge-discharge cycles.

  12. Preparation of MWNTs/Al2O3 composites and their mechanical and electrical properties

    Institute of Scientific and Technical Information of China (English)

    FAN; Jinpeng; ZHAO; Daqing; XU; Zening; WU; Minsheng

    2005-01-01

    The mechanical and electrical properties of MWNTs/Al2O3 composite prepared fabricated by hot pressing are investigated. The relation between properties and microstructure of composites is also discussed. With 4wt% MWNTs as reinforcement, the fracture toughness of composite obtained reaches 5.55 Mpa·m1/2, which is 80% higher than that of pure Al2O3 obtained in the same conditions. The main toughening mechanism is CNTs' pinning alumina grain boundaries, and the pullout of CNTs takes effect also. Through adding 2wt% MWNTs and altering the mix method, the fracture toughness of the composite obtained is 3.97 Mpa·m1/2. Furthermore, the electrical resistivity is as low as 8.4×10-3Ω·m, decreasing by 14 orders of magnitude compared with pure alumina ceramics. The function of CNTs in composite is related to the distribution state of CNTs in composite, and the distribution state of CNTs in matrix is dependent on preparation procedures.

  13. Preparation and characterization of novel elastin-like polypeptide-collagen composites.

    Science.gov (United States)

    Amruthwar, Shruti S; Puckett, Aaron D; Janorkar, Amol V

    2013-08-01

    Collagen-based biomaterials suffer from poor mechanical properties and rapid degradation. Elastin-like polypeptides (ELPs) possess good biocompatibility and have unique solution properties that allow them to coacervate above a critical temperature. The objective of this research was to prepare a series of freeze dried ELP-collagen composite scaffolds as a proof of concept. Combination of ELP and collagen has the potential to produce composite structures with varying strengths. Four different composite structures were prepared by varying the ratio of ELP to collagen. Increased ELP content in the scaffolds appears to have reduced the residual water content based on Fourier transformed infrared spectroscopy and differential scanning calorimetry. Scanning electron microscopy images of ELP-collagen composites showed a three-dimensional, open porous structure with the formation of characteristic aggregates of ELP. The mechanical testing experiments showed that the elastic modulus, tensile strength, and toughness of ELP-collagen scaffolds were significantly greater than neat collagen scaffolds. The improved mechanical properties were attributed to a homogeneous network structure with additional reinforcement coming from the ELP aggregates. Our study confirms that ELP-collagen composites with superior physical and mechanical properties compared to collagen scaffolds can be produced. Further optimization of design parameters will allow producing ELP-collagen composites for specific biomedical applications.

  14. Preparation and characterization of carbonyl iron/glass composite absorber as matched load for isolator

    Science.gov (United States)

    Feng, Yongbao; Li, Yujiao; Qiu, Tai

    2012-09-01

    Composite absorbers made from 66 wt% carbonyl iron and 34 wt% low melting point glass powder were prepared by a pressureless sintering technique in a nitrogen atmosphere. Apparent porosity and bending strength of the as-prepared composites were investigated. The microstructure, heat resisting properties and electromagnetic properties were characterized by scanning electron microscopy, thermal gravimetric analysis-differential scanning calorimetry and vector network analyzer. The results show that the carbonyl iron/glass composite absorbers were difficult to densify. As the sintering temperature and soaking time increased, the apparent porosity first decreased and then increased, whereas the bending strength showed the opposite change. The composite absorber sintered at 520 °C for 40 min achieved the minimum apparent porosity of 13.08% and the highest bending strength of 52 MPa. Compared to the carbonyl iron/silicone rubber absorber, the carbonyl iron/glass composite absorber exhibited better heat resisting properties, and the initial oxidation temperature was increased about 200 °C. The composite absorber with a thickness of 1.25 mm showed a good microwave absorbing property in 8-12 GHz.

  15. Preparation, Characterization and Properties of Alginate/Poly(γ-glutamic acid Composite Microparticles

    Directory of Open Access Journals (Sweden)

    Zongrui Tong

    2017-04-01

    Full Text Available Alginate (Alg is a renewable polymer with excellent hemostatic properties and biocapability and is widely used for hemostatic wound dressing. However, the swelling properties of alginate-based wound dressings need to be promoted to meet the requirements of wider application. Poly(γ-glutamic acid (PGA is a natural polymer with high hydrophility. In the current study, novel Alg/PGA composite microparticles with double network structure were prepared by the emulsification/internal gelation method. It was found from the structure characterization that a double network structure was formed in the composite microparticles due to the ion chelation interaction between Ca2+ and the carboxylate groups of Alg and PGA and the electrostatic interaction between the secondary amine group of PGA and the carboxylate groups of Alg and PGA. The swelling behavior of the composite microparticles was significantly improved due to the high hydrophility of PGA. Influences of the preparing conditions on the swelling behavior of the composites were investigated. The porous microparticles could be formed while compositing of PGA. Thermal stability was studied by thermogravimetric analysis method. Moreover, in vitro cytocompatibility test of microparticles exhibited good biocompatibility with L929 cells. All results indicated that such Alg/PGA composite microparticles are a promising candidate in the field of wound dressing for hemostasis or rapid removal of exudates.

  16. Preparation and applications of a variety of fluoroalkyl end-capped oligomer/hydroxyapatite composites.

    Science.gov (United States)

    Takashima, Hiroki; Iwaki, Ken-Ichi; Furukuwa, Rika; Takishita, Katsuhisa; Sawada, Hideo

    2008-04-15

    A variety of fluoroalkyl end-capped oligomers were applied to the preparation of fluorinated oligomer/hydroxyapatite (HAp) composites (particle size: 38-356 nm), which exhibit a good dispersibility in water and traditional organic solvents. These fluoroalkyl end-capped oligomer/HAp composites were easily prepared by the reactions of disodium hydrogen phosphate and calcium chloride in the presence of self-assembled molecular aggregates formed by fluoroalkyl end-capped oligomers in aqueous solutions. In these fluorinated HAp composites thus obtained, fluoroalkyl end-capped acrylic acid oligomers and 2-methacryloyloxyethanesulfonic acid oligomer/HAp nanocomposites afforded transparent colorless solutions toward water; however, fluoroalkyl end-capped N,N-dimethylacrylamide oligomer and acryloylmorpholine oligomer were found to afford transparent colorless solutions with trace amounts of white-colored HAp precipitants under similar conditions. HAp could be encapsulated more effectively into fluorinated 2-methacryloyloxyethanesulfonic acid oligomeric aggregate cores to afford colloidal stable fluorinated oligomer/HAp composites, compared to that of fluorinated acrylic acid oligomers. These fluorinated oligomer/HAp composites were applied to the surface modification of glass and PVA to exhibit a good oleophobicity imparted by fluorine. HAp formation was newly observed on the modified polyethylene terephthalate film surface treated with fluorinated 2-methacryloyloxyethanesulfonic acid oligomers and acrylic acid oligomer/HAp composites by soaking these films into the simulated body fluid.

  17. PREPARATION AND PROPERTIES OF ETHYL-CYANOETHYL CELLULOSE/POLYACRYLIC ACID COMPOSITE FILMS WITH REFLECTION COLORS

    Institute of Scientific and Technical Information of China (English)

    Yong Huang

    2001-01-01

    Ethyl-cyanoethyl cellulose [(E-CE)C]/acrylic acid (AA) becomes a cholesteric liquid crystalline solution with vivid colors when the (E-CE)C concentration is 42 wt% ~52 wt%. (E-CE)C/polyacrylic acid (PAA) composites with cholesteric structure were prepared by polymerizing AA in (E-CE)C/AA liquid crystalline solutions. The layers of ordered polymer chains in the cholesteric phase were inclined during polymerization and the degree of the inclination depended on the polymerization temperature and the concentration of the solution before polymerization. The cholesteric structure in the composites could not be changed when temperature was lower than 100C. Cross-linking of the PAA in composites improved their water-resistance. The cholesteric order of the composites without cross-linking was destroyed when they where immersed in water. The color derived from the selective reflection of the cholesteric phase of the cross-linked composites turned from blue to red after the composites absorbed water. The color of the composites could be returned to the original one when the absorbed water was removed from the swollen composites.

  18. Improving pharmaceutical preparation in the hospital by good manufacturing practice validation%药品生产质量管理规范验证对医院制剂的影响

    Institute of Scientific and Technical Information of China (English)

    唐安福; 崔恩忠; 汤淏; 王曙东

    2013-01-01

    With the rapid development of medicine technology and pharmaceutical industry , the law and regulations on drugs and their supervision system are being perfected gradually . Pharmaceutical preparation in the hospital is confronted with even more challenges, as in the preparation process and inspection condition . More and more importance has to be attached to the implementation of good manufacturing practice validation in order to promote the development of pharmaceutical preparation in the hospital in accord -ance with the new law and regulations.%随着医药科技和制药工业的飞速发展,药品法规及其监督机制的不断完善,医院制剂的发展正面临着更多的挑战,其配制工艺和检测条件的要求也越来越高.为了适应新形势下的药品法规,进一步发展医院制剂,药品生产质量管理规范(good manufancturing practice,GMP)验证的推行显得尤为重要,以不断提高医院制剂的质量,充分补充医药市场上的品种供应,全面服务于临床,更好地满足医院医疗用药的需求.

  19. Preparation and mechanical properties of photo-crosslinked poly(trimethylene carbonate) and nano-hydroxyapatite composites

    NARCIS (Netherlands)

    Geven, Mike A.; Barbieri, Davide; Yuan, Huipin; de Bruijn, Joost D.; Grijpma, Dirk W.

    2015-01-01

    Composite materials of photo-crosslinked poly(trimethylene carbonate) and nanoscale hydroxyapatite were prepared and their mechanical characteristics for application as orbital floor implants were assessed. The composites were prepared by solvent casting poly(trimethylene carbonate) macromers with v

  20. Kinetic Spectrophotometric Determination of Gemifloxacin Mesylate and Moxifloxacin Hydrochloride in Pharmaceutical Preparations Using 4-Chloro-7-nitrobenzo-2-oxa-1,3-diazole

    Directory of Open Access Journals (Sweden)

    Mohammed G. Abdel Wahed

    2014-01-01

    Full Text Available Simple, sensitive, and accurate kinetic spectrophotometric method was proposed for the determination of gemifloxacin mesylate (GMF and moxifloxacin hydrochloride (MOX in pure forms and pharmaceutical preparations (tablets. The method is based on coupling the studied drugs with 4-chloro-7-nitrobenzo-2-oxa-1,3-diazole (NBD-Cl in the presence of alkaline borate buffer. Spectrophotometric measurement was achieved by recording the absorbance at 466 and 464 nm for GMF and MOX, respectively, after a fixed time of 20 and 15 min on a water bath adjusted at 70 ± 5°C for both drugs. The different experimental parameters affecting the development and stability of the color were carefully studied and optimized. The absorbance-concentration plots were linear over the ranges 0.5–8.0 and 2.0–12 μg mL−1 for GMF and MOX, respectively. The limit of detection of the kinetic method was about 0.12 (2.47 × 10−7 M and 0.36 (8.22 × 10−7 M μg mL−1 for GMF and MOX, respectively. The proposed methods have been applied and validated successfully with percentage relative standard deviation (RSD% ≤ 0.52 as precision and percentage relative error (RE% ≤ 1.33 as accuracy. The robustness of the proposed method was examined with recovery values that were 97.5–100.5 ± 1.3–1.9%. Statistical comparison of the results with the reference spectrophotometric methods shows excellent agreement and indicates no significant difference in accuracy or precision.

  1. Preparation of electromechanically active silicone composites and some evaluations of their suitability for biomedical applications

    Energy Technology Data Exchange (ETDEWEB)

    Iacob, Mihail; Bele, Adrian [“Petru Poni” Institute of Macromolecular Chemistry, Aleea Gr. Ghica Voda 41A, Iasi 700487 (Romania); Patras, Xenia [“Apollonia” University, 2 Muzicii Street, 700511 Iasi (Romania); Pasca, Sorin [“Ion Ionescu de la Brad” University of Agricultural Sciences and Veterinary Medicine Iaşi, Aleea Mihail Sadoveanu nr. 3, Iasi 700490 (Romania); Butnaru, Maria [“Gr. T. Popa” University of Medicine and Pharmacy, Faculty of Medical Bioengineering, 16 University Street, 700115 Iasi (Romania); Alexandru, Mihaela [“Petru Poni” Institute of Macromolecular Chemistry, Aleea Gr. Ghica Voda 41A, Iasi 700487 (Romania); Ovezea, Dragos [National Institute for Research and Development in Electrical Engineering ICPE-CA, 313 Splaiul Unirii, Bucharest 030138 (Romania); Cazacu, Maria, E-mail: mcazacu@icmpp.ro [“Petru Poni” Institute of Macromolecular Chemistry, Aleea Gr. Ghica Voda 41A, Iasi 700487 (Romania)

    2014-10-01

    Some films based on electromechanically active polymer composites have been prepared. Polydimethylsiloxane-α,ω-diols (PDMSs) having different molecular masses (Mv = 60 700 and Mv = 44 200) were used as matrix in which two different active fillers were incorporated: titanium dioxide in situ generated from its titanium isopropoxide precursor and silica particles functionalized with polar aminopropyl groups on surface. A reference sample based on simple crosslinked PDMS was also prepared. The composites processed as films were investigated to evaluate their ability to act as efficient electromechanical actuators for potential biomedical application. Thus, the surface morphology of interest for electrodes compliance was analysed by atomic force microscopy. Mechanical and dielectric characteristics were evaluated by tensile tests and dielectric spectroscopy, respectively. Electromechanical actuation responses were measured by interferometry. The biocompatibility of the obtained materials has been verified through tests in vitro and, for valuable films, in vivo. The experimental, clinical and anatomopathological evaluation of the in vivo tested samples did not reveal significant pathological modifications. - Highlights: • Silicone composites differing by the filler and matrix characteristics were prepared. • Stress–strain curves were registered in normal and cyclic modes for composite films. • The dielectric permittivity, dielectric loss, and conductivity were determined. • Electromechanical response of the films was measured at an applied voltage. • Some biocompatibility tests, both in vitro and in vivo, were performed.

  2. Characterization of Three-Dimensional Printed Composite Scaffolds Prepared with Different Fabrication Methods

    Directory of Open Access Journals (Sweden)

    Szlązak K.

    2016-06-01

    Full Text Available An optimal method for composites preparation as an input to rapid prototyping fabrication of scaffolds with potential application in osteochondral tissue engineering is still needed. Scaffolds in tissue engineering applications play a role of constructs providing appropriate mechanical support with defined porosity to assist regeneration of tissue. The aim of the presented study was to analyze the influence of composite fabrication methods on scaffolds mechanical properties. The evaluation was performed on polycaprolactone (PCL with 5 wt% beta-tricalcium phosphate (TCP scaffolds fabricated using fused deposition modeling (FDM. Three different methods of PCL-TCP composite preparation: solution casting, particles milling, extrusion and injection were used to provide material for scaffold fabrication. The obtained scaffolds were investigated by means of scanning electron microscope, x-ray micro computed tomography, thermal gravimetric analysis and static material testing machine. All of the scaffolds had the same geometry (cylinder, 4×6 mm and fiber orientation (0/60/120°. There were some differences in the TCP distribution and formation of the ceramic agglomerates in the scaffolds. They depended on fabrication method. The use of composites prepared by solution casting method resulted in scaffolds with the best combination of compressive strength (5.7±0.2 MPa and porosity (48.5±2.7 %, both within the range of trabecular bone.

  3. Preparation of conductive polypyrrole (PPy) composites under supercritical carbon dioxide conditions

    Institute of Scientific and Technical Information of China (English)

    LI Gang; LIAO Xia; SUN Xinghua; YU Jian; HE Jiasong

    2007-01-01

    Electrically conductive composites were prepared via the chemical oxidative polymerization of the pyrrole monomer in polystyrene (PS) and zinc neutralized sulfonated polystyrene (Zn-SPS) films under supercritical carbon dioxide (SC-CO2) conditions.The strong swelling effect of SCCO2 made polypyrrole (PPy) particles not only form on the surface,but also become incorporated into the film,resulting in a homogeneous structure with a relatively higher conductivity.By comparison,the composite prepared in aqueous solutions shows a skin-core structure and a conductivity of 3 to 4 orders of magnitude lower than that of the former due to the diffusion-controlled process of the pyrrole monomer.The percolation thresholds of PS/PPy and Zn-SPS/PPy composites were 6.2% and 2.7% of the volume fraction of PPy,respectively,much lower than the theoretically predicted value of 16%.Moreover,the conductive composites prepared under SC-CO2 conditions showed higher thermal stability,especially in the high-temperature region.

  4. Different surface preparation techniques of porcelain repaired with composite resin and fracture resistance

    Directory of Open Access Journals (Sweden)

    Mohd Helmy Khalid Abd Wahab

    2011-01-01

    Full Text Available Background : Porcelain from prosthesis such as crown or bridge can be fractured if exposed to trauma; and, can be repaired at chairside using composite resin. Aim : To investigate the fracture resistance of few techniques of surface preparation in repairing fractured porcelain using composite resin. Materials and Methods : Eighty samples of porcelain blocks were divided into 4 groups for different surface preparations, such as, Cimara repairing kit; porcelain etch kit containing hydrofluoric acid; Panavia F resin cement; and, sandblasting using aluminium oxide, before composite resin (Filtek Z250, 3M ESPE was bonded to the prepared porcelain blocks. Twenty others samples in the control group comprised of pure porcelain blocks. The fracture resistance of each sample was tested using Instron machine (UK. Results : With the exception of the group repaired using hydrofluoric acid (3.04±1.04 Mpa, all the other groups showed significant difference in the fracture resistance values when compared to the control group (3.05 ± 1.42 MPa at P<0.05. Conclusions : Etching of the porcelain blocks with hydrofluoric acid holds promise in the repair of fractured porcelain with composite resin at chairside.

  5. Preparation and characterization of chitosan/nano-hydroxyapatite composite used as bone substitute materials

    Institute of Scientific and Technical Information of China (English)

    Zhang Li; Li Yubao; Zhou Gang; Wu Lan; Mu Yuanhua; Yang Zheng

    2007-01-01

    Chitosan/nano-hydroxyapatite composites with different weight ratios were prepared through a co-precipitation method using Ca(OH)2, H3PO4 and chitosan as starting materials. The properties of these composites were characterized by means of TEM, IR, XRD, TGA, bum-out tests and universal matertial testing machine. The results showed that the HA synthesized here was poorly crystalline carbonated nanometer crystals and dispersed uniformly in chitosan phase and there was no phase-separation between the two phases. The addition of n-HA resulted in a decrease of decomposing temperature of chitosan. Because of the interactions between chitosan and n-HA, the mechanical properties of these composites were improved, and the maximum value of the compressive strength was measured to be about 120MPa corresponding to the chitosan/n-HA composite with a weight ratio of 30/70.

  6. Preparation of gelatin-assisted polypyrrole-poly(3,4-ethylenedioxythiophene) composites

    Energy Technology Data Exchange (ETDEWEB)

    Jo, Eun Jin; Male, Umashankar; Huh, Do Sung [Dept.of Chemistry and Nanosystem Engineering, Center for Nano Manufacturing, Inje University, Kimhae (Korea, Republic of)

    2016-11-15

    Conductive polymer composite was synthesized by the polymerization of pyrrole with 3,4-ethylenedioxythiophene using ammonium persulfate as an oxidant with different concentrations of gelatin dispersed in aqueous medium along with the polymerization. Differently from pure polypyrrole–poly(3,4-ethylenedioxythiophene) (PPy–PEDOT) copolymer, the gelatin-assisted composites showed good solubility in aqueous media. The prepared PPy–PEDOT/gelatin composites were identified with Fourier-transform infrared, UV–visible spectroscopy, and X-ray diffraction. Morphological analysis and temperature-dependent direct current conductivity of PPy–PEDOT/gelatin composites were carried out. Obtained results revealed that added gelatin greatly increased conductivity due to the improved mobility of charge carriers.

  7. Preparation, Characterization and Mechanical Properties of Cu-Sn Alloy/Graphite Composites

    Science.gov (United States)

    Dong, Ruifeng; Cui, Zhenduo; Zhu, Shengli; Xu, Xu; Yang, Xianjin

    2014-10-01

    Ni-B coating was prepared on the surface of graphite particles using the electroless plating method. The Ni-B coating was composed of spherical grains with average diameter of 80 nm. The phases of Ni-B coating were indexed as nanosized crystal Ni phase and amorphous Ni-B phase. Cu-Sn alloy/graphite composites with 0.5, 1.0, 1.5, and 2.0 wt pct graphite contents were synthesized by the powder metallurgy method. Ni-B coating improved the wettability and bonding strength between the Cu-Sn alloy and graphite. The composite with Ni-B coated graphite exhibited higher density, hardness, and compression strength compared with the composites with bare graphite. The crack propagation mechanism of the composites was also analyzed.

  8. Graphene-reinforced aluminum matrix composites prepared by spark plasma sintering

    Institute of Scientific and Technical Information of China (English)

    Wen-ming Tian; Song-mei Li; Bo Wang; Xin Chen; Jian-hua Liu; Mei Yu

    2016-01-01

    Graphene-reinforced 7055 aluminum alloy composites with different contents of graphene were prepared by spark plasma sinter-ing (SPS). The structure and mechanical properties of the composites were investigated. Testing results show that the hardness, compressive strength, and yield strength of the composites are improved with the addition of 1wt% graphene. A clean, strong interface is formed between the metal matrix and graphene via metallurgical bonding on atomic scale. Harmful aluminum carbide (Al4C3) is not formed during SPS processing. Further addition of graphene (above 1wt%) results in the deterioration in mechanical properties of the composites. The agglomeration of graphene plates is exacerbated with increasing graphene content, which is the main reason for this deterioration.

  9. Preparation and Mechanical Properties of Ni-TiN Composite Layers by Ultrasonic Electrode Position

    Directory of Open Access Journals (Sweden)

    Jindong Wang

    2013-07-01

    Full Text Available Ultrasonic electrodeposition was used to prepare nanocermet Ni-TiN composite layers on steel substrates. The action of mechanical disturbance by ultrasonic waves on electrolyte mass transfer, the inhibition of nanoparticle aggregation by ultrasonic cavitation and the effect of electric pulse parameters on the nucleation and growth of grains were investigated. The nanocermet Ni-TiN composite layer consisted of nanocrystalline nickel (30~60 nm. The micro-hardness of the composite layers increases a little when TiN content increases from 0% to 2%. However, micro-hardness increases greatly when V is increased from 2% to 9%. The maximal micro-hardness for Ni-TiN composite layers is 860 HV, 908 HV and 950 HV, respectively.

  10. Preparation and performance of a sulfur/graphene composite for rechargeable lithium-sulfur battery

    Science.gov (United States)

    Zhang, Feifei; Dong, Yunhui; Huang, Yun; Huang, Gang; Zhang, Xinbo; Wang, Limin

    2012-01-01

    The lithium-sulfur (Li-S) battery is a promising electrochemical system that has high theoretical capacity. The sulfur/graphene nanosheets (S/GNS) composite is prepared through thermal reduction between the sulfur (S) and graphene oxide (GO). The morphology and composition of the composite are analyzed by means of x-ray powder diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectroscopic (EDS) characterization. It is found that the element S distributed uniformly between the layers of GNS. Graphene with a two-dimensional structure of carbon atoms is employed as a conductive and absorbing agent for the S cathode materials of rechargeable Li-S battery. The S/GNS composite cathode shows a specific electrochemical capacity, which is about 1598 mAh g-1 S at the initial discharge and remains above 670 mAh g-1 after 80 cycles.

  11. Preparation and Properties of Silver Nanowire-Based Transparent Conductive Composite Films

    Science.gov (United States)

    Tian, Ji-Li; Zhang, Hua-Yu; Wang, Hai-Jun

    2016-06-01

    Silver nanowire-based transparent conductive composite films with different structures were successfully prepared using various methods, including liquid polyol, magnetron sputtering and spin coating. The experimental results revealed that the optical transmittance of all different structural composite films decreased slightly (1-3%) compared to pure films. However, the electrical conductivity of all composite films had a great improvement. Under the condition that the optical transmittance was greater than 78% over the wavelength range of 400-800 nm, the AgNW/PVA/AgNW film became a conductor, while the AZO/AgNW/AZO film and the ITO/AgNW/ITO film showed 88.9% and 94% reductions, respectively, for the sheet resistance compared with pure films. In addition, applying a suitable mechanical pressure can improve the conductivity of AgNW-based composite films.

  12. Preparation and characterization of antibacterial Au/C core-shell composite

    Energy Technology Data Exchange (ETDEWEB)

    Gao Yanhong [Department of Chemistry and Institute of Nanochemistry, Jinan University, 601 Huangpudadaoxi Road, Guangzhou 510632, Guangdong (China); Centers for Disease Control and Prevention of Guangdong Province, Guangzhou 510300, Guangdong (China); Zhang Nianchun [Department of Chemistry and Institute of Nanochemistry, Jinan University, 601 Huangpudadaoxi Road, Guangzhou 510632, Guangdong (China); Zhong Yuwen [Centers for Disease Control and Prevention of Guangdong Province, Guangzhou 510300, Guangdong (China); Cai Huaihong [Department of Chemistry and Institute of Nanochemistry, Jinan University, 601 Huangpudadaoxi Road, Guangzhou 510632, Guangdong (China); Liu Yingliang, E-mail: tliuyl@jnu.edu.cn [Department of Chemistry and Institute of Nanochemistry, Jinan University, 601 Huangpudadaoxi Road, Guangzhou 510632, Guangdong (China)

    2010-09-01

    An environment-friendly oxidation-reduction method was used to prepare Au/C core-shell composite using carbon as core and gold as shell. The chemical structures and morphologies of Au/C core-shell composite and carbon sphere were characterized by X-ray diffraction, transmission electron microscope, energy dispersion X-ray spectrometry (EDS) and X-ray photoelectron spectroscopy (XPS). The antibacterial properties of the Au/C core-shell composite against Escherichia coli (E. coli), Staphylococcus aureus (S. aureus) and Candida albicans (C. albicans) were examined by the disk diffusion assay and minimal inhibition concentration (MIC) methods. In addition, antibacterial ability of Au/C core-shell composite was observed by atomic force microscope. Results demonstrated that gold homogeneously supported on the surface of carbon spheres without aggregation and showed efficient antibacterial abilities.

  13. Preparation and properties of dough-modeling compound/fly ash/reclaim powder composites

    Energy Technology Data Exchange (ETDEWEB)

    Wu, W.L. [Qiqihar University, Qiqihar (China)

    2007-12-15

    A novel composite was prepared with reclaim powder (RP) matrix, dough-modeling compound (DMC) reinforcement and fly ash (FA) filler in this article. The compatibility and crosslinking construction of the FA/RP composites were respectively, studied by the polarizing microscope and IR, the optimal formulation and experimental process were determined by measuring the mechanical properties such as shore A hardness, tensile strength, elongation at break, wear resistance and the thermal stability. The results showed that DMC/FA/RP composites exhibited extremely high mechanical and thermal properties when the mass ratio of the DMC/FA/RP composites was 45/25/100, and the cure condition is at 145 {sup o}C for 30 min under 9 MPa.

  14. Preparation and performance of novel thermally stable polyamide/PPENK composite nanofiltration membranes

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Lijie [State Key Laboratory of Fine Chemical, Dalian 116024 (China); Liaoning High Performance Polymer Engineering Research Center, Dalian 116024 (China); Liaoning Key Laboratory of Polymer Science and Engineering, Dalian 116024 (China); School of Chemical Engineering, Dalian University of Technology, Dalian 116024 (China); Zhang, Shouhai, E-mail: zhangshh@dlut.edu.cn [State Key Laboratory of Fine Chemical, Dalian 116024 (China); Liaoning High Performance Polymer Engineering Research Center, Dalian 116024 (China); Liaoning Key Laboratory of Polymer Science and Engineering, Dalian 116024 (China); School of Chemical Engineering, Dalian University of Technology, Dalian 116024 (China); Han, Runlin [School of Chemical Engineering, Dalian University of Technology, Dalian 116024 (China); Jian, Xigao, E-mail: jian4616@dl.cn [State Key Laboratory of Fine Chemical, Dalian 116024 (China); Liaoning High Performance Polymer Engineering Research Center, Dalian 116024 (China); Liaoning Key Laboratory of Polymer Science and Engineering, Dalian 116024 (China); School of Chemical Engineering, Dalian University of Technology, Dalian 116024 (China)

    2012-09-01

    Highlights: Black-Right-Pointing-Pointer Composite nanofiltration membranes based on PPENK UF membranes were prepared. Black-Right-Pointing-Pointer Preparation parameters of polyamide/PPENK nanofiltration membranes were studied. Black-Right-Pointing-Pointer Polyamide/PPENK nanofitration membrane shows excellent thermal resistance. - Abstract: Novel thermally stable composite nanofiltration (NF) membranes were prepared from piperazine (PIP) and trimesoyl chloride (TMC) on poly (phthalazione ether nitrile ketone) (PPENK) ultrafiltration (UF) membranes by interfacial polymerization. The effects of monomers concentration, reaction time and organic solvents on the performance of composite membranes were investigated. The effects of operating pressure and the salt solution concentration on the performance of composite membranes were also discussed. The different salts rejection of PPENK composite membranes decreased in the order of Na{sub 2}SO{sub 4} > MgSO{sub 4} > Al{sub 2}(SO{sub 4}){sub 3} > NaCl > MgCl{sub 2}, which indicated a negative charge at the membrane surface. The flux and Na{sub 2}SO{sub 4} rejection of PPENK composite membranes reached 57.9 L/m{sup 2} h and 98.4% under the optimized conditions and operating pressure of 1.0 MPa. Furthermore, the morphology and chemical structure of membranes were examined by scanning electronic microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR), respectively. Moreover, the thermal stability of PPENK NF membranes was also investigated. When temperature of the feed solution raised from 20 Degree-Sign C to 80 Degree-Sign C, the permeation flux increased about four times without significant change of rejection. The flux increased first then reached a plateau and the rejection kept constant when PPENK NF membranes in boiling de-ionized water were boiled to 3 h.

  15. Facile preparation of superhydrophobic surface with high adhesive forces based carbon/silica composite films

    Indian Academy of Sciences (India)

    Ruanbing Hu; Guohua Jiang; Xiaohong Wang; Xiaoguang Xi; Rijing Wang

    2013-11-01

    Glass substrates modified by carbon/silica composites are fabricated through a two-step process for the preparation of a superhydrophobic surface (water contact angle ≥ 150°). Carbon nanoparticles were first prepared through a deposition process on glass using a hydrothermal synthesis route, then the glass was modified by SiO2 using the hydrolysis reaction of tetraethylorthosilicate at room temperature. It is not only a facile method to create a superhydrophobic surface, but also helps to form a multi-functional surface with high adhesive forces.

  16. Electroless plating preparation and electromagnetic properties of Co-coated carbonyl iron particles/polyimide composite

    Science.gov (United States)

    Zhou, Yingying; Zhou, Wancheng; Li, Rong; Qing, Yuchang; Luo, Fa; Zhu, Dongmei

    2016-03-01

    To solve the serious electromagnetic interference problems at elevated temperature, one thin microwave-absorbing sheet employing Co-coated carbonyl iron particles and polyimide was prepared. The Co-coated carbonyl iron particles were successfully prepared using an electroless plating method. The microstructure, composition, phase and static magnetic properties of Co-coated carbonyl iron particles were characterized by combination of scanning electron microscope (SEM), energy dispersive spectrometer (EDS), X-ray diffraction (XRD) and vibrating sample magnetometer (VSM). The electromagnetic parameters of Co-coated carbonyl iron particles/polyimide composite were measured in the frequency range of 2-18 GHz, and the electromagnetic loss mechanism of the material-obtained was discussed. The microwave absorption properties of composites before and after heat treatment at 300 °C for 100 h were characterized in 2-18 GHz frequency range. It was established that composites based on Co-coated carbonyl iron demonstrate thermomagnetic stability, indicating that Co coating reduces the oxidation of carbonyl iron. Thus, Co-coated carbonyl iron particles/polyimide composites are useful in the design of microwave absorbers operating at temperatures up to 300 °C.

  17. Preparation, Characterization, and Enhanced Thermal and Mechanical Properties of Epoxy-Titania Composites

    Science.gov (United States)

    Rubab, Zakya; Siddiqi, Humaira M.; Saeed, Shaukat

    2014-01-01

    This paper presents the synthesis and thermal and mechanical properties of epoxy-titania composites. First, submicron titania particles are prepared via surfactant-free sol-gel method using TiCl4 as precursor. These particles are subsequently used as inorganic fillers (or reinforcement) for thermally cured epoxy polymers. Epoxy-titania composites are prepared via mechanical mixing of titania particles with liquid epoxy resin and subsequently curing the mixture with an aliphatic diamine. The amount of titania particles integrated into epoxy matrix is varied between 2.5 and 10.0 wt.% to investigate the effect of sub-micron titania particles on thermal and mechanical properties of epoxy-titania composites. These composites are characterized by X-ray photoelectron (XPS) spectroscopy, scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermogravimetric (TG), and mechanical analyses. It is found that sub-micron titania particles significantly enhance the glass transition temperature (>6.7%), thermal oxidative stability (>12.0%), tensile strength (>21.8%), and Young's modulus (>16.8%) of epoxy polymers. Epoxy-titania composites with 5.0 wt.% sub-micron titania particles perform best at elevated temperatures as well as under high stress. PMID:24578638

  18. Gas sensing properties of graphene–WO{sub 3} composites prepared by hydrothermal method

    Energy Technology Data Exchange (ETDEWEB)

    Chu, Xiangfeng, E-mail: xfchu99@ahut.edu.cn [School of Chemistry and Chemical Engineering, Anhui University of Technology, Maanshan 243002 (China); Hu, Tao [School of Chemistry and Chemical Engineering, Anhui University of Technology, Maanshan 243002 (China); Gao, Feng [Department of Materials Science and Engineering, Nanjing University, Nanjing 210093 (China); Dong, Yongping; Sun, Wenqi; Bai, Linshan [School of Chemistry and Chemical Engineering, Anhui University of Technology, Maanshan 243002 (China)

    2015-03-15

    Graphical abstract: - Highlights: • The amount of graphene had an effect on the morphology of graphene–WO{sub 3} composites. • The optimum temperature of 0.1 wt% graphene–WO{sub 3} sensor to acetaldehyde was 100 °C. • 0.1 wt% graphene–WO{sub 3} sensor exhibited good selectivity to acetaldehyde at 100 °C. - Abstract: Graphene–WO{sub 3} composites mixed with different amounts of graphene (0, 0.1, 0.5, 1 and 3 wt%) were prepared by hydrothermal method at 180 °C for 24 h. The as-prepared graphite oxide, graphene and graphene–WO{sub 3} composites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectra (FT-IR) and Raman spectroscopy, respectively. The effect of the amount of graphene in the composites on the gas-sensing responses and the gas-sensing selectivity of the materials was investigated. The experimental results revealed that the sensor based on 0.1 wt% graphene–WO{sub 3} composite exhibited high response and good selectivity to acetaldehyde vapor at 100 °C, the optimum operating temperature of this sensor to 1000 ppm acetaldehyde vapor decreased from 180 °C to 100 °C comparing with that of pure WO{sub 3}. The response time and the recovery time for 100 ppm acetaldehyde vapor were 250 s and 225 s, respectively.

  19. Activated carbon fibers/poly(lactic-co-glycolic) acid composite scaffolds: Preparation and characterizations

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Yanni [State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Donghua University, Shanghai 201620 (China); College of Materials Science and Engineering, Donghua University, Shanghai 201620 (China); Han, Hao [College of Materials Science and Engineering, Donghua University, Shanghai 201620 (China); Bayer Material Science China Co., Ltd, Shanghai 200120 (China); Quan, Haiyu; Zang, Yongju; Wang, Ning; Ren, Guizhi [College of Materials Science and Engineering, Donghua University, Shanghai 201620 (China); Xing, Melcolm [Department of Mechanical Engineering, Faculty of Engineering and Department of Biochemistry and Genetics, Faculty of Medicine P.I., Manitoba Institute of Child Health, University of Manitoba, Winnipeg, Manitoba (Canada); Wu, Qilin, E-mail: wql@dhu.edu.cn [State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Donghua University, Shanghai 201620 (China); College of Materials Science and Engineering, Donghua University, Shanghai 201620 (China)

    2014-10-01

    The present work is a first trial to introduce activated carbon fibers (ACF) with high adsorption capacity into poly(lactic-co-glycolic) acid (PLGA), resulting in a novel kind of scaffolds for tissue engineering applications. ACF, prepared via high-temperature processing of carbon fibers, are considered to possess bioactivity and biocompatibility. The ACF/PLGA composite scaffolds are prepared by solvent casting/particulate leaching method. Increments in both pore quantity and quality over the surface of ACF as well as a robust combination between ACF and PLGA matrix are observed via scanning electron microscopy (SEM). The high adsorption capacity of ACF is confirmed by methylene blue solution absorbency test. The surfaces of ACF are affiliated with many hydrophilic groups and characterized by Fourier transform infrared spectroscopy. Furthermore, the SEM images show that cells possess a favorable spreading morphology on the ACF/PLGA scaffolds. Besides, vivo experiments are also carried out to evaluate the histocompatibility of the composite scaffolds. The results show that ACF have the potential to become one of the most promising materials in biological fields. - Highlights: • ACF with strong adsorption capacity and porous structure for enhanced surface area • The incorporation of ACF promoting the porosity of composite scaffolds • The composite scaffolds having no side effect on cell adhesion and proliferation • The composite scaffolds presenting good biocompatibility in vivo.

  20. Study onCurrent Status of Registration Management of Pharmaceutical Preparations inMedical Institutions in China%全国医疗机构制剂注册管理现状研究

    Institute of Scientific and Technical Information of China (English)

    战嘉怡; 刘春; 丁建华; 李灿; 李蜀平; 张体灯; 王海南

    2015-01-01

    目的:了解医疗机构制剂注册管理现状和存在问题,为药品监管部门制定相关政策提供参考。方法:采取问卷调查、实地调研、文献分析、会议座谈、深度访谈等多种形式进行调查。结果:通过调研获得了全国医疗机构制剂注册信息,了解了各省、自治区、直辖市制剂管理的具体方式,征求了省级药品监管部门、医疗机构以及部分名老中医专家对现行制剂管理模式的意见和建议。结论:现行管理模式基本适合我国医疗机构制剂现状,《医疗机构制剂注册管理办法(试行)》的实施有效遏制了制剂批准文号的盲目增加,推动了制剂注册管理水平的提高,但尚有需要完善改进之处。%Objective:To understand the current situation of registration management of pharmaceutical preparations in medical institutions and the existing problems so as to provide references for the drug supervision and administration department to draft relevant policies.Methods:A variety of investigation forms were adopted, such as questionnaire survey, ifeld investigation, literature analysis, meeting and depth interviews. Results:The information of pharmaceutical preparations registration of medical institutions in China was obtained. The speciifc management methods in each province, autonomous region and municipality of China were surveyed. The opinions and suggestions on current management mode were collected from the provincial drug supervision and administration departments, medical institutions and famous traditional Chinese medicine doctors.Conclusion:The current management mode is suitable for the current conditions of pharmaceutical preparations in medical institutions in China. The implementation of Provisions for the Registration of Pharmaceutical Preparations in Medical Institutions (interim) effectively slowed down the growth rate of the new approval number, and improved the level of registration

  1. Preparation and Characterization of Ceramizable Kaolin/VMQ and Kaolin/ZB/VMQ Composites

    Science.gov (United States)

    Zhang, X.; Qin, Y.; Pei, Y.; Huang, Z. X.

    Ceramizable silicone-based composite was prepared by using methyl vinyl silicone rubber (VMQ) as matrix, calcined Kaolin and zinc borate (ZB) as additives. This composition can form interpenetrating network structures after crosslinking, and then improve heat-resistant properties by firing in air. The results of different formulations were investigated by FTIR. TG-DTG SEM and XRD. It showed that when the temperature above 600°C. the fillers and silicon rubber started to transform from organic to inorganic and internal microstructure became denser.

  2. A New Route for Preparation of β-TCP/PLLA Composite

    Institute of Scientific and Technical Information of China (English)

    Feng ZHANG; Fang MEI; Xin Zhi WANG; Xiao Yang HU; Yong Ming LUO; Xu Liang DENG

    2006-01-01

    A new facile route for preparation of β-TCP/PLLA composites is reported in this letter.SEM images display that β-TCP particles with average diameter of 400 nm were well bonded and distributed within the pore walls of the PLLA scaffolds. The mixture of the novel complex and human dental pulp cells was transplanted subcutaneously into the dorsal surface of a nude mouse.Two months later histological examination showed that new collagen and new dentin formed.The results revealed that the new nano β-TCP/PLLA composite combined with human pulp cells could induce dentin formation, offering a new way to dental tissue engineering.

  3. Preparation of microcellular composites with biomimetic structure via supercritical fluid technology

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A new microcellular composite material with a biomimetic structure has been prepared via the supercritical fluid (SCF) technology. The resultant material has a clear biomimetic structure like bamboo and wood. The skin region is enriched with oriented high-strength thermotropic liquid crystal polymer fibrils, while the core region with polystyrene (PS) micro-cells. The diameter and density of micro- cells can be controlled by the processing parameters such as temperature and pressure. And the skin thickness can be controlled conveniently by varying the composition of polystyrene and liquid crystal polymer.

  4. Preparation and Magnetism of Gd2O3/X-NBR Composites

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Series of Gd2O3/X-NBR composites were prepared by in-situ reaction at different temperatures (100 and 160 ℃) and different processing time. The influence of processing time and processing temperature on dispersion of Gd2O3 was investigated, and the relationship between magnetic property and temperature was also discussed. The results show that, the mass magnetizability (χg) descends as temperature rising. Processing temperature and time do not exhibit evidenced effects on the mass magnetizability (χg). All the composites show to be antiferromagnetic.

  5. Cu-doped zinc oxide and its polythiophene composites: preparation and antibacterial properties.

    Science.gov (United States)

    Ma, Ge; Liang, Xiaoxi; Li, Liangchao; Qiao, Ru; Jiang, Donghua; Ding, Yan; Chen, Haifeng

    2014-04-01

    Cu-doped zinc oxide and its polythiophene nanocomposites were prepared by the Sol-Gel and in situ polymerization methods, respectively. The structures, morphologies and compositions of the samples were characterized. The antibacterial properties of the samples on three kinds of strains were determined by using powder inhibition zones, minimum inhibitory concentrations and minimal bactericidal concentrations. The study confirmed that the antibacterial activities of the composites were better than those of their each component. The antibacterial mechanisms of the samples were discussed further.

  6. The preparation of the nonlinear optical quantum dots in organic polymer composite

    Science.gov (United States)

    Huang, Guochang; Yu, Dabin; Zhang, Jinhua; Zhao, Minghui; Zhao, Dapeng; Pan, Maosen

    2016-11-01

    Quantum dots (QDs) is some material which particle size is between 1 to 10 nanometers. Because of the unique nonlinear optical properties, QDs has been widely applied in optical, electrical, magnetic, biological fields etc. Though the size of the nanoscale is bringing the QDs a series of characteristic advantages, it has also brought some problems for further application, such as QDs are easily degenerative according to their small size. However, The preparation of quantum dots with special polymer composite film can avoid this phenomenon, This means that the composite is usually with inert matrix can be realized for further application.

  7. Preparation and Properties of Ni-plated Glass Beads/PVC Composite

    Institute of Scientific and Technical Information of China (English)

    ZHANG Wei; WANG Sijie; ZHAO Yang

    2014-01-01

    Ni-plated glass beads (GB) was obtained by electroless plating, based on PVC adhesive, Ni-plated GB/PVC composite was prepared. Temperature insulation, fire retardation and microwave absorption properties were tested, the results showed that the nickel coating was compact and continuous, Ni-plated GB/PVC composite is a kind of excellent temperature insulated, fire retardate and light-weight material, and especially for microwave absorption well;Reflectivity was lower than -2 dB in the frequency range of 11-17 GHz.

  8. Preparation of carbon nanotube composite material with metal matrix by electroplating

    Institute of Scientific and Technical Information of China (English)

    AN Bai-gang; LI Li-xiang; Li Hong-xi

    2005-01-01

    It is demonstrated that the nickel can be deposited directly on the surface of carbon nanotubes without pre-sensitization by Sn2+ and Pd2+ in a watt bath containing suspended nanotubes by electroplating. The nickel is deposited as spherical nanoparticle on the nanotubes. By increasing reaction time, the carbon nanotube is fully coated with nickel. A probable model, which represents the formation process of carbon nanotube-nickel composites by electroplating, is presented. The results show that this method is efficient and simple for preparing carbon nanotube-metal composite.

  9. Preparation and characterization of dense graphite/glassy carbon composite coating for sealing application

    Science.gov (United States)

    Wang, Yang; Chen, Zhaofeng; Yu, Shengjie; Pan, Ning; Liao, Jiahao

    2017-09-01

    Glassy carbon (GC), characterized by a homogeneous structure and glass-like fracture surface once broken, has attracted increasing attention because of its excellent performance. In this paper, a dense graphite/glassy carbon composite coating with low gas permeability was introduced. In this composite coating, small graphite particles acting as second phase were wrapped by glassy carbon matrix. The composite coatings with different mass fractions of graphite particles were prepared. The mass loss of phenolic resin was determined by TG (thermogravimetry) analysis to determine the pyrolysis process. Raman spectrum analysis indicates that graphite content in composite coatings affected the G/D ratio significantly. The permeability of composite coatings with 50% and 100% graphite particles was almost same, which was ranged from 6  ×  10‑13 m3 · µm/m2 · s · Pa to 3  ×  10‑13 m3 · µm/m2 · s · Pa within the differential pressure from 100 kPa to 70 kPa. While the composite coating with 150% graphite particles had higher gas permeability due to the tiny micro-cracks and micro-pores produced. What was more, the densification mechanism of graphite/glassy carbon composite coating was also discussed in detail.

  10. Preparation and characterization of magnetite–PDMS composites by magnetic induction heating

    Energy Technology Data Exchange (ETDEWEB)

    Darwish, Mohamed S.A., E-mail: msa.darwish@gmail.com [Institute for Nanomaterials, Advanced Technologies and Innovation, Technical University of Liberec, Studentská 2, 461 17 Liberec (Czech Republic); Egyptian Petroleum Research Institute, 1 Ahmed El-Zomor Street, El Zohour Region, Nasr City, Cairo 11727 (Egypt); Stibor, Ivan [Institute for Nanomaterials, Advanced Technologies and Innovation, Technical University of Liberec, Studentská 2, 461 17 Liberec (Czech Republic)

    2015-08-15

    Magnetic induction heating was used to produce magnetite–Poly (dimethylsiloxane) (PDMS) composites in the presence of the magnetite nanoparticles. Magnetite nanoparticles under an AC magnetic field generate heat, which used to accelerate polymerization and curing of PDMS. Magnetite nanoparticles were prepared using co-precipitation process in the presence of the basic solution. Magnetite nanoparticle was characterized using Fourier transform infrared (FTIR), thermogravimetric analysis (TGA), zeta potential, dynamic light scattering (DLS), scanning electron microscopy (SEM) and vibrating sample magnetometer (VSM). Magnetite–PDMS composite morphology was characterized using scanning electron microscopy, while curing and thermal stability were assessed through infrared spectroscopy and thermogravimetric analysis, respectively. Heating properties and rate of heating of magnetite nanoparticles and magnetite–PDMS composites were studied as a function of time applied and magnetite content (20% and 30%). The improved thermal stability of magnetite–PDMS composite, which produced in a shorter time without using catalyst, compared with the conventional PDMS will offer potential as thermally stable elastomers. - Highlights: • Magnetic induction heating was used to produce magnetite–PDMS composites. • The composites produced in a shorter time without catalyst with improved in the thermal stability. • Magnetite–PDMS composites are promising as thermally stable elastomers.

  11. [Pharmaceutical technology: development and research].

    Science.gov (United States)

    Traisnel, M

    1994-06-01

    Production of pharmaceutics cannot be compared to the manufacture of consumer goods: pharmaceutical manufacturing is the study and bulk manufacture of the ingredients from which medicines are made, and is concerned with the mixing, preparing, packing, of the ingredients into a dosage form for the patient, in according to the good manufacturing practices (GMP). Development and manufacture are not discrete activities but links in a single chain of activity. Research and development, pharmaceutical training, regulatory requirements: these concepts are present with three ways: bioavailability, targeting and compliance.

  12. [Pharmaceutical chemistry of general anaesthetics].

    Science.gov (United States)

    Szász, György; Takácsné, Novák Krisztina

    2004-01-01

    The paper represents the first part of a planned series of reviews about pharmaceutical chemistry of drugs acting on the central nervous system. The authorial aim and editorial concepts are the same were followed in a former series of papers about pharmaceutical chemistry of agents effecting the heart, blood circulation and vegetative nervous system. Consequently, general anaesthetics are discussed in the present paper through the chapters "history, preparation; structure-properties-activity; application; analysis".

  13. Effect of preparation conditions on the characteristics and photocatalytic activity of TiO{sub 2}/purified diatomite composite photocatalysts

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Zhiming, E-mail: szmcumtb@hotmail.com; Hu, Zhibo; Yan, Yang; Zheng, Shuilin, E-mail: shuilinzh@sina.com

    2014-09-30

    Highlights: • TiO{sub 2}/purified diatomite composites were synthesized under different conditions. • The optimum preparation conditions of composites were obtained. • The obtained photocatalyst showed good photocatalytic activity. • The dispersity and grain size of loaded TiO{sub 2} NPs are the critical factors. - Abstract: TiO{sub 2}/purified diatomite composite materials were prepared through a modified hydrolysis-deposition method under low temperature using titanium tetrachloride as precursor combined with a calcination crystallization process. The microstructure and crystalline phases of the obtained composites prepared under different preparation conditions were characterized by high resolution scanning electron microscope (SEM) and X-ray diffraction (XRD), respectively. The photocatalytic performance of TiO{sub 2}/purified diatomite composites was evaluated by Rhodamine B as the target pollutant under UV irradiation, and the optimum preparation conditions of composites were obtained. The TiO{sub 2} crystal form in composites prepared under optimum conditions was anatase, the grain size of which was 34.12 nm. The relationships between structure and property of composite materials were analyzed and discussed. It is indicated that the TiO{sub 2} nanoparticles uniformly dispersed on the surface of diatoms, and the photocatalytic performance of the composite materials was mainly determined by the dispersity and grain size of loaded TiO{sub 2} nanoparticles.

  14. Properties of composition sinter prepared from fibrous barium titanate and nanometer zirconia

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Fibrous Batium Titanate particles,30-50 μm long,prepared by a hydrothermal reaction,and the monoclinic phase and nanometer Zirconia,11.6 nm long were prepared by citric acid reaction respectively.Then,the two were composite sintered to produce a new functional material by making full use of crystal-axis orientation of fibers and the activity of nanometer powder.The analydid of composition and microstructure of the new material in terms of XRD and SEM.shows that the solid solution was formed between fibers and nanometer powder,and the distance between lattice(d value)of Barium Titanate changed.But the crystal-axis orientations of fibers remain unchanged.

  15. Preparation and characterization of a novel bone graft composite containing bone ash and egg shell powder

    Indian Academy of Sciences (India)

    Gunasekaran Krithiga; Thotapalli P Sastry

    2011-02-01

    Egg shells which were hitherto discarded as wastes were collected, purified and powdered into a particle size in the range of 5–50 m. A composite bone graft material in cylindrical form was prepared using egg shell powder (ESP), bone ash (BA) and gelatin. These bone grafts were characterized for their FT–IR, TGA, XRD, SEM and mechanical properties. The mechanical studies indicate that the composite having a stoichiometric ratio of BA (3 g) and ESP (7 g) has shown better mechanical properties. X-ray diffraction (XRD) data indicated the crystallographic nature of BA is akin to hydroxyapatite (HA) and both BA and ESP did not lose their crystalline nature when bone grafts were prepared. This revealed that ESP may be used as a component in bone graft utilizing the solid waste from the poultry industry.

  16. Composition, XRD and morphology study of laser prepared LiNbO{sub 3} films

    Energy Technology Data Exchange (ETDEWEB)

    Jelinek, M.; Remsa, J.; Kocourek, T. [Institute of Physics ASCR v.v.i., Prague 8 (Czech Republic); Czech Technical University in Prague, Faculty of Biomedical Engineering, Sitna, Kladno (Czech Republic); Havranek, V. [Nuclear Physics Institute ASCR, Rez near Prague (Czech Republic); Vincze, A.; Bruncko, J. [International Laser Centre, Bratislava 4 (Slovakia); Studnicka, V. [Institute of Physics ASCR v.v.i., Prague 8 (Czech Republic); Rubesova, K. [Institute of Chemical Technology, Prague 6 (Czech Republic)

    2013-03-15

    LiNbO{sub 3} films were deposited by PLD from LiNbO{sub 3} crystalline or from three different stoichiometric or Li-enriched LiNbO{sub 3} targets. Polycrystalline films were prepared on SiO{sub 2}/Si or sapphire substrates at temperatures T{sub S} {proportional_to}650-750 C. Main attention was paid to the influence of targets preparation and the deposition conditions on films composition, morphology and crystallinity. The thin-film morphology was determined by SEM microscopy. The composition was measured by SIMS, RBS, PIXE and PIGE methods. Highly oriented, smooth and stoichiometric LiNbO{sub 3} films were synthesized. (orig.)

  17. A systematic investigation of the preparation and properties of composite carbon molecular sieves containing inorganic oxides

    Science.gov (United States)

    Foley, Henry C.

    1990-01-01

    The objective of this research is to define the methodology for the preparation and characterization of new carbon-based molecular sieves with composite structures. Carbon molecular sieves have found increasing application in the field of separation and purification of gases. These materials are relatively easy to prepare and their surfaces can be modified to some extent. It is expected that by combining inorganic oxides with the carbonaceous structure one can begin to design composite materials with a wider range of possible chemical and physical properties. In this way, the IOM-CMS materials may confer distinct advantages over pure carbon molecular sieves, not just for separation, but also for catalysis. The most recent results in the design and characterization of these IOM-CMS materials are reviewed and summarized. Directions for further research are also presented.

  18. The Preparation and Characterization of INTEC Phase 2b Composition Variation Study Glasses

    Energy Technology Data Exchange (ETDEWEB)

    B. A. Staples; B. A. Scholes; L. L. Torres; C. A. Musick; B. R. Boyle (INEEL); D. K. Peeler (SRTC); J. D. Vienna (PNNL)

    2000-02-01

    The second phase of the composition variation study (CVS) for the development of glass compositions to immobilize Idaho Nuclear Technology and Engineering Center (INTEC) high level wastes (HLW) is complete. This phase of the CVS addressed waste composition of high activity waste fractions (HAW) from the initial separations flowsheet. Updated estimates if INTEC calcined HLW compositions and of high activity waste fractions proposed to be separated from dissolved calcine were used as the waste component for this CVS phase. These wastes are of particular interest because high aluminum, calcium, zirconium, fluorine, potassium, and low iron and sodium content places them outside the vitrification experience in the Department of Energy complex. Because of the presence of calcium and fluorine, two major zirconia calcine components not addressed in Phase I, a series of scooping tests, designated Phase 2a, were performed. The results of these tests provided information on the effects of calcium and fluoride solubility and their impacts on product properties and composition boundary information for Phase 2b. Details and results of Phase 2a are reported separately. Through application of statistical techniques and the results of Phase 2a, a test matrix was defined for Phase 2b of the CVS. From this matrix, formulations were systematically selected for preparation and characterization with respect to visual and optical homogeneity, viscosity as a function of melt temperature, liquidus temperature (TL), and leaching properties based on response to the product consistency test. The results of preparing and characterizing the Phase 2b glasses are presented in this document. Based on the results, several formulations investigated have suitable properties for further development. A full analysis of the composition-product characteristic relationship of glasses being developed for immobilizing INTEC wastes will be performed at the completion of composition-property relationship

  19. Assessing the Factors Associated With Iran’s Intra-Industry Trade in Pharmaceuticals

    Science.gov (United States)

    Yusefzadeh, Hassan; Hadian, Mohammad; Gorji, Hassan Abolghasem; Ghaderi, Hossein

    2015-01-01

    Background: Pharmaceutical industry is a sensitive and profitable industry. If this industry wants to survive, it should be able to compete well in international markets. So, study of Iran’s intra-industry trade (IIT) in pharmaceuticals is essential in order to identify competitiveness potential of country and boost export capability in the global arena. Methods: This study assessed the factors associated with Iran’s intra-industry trade in pharmaceuticals with the rest of the world during the 2001–2012 periods using seasonal time series data at the four-digit SITC level. The data was collected from Iran’s pharmaceutical Statistics, World Bank and International Trade Center. Finally, we discussed a number of important policy recommendations to increase Iran’s IIT in pharmaceuticals. Results: The findings indicated that economies of scale, market structure and degree of economic development had a significantly positive impact on Iran’s intra-industry trade in pharmaceuticals and tariff trade barriers were negatively related to IIT. Product differentiation and technological advancement didn’t have the expected signs. In addition, we found that Iran’s IIT in pharmaceuticals have shown an increasing trend during the study period. Thus, the composition of Iran trade in pharmaceuticals has changed from inter-industry trade to intra-industry trade. Conclusions: In order to get more prepared for integration into the global economy, the development of Iran’s IIT in pharmaceuticals should be given priority. Therefore, paying attention to IIT could have an important role in serving pharmaceutical companies in relation to pharmaceutical trade. PMID:26156931

  20. Preparation and Mechanical Performance of Rare Earth-Containing Composite Elastomer

    Institute of Scientific and Technical Information of China (English)

    邱关明; 周兰香; 张明; 中北里志; 井上真一; 冈本弘

    2001-01-01

    Rare earth-containing PSBR sheet was prepared by reaction of rare earth alkoxide with quaternary ammonium salt of pyridine modified SBR (PSBR) latex, and then it was blended with natural rubber (NR) to produce rare earth-containing composite elastomer. It is found that mechanical performance can be improved remarkably. Analyzed by infrared spectrometry (IR), differential scanning calorimetry (DSC) and cross-linking densitometry, the relationship between structure and performance was discussed.

  1. Preparation and corrosion behavior evaluation of amalgam/titania nano composite

    OpenAIRE

    Neda Bahremandi Tolou; Mohammadhossein Fathi; Ahmad Monshi; Vajihesadat Mortazavi; Farzaneh Shirani

    2011-01-01

    Background: Many attempts have been performed and continued for improvement of dental amalgam properties during last decades. The aim of present research was fabrication and characterization of amalgam/titania nano composite and evaluation of its corrosion behavior. Materials and Methods: In this experimental research, nano particles of titania were added to initial amalgam alloy powder and then, dental amalgam was prepared. In order to investigate the effect of nano particle amounts on p...

  2. UTILIZATION OF BAGASSE FIBER FOR PREPARATION OF BIODEGRADABLE FLAME RETARDING COMPOSITES (BFRCS)

    OpenAIRE

    2010-01-01

    Bagasse is a renewable resource characterized by its low cost and environmental friendliness. In this work a novel technological process was proposed to make flame retarding composites (BFRCs) by using bagasse fiber. The bagasse was disintegrated by twisting it up and applying high consistency refining, and then it was used to prepare BFRCs via hot pressure. Chemical groups and thermal properties of bagasse fiber were studied through the use of FTIR spectroscopy, a universal mechanical testin...

  3. Photochromic organic-inorganic composite materials prepared by sol-gel processing : properties and potentials

    OpenAIRE

    Hou, Lisong; Mennig, Martin; Schmidt, Helmut K.

    1994-01-01

    The sol-gel method which features a low-temperature wet-chemical process opens vast possibilities to incorporating organic dyes into solid matrices for various optical applications. In this paper we present our experimental results on the sol-gel derived photochromic organic-inorganic composite (ORMOCER) materials follwoing an introductory description of the sol-gel process and a brief review on the state of the art of the photochromic solids prepared using this method. Our photochromic spiro...

  4. Electrocatalysis of Puerarin on a Nano-CeO2/MWCNTs Composite Modified Electrode and Its Determination in Pharmaceutical Preparations

    Institute of Scientific and Technical Information of China (English)

    Ji Yulan; Wang Guangfeng; Zhang Cuihong; Fang Bin

    2011-01-01

    A good route for the fabrication of CeO2 nanoparticles (nano-CeO2)/multi-walled carbon nanotubes (MWCNTs) modified glassy carbon electrodes (GCE) was proposed. MWCNTs are used to immobilize nano-CeO2. What's more, with the addition of the MWCNTs, the agglomeration level of CeO2 nanoparticles can be reduced, the ex-tremely large surface area can be obtained and the electron transfer rate can be increased. The morphological char-acterization of nano-CeO2/MWCNTs was examined by scanning electron microscopy (SEM). The performances of the nano-CeO2/MWCNTs/GCE were characterized with cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and typical amperometric response (i-t). The potential utility of the constructed electrodes was demonstrated by applying them to the analytical determination of puerarin concentration. The catalytic oxidation of puerarin has a better result on nano-CeO2/MWCNTs/GCE because of the synergistic effect of nano-CeO2 and MWCNTs. An optimized limit of detection of 8.0 × 10-9 mol/L was obtained at a signal-to-noise ratio of 3 and with a fast response time (within 3 s). Additionally, the nano-CeO2/MWCNTs/GCE exhibited a wide linear range from 0.04 to 6.0 μmol/L and high sensitivity.

  5. A novel approach in preparing polymer/nano-CaCO3 composites

    Institute of Scientific and Technical Information of China (English)

    Zhengying LIU; Runze YU; Mingbo YANG; Jianmin FENG; Wei YANG; Bo YIN

    2008-01-01

    An novel compounding process using nano-CaCO3 aqueous suspension for preparing polymer/ nano-CaCO3 composites with nanoparticles dispersed at the nanoscale is reported. The process is called the mild mixing method. In this method, the pre-dispersed nano-particle suspensions are blended with melting polymers in a weak shearing field using an extruder, followed by removing the water from the vent. The four typical poly-meric nanocomposites were prepared by mild mixing method. The dispersion of nano-CaCO3 in the matrix of the polymer at the nanoscale was confirmed by scanning electron microscopy (SEM). The molecular weights of polycarbonate (PC) and its nanocomposite showed that the degradation had not occurred during the mild mixing processing. The mechanical properties of the composite with 1.5 wt-% nano-CaCO3 improve slightly. It proved that this approach is suitable for the preparation of nano-composites based on both polar and non-polar polymers.

  6. A simple preparation of graphite/gelatin composite for electrochemical detection of dopamine.

    Science.gov (United States)

    Rajkumar, Chellakannu; Thirumalraj, Balamurugan; Chen, Shen-Ming; Chen, His-An

    2017-02-01

    In this study, we demonstrate a simple preparation of graphite (GR) sheets assisted with gelatin (GLN) polypeptide composite was developed for sensitive detection of dopamine (DA) sensor. The GR/GLN composite was prepared by GR powder in GLN solution (5mg/mL) via sonication process. The prepared GR/GLN composite displays well dispersion ability in biopolymer matrix and characterized via scanning electron microscope (SEM), Fourier transform infrared (FTIR) spectroscopy and electrochemical impedance spectroscopy (EIS) studies. The GR/GLN modified electrode showed an excellent electrocatalytic activity toward the oxidation of DA, suggesting that the successful formation of GR sheets crosslinked with the functional groups of GLN polypeptide. In addition, the GR/GLN modified electrode achieved a wide linear response ranging from 0.05 to 79.5μM with a detection limit of 0.0045μM. The calculated analytical sensitivity of the sensor was 1.36±0.02μAμM(-1)cm(-2). Conversely, the modified electrode demonstrates a good storage stability, reproducibility and repeatability. In addition, the sensor manifests the determination of DA in human serum and urine samples for practical applications. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Application of first stage RO-EDI process in purified water preparation for pharmaceutical industry%一级RO-EDI工艺在制药纯化水制备中的应用

    Institute of Scientific and Technical Information of China (English)

    尤璐

    2016-01-01

    A pharmaceutical company in Tianjin city using municipal tap water as raw water to prepare purified water by process of filtration-softening-RO-EDI-circulating sterilization. After two years of field opera-tion, both of the desalination rates of RO device and EDI device could still reach about 97%, the water output flow was stable, and the product water quality met the requirement of purified water for pharmaceutical industry. It could be seen that, in the field of purified water preparation for pharmaceutical industry, first stage RO-EDI process had advantages of good treatment effect, stable operation, low running cost, and so on.%天津市某医药公司以自来水为水源, 采用过滤-软化-RO-EDI-循环杀菌的方式制取纯化水. 经过2年的现场运行, RO装置和EDI装置的脱盐率依然能达到97%左右, 产水量稳定, 产水水质满足制药纯化水要求,一级RO-EDI工艺在制药行业纯化水制备中具有处理效果好、 运行稳定、 运行成本低等优点.

  8. Preparation and thermal energy storage properties of paraffin/calcined diatomite composites as form-stable phase change materials

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Zhiming [School of Chemical and Environmental Engineering, China University of Mining and Technology, Beijing 100083 (China); Chemistry Discipline, Faculty of Science and Technology, Queensland University of Technology, 2 George Street, GPO Box 2434, Brisbane, Queensland 4001 (Australia); Zhang, Yuzhong [School of Chemical and Environmental Engineering, China University of Mining and Technology, Beijing 100083 (China); Zheng, Shuilin, E-mail: shuilinzh@yahoo.com.cn [School of Chemical and Environmental Engineering, China University of Mining and Technology, Beijing 100083 (China); Park, Yuri [Chemistry Discipline, Faculty of Science and Technology, Queensland University of Technology, 2 George Street, GPO Box 2434, Brisbane, Queensland 4001 (Australia); Frost, Ray L., E-mail: r.frost@qut.edu.au [Chemistry Discipline, Faculty of Science and Technology, Queensland University of Technology, 2 George Street, GPO Box 2434, Brisbane, Queensland 4001 (Australia)

    2013-04-20

    Highlights: ► Composite phase change material (PCM) was prepared by blending composite paraffin and calcined diatomite. ► The optimum mixed proportion was obtained through differential scanning calorimetry. ► Thermal energy storage properties of the composite PCMs were determined by DSC. ► Thermal cycling test showed that the prepared PCMs are thermally reliable and chemically stable. - Abstract: A composite paraffin-based phase change material (PCM) was prepared by blending composite paraffin and calcined diatomite through the fusion adsorption method. In this study, raw diatomite was purified by thermal treatment in order to improve the adsorption capacity of diatomite, which acted as a carrier material to prepare shape-stabilized PCMs. Two forms of paraffin (paraffin waxes and liquid paraffin) with different melting points were blended together by the fusion method, and the optimum mixed proportion with a suitable phase-transition temperature was obtained through differential scanning calorimetry (DSC) analysis. Then the prepared composite paraffin was adsorbed in calcined diatomite. The prepared paraffin/calcined diatomite composites were characterized by the scanning electron microscope (SEM) and Fourier transformation infrared (FT-IR) analysis techniques. Thermal energy storage properties of the composite PCMs were determined by DSC method. DSC results showed that there was an optimum adsorption ratio between composite paraffin and calcined diatomite and the phase-transition temperature and the latent heat of the composite PCMs were 33.04 °C and 89.54 J/g, respectively. Thermal cycling test of composite PCMs showed that the prepared material is thermally reliable and chemically stable. The obtained paraffin/calcined diatomite composites have proper latent heat and melting temperatures, and show practical significance and good potential application value.

  9. Microwave Irradiation Assisted Preparation of Chitosan Composite Microsphere for Dye Adsorption

    Directory of Open Access Journals (Sweden)

    Xiaoyu Chen

    2017-01-01

    Full Text Available Chitosan-activated carbon composite microspheres were prepared by emulsion cross-linking method and its adsorption properties for methyl orange were studied. Chitosan solution was mixed with activated carbon powder and then chitosan was cross-linked by epichlorohydrin under microwave irradiation. SEM photos show that the composite microspheres have diameters of 200–400 μm and activated carbon powder dispersed on the surface of composite microsphere. FTIR spectrum indicates chitosan is successfully cross-linked. Microwave irradiation can effectively shorten the cross-linking time. Composite microspheres have enhanced dye adsorption capacity for methyl orange compared to chitosan microspheres. Kinetic studies showed that the adsorption followed a pseudo-second-order model. Isotherm studies show that the isotherm adsorption equilibrium is better described by Freundlich isotherm. Regeneration results show that adsorption capacity of composite microsphere decreased about 5.51% after being reused for three times. These results indicated that chitosan-activated carbon composite microsphere has potential application in the removal of dye from wastewaters.

  10. Preparation of Conductive PANI/PVA Composites via an Emulsion Route

    Directory of Open Access Journals (Sweden)

    Xiang-Qin Wang

    2013-01-01

    Full Text Available A facile and novel strategy for preparing polyaniline/polyvinyl alcohol (PANI/PVA composite emulsion is reported wherein the reaction is carried out via the emulsion polymerization using ammonium peroxydisulfate (APS as the oxidizing agent and dodecylbenzene sulfonic acid (DBSA as the protonic acid. The PANI/PVA composite membranes have been characterized using optical microscope, scanning electron microscope (SEM, thermogravimetric analysis (TGA, Fourier transform infrared spectroscopy (FTIR, and electrochemical workstation. It is interesting that the electrical conductivity of the PANI/PVA composites is estimated to be as high as 1.28 S/cm. The experimental results show that the surface of PANI/PVA composite membranes exhibits good integrity. The PANI particles at the nanoscale are dispersed in the PVA matrix, and the electrochromic behaviors of PANI/PVA composites obtained at different polymerization temperatures can be compared based on cyclic voltammetry (CV curves, revealing that PANI/PVA composites synthesized at room temperature are better than those synthesized at low temperature.

  11. Morphology and Frictional Characteristics Under Electrical Currents of Al203/Cu Composites Prepared by Internal Oxidation

    Institute of Scientific and Technical Information of China (English)

    Liu Ruihua; Song Kexing; Jia Shuguo; Xu Xiaofeng; Gao Jianxin; Guo Xiuhua

    2008-01-01

    Two AhO3/Cu composites containing 0.24 wt.% A1203 and 0.60 wt.% A1203 separately are prepared by internal oxidation.Effectsof sliding speed and pressure on the fi-ictional characteristics of the composites and copper against brass are investigated and compared.The changes in morphology of the sliding surface and subsurface are examined with scanning electron microscope (SEM) and energy dispersive X-ray spectrum (EDS).The results show that the wear resistance of the AI203/Cu composites is superior to that of copperunder the same conditions.Under a given electrical current,the wear rate of AI203/Cu composites decreases as the AleO3-content increases.However,the wear rates of the Al203/Cu composites and copper increase as the sliding speed and pressure increase under drysliding condition.The main wear mechanisms for AleO3/Cu composites are of abrasion and adhesion;for copper,it is adhesion,although wear by oxidation and electrical erosion can also be observed as the speed and pressure rise.

  12. Nacre biomimetic design--a possible approach to prepare low infrared emissivity composite coatings.

    Science.gov (United States)

    Zhang, Weigang; Xu, Guoyue; Ding, Ruya; Duan, Kaige; Qiao, Jialiang

    2013-01-01

    Mimicking the highly organized brick-and-mortar structure of nacre, a kind of nacre-like organic-inorganic composite material of polyurethane (PU)/flaky bronze composite coatings with low infrared emissivity was successfully designed and prepared by using PU and flaky bronze powders as adhesives and pigments, respectively. The infrared emissivity and microstructure of the coatings were systematically investigated by infrared emissometer and scanning electron microscopy, respectively, and the cause of low infrared emissivity of the coatings was discussed by using the theories of one-dimensional photonic structure. The results show that the infrared emissivity of the nacre-like PU/flaky bronze composite coatings can be as low as 0.206 at the bronze content of 60 wt. %, and it is significantly lower than the value of PU/sphere bronze composite coatings. Microstructure observation illustrated that the nacre-like PU/flaky bronze composite coatings have similar one-dimensional photonic structural characteristics. The low infrared emissivity of PU/flaky bronze composite coatings is derived from the similar one-dimensional photonic structure in the coatings. Copyright © 2012 Elsevier B.V. All rights reserved.

  13. Preparation and characterization of fly ash cenospheres supported CuO-BiVO4 heterojunction composite

    Science.gov (United States)

    Zhang, Jin; Cui, Hao; Wang, Bing; Li, Chuang; Zhai, Jianping; Li, Qin

    2014-05-01

    Novel fly ash cenospheres supported CuO-BiVO4 heterojunction composites (CuO-BiVO4/FACs) were prepared by modified metalorganic decomposition and impregnation methods. The as-prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), X-ray photoelectron spectra (XPS), and UV-vis diffused reflectance spectroscopy (DRS) techniques. The XPS and SEM analyses indicated that Cu was present as CuO dispersed on the surface of BiVO4. The DRS spectra revealed that the composites had improved optical adsorption in the visible light region, and the composites exhibited enhanced photocatalytic activity for methylene blue (MB) degradation under visible light irradiation. It was found that the 5 wt% CuO-loaded composite showed the highest photocatalytic activity for MB dye wastewater treatment. FACs, a by-product generated in coal-firing power plants, were used as a low cost support which favored phase separation after the reaction owing to their low density.

  14. The Preparation and Characterization of INTEC HAW Phase I Composition Variation Study Glasses

    Energy Technology Data Exchange (ETDEWEB)

    Musick, C. A.; Peeler, D. K.; Piepel, G. F.; Scholes, B. A.; Staples, B. A.; Vienna, J. D.

    1999-03-01

    A glass composition variation study (CVS) is in progress to define formulations for the vitrification of high activity waste (HAW) proposed to be separated from dissolved calcine stored at the Idaho National Engineering and Environmental Laboratory (INEEL). Estimates of calcine and HAW compositions prepared in FY97 were used to define test matrix glasses. The HAW composition is of particular interest because high aluminum, zirconium, phosphorous and potassium, and low iron and sodium content places it outside the realm of vitrification experience in the Department of Energy (DOE) complex. Through application of statistical techniques, a test matrix was defined for Phase 1 of the CVS. From this matrix, formulations were systematically selected for preparation and characterization with respect to homogeneity, viscosity, liquidus temperature (TL), and leaching response when subjected to the Product Consistency Test (PCT). Based on the properties determined, certain formulations appear suitable for further development including use in planning Phase 2 of the study. It is recommended that glasses to be investigated in Phase 2 be limited to 3-5 wt % phosphate. The results of characterizing the Phase 1 glasses are presented in this document. A full analysis of the composition-property relationships of glasses being developed for immobilizing HAWs will be performing at the completion of CVS phases. This analysis will be needed for the optimization of the glass formulations of vitrifying HAW. Contributions were made to this document by personnel working at the INEEL, Pacific Northwest National Laboratories (PNNL), and the Savannah River Technology Center (SRTC).

  15. Preparation and evaluation of cerium oxide-bovine hydroxyapatite composites for biomedical engineering applications.

    Science.gov (United States)

    Gunduz, O; Gode, C; Ahmad, Z; Gökçe, H; Yetmez, M; Kalkandelen, C; Sahin, Y M; Oktar, F N

    2014-07-01

    The fabrication and characterization of bovine hydroxyapatite (BHA) and cerium oxide (CeO2) composites are presented. CeO2 (at varying concentrations 1, 5 and 10wt%) were added to calcinated BHA powder. The resulting mixtures were shaped into green cylindrical samples by powder pressing (350MPa) followed by sintering in air (1000-1300°C for 4h). Density, Vickers microhardness (HV), compression strength, scanning electron microscopy (SEM) and X-ray diffraction (XRD) studies were performed on the products. The sintering behavior, microstructural characteristics and mechanical properties were evaluated. Differences in the sintering temperature (for 1wt% CeO2 composites) between 1200 and 1300°C, show a 3.3% increase in the microhardness (564 and 582.75HV, respectively). Composites prepared at 1300°C demonstrate the greatest compression strength with comparable results for 5 and 10wt% CeO2 content (106 and 107MPa) which are significantly better than those for 1wt% and those that do not include any CeO2 (90 and below 60MPa, respectively). The results obtained suggest optimal parameters to be used in preparation of BHA and CeO2 composites, while also highlighting the potential of such materials in several biomedical engineering applications.

  16. Preparation and Characterization of Titania-silica Composite Particles by Pechini Sol-gel Method

    Directory of Open Access Journals (Sweden)

    Wu Yuanting

    2016-01-01

    Full Text Available Two Pechini sol-gel processes were used to prepare titania-silica composite particles. The dynamic oxidation behavior of the TiO2-SiO2 powders has been characterized by thermogravimetry-differential scanning calorimetry (TG-DTG-DSC. The crystal phase and microstructure of the composite particles were investigated by X-ray diffraction (XRD and field emission scanning electron microscope (FE-SEM. The effects of Si:Ti molar ratio and sol-gel process on the TiO2-SiO2 powders were studied. The preparation of the polymeric precursors can influence the morphology of obtained TiO2-SiO2 composite particles. The spherical TiO2-SiO2 composite particles which are 20 nm~400 nm in diameter appear in gel-1 system. However, the TiO2-SiO2 powders obtained by gel-2 system are irregular in shape and 2~15 μm in diameter which show a loose porous structure consisted of very fine granules.

  17. [Preparation and clinical application of polyvinyl alcohol/drug-loaded chitosan microsphere composite wound dressing].

    Science.gov (United States)

    Zhang, Xiuju; Lin, Zhidan; Chen, Wenbin; Song, Ying; Li, Zhizhong

    2011-04-01

    In order to prepare and apply the polyvinyl alcohol/drug-loaded chitosan microspheres composite wound dressing, we first prepared chitosan microspheres by emulsion cross-linking method, and then added chitosan microspheres into the reactants during the acetalization of polyvinyl alcohol and formaldehyde. We further studied the morphology, water absorption, swelling degree, mechanical properties and in vitro release of the sponge with different amount of chitosan microspheres. The results showed that polyvinyl alcohol/drug-loaded chitosan composite sponge has porous structure with connectionism. Increasing the amount of chitosan microspheres would make the apertures smaller, so that the water absorption and the swelling of sponge decreased, but the tensile strength and compressive strength increased. With the increase of the amount of chitosan microspheres, the drug absorption of cefradine and the release rate increase, and the release time become longer. With the results of toxicity grade of 0 to 1, this type of composite sponge is non-toxic and meets the requirement of biocompatibility. The observation of rabbit nasal cavity after surgical operation suggested that polyvinyl acetal sponge modified with the chitosan has antiphlogistic, hemostatic and non-adherent characteristic, and can promote the healing and recovering of the nasalmucosa. After using this composite material, best growing surroundings for patients' granulation tissue were provided. Exposed bone and tendon were covered well with granulation tissue.

  18. PREPARATION AND CHARACTERIZATION OF CHITOSAN-ZnO/Al2O3 COMPOSITE

    Directory of Open Access Journals (Sweden)

    Dina Kartika Maharani

    2015-11-01

    Full Text Available The purpose of this research was to prepare novel composite based on biopolymer and nontoxic inorganic materials that can be applied for many uses such as coating agent on textile for antibacterial purposes. In this research, Chitosan-ZnO/ Al2O3 composites were prepared by mixing chitosan solution with ZnO particles and Al2O3 (alumina sol produced by sol-gel method. The products were characterized with Fourier Transform Infra Red (FTIR Spectrophotometer and X-Ray Diffractometer (XRD. The result of this research showed that composites exist as transparent solution that was suitable for coating agent application. The result of FTIR Spectrophotometer analysis showed that there were interactions between chitosan, ZnO particles and Al2O3 particles which indicated from absorption bands in the region of wave number 3500-3400 cm-1, 1600-1500 cm-1 and 600-450 cm-1. It mean that chitosan interacted to ZnO particles and alumina particles . The XRD analysis of composites showed that there were change in the diffraction peak in the 2 theta value of 10o and 19o which indicated interaction of chitosan with ZnO particles and alumina particles

  19. The Dielectric Properties and Preparation Method of BaTiO3/PVDF 0-3 Composites

    Institute of Scientific and Technical Information of China (English)

    XIONG Chuan-xi; CHEN Juan; DONG Li-jie; NAN Ce-wen; ZHANG Xuan

    2002-01-01

    A series of 0 - 3 composites of the polyvinylidene fluoride (PVDF) and BaTiO3 was prepared.BaTiO3 was modified with titanate coupling agent. The dielectric properties and the interfacial interaction of composites by different preparation methods were examined and cormpared. The result shows that the relative dielectric constant ε of the composite prepared in solution has a maximum value at about 70% weight fraction of BaTiO3and the dielectric loss tanδ increases rapidly when the fraction exceeds 70%. For the composite prepared in melt,the relative dielectric constant ε almost reaches a maximum value at about 60% weight fraction of BaTiO3 and the dielectric loss is comparatively lower. The dielectric properties of composites are improved by using a coupling agent.

  20. PREPARATION AND PROPERTIES OF WHEAT GLUTEN/RICE PROTEIN COMPOSITES PLASTICIZED WITH GLYCEROL

    Institute of Scientific and Technical Information of China (English)

    Yan-yan Yang; Kai-zhou Zhang; Yi-hu Song; Qiang Zheng

    2011-01-01

    Environment friendly thermosetting composites were prepared by blending wheat gluten (WG) and rice protein (RP) at different weight ratios with glycerol as plasticizer followed by compression molding the mixture at 120C to crosslink the proteins. Reducing agent of sodium bisulfate and sodium sulfite and crosslinking agent formaldehyde were used to adjust the properties of the composites. Morphology, moisture absorption and tensile properties were evaluated. The results showed that formaldehyde could increase tensile strength of the composites without significant influence on Young's modulus and elongation at break. On the other hand, reducing agents could improve tensile strength and extensibility simultaneously, which was much marked at WG/RP ratios from 7/3 to 3/7.

  1. ELECTRICALLY CONDUCTIVE COMPOSITE PREPARED BY ELECTROCHEMICAL POLYMERIZATION OF PYRROLE IN POLY- (p- PHENYLENE TEREPHTHALAMIDE ) MATRIX

    Institute of Scientific and Technical Information of China (English)

    BI Xiantong; PEI Qibing; HAN Baozhen; BAO Jingshen

    1991-01-01

    The preparation of PPy/PPTA conductive composite films by electrochemical method is presented.The first step is to cast a thin layer of poly (p-phenylene-terephthalamide)(PPTA)on a slice of Pt working electrode. The second step is to electrochemically polymerize pyrrole on the PPTA/Pt working electrode. Both of the electrical conductivity and the mechanical properties of the PPy/PPTA composite film are better than those of the pure PPy film, and the film has excellent flexibility at low temperature, even in liquid nitrogen.The SEM picture of the cross-section of PPy/PPTA composite film showed that the two components were well mixed.Cyclic voltammograms of PPy/PPTA film in aqueous solution showed that the conductive films could be reduced and reoxidized.

  2. Carbon-based Composite Electrodes: Preparation, Characterization and Application in Electroanalysis

    Directory of Open Access Journals (Sweden)

    Joop Schoonman

    2007-11-01

    Full Text Available Electrodes based on carbon, i.e., expanded graphite (20%, wt.-epoxy composite(20EG-Epoxy and expanded graphite (20%, wt.-polystyrene composite (20EG-PS havebeen prepared, characterized using scanning electron microscopy (SEM and cyclicvoltammetry (CV, and tested as anodic sensors. The electrodes exhibited good mechanicalresistance and low electrical resistances. Scan rate dependent cyclic voltammetry responsesat 20EG-Epoxy and 20EG-PS composite electrodes, which were exemplified for thiourea(TU, a toxic sulphur organic compound selected as testing target analyte in 0.1 M Na2SO4 supporting electrolyte, were investigated. The obtained voltammetric data were inaccordance with those for a random array of microelectrodes. The voltammetric andchronoamperometric detection results of TU in tap water samples, without a supplementaryaddition of supporting electrolyte, at 20EG-Epoxy electrode proved its use for directanalysis of environmental samples.

  3. Preparation of Composite Films of a Conjugated Polymer and C60NWs and Their Photovoltaic Application

    Directory of Open Access Journals (Sweden)

    Takatsugu Wakahara

    2016-01-01

    Full Text Available Composite films of conjugated polymers, such as poly[2-methoxy-5-(3′,7′-dimethyloctyloxy-1,4-phenylenevinylene] (MDMO-PPV and poly(3-hexylthiophene (P3HT, with C60 nanowhiskers (C60NWs were prepared. The photoluminescence originating from the conjugated MDMO-PPV polymers was effectively quenched in the composite film, indicating a strong interaction between the conjugated polymer and C60NWs. The photovoltaic devices were fabricated using C60NW (conjugated polymer composite films, resulting in a power conversion efficiency of ~0.01% for P3HT with short length thin C60NWs, which is higher than that previously reported for thick C60 nanorods. The present study gives new guidance on the selection of the type of C60NWs and the appropriate polymer for new photovoltaic devices.

  4. Preparation of Machinable Y-TZP/LaPO4 Composite Ceramics by Liquid Precursor Infiltration

    Institute of Scientific and Technical Information of China (English)

    周振君; 杨正方; 袁启明; 李秀华

    2002-01-01

    A machinable Y-TZP/LaPO4 composite ceramic was prepared by infiltrating LaPO4 liquid precursor into Y-TZP porous ceramic. Sintered Y-TZP ceramic preformed with 35% (volume fraction) open pore volume was made by adding graphite (30%, volume fraction). The Y-TZP/LaPO4 composite ceramics containing different LaPO4 contents were obtained by infiltration and pyrolysis cycles. The machinability and mechanical properties of materials were investigated. The results show that the machinable Y-TZP/LaPO4 composite ceramics containing 2.3% to 7.5% (volume fraction) LaPO4 has good machinability as well as outstanding mechanical properties.

  5. Preparation of TiC/Ni3Al Composites by Upward Melt Infiltration

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    TiC/Ni3Al composites have been prepared using upward infiltration method. The densificstion was performed by both Ni3Al melt filling and TiC sintering during the infiltration. The dissolution of TiC in liquid Ni3Al has been evidenced by finding Ni3(Al,Ti)C after fast cooling in the TiC/Ni3Al composites. The dissolution may be responsible for the infiltration and sintering. Compared with downward infiltration, the upward infiltration brought about higher strength and fracture toughness and shorter infiltration time. TiC/20 vol. pct Ni3Al composite processed by upward infiltration had a flexural strength of 1476 Mpa with a statistic Weibull modulus of 20.2 and a fracture toughness of 20.4 Mpa(m). Better mechanical properties may be attributed to melt unidirectional movement in upward infiltration.

  6. Study of Al composites prepared by high-energy ball milling; Effect of processing conditions

    Energy Technology Data Exchange (ETDEWEB)

    Mendoza-Duarte, J.M.; Estrada-Guel, I.; Carreño-Gallardo, C.; Martínez-Sánchez, R.

    2015-09-15

    The present work deals with the synthesis of some Al-based composites prepared by mechanical milling and processing by powder metallurgy followed by the evaluation of process conditions as: type of additive, their concentration and milling intensity studying its effect on the characteristics of the powder composite and mechanical performance of the composite. Powder samples were microstructural characterized by electronic microscopy (SEM–TEM) and the mechanical response was followed by hardness and compressive tests. A pronounced effect on the mechanical response of the specimens was evident after the addition of reinforced particles and milling intensity. Microscopy studies showed a uniform dispersion of the reinforcing particles in the metallic matrix at nanometric scale and an important grain refinement of the Al matrix was confirmed. After processing, a 66% increase on the mechanical response was reached with 1% of additive complemented with short milling intensities.

  7. Preparation and Characterization of Fe2O3/Al2O3 Nano-composites

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Al2O3/Fe2O3 nano-composites were prepared by sol-gel route. The effect of Fe2O3 content on the structure, grain size and characterization of the composite were investigated through X-ray diffraction and M(o)ssbauer spectrum. The X-ray diffraction results show that Al2O3/Fe2O3 nano-composites with the Fe2O3, content of 40 wt% can be obtained after heat-treated at 900℃. The M(o)ssbauer effect results show that all samples exhibit clear super-paramagnetic phenomenon. Particles grow and defects reduce with the increasing of Fe2O3 conteni and some α-Fe2O3 stay magnetic order.

  8. Preparation and catalytic application of Ag/polydopamine composite on surface of glass substrates

    Science.gov (United States)

    Yu, Jianying; Sun, Chengyi; Lu, Shixiang; Xu, Wenguo; Liu, Zhehan; He, Dongsheng

    2017-01-01

    In this work, Ag/polydopamine composite on glass substrates (Ag/PDA@slides) were formed by using polydopamine (PDA) as both reducing and stabilizing agent to reduce silver salts to silver nanoparticles (NPs) and adhesive them to slides. The morphology and chemical composition of the composite material was characterized by scanning electron microscopy (SEM) and X-ray diffraction pattern (XRD). The prepared Ag/PDA@slide was a highly active catalyst for the reduction of 4-nitrophenol (4-NP) in the presence of sodium borohydride (NaBH4) aqueous solution at room temperature. The reduction rate of the optimal catalyst was as fast as 10 s and it was stable up to 6 cycles without a significant loss of its catalytic activity. By measuring the UV-Vis absorption bonds of Ag/PDA@slides, it proved that condition of the strongest surface plasmon resonance of Ag/PDA@slides is the optimal condition of catalytic reduction of 4-NP.

  9. Rheological properties of magnetorheological fluid prepared by gelatin-carbonyl iron composite particles

    Institute of Scientific and Technical Information of China (English)

    PAN Hua-jin; HUANG Hong-jun; ZHANG Ling-zhen; QI Jian-ying; CAO Shao-kun

    2005-01-01

    Gelatin-carbonyl iron composite particle was prepared by micro emulsion method. The analysis of scanning electron microscope(SEM) shows that the ultrafine particles are spheroids coated by gelatin, and the average sizes of particles are 3-10 μm. The specific saturation magnetization σs is 130.9 A·m2/kg, coercivity Hc is 0.823 A/m, and residual magnetism r is 4.98 Am2/kg for the composite particles. It is shown that the particles possess properties of soft magnetic. The yield stress of magnetorheological fluid(MRF) with composite particle reaches 70 kPa at 0.5 T magnetic induction. Magnetorheological effects are superior in lower magnetic field intensity and the subsidence stability of the MRF is excellent compared with pure carbonyl iron powder.

  10. A novel approach for filling tunnel-prepared teeth with composites of two different consistencies: a case presentation.

    Science.gov (United States)

    Ebert, Johannes; Frankenberger, Roland; Petschelt, Anselm

    2012-02-01

    A new approach to fill tunnel preparations with composites of two different consistencies is presented. Removal of caries through a narrow access space and reliably filling this cavity are the two main problems with tunnel-prepared teeth. Caries removal can be supplemented by the use of hand instruments, especially curettes, but filling the lesion with composite of a single consistency is problematic. Flowable composite alone does not create enough pressure to place the filling material into shallow extensions of the lesion; packable composite does not flow well enough. A solution for this problem may be a dual-consistency technique: flowable composite is placed, followed by packable composite, with no light curing in between. The flowable composite is pressed into small details of the cavity by the pressure created by the packable composite.

  11. Release Mechanism and Pharmaceutical Care of Oral Sustained/Controlled Release Preparations in Clinical Application%临床常用口服缓控释制剂的释药原理与服用要点

    Institute of Scientific and Technical Information of China (English)

    钱卿; 谢云芬

    2011-01-01

    缓控释药物在现今临床使用上已日趋广泛,也是药物制剂学研究的热点内容.本文简要地介绍了缓控释制剂的释药原理,并列举了常用的缓控释药品及正确的使用方法,为临床工作者合理应用提供了必要的依据.%With the increasing application in modern clinical therapy, the sustained/controlled release drug delivery systems (DDSs) are the hot spot and main trend of pharmaceutic research. The release characteristics and mechanisms for oral sustained/controlled release preparations are discussed, and those commonly used in the hospitals are introduced in this article. Providing rational administration of the drugs and strengthening pharmaceutical care is critical to ensure their safe and effective application.

  12. Crumpled graphene-molybdenum oxide composite powders: preparation and application in lithium-ion batteries.

    Science.gov (United States)

    Choi, Seung Ho; Kang, Yun Chan

    2014-02-01

    Crumpled graphene-MoO2 composite powders are directly prepared by means of spray pyrolysis and from a stable graphene oxide colloidal solution in the presence of Mo ions. The crumpled graphene-MoO2 composite powders are transformed into MoO3 -based composite powders after post-treatment at 300 °C. The transmission electron microscopy and dot-mapping images of the post-treatment composite powders show uniform distribution of MoO3 nanocrystals in the crumpled graphene powders. The two typical D and G bands of graphene are observed at 1350 and 1590 cm(-1) , respectively, in the Raman spectrum of the graphene-MoO3 composite. In addition, the crumpled graphene-MoO3 powders exhibit superior electrochemical behavior compared to that of pure MoO3 as an anode material for lithium-ion batteries. The initial discharge capacities of the graphene-MoO3 composite and bare MoO3 powders at a current density of 2 A g(-1) are 1490 and 1225 mA h g(-1) , respectively. The capacity retention of the graphene-MoO3 composite is 87 % after the first cycle, whereas that of bare MoO3 is 47 %, as measured after 100 cycles. The reversible discharge capacity of the graphene-MoO3 composite decreases slightly from 1228 to 845 mA h g(-1) as the current density increases from 0.5 to 3 A g(-1) .

  13. Surface modification of bioactive glasses and preparation of PDLLA/bioactive glass composite films.

    Science.gov (United States)

    Gao, Yuan; Chang, Jiang

    2009-08-01

    In order to improve the homogeneous dispersion of particles in the polymeric matrix, 45S5, mesoporous 58S, and 58S bioactive glasses were surface modified by esterification reactions with dodecyl alcohol at reflux temperature of 260 degrees C (named as m-45S5, m-mesoporous 58S, and m-58S, respectively). The modified particles showed better hydrophobicity and longer time of suspension in organic matrix. The PDLLA/bioactive glass composite films were fabricated using surface modified bioactive glass particles through solvent casting-evaporation method. Surface morphology, mechanical property, and bioactivity were investigated. The results revealed that the inorganic particle distribution and tensile strength of the composite films with modified bioactive glass particles were significantly improved while great bioactive properties were maintained. Scanning electron microscopy (SEM) observation illustrated that the modified bioactive glass particles were homogeneously dispersed in the PDLLA matrix. The maximum tensile strengths of composite films with modified bioactive glass particles were higher than that of composite films with unmodified bioactive glass particles. The bioactivity of the composite films were evaluated by being soaked in the simulated body fluid (SBF) and the SEM observation of the films suggested that the modified composite films were still bioactive in that they could induce the formation of HAp on its surface and the distribution of HAp was even more homogeneous on the film. The results mentioned above indicated that the surface modification of bioactive glasses with dodecyl alcohol was an effective method to prepare PDLLA/bioactive glass composites with enhanced properties. By studying the comparisons of modification effects among the three types of bioactive glasses, we could get the conclusion that the size and morphology of the inorganic particles would greatly affect the modification effects and the properties of composites.

  14. Preparation and bioactive properties of nano bioactive glass and segmented polyurethane composites.

    Science.gov (United States)

    Aguilar-Pérez, Fernando J; Vargas-Coronado, Rossana F; Cervantes-Uc, Jose M; Cauich-Rodríguez, Juan V; Covarrubias, Cristian; Pedram-Yazdani, Merhdad

    2016-04-01

    Composites of glutamine-based segmented polyurethanes with 5 to 25 wt.% bioactive glass nanoparticles were prepared, characterized, and their mineralization potential was evaluated in simulated body fluid. Biocompatibility with dental pulp stem cells was assessed by MTS to an extended range of compositions (1 to 25 wt.% of bioactive glass nanoparticles). Physicochemical characterization showed that composites retained many of the matrix properties, i.e. those corresponding to semicrystalline elastomeric polymers as they exhibited a glass transition temperature (Tg) between -41 and -36℃ and a melting temperature (Tm) between 46 and 49℃ in agreement with X-ray reflections at 23.6° and 21.3°. However, with bioactive glass nanoparticles addition, tensile strength and strain were reduced from 22.2 to 12.2 MPa and 667.2 to 457.8%, respectively with 25 wt.% of bioactive glass nanoparticles. Although Fourier transform infrared spectroscopy did not show evidence of mineralization after conditioning of these composites in simulated body fluid, X-ray diffraction, scanning electron microscopy, and energy dispersive X-ray microanalysis showed the formation of an apatite layer on the surface which increased with higher bioactive glass concentrations and longer conditioning time. Dental pulp stem cells proliferation at day 5 was improved in bioactive glass nanoparticles composites containing lower amounts of the filler (1-2.5 wt.%) but it was compromised at day 9 in composites containing high contents of nBG (5, 15, 25 wt.%). However, Runx2 gene expression was particularly upregulated for the dental pulp stem cells cultured with composites loaded with 15 and 25 wt.% of bioactive glass nanoparticles. In conclusion, low content bioactive glass nanoparticles and segmented polyurethanes composites deserve further investigation for applications such as guided bone regeneration membranes, where osteoconductivity is desirable but not a demanding mechanical performance.

  15. Pharmaceutical virtue.

    Science.gov (United States)

    Martin, Emily

    2006-06-01

    In the early history of psychopharmacology, the prospect of developing technologically sophisticated drugs to alleviate human ills was surrounded with a fervor that could be described as religious. This paper explores the subsequent history of the development of psychopharmacological agents, focusing on the ambivalent position of both the industry and its employees. Based on interviews with retired pharmaceutical employees who were active in the industry in the 1950s and 1960s when the major breakthroughs were made in the development of MAOIs and SSRIs, the paper explores the initial development of educational materials for use in sales campaigns. In addition, based on interviews with current employees in pharmaceutical sales and marketing, the paper describes the complex perspective of contemporary pharmaceutical employees who must live surrounded by the growing public vilification of the industry as rapacious and profit hungry and yet find ways to make their jobs meaningful and dignified. The paper will contribute to the understudied problem of how individuals function in positions that require them to be part of processes that on one description constitute a social evil, but on another, constitute a social good.

  16. [Composition, physico-chemical properties and molecular superstructure of dietary fiber preparations of the cellan type].

    Science.gov (United States)

    Dongowski, G; Frigge, K; Zenke, I

    1995-07-01

    Dietary fiber preparations of "cellan" type were prepared from apples, white cabbage, sugar beet pulp, soy hulls and wheat bran by treatment with amylolytic and proteolytic enzymes as well as by chemical extractions. Scanning electron microscopic examinations show different morphological structures of the preparations and a high maintenance of native biomolecular superstructure. The content of pectin, protein, polysaccharide-hexoses and -pentoses and the composition of monosaccharides (also after their treatment with 4 or 8% sodium hydroxide) were determined. The cellans possess waterbinding capacities (WBC) between 25 g H2O/g and waterholding capacities between 50 g H2O/g. The WBC is related to the internal surface; it diminishes after treatment with NaOH. The interactions between the cellans and the adsorbed water were characterized by NMR-spin-lattice relaxation time T1. The molecular mobility increases as the water content grows. The T1-values of dried cellans decreased with increasing degree of moisture before drying. The supermolecular structure is comparatively disordered. Only in case of soy cellan a crystalline cellulose-I-modification could be identified by X-ray-diffraction pattern, esp. after NaOH treatment. The low degree of order of cellans was observed in the 13C-NMR spectra, too. Only the soy hull preparation resulted in a spectrum corresponding to well-ordered cellulose. The botanic source has an essential influence on the physico-chemical properties of dietary fiber preparations of cellan type.

  17. A sensitive determination of terbutaline in pharmaceuticals and urine samples using a composite electrode based on zirconium oxide nanoparticles.

    Science.gov (United States)

    Baytak, Aysegul Kutluay; Teker, Tugce; Duzmen, Sehriban; Aslanoglu, Mehmet

    2016-10-01

    An accurate and precise determination of terbutaline has been carried out using a glassy carbon electrode (GCE) modified with a composite of multi-walled carbon nanotubes (MWCNTs) and nanoparticles of zirconium oxide (ZrO2NPs). Energy dispersive X-ray and scanning electron microscopic techniques were utilized for the characterization of the composite layer. Terbutaline exhibited a broad oxidation peak at 770mV on a GCE. However, MWCNTs/GCE presented an electrocatalytic effect toward the oxidation of terbutaline with a better anodic peak at 660mV. Furthermore, the electrochemical behavior of terbutaline has greatly been improved at a GCE modified with a composite of MWCNTs and nanoparticles of ZrO2. The ZrO2NPs/MWCNTs/GCE exhibited a sharp anodic wave at 645mV with a large enhancement of the current response for terbutaline. Square wave voltammetry (SWV) was performed for the determination of terbutaline at ZrO2NPs/MWCNTs/GCE. A linear plot was obtained for the current responses of terbutaline against concentrations in the range of 10-160nM yielding a detection limit of 2.25nM (based on 3Sb/m). Improved voltammetric behavior, long-time stability and good reproducibility were obtained for terbutaline at the proposed electrode. A mean recovery of 101.2% with an RSD% of 1.9 was obtained for the analysis of the drug formulation. The accurate and precise quantification of terbutaline makes the ZrO2NPs/MWCNTs/GCE system of great interest for monitoring its therapeutic use.

  18. Preparation and photochromic properties of NiAl-NO3-LDHs/LDPE composite

    Institute of Scientific and Technical Information of China (English)

    CHO Kyuhaeng; LIN YanJun; David G. EVANS; LI DianQing

    2007-01-01

    Nanoscale NiAl-NO3-LDHs with good crystallinity have been synthesized by a method, Separate Nucleation and Aging Steps (SNAS). An NiAl-NO3-LDHs/LDPE composite was prepared by blending NiAl-NO3-LDHs and LDPE in a heated double-roller mixer. The color of this composite changed from olive green to steel gray under UV irradiation. After heating at 80℃ for 2 h, the color returned to olive green. The effect of varying the amount of added NiAl-NO3-LDHs and UV exposure time on the photochromic properties of the composite has been investigated. The results showed that the photochromic phenomenon becomes more apparent with increasing amount of NiAl-NO3-LDHs. When the amount reaches 5%, the composite exhibits good photochromic properties and reproducibility. The color change rate of the composite reaches a maximum when the irradiation time exceeds 20 min. The addition of LDPE improves the photochromic cyclability of NiAl-NO3-LDHs significantly. The addition of nanoscale NiAl-NO3-LDHs also improves the mechanical properties of LDPE to some extent.

  19. Preparation and microwave-absorbing property of EP/BaFe12O19/PANI composites

    Science.gov (United States)

    Feng, Huixia; Bai, Dezhong; Tan, Lin; Chen, Nali; Wang, Yueyi

    2017-07-01

    In this paper, we introduced expanded perlite (EP) into the system of ferrite composites for the first time. By sol-gel self-propagating combustion method, expanded perlite/barium ferrite (EP/BaFe12O19) was prepared, and then ternary composites of expanded perlite/barium ferrite/polyaniline (EP/BaFe12O19/PANI) were obtained by in-situ oxidative polymerization of aniline on EP/BaFe12O19 mixture. Although, as is well known, the values of saturation magnetization (Ms), remnant magnetization (Mr) and coercivity (Hc) of composites are all lower than the pure BaFe12O19 particles owing to the existence of the nonmagnetic EP and PANI, the EP/BaFe12O19/PANI composites exhibit absorption characteristics at the range of 2-18 GHz, the effective absorption bandwidth (less than -4 dB) reached 12.12 GHz and the minimum reflection loss of -5.66 dB at 8.48 GHz with only 2 mm thickness of absorbing layer. So the composites could resist urban electromagnetic pollution, such as wireless network, communication and so on, effectively.

  20. Preparation, characterization, biological activity, and transport study of polystyrene based calcium–barium phosphate composite membrane

    Energy Technology Data Exchange (ETDEWEB)

    Khan, Mohammad Mujahid Ali; Rafiuddin,, E-mail: rafi_amu@rediffmail.com

    2013-10-15

    Calcium–barium phosphate (CBP) composite membrane with 25% polystyrene was prepared by co-precipitation method. Scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transformed infrared (FTIR), and Thermogravimetric analysis (TGA) were used to characterize the membrane. The membrane was found to be crystalline in nature with consistent arrangement of particles and no indication of visible cracks. The electrical potentials measured across the composite membrane in contact with univalent electrolytes (KCl, NaCl and LiCl), have been found to increase with decrease in concentrations. Thus the membrane was found to be cation-selective. Transport properties of developed membranes may be utilized for the efficient desalination of saline water and more importantly demineralization process. The antibacterial study of this composite membrane shows good results for killing the disease causing bacteria along with waste water treatment. Highlights: • Transport properties of composite membrane are evaluated. • The composite membrane was found to be stable in all media. • TMS method is used for electrochemical characterization. • The membrane was found to be cation selective. • The order of surface charge density was found to be LiCl < NaCl < KCl.

  1. [An investigation of HAP/organic polymer composite coatings prepared by electrochemical co-deposition technique].

    Science.gov (United States)

    Hu, Haobing; Lin, Changjian; Leng, Yang

    2003-03-01

    An electrochemical co-deposition technique has been developed to prepare a hydroxyapatite (HAP)/organic polymer composite coatings on Ti surface as new biomaterial of hard tissue. The composite coating of organic polymer and calcium phosphate is formed by adding a water soluble polymer of the ethylene series to NH4H2PO4-Ca (NO3)2 solution when conducting an appropriate electrochemical co-deposition experiment. The XRD, SEM, XPS, SIMS and nano indent measurements were performed to characterize the morphology, composition, structure and surface stiffness of the composite coating. It was found that the morphology and surface hardness of the coatings showed a remarkable modification when introducing a minor polymer to HAP coating, and the bonding force between the coating and metal substrate was distinctly increased. The incorporation of minor organic polymer into the HAP compound at molecular level will improve the mechanical properties and morphology of the composite coatings, and this may be helpful to raising its bio-activity.

  2. Preparation and wear resistance of Ti-Zr-Ni quasicrystal and polyamide composite materials

    Science.gov (United States)

    Wang, Xinlu; Li, Xuesong; Zhang, Zhenjiang; Zhang, Shanshan; Liu, Wanqiang; Wang, Limin

    2011-07-01

    Ti-Zr-Ni icosahedral quasicrystal powders (Ti-QC), prepared by mechanical alloying and then annealing in a vacuum furnace, were used as a novel filler material in polyamide 12 (PA12). The melt processability of the composite was studied using a Haake torque rheometer. This indicates that PA12/Ti-QC composites can be melt-processed into a wear-resistant material. Further, these composites, fabricated by compression molding, were tested in sliding wear against a polished bearing steel counterface. The results from wear testing show that the addition of Ti-QC filler to PA12 enhances wear resistance and reduces volume loss by half compared with neat PA12. Furthermore, it is found that the hardness of the composite increases with increasing content of Ti-QC filler. In addition, PA12/Ti-QC composites exhibit a slightly higher crystallization temperature and better thermal stability than PA12. These combined results demonstrate that Ti-QC filler may be a desirable alternative when attempting to increase the wear resistance of PA12.

  3. Preparation of Ni-CNT composite coatings on aluminum substrate and its friction and wear behavior

    Institute of Scientific and Technical Information of China (English)

    涂江平; 朱丽萍; 陈卫祥; 赵新兵; 刘芙; 张孝彬

    2004-01-01

    Nickel-carbon nanotube(CNT) composite coatings with a Zn-Ni interlayer were prepared by electrodeposition technique on aluminum substrate. The effects of CNT concentration in plating bath on the volume fraction of CNTs in the deposits and the coating growth rate were investigated. The friction and wear behavior of the Ni-CNT composite coatings were examined using a pin-on-disk wear tester under dry sliding conditions at a sliding speed of 0. 062 3 m/s and load range from 12 N to 150 N. Because of the reinforcement of CNTs in the composite coatings, at lower applied loads, the wear resistance was improved with increasing volume fraction of CNTs. Since cracking and peeling occur on the worn surface, the wear rates of composite coatings with high volume fraction of CNTs increase rapidly at higher applied loads. The friction coefficient of the composite coatings decreases with the increasing volume fraction of CNTs due to the reinforcement and self-lubrication of CNTs.

  4. Densification of in situ prepared mesocarbon microbead/carbon nanotube composites by hot-press sintering

    Institute of Scientific and Technical Information of China (English)

    WU Bin; GONG Qian-ming; WU Jian-jun; SONG Huai-he; LIANG Ji

    2009-01-01

    In situ prepared mesocarbon microbead/carbon nanotube(MCMB/CNT) composites are potential precursors of high density carbon materials for various applications. Integrated MCMB/CNT composites were successfully fabricated by hot-press sintering at 550 ℃ under 30 MPa. After further calcination at 900 ℃, the hot-press sintering fabricated MCMB block has an apparent density of 1.77 g/cm3 and the open porosity 5.1%. With the addition of 5%(mass fraction) CNTs, the density of the composite block is elevated to 1.84 g/cm3, and its open porosity is reduced to 3.5%. The flexural strength of composite block with 5% CNTs is elevated to 116 MPa. Through the hot-press sintering, pores of 10-50 nm in the calcinated bulks are remarkably eliminated. The interstice between microbeads in the composite blocks is filled up by CNTs together with β-resin and quinoline-insoluble spheres, which can further contribute to the densification.

  5. Photocatalytic properties of TiO2 bonded active carbon composites prepared by SOL-GEL

    Institute of Scientific and Technical Information of China (English)

    李佑稷; 李效东; 李君文; 尹静

    2004-01-01

    Photocatalyst of TiO2 bonded active carbon (TiO2/AC), was prepared via sol-gel method from a mixture of TiO2 sol with active carbon. Post heat treatment was performed at 250 ℃ for 2 h in air and then kept at 400 ℃ to 600 ℃ under a flow of nitrogen for 2 h. The TiO2/AC composites obtained were characterized by SEM, XRD, UV-vis and BET. The photocatalytic activities of the TiO2/AC composites were studied in comparison with TiO2, AC,P-25 and a mixture of TiO2 and AC, respectively. The Ramnant rate of Rhodamine B absorbed by the active carbon is found to be almost 70% and the remnant rates of the Rhodamine B decolorized by TiO2 and the mixture of TiO2 and the active carbon are 30% and 25%, respectively. However, nearly complete removal of Rhodamine B is observed for a TiO2/AC composite after 200 min under UV irradiation, which will take the P-25 commercial product 5 h. Therefore, the TiO2/AC composite is much more effective in decolorization of aqueous Rhodamine B. In addition, the composite can be easily separated from solutions.

  6. Design and Preparation of Carbon Based Composite Phase Change Material for Energy Piles

    Directory of Open Access Journals (Sweden)

    Haibin Yang

    2017-04-01

    Full Text Available Energy piles—A fairly new renewable energy concept—Use a ground heat exchanger (GHE in the foundation piles to supply heating and cooling loads to the supported building. Applying phase change materials (PCMs to piles can help in maintaining a stable temperature within the piles and can then influence the axial load acting on the piles. In this study, two kinds of carbon-based composite PCMs (expanded graphite-based PCM and graphite nanoplatelet-based PCM were prepared by vacuum impregnation for potential application in energy piles. Thereafter, a systematic study was performed and different characterization tests were carried out on two composite PCMs. The composite PCMs retained up to 93.1% of paraffin and were chemically compatible, thermally stable and reliable. The latent heat of the composite PCM was up to 152.8 J/g while the compressive strength of cement paste containing 10 wt % GNP-PCM was found to be 37 MPa. Hence, the developed composite PCM has potential for thermal energy storage applications.

  7. Preparation and In Vitro Behavior of a Poly(lactic acid-Fiber/Hydroxyapatite Composite Sheet

    Directory of Open Access Journals (Sweden)

    Yasuhiro Tanimoto

    2009-01-01

    Full Text Available This paper describes the processing and in vitro behavior of a poly(lactic acid (PLA-fiber/hydroxyapatite (HA composite sheet consisting of a knitted PLA-fiber sheet and HA powder for bone tissue engineering. Type I collagen was used as a binding agent to combine the PLA fibers and the HA powder. Precipitate formation in Hanks' balanced salt (HBS solution was monitored to evaluate the in vitro apatite formation ability of the PLA-fiber/HA composite sheet. Precipitate formation was observed on the surface of the PLA-fiber/HA composite sheet after immersion in HBS solution for only 1 day, while no precipitate formation was observed on the PLA-fiber sheet without HA as a control. In conclusion, a PLA-fiber/HA composite sheet for use as a scaffold was successfully prepared. Within the limitations of this investigation, we confirmed that the PLA-fiber/HA composite sheet has a high apatite formation activity compared with the PLA-fiber sheet and represents a promising material for use as a scaffold.

  8. Nylon 610/graphene oxide composites prepared by in-situ interfacial polymerization.

    Science.gov (United States)

    Lee, Jaehoon; Yun, Young Soo; Kim, Bona; Cho, Se Youn; Jin, Hyoung-Joon

    2014-08-01

    Nylon 610/nylon 610-grafted graphene oxide (nylon 610/GO-g-nylon 610) composites were fabricated using acyl chloride-functionalized graphene oxide by in-situ interfacial polymerization. GO-g-nylon 610 was synthesized by the condensation reaction between the acyl chloride groups of GO and the amino groups at the nylon 610 chains during the in-situ polymerization. Nylon 610/GO composites without grafting nylon 610 onto GO were also prepared to investigate the influence of grafting nylon 610 on the interfacial adhesion between GO and the nylon 610 matrix. The thermal properties of the nylon 610/GO-g-nylon 610 composites were enhanced with increasing GO-g-nylon 610 content in the nylon 610 matrix. The degradation temperature and thermal conductivity of the nylon 610/GO-g-nylon 610-10 composite were increased to 72.2 °C and 36.9%, respectively, compared with those of pure nylon 610. The crystallinity of the nylon 610/GO-g-nylon 610-10 composite was significantly lower than that of pure nylon 610 due to the hindered mobility of the nylon 610 chains by the strong interfacial adhesion between the GO-g-nylon 610 and the nylon 610 matrix.

  9. Preparation and multicolored fluorescent properties of CdTe quantum dots/polymethylmethacrylate composite films

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Yanni; Liu, Jianjun, E-mail: jjliu717@aliyun.com; Yu, Yingchun; Zuo, Shengli

    2015-10-25

    A new simple route was presented for the preparation of stable fluorescent CdTe/polymethylmethacrylate (CdTe/PMMA) composite films by using hydrophilic thioglycolic acid capped CdTe quantum dots (TGA-CdTe QDs) and polymethylmethacrylate (PMMA) as raw materials. The TGA-CdTe QDs were firstly exchanged with n-dodecanethiol (DDT) to become hydrophobic DDT-CdTe QDs via a ligand exchange strategy, and then incorporated into PMMA matrix to obtain fluorescent CdTe/PMMA composite films. The structure and optical properties of DDT-CdTe QDs and CdTe/PMMA composite films were investigated by XRD, IR, UV and PL techniques. The results indicated that the obtained DDT-CdTe QDs well preserved the intrinsic structure and the maximum emission wavelength of the initial water-soluble QDs and the resulting 6.10 wt% CdTe/PMMA composite film exhibited significantly enhanced PL intensity. Furthermore, the multicolored composite films with green, yellow-green, yellow and orange light emissions were well tuned by incorporating the CdTe QDs of various maximum emission wavelengths. The TEM image demonstrated that the CdTe QDs were well-dispersed in the PMMA matrix without aggregation. Superior photostability of QDs in the composite film was confirmed by fluorescence lifetime measurement. Thermo-gravimetric analysis of CdTe/PMMA composite films showed no obvious enhancement of thermal stability compared with pure PMMA. - Highlights: • Ligand-exchange strategy was used to render CdTe QDs oil-soluble. • CdTe QDs were incorporated into PMMA matrix to fabricate fluorescent films. • The resulting 6.10 wt% CdTe/PMMA film exhibited significantly enhanced PL intensity. • Fluorescent colors of films were tuned by varying the λ{sub em} of incorporated CdTe QDs.

  10. Scalable Preparation of Ternary Hierarchical Silicon Oxide-Nickel-Graphite Composites for Lithium-Ion Batteries.

    Science.gov (United States)

    Wang, Jing; Bao, Wurigumula; Ma, Lu; Tan, Guoqiang; Su, Yuefeng; Chen, Shi; Wu, Feng; Lu, Jun; Amine, Khalil

    2015-12-07

    Silicon monoxide is a promising anode candidate because of its high theoretical capacity and good cycle performance. To solve the problems associated with this material, including large volume changes during charge-discharge processes, we report a ternary hierarchical silicon oxide-nickel-graphite composite prepared by a facile two-step ball-milling method. The composite consists of nano-Si dispersed silicon oxides embedded in nano-Ni/graphite matrices (Si@SiOx /Ni/graphite). In the composite, crystalline nano-Si particles are generated by the mechanochemical reduction of SiO by ball milling with Ni. These nano-Si dispersed oxides have abundant electrochemical activity and can provide high Li-ion storage capacity. Furthermore, the milled nano-Ni/graphite matrices stick well to active materials and interconnect to form a crosslinked framework, which functions as an electrical highway and a mechanical backbone so that all silicon oxide particles become electrochemically active. Owing to these advanced structural and electrochemical characteristics, the composite enhances the utilization efficiency of SiO, accommodates its large volume expansion upon cycling, and has good ionic and electronic conductivity. The composite electrodes thus exhibit substantial improvements in electrochemical performance. This ternary hierarchical Si@SiOx /Ni/graphite composite is a promising candidate anode material for high-energy lithium-ion batteries. Additionally, the mechanochemical ball-milling method is low cost and easy to reproduce, indicating potential for the commercial production of the composite materials. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Highly flexible magnetic composite aerogels prepared by using cellulose nanofibril networks as templates.

    Science.gov (United States)

    Liu, Shilin; Yan, Qiufang; Tao, Dandan; Yu, Tengfei; Liu, Xiaoya

    2012-06-20

    Nanostructured cellulose nanofibrils can form ductile or tough networks that are suitable templates for the creation of materials with functional properties. In this work, a facile method has been developed for the preparation of magnetic hybrid cellulose aerogels. The preparation processes followed by two steps, firstly, preparation of cellulose hydrogel films from LiOH/urea solvent, then CoFe2O4 nanoparticles were synthesized in the porous structured cellulose scaffolds. After being freeze-dried, CoFe2O4/cellulose magnetic aerogels were obtained. The porosity of the composite aerogels ranged from 78 to 52% with pore size distribution in a few tens of nanometers. The internal specific surface areas were around 300-320 m2/g, and the densities were in the range of 0.25-0.39 g/cm3. The hybrid aerogels showed improved mechanical strength, superparamagnetic properties. Unlike solvent-swollen gels and ferrogels, the magnetic composite aerogels were lightweight, flexibility, high porosity and with large specific surface area and could be expected to be used in many fields. Copyright © 2012 Elsevier Ltd. All rights reserved.

  12. submitter Preparation and luminescence properties of ZnO:Ga – polystyrene composite scintillator

    CERN Document Server

    Burešová, Hana; Turtos, Rosana Martinez; Jarý, Vítězslav; Mihóková, Eva; Beitlerová, Alena; Pjatkan, Radek; Gundacker, Stefan; Auffray, Etiennette; Lecoq, Paul; Nikl, Martin; Čuba, Václav

    2016-01-01

    Highly luminescent ZnO:Ga-polystyrene composite (ZnO:Ga-PS) with ultrafast subnanosecond decay was prepared by homogeneous embedding the ZnO:Ga scintillating powder into the scintillating organic matrix. The powder was prepared by photo-induced precipitation with subsequent calcination in air and Ar/H2 atmospheres. The composite was subsequently prepared by mixing the ZnO:Ga powder into the polystyrene (10 wt% fraction of ZnO:Ga) and press compacted to the 1 mm thick pellet. Luminescent spectral and kinetic characteristics of ZnO:Ga were preserved. Radioluminescence spectra corresponded purely to the ZnO:Ga scintillating phase and emission of polystyrene at 300-350 nm was absent. These features suggest the presence of non-radiative energy transfer from polystyrene host towards the ZnO:Ga scintillating phase which is confirmed by the measurement of X-ray excited scintillation decay with picosecond time resolution. It shows an ultrafast rise time below the time resolution of the experiment (18 ps) and a single-...

  13. Resistance to maxillary premolar fractures after restoration of class II preparations with resin composite or ceromer.

    Science.gov (United States)

    de Freitas, Cláudia Regina Buainain; Miranda, Maria Isabel Serra; de Andrade, Marcelo Ferrarezi; Flores, Victor Humberto Orbegoso; Vaz, Luís Geraldo; Guimarães, Catanzaro

    2002-09-01

    The aim of this study was to evaluate the resistance to fracture of intact and restored human maxillary premolars. Thirty noncarious human maxillary premolars, divided into three groups of 10, were submitted to mechanical tests to evaluate their resistance to fracture. Group 1 consisted of intact teeth. Teeth in group 2 received mesio-occlusodistal cavity preparations and were restored with direct resin composite restorations. Teeth in group 3 received mesio-occlusodistal cavity preparations and were restored with ceromer inlays placed with the indirect technique. After restoration, teeth were stored at 37 degrees C for 24 hours and then thermocycled for 500 cycles at temperatures of 5 degrees C and 55 degrees C. Statistical analysis revealed that group 3 (178.765 kgf) had a significantly greater maximum rupture load than did group 1 (120.040 kgf). There was no statistically significant difference between groups 1 and 2 or between groups 2 and 3. Class II cavity preparations restored with indirect ceromer inlays offered greater resistance to fracture than did intact teeth. The fracture resistance of teeth restored with resin composite was not significantly different from that of either the ceromer or intact teeth.

  14. Preparation and Photocatalytic Behaviors of Nanoporous Polyoxotungstate-Anatase TiO2 Composites

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Nanoporous anatase TiO2 crystalline particles coupled with Keggin or Wells-Dawson unit, H3PW12O40/TiO2 or H6P2W18O62/TiO2, were prepared at a low temperature (200 ℃) using sol-gel method combined with hydrothermal treatment at programmed temperature. The as-prepared composites have uniform anatase phase, and they exhibit both micro-and mesoporosities with pore sizes of 0.6 and 4.0 nm, respectively, and their average size is lower than 10 nm. Photocatalytic tests show the composites exhibit relatively higher photocatalytic activities to decompose the organocholorine pesticide hexachlorobenzene(HCB) than anatase TiO2, the starting polyoxotungstates, and Eu2O3/TiO2 prepared by using sol-gel method, and this was attributed to (1) the synergistic effect of photoactive anatase TiO2 with the polyoxotungstate, and (2) the fascinating physical and chemical properties of the porous materials.

  15. Preparation and Application of Active Composite Antibacterial Material Containing Ag + and Zn2+

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    A kind of active composite antibacterial material was prepared with CaHPO4 as the container,Ag + and Zn2+ were adsorbed through ion-exchange, then it was doped with small scale of rare earth and photocatalyst, and was finally calcined at a certain temperature. The properties and application of the composite material antibacterial were investigated. Some tests show that the as-prepared antibacterial powders modified by opaque agents such as SnO2 and ZrO2 , possess beautiful white and excellent climate resistance at normal temperatures and are promising candidate materials for antibacterial plastics and dope. The result of the application in glaze indicates that Ag + can still exist stably, with no color change for the glaze, even being sintered at 1 200 ℃.SEM, EDS, antibacterial activity analyses and contrast tests reveal that the as-prepared antibacterial powders and the antibacterial glaze both have excellent antibacterial activities, without color change, in the case of dark or brightness.

  16. Indium tin oxide nanosized composite powder prepared using waste ITO target

    Institute of Scientific and Technical Information of China (English)

    LIU Jiaxiang; GAN Yong; ZENG Shengnan

    2005-01-01

    Indium tin oxide (TTO) nano-particles were prepared directly using waste ITO target, which had been coated by magnetron controlled sputtering. The waste ITO target was cleaned with de-ionized water, and then dissolved in acid, filtrated, neutralized, manipulated through azeotropic distillation and finally dried, and in this way the precursor of indium tin hydroxide was obtained. The nanosized ITO composite powder was prepared after the precursor heat-treated at 500C for 2h. TEM images show a narrow distribution of particle size is 5-20 nm and the particle size can be controlled. Its granule has a spherical shape and the dispersion of the particle is well. X-ray diffraction (XRD) patterns indicate the only cubic In2O3 phase in the ITO powder heat-treated at 500C. The purity of ITO composite powder is 99.9907%. The content of indium within filtrate was detected by using the EDTA titration of determination of indium in the ITO powder and ITO target. Apfully prepared by heat-treating.

  17. Thermodynamic analysis and preparation of β-SiC/ZrO2 composites

    Institute of Scientific and Technical Information of China (English)

    Bei-yue Ma; Jing-kun Yu; Qiang Zhu; Yong Sun

    2009-01-01

    A predominance area diagram for the Zr-Si-C-O system at 1773 K was plotted according to correlative thermodynamic data. β-SiC/ZrO_2 composites were prepared based on the phase diagram by carbothermal reduction of zircon (ZrSiO_4) in argon at-mosphere. Zircon and carbon black were mixed according to the C/ZrSiO_4 mass ratio of 0.2, and with 0, 1wt% and 2wt% extra addi-tion of La_2O_3. Phase evolution of the mixture was investigated at 1723-1803 K by X-ray powder diffraction, and the microstructure of the product prepared at 1803 K for 4 h was examined by scanning electronic microscope. The results show that the decomposition of ZrSiO_4 and the formation of β-SIC can be promoted by increasing the heating temperature and adding La2O3. The β-SiC/ZrO_2 composites can be prepared at 1803 K for 4 h in a mixture of zircon, carbon black and La_2O_3, and the contents of β-SiC and m-ZrO_2 in the product sample with 2wt% La_2O_3 reach the highest values of 10.8wt% and 89.2wt%, respectively. The crystal size of the prod-ucts is about 200 nm.

  18. Silica-Copper Oxide Composite Thin Films as Solar Selective Coatings Prepared by Dipping Sol Gel

    Directory of Open Access Journals (Sweden)

    E. Barrera-Calva

    2008-01-01

    Full Text Available Silica-copper oxide (silica-CuO composite thin films were prepared by a dipping sol-gel route using ethanolic solutions comprised TEOS and a copper-propionate complex. Sols with different TEOS/Cu-propionate (Si/Cu molar ratios were prepared and applied on stainless steel substrates using dipping process. During the annealing process, copper-propionate complexes developed into particulate polycrystalline CuO dispersed in a partially crystallized silica matrix, as indicated by the X-ray diffraction (XRD and X-ray photoelectron spectroscopy (XPS analyses. The gel thermal analysis revealed that the prepared material might be stable up to 400°C. The silica-CuO/stainless steel system was characterized as a selective absorber surface and its solar selectivity parameters, absorptance (α, and emittance (ε were evaluated from UV-NIR reflectance data. The solar parameters of such a system were mostly affected by the thickness and phase composition of the SiO2-CuO film. Interestingly, the best solar parameters (α = 0.92 and ε = 0.2 were associated to the thinnest films, which comprised a CuO-Cu2O mixture immersed in the silica matrix, as indicated by XPS.

  19. PREPARATION AND CORROSION RESISTANCE OF NiP/TiO2 COMPOSITE FILM ON CARBON STEEL IN SULFURIC ACID SOLUTION

    Institute of Scientific and Technical Information of China (English)

    L.Z. Song; S.Z. Song; J. Zhao

    2006-01-01

    A NiP/TiO2 composite film on carbon steel was prepared by electroless plating and sol-gel composite process. An artificial neural network was applied to optimize the prepared condition of the composite film. Corrosion behavior of the NiP/TiO2 composite film was investigated by polarization resistance measurement, anode polarization, ESEM (environmental scanning electron microscopy)and EIS (electrochemical impedance spectroscopy) measurements. Results showed that the NiP/TiO2 composite film has a good corrosion resistance in 0.5mol/L H2SO4 solution. The element valence of the composite film was characterized by XPS (X-ray photoelectron spectroscopy) spectrum, and an anticorrosion mechanism of the composite film was discussed.

  20. Spray-coating process in preparing PTFE-PPS composite super-hydrophobic coating

    Directory of Open Access Journals (Sweden)

    Rui Weng

    2014-03-01

    Full Text Available In order to improve the performance of a liquid-floated rotor micro-gyroscope, the resistance of the moving interface between the rotor and the floating liquid must be reduced. Hydrophobic treatment can reduce the frictional resistance between such interfaces, therefore we proposed a method to prepare a poly-tetrafluoroethylene (PTFE-poly-phenylene sulphide (PPS composite super-hydrophobic coating, based on a spraying process. This method can quickly prepare a continuous, uniform PTFE-PPS composite super-hydrophobic surface on a 2J85 material. This method can be divided into three steps, namely: pre-treatment; chemical etching; and spraying. The total time for this is around three hours. When the PTFE concentration is 4%, the average contact angle of the hydrophobic coating surface is 158°. If silicon dioxide nanoparticles are added, this can further improve the adhesion and mechanical strength of the super-hydrophobic composite coating. The maximum average contact angle can reach as high as 164° when the mass fraction of PTFE, PPS and silicon dioxide is 1:1:1.