WorldWideScience

Sample records for solution dosage form

  1. 76 FR 81806 - Ophthalmic and Topical Dosage Form New Animal Drugs; Ivermectin Topical Solution

    Science.gov (United States)

    2011-12-29

    .... FDA-2011-N-0003] Ophthalmic and Topical Dosage Form New Animal Drugs; Ivermectin Topical Solution... solution of ivermectin. DATES: This rule is effective December 29, 2011. FOR FURTHER INFORMATION CONTACT... ANADA 200-318 for [[Page 81807

  2. 75 FR 26647 - Ophthalmic and Topical Dosage Form New Animal Drugs; Ivermectin Topical Solution

    Science.gov (United States)

    2010-05-12

    .... FDA-2010-N-0002] Ophthalmic and Topical Dosage Form New Animal Drugs; Ivermectin Topical Solution... are treated with a topical solution of ivermectin. DATES: This rule is effective May 12, 2010. FOR... ANADA 200-340 for PRIVERMECTIN (ivermectin), a topical solution used on cattle to control infestations...

  3. Physicochemical characterization of berberine chloride: a perspective in the development of a solution dosage form for oral delivery.

    Science.gov (United States)

    Battu, Sunil Kumar; Repka, Michael A; Maddineni, Sindhuri; Chittiboyina, Amar G; Avery, Mitchell A; Majumdar, Soumyajit

    2010-09-01

    The objective of the present research was to evaluate the physicochemical characteristics of berberine chloride and to assess the complexation of drug with 2-hydroxypropyl-β-cyclodextrin (HPβCD), a first step towards solution dosage form development. The parameters such as log P value were determined experimentally and compared with predicted values. The pH-dependent aqueous solubility and stability were investigated following standard protocols at 25°C and 37°C. Drug solubility enhancement was attempted utilizing both surfactants and cyclodextrins (CDs), and the drug/CD complexation was studied employing various techniques such as differential scanning calorimetry, Fourier transform infrared, nuclear magnetic resonance, and scanning electron microscopy. The experimental log P value suggested that the compound is fairly hydrophilic. Berberine chloride was found to be very stable up to 6 months at all pH and temperature conditions tested. Aqueous solubility of the drug was temperature dependent and exhibited highest solubility of 4.05 ± 0.09 mM in phosphate buffer (pH 7.0) at 25°C, demonstrating the effect of buffer salts on drug solubility. Decreased drug solubility was observed with increasing concentrations of ionic surfactants such as sodium lauryl sulfate and cetyl trimethyl ammonium bromide. Phase solubility studies demonstrated the formation of berberine chloride-HPβCD inclusion complex with 1:1 stoichiometry, and the aqueous solubility of the drug improved almost 4.5-fold in the presence of 20% HPβCD. The complexation efficiency values indicated that the drug has at least threefold greater affinity for hydroxypropyl-β-CD compared to randomly methylated-β-CD. The characterization techniques confirmed inclusion complex formation between berberine chloride and HPβCD and demonstrated the feasibility of developing an oral solution dosage form of the drug.

  4. [Pharmaceutical advice concerning different pharmaceutical dosage forms].

    Science.gov (United States)

    Szakonyi, Gergely; Zelkó, Romána

    2010-01-01

    The present paper summarizes the commonly applied types of drug uptake and the pharmacists' advice concerning a certain dosage form. The manuscript also deals with the modified release dosage forms and their abbreviations in the name of the marketing authorized products.

  5. Advances in solid dosage form manufacturing technology.

    Science.gov (United States)

    Andrews, Gavin P

    2007-12-15

    Currently, the pharmaceutical and healthcare industries are moving through a period of unparalleled change. Major multinational pharmaceutical companies are restructuring, consolidating, merging and more importantly critically assessing their competitiveness to ensure constant growth in an ever-more demanding market where the cost of developing novel products is continuously increasing. The pharmaceutical manufacturing processes currently in existence for the production of solid oral dosage forms are associated with significant disadvantages and in many instances provide many processing problems. Therefore, it is well accepted that there is an increasing need for alternative processes to dramatically improve powder processing, and more importantly to ensure that acceptable, reproducible solid dosage forms can be manufactured. Consequently, pharmaceutical companies are beginning to invest in innovative processes capable of producing solid dosage forms that better meet the needs of the patient while providing efficient manufacturing operations. This article discusses two emerging solid dosage form manufacturing technologies, namely hot-melt extrusion and fluidized hot-melt granulation.

  6. Amorphous drugs and dosage forms

    DEFF Research Database (Denmark)

    Grohganz, Holger; Löbmann, K.; Priemel, P.

    2013-01-01

    The transformation to an amorphous form is one of the most promising approaches to address the low solubility of drug compounds, the latter being an increasing challenge in the development of new drug candidates. However, amorphous forms are high energy solids and tend to recry stallize. New...... formulation principles are needed to ensure the stability of amorphous drug forms. The formation of solid dispersions is still the most investigated approach, but additional approaches are desirable to overcome the shortcomings of solid dispersions. Spatial separation by either coating or the use of micro-containers...... before single molecules are available for the formation of crystal nuclei, thus stabilizing the amorphous form....

  7. Buccal Dosage Forms: General Considerations for Pediatric Patients.

    Science.gov (United States)

    Montero-Padilla, Soledad; Velaga, Sitaram; Morales, Javier O

    2017-02-01

    The development of an appropriate dosage form for pediatric patients needs to take into account several aspects, since adult drug biodistribution differs from that of pediatrics. In recent years, buccal administration has become an attractive route, having different dosage forms under development including tablets, lozenges, films, and solutions among others. Furthermore, the buccal epithelium can allow quick access to systemic circulation, which could be used for a rapid onset of action. For pediatric patients, dosage forms to be placed in the oral cavity have higher requirements for palatability to increase acceptance and therapy compliance. Therefore, an understanding of the excipients required and their functions and properties needs to be particularly addressed. This review is focused on the differences and requirements relevant to buccal administration for pediatric patients (compared to adults) and how novel dosage forms can be less invasive and more acceptable alternatives.

  8. Pharmaceutical development of an intravenous dosage form of diacetylmorphine hydrochloride

    NARCIS (Netherlands)

    Klous, Marjolein G.; Nuijen, Bastiaan; van den Brink, Wim; van Ree, Jan M.; Beijnen, Jos H.

    2004-01-01

    A solid dosage form for multiple use was developed for parenteral administration of diacetylmorphine in a clinical trial on co-prescription of heroin to heroin addicts. A 300-mg/mL diacetylmorphine hydrochloride solution was lyophilised as 10-mL aliquots in 30-mL glass vials, to be reconstituted to

  9. The characteristics of novel dosage forms

    Directory of Open Access Journals (Sweden)

    Milić-Aškrabić Jela

    2003-01-01

    Full Text Available The objective of pharmaceutical-technological development is to find a procedure of transforming an active substance (a drug into a drug dosage form which is not only acceptable for application, but also enables the active substance to be released following administration, pursuant to therapy objectives. The aim is that the concentration of the active substance in the action location rapidly reaches a therapeutic level and maintains an approximately constant level in the course of a particular time, according to the established therapeutic goal. The primary objective is to present the active ingredient (drug in the form and concentration/quantity that enables the corresponding therapeutic response, i.e. to control the site and rate of medicinal substance release from the drug, as well as the rate at which it reaches the membranes and surfaces to which it is absorbed, while applying a common method of administration. The procedures used to achieve this goal are becoming highly complex and demanding and are aiming at sophisticated drug delivery systems and functional packaging material. Development from the existing drug molecule, through the conventional drug dosage form, to a new system of drug "delivery" (novel delivery system, can improve the drug (active substance characteristics significantly in view of compliance (acceptability by the patient, safety and efficiency. The paper presents an overview of the most important examples of pharmaceutical forms with controlled release and advanced drug "carriers".

  10. [Oral films as perspective dosage form].

    Science.gov (United States)

    Walicová, Veronika; Gajdziok, Jan

    Oral films, namely buccal mucoadhesive films and orodispersible films represent innovative formulations for administration of a wide range of drugs. Oral films show many advantageous properties and are intended for systemic drug delivery or for local treatment of the oral mucosa. In both cases, the film represents a thin layer, which could be intended to adhere to the oral mucosa by means of mucoadhesion; or to rapid dissolution and subsequent swallowing without the need of liquid intake, in the case of orodispersible films. Main constitutive excipients are film-forming polymers, which must in the case of mucoadhesive forms remain on the mucosa within the required time interval. Oral films are currently available on the pharmaceutical market and could compete with conventional oral dosage forms in the future. oral cavity oral films buccal mucoadhesive films orodispersible films film-forming polymers.

  11. Microbial quality of some herbal solid dosage forms

    African Journals Online (AJOL)

    STORAGESEVER

    2010-03-15

    Mar 15, 2010 ... Key words: Microbial quality, herbal, contamination, solid dosage form ... The type of dosage form, packaging, manufacturing and expiration dates of subject solid herbal .... According to WHO report (2002), Salmonella food.

  12. Prevalence and trends of cellulosics in pharmaceutical dosage forms.

    Science.gov (United States)

    Mastropietro, David J; Omidian, Hossein

    2013-02-01

    Many studies have shown that cellulose derivatives (cellulosics) can provide various benefits when used in virtually all types of dosage forms. Nevertheless, the popularity of their use in approved drug products is rather unknown. This research reports the current prevalence and trends of use for 15 common cellulosics in prescription drug products. The cellulosics were powdered and microcrystalline cellulose (MCC), ethyl cellulose, hydroxypropyl cellulose (HPC), hydroxyethyl cellulose (HEC), hypromellose (HPMC), HPMC phthalate, HPMC acetate succinate, cellulose acetate (CA), CA phthalate, sodium (Na) and calcium (Ca) carboxymethylcellulose (CMC), croscarmellose sodium (XCMCNa), methyl cellulose, and low substituted HPC. The number of brand drug products utilizing each cellulosics was determined using the online drug index Rxlist. A total of 607 brand products were identified having one or more of the cellulosics as an active or inactive ingredient. An array of various dosage forms was identified and revealed HPMC and MCC to be the most utilized cellulosics in all products followed by XCMCNa and HPC. Many products contained two or more cellulosics in the formulation (42% containing two, 23% containing three, and 4% containing 4-5). The largest combination occurrence was HPMC with MCC. The use of certain cellulosics within different dosage form types was found to contain specific trends. All injectables utilized only CMCNa, and the same with all ophthalmic solutions utilizing HPMC, and otic suspensions utilizing HEC. Popularity and trends regarding cellulosics use may occur based on many factors including functionality, safety, availability, stability, and ease of manufacturing.

  13. 21 CFR 522.1222 - Ketamine hydrochloride injectable dosage forms.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Ketamine hydrochloride injectable dosage forms. 522.1222 Section 522.1222 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... ANIMAL DRUGS § 522.1222 Ketamine hydrochloride injectable dosage forms. ...

  14. 21 CFR 520.1696 - Penicillin oral dosage forms.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Penicillin oral dosage forms. 520.1696 Section 520.1696 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.1696 Penicillin oral...

  15. 21 CFR 526.1696 - Penicillin intramammary dosage forms.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Penicillin intramammary dosage forms. 526.1696 Section 526.1696 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS INTRAMAMMARY DOSAGE FORMS § 526.1696 Penicillin...

  16. 21 CFR 522.1660 - Oxytetracycline injectable dosage forms.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Oxytetracycline injectable dosage forms. 522.1660 Section 522.1660 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... § 522.1660 Oxytetracycline injectable dosage forms. ...

  17. 21 CFR 520.905 - Fenbendazole oral dosage forms.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Fenbendazole oral dosage forms. 520.905 Section 520.905 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... Fenbendazole oral dosage forms. ...

  18. 21 CFR 520.45 - Albendazole oral dosage forms.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Albendazole oral dosage forms. 520.45 Section 520.45 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.45 Albendazole oral...

  19. Automatic identification and normalization of dosage forms in drug monographs

    Science.gov (United States)

    2012-01-01

    Background Each day, millions of health consumers seek drug-related information on the Web. Despite some efforts in linking related resources, drug information is largely scattered in a wide variety of websites of different quality and credibility. Methods As a step toward providing users with integrated access to multiple trustworthy drug resources, we aim to develop a method capable of identifying drug's dosage form information in addition to drug name recognition. We developed rules and patterns for identifying dosage forms from different sections of full-text drug monographs, and subsequently normalized them to standardized RxNorm dosage forms. Results Our method represents a significant improvement compared with a baseline lookup approach, achieving overall macro-averaged Precision of 80%, Recall of 98%, and F-Measure of 85%. Conclusions We successfully developed an automatic approach for drug dosage form identification, which is critical for building links between different drug-related resources. PMID:22336431

  20. A benefit/risk approach towards selecting appropriate pharmaceutical dosage forms - an application for paediatric dosage form selection.

    Science.gov (United States)

    Sam, Tom; Ernest, Terry B; Walsh, Jennifer; Williams, Julie L

    2012-10-05

    The design and selection of new pharmaceutical dosage forms involves the careful consideration and balancing of a quality target product profile against technical challenges and development feasibility. Paediatric dosage forms present particular complexity due to the diverse patient population, patient compliance challenges and safety considerations of this vulnerable population. This paper presents a structured framework for assessing the comparative benefits and risks of different pharmaceutical design options against pre-determined criteria relating to (1) efficacy, (2) safety and (3) patient access. This benefit/risk framework has then been applied to three hypothetical, but realistic, scenarios for paediatric dosage forms in order to explore its utility in guiding dosage form design and formulation selection. The approach allows a rigorous, systematic and qualitative assessment of the merits and disadvantages of each dosage form option and helps identify mitigating strategies to modify risk. The application of a weighting and scoring system to the criteria depending on the specific case could further refine the analysis and aid decision-making. In this paper, one case study is scored for illustrative purposes. However, it is acknowledged that in real development scenarios, the generation of actual data considering the very specific situation for the patient/product/developer would come into play to drive decisions on the most appropriate dosage form strategy. Copyright © 2012 Elsevier B.V. All rights reserved.

  1. Influence of dosage form on the intravitreal pharmacokinetics of diclofenac.

    Science.gov (United States)

    Durairaj, Chandrasekar; Kim, Stephen J; Edelhauser, Henry F; Shah, Jaymin C; Kompella, Uday B

    2009-10-01

    To prepare a suspension form of diclofenac and compare the influence of the injected form (suspension versus solution) on the intravitreal pharmacokinetics of diclofenac in Dutch belted pigmented rabbits. Diclofenac acid was prepared and characterized in a suspension formulation. Rabbit eyes were injected with either diclofenac sodium solution (0.3 mg) or diclofenac acid suspension (10 mg) prepared in 0.1 mL balanced salt solution. Rabbits were killed at regular time intervals, the eyes enucleated, and drug content quantified in the vitreous humor and retina-choroid tissue by high-performance liquid chromatography. Pharmacokinetic models were developed for both the dosage forms, and simulations were performed for different doses. Diclofenac acid with an approximate 5-mum particle size exhibited 3.5-fold lower solubility in vitreous humor, when compared with its sodium salt. The estimated settling velocity of the suspension in the vitreous humor was 3 cm/h. After diclofenac sodium salt solution injection, drug levels declined rapidly with no drug levels detectable after 24 hours in the vitreous humor and 4 hours in the RC. Throughout the assessed time course, drug levels were higher in the vitreous. However, sustained, high drug levels were observed in both the vitreous humor and the retina-choroid even on day 21 after diclofenac acid suspension injection, with retina-choroid drug levels being higher beginning at 0.25 hour. The elimination half-life of diclofenac suspension was 24 and 18 days in vitreous and retina-choroid, respectively, compared to 2.9 and 0.9 hours observed with diclofenac sodium. The pharmacokinetic models developed indicated a slow-release distribution or depot compartment for the diclofenac acid suspension in the posterior segment. Simulations indicated the inability of a 10-mg dose of diclofenac sodium solution to sustain drug levels in the vitreous beyond 11 days. By choosing a less soluble form of a drug such as diclofenac acid, vitreous

  2. 76 FR 22610 - Implantation or Injectable Dosage Form New Animal Drugs; Enrofloxacin

    Science.gov (United States)

    2011-04-22

    .... FDA-2011-N-0003] Implantation or Injectable Dosage Form New Animal Drugs; Enrofloxacin AGENCY: Food... the indications for use of enrofloxacin solution in cattle, as a single injection, for the treatment... supplement to NADA 141-068 for BAYTRIL 100 (enrofloxacin), an injectable solution. The supplemental NADA...

  3. 76 FR 59023 - Oral Dosage Form New Animal Drugs; Tylosin

    Science.gov (United States)

    2011-09-23

    ... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration 21 CFR Part 520 [Docket No. FDA-2011-N-0003] Oral Dosage Form New Animal Drugs; Tylosin AGENCY: Food and Drug Administration, HHS. ACTION: Final rule. SUMMARY: The Food and Drug Administration (FDA) is amending the animal drug...

  4. 77 FR 3927 - Oral Dosage Form New Animal Drugs; Deracoxib

    Science.gov (United States)

    2012-01-26

    ... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration 21 CFR Part 520 [Docket No. FDA-2011-N-0003] Oral Dosage Form New Animal Drugs; Deracoxib AGENCY: Food and Drug Administration, HHS. ACTION: Final rule. SUMMARY: The Food and Drug Administration (FDA) is amending the animal drug...

  5. 76 FR 18648 - Oral Dosage Form New Animal Drugs; Robenacoxib

    Science.gov (United States)

    2011-04-05

    ... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration 21 CFR Part 520 [Docket No. FDA-2011-N-0003] Oral Dosage Form New Animal Drugs; Robenacoxib AGENCY: Food and Drug Administration, HHS. ACTION: Final rule. SUMMARY: The Food and Drug Administration (FDA) is amending the animal drug...

  6. 76 FR 40808 - Oral Dosage Form New Animal Drugs; Amprolium

    Science.gov (United States)

    2011-07-12

    ... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration 21 CFR Part 520 [Docket No. FDA-2011-N-0003] Oral Dosage Form New Animal Drugs; Amprolium AGENCY: Food and Drug Administration, HHS. ACTION: Final rule. SUMMARY: The Food and Drug Administration (FDA) is amending the animal drug...

  7. 77 FR 15960 - Oral Dosage Form New Animal Drugs; Pergolide

    Science.gov (United States)

    2012-03-19

    ... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration 21 CFR Part 520 [Docket No. FDA-2011-N-0003] Oral Dosage Form New Animal Drugs; Pergolide AGENCY: Food and Drug Administration, HHS. ACTION: Final rule. SUMMARY: The Food and Drug Administration (FDA) is amending the animal drug...

  8. 75 FR 67031 - Oral Dosage Form New Animal Drugs; Domperidone

    Science.gov (United States)

    2010-11-01

    ... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration 21 CFR Part 520 [Docket No. FDA-2010-N-0002] Oral Dosage Form New Animal Drugs; Domperidone AGENCY: Food and Drug Administration, HHS. ACTION: Final rule. SUMMARY: The Food and Drug Administration (FDA) is amending the animal drug...

  9. 76 FR 78149 - Oral Dosage Form New Animal Drugs; Estriol

    Science.gov (United States)

    2011-12-16

    ... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration 21 CFR Part 520 [Docket No. FDA-2011-N-0003] Oral Dosage Form New Animal Drugs; Estriol AGENCY: Food and Drug Administration, HHS. ACTION: Final rule. SUMMARY: The Food and Drug Administration (FDA) is amending the animal drug...

  10. 21 CFR 520.1448 - Monensin oral dosage forms.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Monensin oral dosage forms. 520.1448 Section 520.1448 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... distance the spots travel from the starting line divided by the distance the solvent front travels from the...

  11. Formulation of Croton penduliflorus seed into tablet dosage form ...

    African Journals Online (AJOL)

    Formulation of Croton penduliflorus seed into tablet dosage form. GC Onunkwo. Abstract. No Abstract. Global Journal of Medical Sciences Vol. 5(1) 2006: 29-33. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · http://dx.doi.org/10.4314/gjms.v5i1.10145.

  12. Formulation and evaluation of tablet dosage form of Hunteria ...

    African Journals Online (AJOL)

    The present study was aimed at formulating and evaluating tablet dosage form of Hunteria umbellata (HU) seed aqueous and purified extracts. HU seeds were dried, pulverized and the powder macerated in water to obtain aqueous extract, while alkaloidal extraction process was used to obtain purified extract. Extracts ...

  13. Biowaiver monographs for immediate release solid oral dosage forms: cimetidine.

    NARCIS (Netherlands)

    Jantratid, E; Prakongpan, S; Dressman, J B; Amidon, G L; Junginger, H E; Midha, K K; Barends, D M

    2006-01-01

    Literature data relevant to the decision to allow a waiver of in vivo bioequivalence (BE) testing for the approval of immediate release (IR) solid oral dosage forms containing cimetidine are reviewed. According to the current Biopharmaceutics Classification System (BCS), cimetidine would be assigned

  14. Spectrophotometric Determination of Cilostazol in Tablet Dosage Form

    African Journals Online (AJOL)

    Purpose: To develop simple, rapid and selective spectrophotometric methods for the determination of cilostazol in tablet dosage form. Methods: Cilostazol was dissolved in 50 % methanol and its absorbance was scanned by ultraviolet (UV) spectrophotometry. Both linear regression equation and standard absorptivity were ...

  15. 76 FR 3488 - Implantation or Injectable Dosage Form New Animal Drugs; Oxytetracycline and Flunixin

    Science.gov (United States)

    2011-01-20

    .... FDA-2010-N-0002] Implantation or Injectable Dosage Form New Animal Drugs; Oxytetracycline and Flunixin... combination drug injectable solution containing oxytetracycline and flunixin meglumine in cattle. [[Page 3489... veterinary prescription use of HEXASOL (oxytetracycline and flunixin meglumine) Injection for the treatment...

  16. QR encoded smart oral dosage forms by inkjet printing.

    Science.gov (United States)

    Edinger, Magnus; Bar-Shalom, Daniel; Sandler, Niklas; Rantanen, Jukka; Genina, Natalja

    2018-01-30

    The use of inkjet printing (IJP) technology enables the flexible manufacturing of personalized medicine with the doses tailored for each patient. In this study we demonstrate, for the first time, the applicability of IJP in the production of edible dosage forms in the pattern of a quick response (QR) code. This printed pattern contains the drug itself and encoded information relevant to the patient and/or healthcare professionals. IJP of the active pharmaceutical ingredient (API)-containing ink in the pattern of QR code was performed onto a newly developed porous and flexible, but mechanically stable substrate with a good absorption capacity. The printing did not affect the mechanical properties of the substrate. The actual drug content of the printed dosage forms was in accordance with the encoded drug content. The QR encoded dosage forms had a good print definition without significant edge bleeding. They were readable by a smartphone even after storage in harsh conditions. This approach of efficient data incorporation and data storage combined with the use of smart devices can lead to safer and more patient-friendly drug products in the future. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Stability of pharmaceutical salts in solid oral dosage forms.

    Science.gov (United States)

    Nie, Haichen; Byrn, Stephen R; Zhou, Qi Tony

    2017-08-01

    Using pharmaceutical salts in solid dosage forms can raise stability concerns, especially salt dissociation which can adversely affect the product performance. Therefore, a thorough understanding of the salt instability encountered in solid-state formulations is imperative to ensure the product quality. The present article uses the fundamental theory of acid base, ionic equilibrium, relationship of pH and solubility as a starting point to illustrate and interpret the salt formation and salt disproportionation in pharmaceutical systems. The criteria of selecting the optimal salt form and the underlying theory of salt formation and disproportionation are reviewed in detail. Factors influencing salt stability in solid dosage forms are scrutinized and discussed with the case studies. In addition, both commonly used and innovative strategies for preventing salt dissociations in formulation, on storage and during manufacturing will be suggested herein. This article will provide formulation scientists and manufacturing engineers an insight into the mechanisms of salt disproportionation and salt formation, which can help them to avoid and solve the instability issues of pharmaceutical salts in the product design.

  18. Biowaiver monographs for immediate release solid oral dosage forms: efavirenz.

    Science.gov (United States)

    Cristofoletti, Rodrigo; Nair, Anita; Abrahamsson, Bertil; Groot, D W; Kopp, Sabine; Langguth, Peter; Polli, James E; Shah, Vinod P; Dressman, Jennifer B

    2013-02-01

    Literature data pertaining to the decision to allow a waiver of in vivo bioequivalence testing for the approval of immediate-release (IR) solid oral dosage forms containing efavirenz as the only active pharmaceutical ingredient (API) are reviewed. Because of lack of conclusive data about efavirenz's permeability and its failure to comply with the "high solubility" criteria according to the Biopharmaceutics Classification System (BCS), the API can be classified as BCS Class II/IV. In line with the solubility characteristics, the innovator product does not meet the dissolution criteria for a "rapidly dissolving product." Furthermore, product variations containing commonly used excipients or in the manufacturing process have been reported to impact the rate and extent of efavirenz absorption. Despite its wide therapeutic index, subtherapeutic levels of efavirenz can lead to treatment failure and also facilitate the emergence of efavirenz-resistant mutants. For all these reasons, a biowaiver for IR solid oral dosage forms containing efavirenz as the sole API is not scientifically justified for reformulated or multisource drug products. Copyright © 2012 Wiley Periodicals, Inc.

  19. Gamma scintigraphy in the evaluation of pharmaceutical dosage forms

    International Nuclear Information System (INIS)

    Davis, S.S.; Hardy, J.G.; Newman, S.P.; Wilding, I.R.

    1992-01-01

    Gamma-scintigraphy is applied extensively in the development and evaluation of pharmaceutical drug delivery systems. It is used particularly for monitoring formulations in the gastrointestinal and respiratory tracts. The radiolabelling is generally achieved by the incorporation of an appropriate technetium-99m or indium-111 labelled radiopharmaceutical into the formulation. In the case of complex dosage forms, such as enteric-coated tablets, labelling is best undertaken by the addition of a non-radioactive tracer such as samarium-152 or erbium-170 followed by neutron activation of the final product. Systems investigated include tablets and multiparticulates for oral administration, enemas and suppositories, metered dose inhalers and nebulisers, and nasal sprays and drops. Gamma-scintigraphy provides information on the deposition, dispersion and movement of the formulation. The combination of such studies with the assay of drug levels in blood or urine specimens, pharmacoscintigraphy, provides information concerning the sites of drug release and absorption. Data acquired from the scintigraphic evaluation of pharmaceutical dosage forms are now being used increasingly at all stages of product development, from the assessment of prototype delivery systems to supporting the product licence application. (orig.)

  20. Emergence of 3D Printed Dosage Forms: Opportunities and Challenges.

    Science.gov (United States)

    Alhnan, Mohamed A; Okwuosa, Tochukwu C; Sadia, Muzna; Wan, Ka-Wai; Ahmed, Waqar; Arafat, Basel

    2016-08-01

    The recent introduction of the first FDA approved 3D-printed drug has fuelled interest in 3D printing technology, which is set to revolutionize healthcare. Since its initial use, this rapid prototyping (RP) technology has evolved to such an extent that it is currently being used in a wide range of applications including in tissue engineering, dentistry, construction, automotive and aerospace. However, in the pharmaceutical industry this technology is still in its infancy and its potential yet to be fully explored. This paper presents various 3D printing technologies such as stereolithographic, powder based, selective laser sintering, fused deposition modelling and semi-solid extrusion 3D printing. It also provides a comprehensive review of previous attempts at using 3D printing technologies on the manufacturing dosage forms with a particular focus on oral tablets. Their advantages particularly with adaptability in the pharmaceutical field have been highlighted, which enables the preparation of dosage forms with complex designs and geometries, multiple actives and tailored release profiles. An insight into the technical challenges facing the different 3D printing technologies such as the formulation and processing parameters is provided. Light is also shed on the different regulatory challenges that need to be overcome for 3D printing to fulfil its real potential in the pharmaceutical industry.

  1. Gamma scintigraphy in the evaluation of pharmaceutical dosage forms

    Energy Technology Data Exchange (ETDEWEB)

    Davis, S.S.; Hardy, J.G.; Newman, S.P.; Wilding, I.R. (Pharmaceutical Profiles Ltd., Nottingham (United Kingdom))

    1992-11-01

    Gamma-scintigraphy is applied extensively in the development and evaluation of pharmaceutical drug delivery systems. It is used particularly for monitoring formulations in the gastrointestinal and respiratory tracts. The radiolabelling is generally achieved by the incorporation of an appropriate technetium-99m or indium-111 labelled radiopharmaceutical into the formulation. In the case of complex dosage forms, such as enteric-coated tablets, labelling is best undertaken by the addition of a non-radioactive tracer such as samarium-152 or erbium-170 followed by neutron activation of the final product. Systems investigated include tablets and multiparticulates for oral administration, enemas and suppositories, metered dose inhalers and nebulisers, and nasal sprays and drops. Gamma-scintigraphy provides information on the deposition, dispersion and movement of the formulation. The combination of such studies with the assay of drug levels in blood or urine specimens, pharmacoscintigraphy, provides information concerning the sites of drug release and absorption. Data acquired from the scintigraphic evaluation of pharmaceutical dosage forms are now being used increasingly at all stages of product development, from the assessment of prototype delivery systems to supporting the product licence application. (orig.).

  2. ORODISPERSIBLE TABLET: A Patient Friendly Dosage Form (a Review

    Directory of Open Access Journals (Sweden)

    C. K. Rameesa

    2015-03-01

    Full Text Available Background: The most common and preferred route of drug administration is through the oral route. Orodispersible tablets are gaining importance among novel oral drug delivery system as they have improved patient compliance and have some additional advantages compared to other formulation. They are also solid unit dosage forms, which disintegrate in the mouth within a minute in the presence of saliva due to superdisintegrants in the formulation. Thus this type of drug delivery helps a proper per oral administration in pediatric and geriatric population where swallowing is a matter of trouble. Various scientists have prepared orodispersible tablets by following various methods. However, the most common method is the direct compression method. Other special methods are Freeze Drying,Tablet Molding, Sublimation, Spray Drying, Mass extrusion, Phase transition process, etc. Since these tablets dissolve directly in the mouth, so, their taste is also an important factor. Various approaches have been taken in order to mask the bitter taste of the drug. A number of scientists have explored several drugs in this field. Like all other solid dosage forms, they are also evaluated in the field of hardness, friability, wetting time, moisture uptake, disintegration test and dissolution test.

  3. 21 CFR 330.3 - Imprinting of solid oral dosage form drug products.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 5 2010-04-01 2010-04-01 false Imprinting of solid oral dosage form drug products... AS SAFE AND EFFECTIVE AND NOT MISBRANDED General Provisions § 330.3 Imprinting of solid oral dosage form drug products. A requirement to imprint an identification code on solid oral dosage form drug...

  4. 21 CFR 522.1696 - Penicillin G procaine implantation and injectable dosage forms.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Penicillin G procaine implantation and injectable dosage forms. 522.1696 Section 522.1696 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH... DOSAGE FORM NEW ANIMAL DRUGS § 522.1696 Penicillin G procaine implantation and injectable dosage forms. ...

  5. 21 CFR 524.1662 - Oxytetracycline hydrochloride ophthalmic and topical dosage forms.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Oxytetracycline hydrochloride ophthalmic and topical dosage forms. 524.1662 Section 524.1662 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... DOSAGE FORM NEW ANIMAL DRUGS § 524.1662 Oxytetracycline hydrochloride ophthalmic and topical dosage forms. ...

  6. Oral Solid Dosage Form Disintegration Testing - The Forgotten Test.

    Science.gov (United States)

    Al-Gousous, Jozef; Langguth, Peter

    2015-09-01

    Since its inception in the 1930s, disintegration testing has become an important quality control (QC) test in pharmaceutical industry, and disintegration test procedures for various dosage forms have been described by the different pharmacopoeias, with harmonization among them still not quite complete. However, because of the fact that complete disintegration does not necessarily imply complete dissolution, much more research has been focused on dissolution rather than on disintegration testing. Nevertheless, owing to its simplicity, disintegration testing seems to be an attractive replacement to dissolution testing as recognized by the International Conference on Harmonization guidelines, in some cases. Therefore, with proper research being carried out to overcome the associated challenges, the full potential of disintegration testing could be tapped saving considerable efforts allocated to QC testing and quality assurance. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association.

  7. Nanofibrous solid dosage form of living bacteria prepared by electrospinning

    Directory of Open Access Journals (Sweden)

    I. Wagner

    2014-05-01

    Full Text Available The aim of this work was to investigate the suitability of electrospinning for biodrug delivery and to develop an electrospinning-based method to produce vaginal drug delivery systems. Lactobacillus acidophilus bacteria were encapsulated into nanofibers of three different polymers (polyvinyl alcohol and polyvinylpyrrolidone with two different molar masses. Shelf life of the bacteria could be enhanced by the exclusion of water and by preparing a solid dosage form, which is an advantageous and patient-friendly way of administration. The formulations were stored at –20, 7 and 25°C, respectively. Viability testing showed that the nanofibers can provide long term stability for huge amounts of living bacteria if they are kept at (or below 7°C. Furthermore, all kinds of nanowebs prepared in this work dissolved instantly when they got in contact with water, thus the developed biohybrid nanowebs can provide new potential ways for curing bacterial vaginosis.

  8. Comprehensive review on additives of topical dosage forms for drug delivery.

    Science.gov (United States)

    Garg, Tarun; Rath, Goutam; Goyal, Amit K

    2015-12-01

    Skin is the largest organ of the human body and plays the most important role in protecting against pathogen and foreign matter. Three important modes such as topical, regional and transdermal are widely used for delivery of various dosage forms. Among these modes, the topical dosage forms are preferred because it provides local therapeutic activity when applied to the skin or mucous membranes. Additives or pharmaceutical excipients (non-drug component of dosage form) are used as inactive ingredients in dosage form or tools for structuring dosage forms. The main use of topical dosage form additives are controling the extent of absorption, maintaining the viscosity, improving the stability as well as organoleptic property and increasing the bulk of the formulation. The overall goal of this article is to provide the clinician with information related to the topical dosage form additives and their current major applications against various diseases.

  9. Biowaiver monographs for immediate release solid oral dosage forms: piroxicam.

    Science.gov (United States)

    Shohin, Igor E; Kulinich, Julia I; Ramenskaya, Galina V; Abrahamsson, Bertil; Kopp, Sabine; Langguth, Peter; Polli, James E; Shah, Vinod P; Groot, D W; Barends, Dirk M; Dressman, Jennifer B

    2014-02-01

    Literature and experimental data relevant to the decision to allow a waiver of in vivo bioequivalence (BE) testing for the approval of immediate release (IR) solid oral dosage forms containing piroxicam in the free acid form are reviewed. Piroxicam solubility and permeability, its therapeutic use and therapeutic index, pharmacokinetic properties, data related to the possibility of excipient interactions and reported BE/bioavailability (BA), and corresponding dissolution data are taken into consideration. The available data suggest that according to the current biopharmaceutics classification system (BCS) and all current guidances, piroxicam would be assigned to BCS Class II. The extent of piroxicam absorption seems not to depend on manufacturing conditions or excipients, so the risk of bioinequivalence in terms of area under the curve (AUC) is very low, but the rate of absorption (i.e., BE in terms of Cmax ) can be affected by the formulation. Current in vitro dissolution methods may not always reflect differences in terms of Cmax for BCS Class II weak acids; however, minor differences in absorption rate of piroxicam would not subject the patient to unacceptable risks: as piroxicam products may be taken before or after meals, the rate of absorption cannot be considered crucial to drug action. Therefore, a biowaiver for IR piroxicam solid oral dosage form is considered feasible, provided that (a) the test product contains only excipients, which are also present in IR solid oral drug products containing piroxicam, which have been approved in ICH or associated countries, for instance, those presented in Table 3 of this paper; (b) both the test and comparator drug products dissolve 85% in 30 min or less at pH 1.2, 4.5, and 6.8; and (c) the test product and comparator show dissolution profile similarity in pH 1.2, 4.5, and 6.8. When not all of these conditions can be fulfilled, BE of the products should be established in vivo. © 2013 Wiley Periodicals, Inc. and the

  10. Preactivated thiolated nanoparticles: A novel mucoadhesive dosage form.

    Science.gov (United States)

    Menzel, Claudia; Bonengel, Sonja; Pereira de Sousa, Irene; Laffleur, Flavia; Prüfert, Felix; Bernkop-Schnürch, Andreas

    2016-01-30

    Within this study a novel form of mucoadhesive nanoparticles (NPs) exhibiting a prolonged residence time on mucosal tissues was developed. In order to achieve this goal a new thiomer was synthesized by the covalent attachment of the amino acid l-cysteine ethyl ester to poly(acrylic acid) (100 kDa). The free thiol groups were in the following preactivated with the aromatic thiol bearing ligand 2-mercaptonicotinic acid (2-MNA) and the amount of coupled l-cysteine ethyl ester as well as the amount of attached 2-MNA was determined. Based on this, preactivated thiomer NPs were prepared by ionic gelation with polyethylenimine (PEI). The resulting NPs were characterized regarding size and zeta potential. Furthermore their mucoadhesive properties were investigated via rheological measurements with porcine intestinal mucus and via determination of the particles' mucosal residence time. Results showed that 1666.74 μmol l-cysteine ethyl ester and 603.07 μmol 2-MNA could be attached per gram polymer. NPs were in a size range of 112.67-252.84 nm exhibiting a zeta potential of -29 mV. Thiolated NPs only led to a 2-fold increase in mucus viscosity whereas preactivated NPs showed a 6-fold higher mucus viscosity than unmodified NPs. The mucosal residence time of thiolated NPs was 1.6-fold prolonged and that of preactivated NPs even 4.4-fold higher compared to unmodified particles. Accordingly, preactivated thiolated NPs providing a prolonged residence time on mucosal membranes could be a promising dosage form for various applications. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Applications of Polymers as Pharmaceutical Excipients in Solid Oral Dosage Forms.

    Science.gov (United States)

    Debotton, Nir; Dahan, Arik

    2017-01-01

    Over the last few decades, polymers have been extensively used as pharmaceutical excipients in drug delivery systems. Pharmaceutical polymers evolved from being simply used as gelatin shells comprising capsule to offering great formulation advantages including enabling controlled/slow release and specific targeting of drugs to the site(s) of action (the "magic bullets" concept), hence hold a significant clinical promise. Oral administration of solid dosage forms (e.g., tablets and capsules) is the most common and convenient route of drug administration. When formulating challenging molecules into solid oral dosage forms, polymeric pharmaceutical excipients permit masking undesired physicochemical properties of drugs and consequently, altering their pharmacokinetic profiles to improve the therapeutic effect. As a result, the number of synthetic and natural polymers available commercially as pharmaceutical excipients has increased dramatically, offering potential solutions to various difficulties. For instance, the different polymers may allow increased solubility, swellability, viscosity, biodegradability, advanced coatings, pH dependency, mucodhesion, and inhibition of crystallization. The aim of this article is to provide a wide angle prospect of the different uses of pharmaceutical polymers in solid oral dosage forms. The various types of polymeric excipients are presented, and their distinctive role in oral drug delivery is emphasized. The comprehensive know-how provided in this article may allow scientists to use these polymeric excipients rationally, to fully exploit their different features and potential influence on drug delivery, with the overall aim of making better drug products. © 2016 Wiley Periodicals, Inc.

  12. Mathematical modeling of drug release from lipid dosage forms.

    Science.gov (United States)

    Siepmann, J; Siepmann, F

    2011-10-10

    Lipid dosage forms provide an interesting potential for controlled drug delivery. In contrast to frequently used poly(ester) based devices for parenteral administration, they do not lead to acidification upon degradation and potential drug inactivation, especially in the case of protein drugs and other acid-labile active agents. The aim of this article is to give an overview on the current state of the art of mathematical modeling of drug release from this type of advanced drug delivery systems. Empirical and semi-empirical models are described as well as mechanistic theories, considering diffusional mass transport, potentially limited drug solubility and the leaching of other, water-soluble excipients into the surrounding bulk fluid. Various practical examples are given, including lipid microparticles, beads and implants, which can successfully be used to control the release of an incorporated drug during periods ranging from a few hours up to several years. The great benefit of mechanistic mathematical theories is the possibility to quantitatively predict the effects of different formulation parameters and device dimensions on the resulting drug release kinetics. Thus, in silico simulations can significantly speed up product optimization. This is particularly useful if long release periods (e.g., several months) are targeted, since experimental trial-and-error studies are highly time-consuming in these cases. In the future it would be highly desirable to combine mechanistic theories with the quantitative description of the drug fate in vivo, ideally including the pharmacodynamic efficacy of the treatments. Copyright © 2011 Elsevier B.V. All rights reserved.

  13. Carboxymethyl starch mucoadhesive microspheres as gastroretentive dosage form.

    Science.gov (United States)

    Lemieux, Marc; Gosselin, Patrick; Mateescu, Mircea Alexandru

    2015-12-30

    Carboxymethyl starch microspheres (CMS-MS) were produced from carboxymethyl starch powder (CMS-P) with a degree of substitution (DS) from 0.1 to 1.5 in order to investigate the influence of DS on physicochemical, drug release and mucoadhesion properties as well as interactions with gastrointestinal tract (GIT) epithelial barrier models. Placebo and furosemide loaded CMS-MS were obtained by emulsion-crosslinking with sodium trimetaphosphate (STMP). DS had an impact on increasing equilibrium water uptake and modulating drug release properties of the CMS-MS according to the surrounding pH. The transepithelial electrical resistance (TEER) of NCI-N87 gastric cell monolayers was not influenced in presence of CMS-MS, whereas that of Caco-2 intestinal cell monolayers decreased with increasing DS but recovered initial values at about 15h post-treatment. CMS-MS with increasing DS also enhanced furosemide permeability across both NCI-N87 and Caco-2 monolayers at pH gradients from 3.0 to 7.4. Mucoadhesion of CMS-MS on gastric mucosa (acidic condition) increased with the DS up to 55% for a DS of 1.0 but decreased on neutral intestinal mucosa to less than 10% with DS of 0.1. The drug release, permeability enhancement and mucoadhesive properties of the CMS-MS suggest CMS-MS with DS between 0.6 and 1.0 as suitable excipient for gastroretentive oral delivery dosage forms. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Microstructural effects in drug release by solid and cellular polymeric dosage forms: A comparative study.

    Science.gov (United States)

    Blaesi, Aron H; Saka, Nannaji

    2017-11-01

    In recent studies, we have introduced melt-processed polymeric cellular dosage forms to achieve both immediate drug release and predictable manufacture. Dosage forms ranging from minimally-porous solids to highly porous, open-cell and thin-walled structures were prepared, and the drug release characteristics investigated as the volume fraction of cells and the excipient molecular weight were varied. In the present study, both minimally-porous solid and cellular dosage forms consisting of various weight fractions of Acetaminophen drug and polyethylene glycol (PEG) excipient are prepared and analyzed. Microstructures of the solid forms and the cell walls range from single-phase solid solutions of the excipient and a small amount of drug molecules to two-phase composites of the excipient and tightly packed drug particles. Results of dissolution experiments show that the minimally-porous solid forms disintegrate and release drug by slow surface erosion. The erosion rate decreases as the drug weight fraction is increased. By contrast, the open-cell structures disintegrate rapidly by viscous exfoliation, and the disintegration time is independent of drug weight fraction. Drug release models suggest that the solid forms erode by convective mass transfer of the faster-eroding excipient if the drug volume fraction is small. At larger drug volume fractions, however, the slower-eroding drug particles hinder access of the free-flowing fluid to the excipient, thus slowing down erosion of the composite. Conversely, the disintegration rate of the cellular forms is limited by diffusion of the dissolution fluid into the excipient phase of the thin cell walls. Because the wall thickness is of the order of the drug particle size, and the particles are enveloped by the excipient during melt-processing, the drug particles cannot hinder diffusion through the excipient across the walls. Thus the disintegration time of the cellular forms is mostly unaffected by the volume fraction of drug

  15. A step toward development of printable dosage forms for poorly soluble drugs

    DEFF Research Database (Denmark)

    Raijada, Dharaben Kaushikkumar; Genina, Natalja; Fors, Daniela

    2013-01-01

    The purpose of this study was to formulate printable dosage forms for a poorly soluble drug (piroxicam; PRX) and to gain understanding of critical parameters to be considered during development of such dosage forms. Liquid formulations of PRX were printed on edible paper using piezoelectric inkjet...

  16. 21 CFR 522.1662 - Oxytetracycline hydrochloride implantation or injectable dosage forms.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Oxytetracycline hydrochloride implantation or injectable dosage forms. 522.1662 Section 522.1662 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... INJECTABLE DOSAGE FORM NEW ANIMAL DRUGS § 522.1662 Oxytetracycline hydrochloride implantation or injectable...

  17. HPLC FOR CONTROL STABILITY OF QUERCETIN INJECTABLE DOSAGE FORM

    Directory of Open Access Journals (Sweden)

    Martynov AV

    2016-12-01

    Full Text Available Introduction. Quercetin is a flavone derivatives which known like a substances with vitamin activity, high antioxidant, antimutagenic and anticarcinogenic activity and many other types of biological activity. Wide usage of quercetin prevents their polyphenolic nature structure which does not allow a high bioavailability of pure quercetin when administered orally. This is associated with a wide spectrum variety of chemical reactions for the phenolic groups: from interaction with amino acid residues in proteins to reactions with amine heterocyclic alkaloids and polysaccharides. In our days Corvitin – one from the number of quercetin based drugs with sufficiently low levels all types toxicity, allergenic and has no irritating action on intravenous administration. In the same time quercetin cannot be used in full measure because of the limited number of publications with analysis methods, especially HPLC. Determining the stability over time of concentrate quercetin solution, as well as determining the stability of the concentrate to the original autoclave sterilization conditions is a promising direction in creating new drugs. Materials and methods The objective was to research quercetin soluble formulation samples in different conditions: 1 fresh dilute concentrate (0.9% sodium chloride; 2 the original dilute concentrate, which was stored at room temperature for 14 days in light and 3 similar to the first sample dilute concentrate, which went before breeding in autoclaving at 120 0 C for 20 minutes. The objects used in the studies were industrial drug-substance quercetin (Sinkea manufactured (China, the original pharmaceutical composition as the soluble form of quercetin for injection and aerosol applications, glycerol (Sigma, Polysorbat 80 (Merk, ethanol 96 %. For the HPLC – analysis, chromatograph "Milichrom A-02" (SiChrom, Knauer (Econova, Novosibirsk, Russia was used. Results and discussion Quercetin was identified using information on its

  18. Development and Validation of UV Spectrophotometric Method For Estimation of Dolutegravir Sodium in Tablet Dosage Form

    International Nuclear Information System (INIS)

    Balasaheb, B.G.

    2015-01-01

    A simple, rapid, precise and accurate spectrophotometric method has been developed for quantitative analysis of Dolutegravir sodium in tablet formulations. The initial stock solution of Dolutegravir sodium was prepared in methanol solvent and subsequent dilution was done in water. The standard solution of Dolutegravir sodium in water showed maximum absorption at wavelength 259.80 nm. The drug obeyed Beer-Lamberts law in the concentration range of 5-40 μg/ mL with coefficient of correlation (R"2) was 0.9992. The method was validated as per the ICH guidelines. The developed method can be adopted in routine analysis of Dolutegravir sodium in bulk or tablet dosage form and it involves relatively low cost solvents and no complex extraction techniques. (author)

  19. 76 FR 78815 - Oral Dosage Form New Animal Drugs; Cyclosporine

    Science.gov (United States)

    2011-12-20

    ..., Inc. The NADA provides for the veterinary prescription use of cyclosporine oral solution, USP.... FOR FURTHER INFORMATION CONTACT: Angela K.S. Clarke, Center for Veterinary Medicine (HFV-112), Food... (cyclosporine oral solution, USP (MODIFIED)) by veterinary prescription for the control of feline allergic...

  20. Ophthalmic Drug Dosage Forms: Characterisation and Research Methods

    OpenAIRE

    Baranowski, Przemysław; Karolewicz, Bożena; Gajda, Maciej; Pluta, Janusz

    2014-01-01

    This paper describes hitherto developed drug forms for topical ocular administration, that is, eye drops, ointments, in situ gels, inserts, multicompartment drug delivery systems, and ophthalmic drug forms with bioadhesive properties. Heretofore, many studies have demonstrated that new and more complex ophthalmic drug forms exhibit advantage over traditional ones and are able to increase the bioavailability of the active substance by, among others, reducing the susceptibility of drug forms to...

  1. Biowaiver Monographs for Immediate Release Solid Oral Dosage Forms: Proguanil Hydrochloride.

    NARCIS (Netherlands)

    Plöger, Gerlinde F; Abrahamsson, Bertil; Cristofoletti, Rodrigo; Groot, D I R K W; Langguth, Peter; Mehta, Mehul U; Parr, Alan; Polli, James E; Shah, Vinod P; Tajiri, Tomokazu; Dressman, Jennifer B

    2018-01-01

    Literature data relevant to the decision to waive in vivo bioequivalence testing for the approval of generic immediate release solid oral dosage forms of proguanil hydrochloride are reviewed. To clarify the Biopharmaceutics Classification System (BCS) classification, experimental solubility and

  2. Miniaturized approach for excipient selection during the development of oral solid dosage form

    DEFF Research Database (Denmark)

    Raijada, Dharaben Kaushikkumar; Müllertz, Anette; Cornett, Claus

    2014-01-01

    The present study introduces a miniaturized high-throughput platform to understand the influence of excipients on the performance of oral solid dosage forms during early drug development. Wet massing of binary mixtures of the model drug (sodium naproxen) and representative excipients was followed...... for excipient selection and for early-stage performance testing of active pharmaceutical ingredient intended for oral solid dosage form. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 103:900-908, 2014....

  3. Ophthalmic Drug Dosage Forms: Characterisation and Research Methods

    Directory of Open Access Journals (Sweden)

    Przemysław Baranowski

    2014-01-01

    Full Text Available This paper describes hitherto developed drug forms for topical ocular administration, that is, eye drops, ointments, in situ gels, inserts, multicompartment drug delivery systems, and ophthalmic drug forms with bioadhesive properties. Heretofore, many studies have demonstrated that new and more complex ophthalmic drug forms exhibit advantage over traditional ones and are able to increase the bioavailability of the active substance by, among others, reducing the susceptibility of drug forms to defense mechanisms of the human eye, extending contact time of drug with the cornea, increasing the penetration through the complex anatomical structure of the eye, and providing controlled release of drugs into the eye tissues, which allows reducing the drug application frequency. The rest of the paper describes recommended in vitro and in vivo studies to be performed for various ophthalmic drugs forms in order to assess whether the form is acceptable from the perspective of desired properties and patient’s compliance.

  4. 75 FR 54492 - Oral Dosage Form New Animal Drugs; Tiamulin

    Science.gov (United States)

    2010-09-08

    ... certain bacterial respiratory and enteric diseases in swine. The supplemental NADA provides for use of a... Health US, Inc. The supplemental NADA provides for use of an increased strength of tiamulin concentrate solution in the drinking water of swine for the treatment of certain bacterial respiratory and enteric...

  5. Design and evaluation of buccal films as paediatric dosage form for transmucosal delivery of ondansetron.

    Science.gov (United States)

    Trastullo, Ramona; Abruzzo, Angela; Saladini, Bruno; Gallucci, Maria Caterina; Cerchiara, Teresa; Luppi, Barbara; Bigucci, Federica

    2016-08-01

    In the process of implementation and innovation of paediatric dosage forms, buccal films for transmucosal administration of drug represent one of the most interesting approach. In fact, films are able to provide an extended duration of activity allowing minimal dosage and frequency and offer an exact and flexible dose, associated with ease of handling. The objective of the present study was to develop polymeric films for the sustained release of ondansetron hydrochloride, a selective inhibitor of 5-HT3 receptors indicated in paediatrics for the prevention and treatment of nausea and vomiting caused by cytotoxic chemotherapy or radiotherapy and postoperatively. Films were prepared by casting and drying of aqueous solutions containing different weight ratios of hydroxypropylmethylcellulose (HPMC) with chitosan (CH) or sodium hyaluronate (HA) or gelatin (GEL) and characterized for their physico-chemical and functional properties. The presence of HA, GEL and CH did not improve the mucoadhesive properties of HPMC film. The inclusion of GEL and CH in HPMC film increased in vitro drug release with respect to the inclusion of HA, although films containing HA showed the highest water uptake. Moreover in agreement with the release behaviour, the inclusion of CH and GEL provided higher drug permeation through porcine buccal mucosa with respect to HPMC film and ensured linear permeation profiles of drug. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Ocular Insert: Dosage Form for Sustain Opthalmic Drug Delivery

    Directory of Open Access Journals (Sweden)

    Sunil Kumar

    2012-06-01

    Full Text Available Except for skin, the eye is the most easily accessible site for topical administration of a medication. Traditional topical ophthalmic formulations (eye drops and ointments have poor bioavailability because of rapid pre-corneal elimination, conjunctival absorption, solution drainage by gravity, induced lacrimation and normal tear turnover. This leads to frequent installations of concentrated medication to achieve a therapeutic effect. The typical “pulse-entry” type drug release observed with ocular aqueous solutions (eye drops, suspensions and ointments can be replaced by more controlled, sustained, and continuous drug delivery, using a controlled-release ocular drug delivery system. Ocular inserts are solid or semisolid sterile preparations, of appropriate size and shape, designed to be inserted behind the eyelid or held on the eye and to deliver drugs for topical or systemic effect. These are polymeric systems into which the drug is incorporated as a solution or dispersion. They are better tolerated as to drainage and tear flow compared with other ophthalmic formulation and produce reliable drug release in the conjunctival cul-de-sac.

  7. Determination of the mechanical properties of solid and cellular polymeric dosage forms by diametral compression.

    Science.gov (United States)

    Blaesi, Aron H; Saka, Nannaji

    2016-07-25

    At present, the immediate-release solid dosage forms, such as the oral tablets and capsules, are granular solids. They release drug rapidly and have adequate mechanical properties, but their manufacture is fraught with difficulties inherent in processing particulate matter. Such difficulties, however, could be overcome by liquid-based processing. Therefore, we have recently introduced polymeric cellular (i.e., highly porous) dosage forms prepared from a melt process. Experiments have shown that upon immersion in a dissolution medium, the cellular dosage forms with polyethylene glycol (PEG) as excipient and with predominantly open-cell topology disintegrate by exfoliation, thus enabling rapid drug release. If the volume fraction of voids of the open-cell structures is too large, however, their mechanical strength is adversely affected. At present, the common method for determining the tensile strength of brittle, solid dosage forms (such as select granular forms) is the diametral compression test. In this study, the theory of diametral compression is first refined to demonstrate that the relevant mechanical properties of ductile and cellular solids (i.e., the elastic modulus and the yield strength) can also be extracted from this test. Diametral compression experiments are then conducted on PEG-based solid and cellular dosage forms. It is found that the elastic modulus and yield strength of the open-cell structures are about an order of magnitude smaller than those of the non-porous solids, but still are substantially greater than the stiffness and strength requirements for handling the dosage forms manually. This work thus demonstrates that melt-processed polymeric cellular dosage forms that release drug rapidly can be designed and manufactured to have adequate mechanical properties. Copyright © 2016. Published by Elsevier B.V.

  8. ANTITUBERCULOSIS DRUG DOSAGE FORMS: RANGE, KEY BENEFITS AND PROSPECTS OF TECHNOLOGICAL IMPROVEMENT

    Directory of Open Access Journals (Sweden)

    M. E. Kim

    2016-01-01

    Full Text Available Interest to research in the development of new formulations of antituberculosis drugs due to the high incidence of tuberculosis in the Republic of Kazakhstan and the Russian Federation nowadays, including with acquired drug resistance. The reason for the development of acquired drug resistance is to interrupt the treatment of patients is the high toxicity of antituberculosis drugs. The improving the efficiency of antituberculosis therapy remains one of the most pressing.The aim this study was to review the dosage forms of antituberculosis drugs currently used and the ways to improve them.Methods. The study was conducted on the basis of scientific analysis (eLibrary database, PubMed, Cyberleninca, patent (kzpatents, reference (Klifar, Drugs register and technical literature.Results. It was revealed that the antituberculosis drugs are available in the form of tablets, capsules, granules for oral use and injection solutions. The advantages and disadvantages of oral dosage forms of antituberculosis drugs: tablets, capsules, granules, syrups, suspensions are described. The importance of the development and implementation in practice of pediatric formulations of antituberculosis drugs is mentioned. The state of current research inhaled formulations for the treatment of tuberculosis is described. The prospects of directional inhalation exposure by immobilization of antituberculosis drugs in liposomes, niosomes, nanocapsules, micelles, micro- and nanoparticles are mentioned. The prospect of the rectal formulations use is described. The increase in interest in the molecular encapsulation of medicinal substances with cyclodextrins in connection with the possibility of increasing the bioavailability of active ingredients, reduce the harmful effects on the gastrointestinal tract, extension, elimination of interaction of incompatible components in combination preparations, the protection of unstable substances is

  9. Design and monitoring of photostability systems for amlodipine dosage forms.

    Science.gov (United States)

    Ragno, G; Cione, E; Garofalo, A; Genchi, G; Ioele, G; Risoli, A; Spagnoletta, A

    2003-10-20

    Photostability of amlodipine (AML) has been monitored in several pharmaceutical inclusion systems characterized by plurimolecular aggregation of the drug and excipients with high molecular weight. Several formulations including cyclodextrins, liposomes and microspheres have been prepared and characterized. The photodegradation process has been monitored according to the conditions suggested by the ICH Guideline for photostability testing, by using a light cabinet equipped with a Xenon lamp and monitored by spectrophotometry. The formulations herein tested have been found to be able to considerably increase drug stability, when compared with usual pharmaceutical forms. The residual concentration detected in the inclusion complexes with cyclodextrins and liposomes was 90 and 77%, respectively, while a very good value of 97% was found for microspheres, after a radiant exposure of 11,340 kJm(-2).

  10. Semi-solid dosage form of clonazepam for rapid oral mucosal absorption.

    Science.gov (United States)

    Sakata, Osamu; Machida, Yoshiharu; Onishi, Hiraku

    2011-07-01

    In order to obtain an alternative to the intravenous (i.v.) dosage form of clonazepam (CZ), an oral droplet formulation of CZ was developed previously; however, the droplet was physically unstable. Therefore, in the present study, it was attempted to develop an easily-handled dosage form, which was more physically stable and allowed rapid drug absorption from oral mucosa. A semi-solid dosage form, composed of polyethylene glycol 1500 (PEG), CZ, and oleic acid (OA) at 37/1/2 (w/w) and named PEG/CZ/OA, and a semi-solid dosage form containing PEG and CZ at 39/1 (w/w), called PEG/CZ, were prepared. Their physical stability in air at room temperature and oral mucosal absorption in rats were investigated. The semi-solid dosage forms were much more stable physically than the droplet, that is, no recrystallization of CZ was observed for at least 8 days. The effective concentration for humans and rats (20 ng/mL or more) was achieved within 30 min after buccal administration for both PEG/CZ/OA and PEG/CZ. The plasma concentration increased gradually and less varied at each time point for PEG/CZ/OA. PEG/CZ/OA was found to show more rapid and higher absorption of CZ in buccal administration than in sublingual administration. Buccal administration with the semi-solid dosage PEG/CZ with or without OA was suggested to be a possibly useful novel dosage form as an alternative to i.v. injection.

  11. Spectroscopic determination of succinylcholine in dosage forms using eosin Y.

    Science.gov (United States)

    Ayad, Magda M; Belal, Fathalla; Hosney, Mervet M; Abo El Abass, Samah; Elsayed, Nora

    2018-03-01

    Two simple and sensitive analytical assay methods using spectrophotometry and spectrofluorimetry techniques were developed for the estimation of succinylcholine chloride (SUC) in pharmaceutical preparations. The suggested methods are based on the formation of an ion pair complex formed between the drug and eosin Y spectrophotometrically (Method I), or the suppressive effect of succinylcholine on the native fluorescence property of eosin Y (Method II). The spectrophotometric method (Method I) involves measuring the absorbance of the complex between succinylcholine and eosin Y at 550 nm in Britton Robinson buffer of pH 3. However, the spectrofluorimetric method (Method II) involves measuring the quenching effect of the studied drug on the native fluorescence property of eosin Y at the same pH at 550 nm after excitation at 480 nm. The absorbance versus concentration of the drug is rectilinear over the range of 0.5 to 15 μg/ml. The formation constant was 3.5 × 10 4 and the Gibb's free energy change was -2.5 × 10 4  J/mol. In Method II, the relative fluorescence intensity was directly proportional to SUC concentration over the range of 0.05 to 1 μg/ml. The proposed methods allowed a successful application to the estimation of succinylcholine ampoules. An explanation of the reaction pathway was postulated. Copyright © 2017 John Wiley & Sons, Ltd.

  12. Effects of pharmaceutical processing on pepsin activity during the formulation of solid dosage forms.

    Science.gov (United States)

    Kristó, Katalin; Pintye-Hódi, Klára

    2013-02-01

    The main aim of this study was to investigate the effects of pharmaceutical technological methods on pepsin activity during the formulation of solid dosage forms. The circumstances of direct compression and wet granulation were modeled. During direct compression, the heat and the compression force must be taken into consideration. The effects of these parameters were investigated in three materials (pure pepsin, and 1:1 (w/w) pepsin-tartaric acid and 1:1 (w/w) pepsin-citric acid powder mixtures). It was concluded that direct compression is appropriate for the formulation of solid dosage forms containing pepsin through application without acids or with acids at low compression force. The effects of wet granulation were investigated with a factorial design for the same three materials. The factors were time, temperature and moisture content. There was no significant effect of the factors when acids were not applied. Temperature was a significant factor when acids were applied. The negative effect was significantly higher for citric acid than for tartaric acid. It was found that wet granulation can be utilized for the processing of pepsin into solid dosage forms under well-controlled circumstances. The application of citric acid is not recommended during the formulation of solid dosage forms through wet granulation. A mathematically based optimization may be necessary for preformulation studies of the preparation of dosage forms containing sensitive enzymes.

  13. Effect of Calcium Ions on the Disintegration of Enteric-Coated Solid Dosage Forms.

    Science.gov (United States)

    Al-Gousous, Jozef; Langguth, Peter

    2016-02-01

    To investigate the effect of calcium ions on the disintegration of enteric-coated dosage forms, disintegration testing was performed on enteric-coated aspirin tablets in the presence and absence of calcium in the test media. The results show that the presence of calcium ions retards the disintegration of enteric-coated dosage forms. This finding, which has not been reported in scientific literature, sheds light on the importance of conducting well-designed detailed investigations into the potential of calcium from dietary sources, calcium supplements, antacids, and/or phosphate binders affecting the absorption of drugs formulated into enteric-coated dosage forms. Moreover, it shows the necessity to investigate the potential of the occurrence of additional nutrient-excipient interactions. Copyright © 2016 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  14. On the exfoliating polymeric cellular dosage forms for immediate drug release.

    Science.gov (United States)

    Blaesi, Aron H; Saka, Nannaji

    2016-06-01

    The most prevalent pharmaceutical dosage forms at present-the oral immediate-release tablets and capsules-are granular solids. Though effective in releasing drug rapidly, development and manufacture of such dosage forms are fraught with difficulties inherent to particulate processing. Predictable dosage form manufacture could be achieved by liquid-based processing, but cast solid dosage forms are not suitable for immediate drug release due to their resistance to fluid percolation. To overcome this limitation, we have recently introduced cellular dosage forms that can be readily prepared from polymeric melts. It has been shown that open-cell structures comprising polyethylene glycol 8000 (PEG 8k) excipient and a drug exfoliate upon immersion in a dissolution medium. The drug is then released rapidly due to the large specific surface area of the exfoliations. In this work, we vary the molecular weight of the PEG excipient and investigate its effect on the drug release kinetics of structures with predominantly open-cell topology. We demonstrate that the exfoliation rate decreases substantially if the excipient molecular weight is increased from 12 to 100kg/mol, which causes the drug dissolution time to increase by more than a factor of ten. A model is then developed to elucidate the exfoliation behavior of cellular structures. Diverse transport processes are considered: percolation due to capillarity, diffusion of dissolution medium through the cell walls, and viscous flow of the saturated excipient. It is found that the lower exfoliation rate and the longer dissolution time of the dosage forms with higher excipient molecular weight are primarily due to the greater viscosity of the cell walls after fluid penetration. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Derivative spectrophotometric method for simultaneous determination of clindamycin phosphate and tretinoin in pharmaceutical dosage forms.

    Science.gov (United States)

    Barazandeh Tehrani, Maliheh; Namadchian, Melika; Fadaye Vatan, Sedigheh; Souri, Effat

    2013-04-10

    A derivative spectrophotometric method was proposed for the simultaneous determination of clindamycin and tretinoin in pharmaceutical dosage forms. The measurement was achieved using the first and second derivative signals of clindamycin at (1D) 251 nm and (2D) 239 nm and tretinoin at (1D) 364 nm and (2D) 387 nm.The proposed method showed excellent linearity at both first and second derivative order in the range of 60-1200 and 1.25-25 μg/ml for clindamycin phosphate and tretinoin respectively. The within-day and between-day precision and accuracy was in acceptable range (CVpharmaceutical dosage form.

  16. Accelerated in-vitro release testing methods for extended-release parenteral dosage forms.

    Science.gov (United States)

    Shen, Jie; Burgess, Diane J

    2012-07-01

    This review highlights current methods and strategies for accelerated in-vitro drug release testing of extended-release parenteral dosage forms such as polymeric microparticulate systems, lipid microparticulate systems, in-situ depot-forming systems and implants. Extended-release parenteral dosage forms are typically designed to maintain the effective drug concentration over periods of weeks, months or even years. Consequently, 'real-time' in-vitro release tests for these dosage forms are often run over a long time period. Accelerated in-vitro release methods can provide rapid evaluation and therefore are desirable for quality control purposes. To this end, different accelerated in-vitro release methods using United States Pharmacopeia (USP) apparatus have been developed. Different mechanisms of accelerating drug release from extended-release parenteral dosage forms, along with the accelerated in-vitro release testing methods currently employed are discussed. Accelerated in-vitro release testing methods with good discriminatory ability are critical for quality control of extended-release parenteral products. Methods that can be used in the development of in-vitro-in-vivo correlation (IVIVC) are desirable; however, for complex parenteral products this may not always be achievable. © 2012 The Authors. JPP © 2012 Royal Pharmaceutical Society.

  17. Accelerated in vitro release testing methods for extended release parenteral dosage forms

    Science.gov (United States)

    Shen, Jie; Burgess, Diane J.

    2012-01-01

    Objectives This review highlights current methods and strategies for accelerated in vitro drug release testing of extended release parenteral dosage forms such as polymeric microparticulate systems, lipid microparticulate systems, in situ depot-forming systems, and implants. Key findings Extended release parenteral dosage forms are typically designed to maintain the effective drug concentration over periods of weeks, months or even years. Consequently, “real-time” in vitro release tests for these dosage forms are often run over a long time period. Accelerated in vitro release methods can provide rapid evaluation and therefore are desirable for quality control purposes. To this end, different accelerated in vitro release methods using United States Pharmacopoeia (USP) apparatus have been developed. Different mechanisms of accelerating drug release from extended release parenteral dosage forms, along with the accelerated in vitro release testing methods currently employed are discussed. Conclusions Accelerated in vitro release testing methods with good discriminatory ability are critical for quality control of extended release parenteral products. Methods that can be used in the development of in vitro-in vivo correlation (IVIVC) are desirable, however for complex parenteral products this may not always be achievable. PMID:22686344

  18. Material Considerations for Fused-Filament Fabrication of Solid Dosage Forms

    Directory of Open Access Journals (Sweden)

    Evert Fuenmayor

    2018-04-01

    Full Text Available Material choice is a fundamental consideration when it comes to designing a solid dosage form. The matrix material will ultimately determine the rate of drug release since the physical properties (solubility, viscosity, and more of the material control both fluid ingress and disintegration of the dosage form. The bulk properties (powder flow, concentration, and more of the material should also be considered since these properties will influence the ability of the material to be successfully manufactured. Furthermore, there is a limited number of approved materials for the production of solid dosage forms. The present study details the complications that can arise when adopting pharmaceutical grade polymers for fused-filament fabrication in the production of oral tablets. The paper also presents ways to overcome each issue. Fused-filament fabrication is a hot-melt extrusion-based 3D printing process. The paper describes the problems encountered in fused-filament fabrication with Kollidon® VA64, which is a material that has previously been utilized in direct compression and hot-melt extrusion processes. Formulation and melt-blending strategies were employed to increase the printability of the material. The paper defines for the first time the essential parameter profile required for successful 3D printing and lists several pre-screening tools that should be employed to guide future material formulation for the fused-filament fabrication of solid dosage forms.

  19. Biowaiver monograph for immediate-release solid oral dosage forms: bisoprolol fumarate.

    Science.gov (United States)

    Charoo, Naseem A; Shamsher, Areeg A A; Lian, Lai Y; Abrahamsson, Bertil; Cristofoletti, Rodrigo; Groot, D W; Kopp, Sabine; Langguth, Peter; Polli, James; Shah, Vinod P; Dressman, Jennifer

    2014-02-01

    Literature data relevant to the decision to allow a waiver of in vivo bioequivalence (BE) testing for the approval of immediate-release (IR) solid oral dosage forms containing bisoprolol as the sole active pharmaceutical ingredient (API) are reviewed. Bisoprolol is classified as a Class I API according to the current Biopharmaceutics Classification System (BCS). In addition to the BCS class, its therapeutic index, pharmacokinetic properties, data related to the possibility of excipient interactions, and reported BE/bioavailability problems are taken into consideration. Qualitative compositions of IR tablet dosage forms of bisoprolol with a marketing authorization (MA) in ICH (International Conference on Harmonisation) countries are tabulated. It was inferred that these tablets had been demonstrated to be bioequivalent to the innovator product. No reports of failure to meet BE standards have been made in the open literature. On the basis of all these pieces of evidence, a biowaiver can currently be recommended for bisoprolol fumarate IR dosage forms if (1) the test product contains only excipients that are well known, and used in normal amounts, for example, those tabulated for products with MA in ICH countries and (2) both the test and comparator dosage form are very rapidly dissolving, or, rapidly dissolving with similarity of the dissolution profiles demonstrated at pH 1.2, 4.5, and 6.8. © 2013 Wiley Periodicals, Inc. and the American Pharmacists Association.

  20. 78 FR 30197 - Oral Dosage Form New Animal Drugs; Clindamycin; Enrofloxacin

    Science.gov (United States)

    2013-05-22

    ...-0002] Oral Dosage Form New Animal Drugs; Clindamycin; Enrofloxacin AGENCY: Food and Drug Administration...- Tallaght, Dublin Oral Drops. 940. 24, Ireland. 200-551........ Putney, Inc., 400 Enrofloxacin Original....812 Enrofloxacin. (a) Specifications. Each tablet contains 22.7, 68.0, or 136.0 milligrams (mg) of...

  1. Rheology as a tool for evaluation of melt processability of innovative dosage forms

    DEFF Research Database (Denmark)

    Aho, Johanna Maaria; Boetker, Johan P; Baldursdottir, Stefania

    2015-01-01

    ) printing, will have an increasingly important role when designing products for flexible dosing, since dosage forms based on compacting of a given powder mixture do not enable manufacturing of optimal pharmaceutical products for personalized treatments. The melt processability of polymers and API...

  2. Study of hydrogels based on polyacrilamide as new controlled release dosage forms produced by frontal polymerization

    OpenAIRE

    Sechi, Rossana; Gavini, Elisabetta; Mariani, Alberto; Bidali, Simone; Bonferoni, Maria Cristina; Sanna, Vanna Annunziata; Rassu, Giovanna; Pirisino, Gerolamo Antonio; Giunchedi, Paolo

    2006-01-01

    The work purpose was the evaluation of the potential application of the Frontal Polymerization (FP) technique as a new method for the preparation of controlled release dosage forms based on polyacrilamide, in which the drug loading and the polymer preparation occur at the same time.

  3. 3D printing of high drug loaded dosage forms using thermoplastic polyurethanes.

    Science.gov (United States)

    Verstraete, G; Samaro, A; Grymonpré, W; Vanhoorne, V; Van Snick, B; Boone, M N; Hellemans, T; Van Hoorebeke, L; Remon, J P; Vervaet, C

    2018-01-30

    It was the aim of this study to develop high drug loaded (>30%, w/w), thermoplastic polyurethane (TPU)-based dosage forms via fused deposition modelling (FDM). Model drugs with different particle size and aqueous solubility were pre-processed in combination with diverse TPU grades via hot melt extrusion (HME) into filaments with a diameter of 1.75 ± 0.05 mm. Subsequently, TPU-based filaments which featured acceptable quality attributes (i.e. consistent filament diameter, smooth surface morphology and good mechanical properties) were printed into tablets. The sustained release potential of the 3D printed dosage forms was tested in vitro. Moreover, the impact of printing parameters on the in vitro drug release was investigated. TPU-based filaments could be loaded with 60% (w/w) fine drug powder without observing severe shark skinning or inconsistent filament diameter. During 3D printing experiments, HME filaments based on hard TPU grades were successfully converted into personalized dosage forms containing a high concentration of crystalline drug (up to 60%, w/w). In vitro release kinetics were mainly affected by the matrix composition and tablet infill degree. Therefore, this study clearly demonstrated that TPU-based FDM feedstock material offers a lot of formulation freedom for the development of personalized dosage forms. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. 75 FR 21162 - Certain Other Dosage Form New Animal Drugs; Detomidine

    Science.gov (United States)

    2010-04-23

    .... FDA-2010-N-0002] Certain Other Dosage Form New Animal Drugs; Detomidine AGENCY: Food and Drug... NADA provides for veterinary prescription use of detomidine hydrochloride oromucosal gel for sedation... prescription use of DORMOSEDAN GEL (detomidine hydrochloride) for sedation and restraint of horses. The...

  5. 76 FR 16533 - Certain Other Dosage Form New Animal Drugs; Detomidine; Correction

    Science.gov (United States)

    2011-03-24

    .... FDA-2010-N-0002] Certain Other Dosage Form New Animal Drugs; Detomidine; Correction AGENCY: Food and... paragraph describing limitations to the approved conditions of use for detomidine hydrochloride oromucosal... conditions of use for detomidine hydrochloride oromucosal gel in horses. This correction is being made to...

  6. Dropwise additive manufacturing of pharmaceutical products for solvent-based dosage forms.

    Science.gov (United States)

    Hirshfield, Laura; Giridhar, Arun; Taylor, Lynne S; Harris, Michael T; Reklaitis, Gintaras V

    2014-02-01

    In recent years, the US Food and Drug Administration has encouraged pharmaceutical companies to develop more innovative and efficient manufacturing methods with improved online monitoring and control. Mini-manufacturing of medicine is one such method enabling the creation of individualized product forms for each patient. This work presents dropwise additive manufacturing of pharmaceutical products (DAMPP), an automated, controlled mini-manufacturing method that deposits active pharmaceutical ingredients (APIs) directly onto edible substrates using drop-on-demand (DoD) inkjet printing technology. The use of DoD technology allows for precise control over the material properties, drug solid state form, drop size, and drop dynamics and can be beneficial in the creation of high-potency drug forms, combination drugs with multiple APIs or individualized medicine products tailored to a specific patient. In this work, DAMPP was used to create dosage forms from solvent-based formulations consisting of API, polymer, and solvent carrier. The forms were then analyzed to determine the reproducibility of creating an on-target dosage form, the morphology of the API of the final form and the dissolution behavior of the drug over time. DAMPP is found to be a viable alternative to traditional mass-manufacturing methods for solvent-based oral dosage forms. © 2013 Wiley Periodicals, Inc. and the American Pharmacists Association.

  7. Effect of low-molecular-weight beta-cyclodextrin polymer on release of drugs from mucoadhesive buccal film dosage forms.

    Science.gov (United States)

    Arakawa, Yotaro; Kawakami, Shigeru; Yamashita, Fumiyoshi; Hashida, Mitsuru

    2005-09-01

    We investigated the effect of low-molecular-weight beta-cyclodextrin (beta-CyD) polymer on in vitro release of two drugs with different lipophilicities (i.e., lidocaine and ketoprofen) from mucoadhesive buccal film dosage forms. When beta-CyD polymer was added to hydroxypropylcellulose (HPC) or polyvinylalcohol (PVA) film dosage forms, the release of lidocaine into artificial saliva (pH 5.7) was reduced by 40% of the control. In contrast, the release of ketoprofen from the polymer film was enhanced by addition of beta-CyD polymer to the vehicle. When lidocaine and ketoprofen was incubated with beta-CyD polymer in the artificial saliva, concentration of free lidocaine molecules decreased in a beta-CyD polymer concentration-dependent manner. The association constant with beta-CyD polymer was 6.9+/-0.6 and 520+/-90 M(-1) for lidocaine and ketoprofen, respectively. Retarded release of the hydrophilic lidocaine by beta-CyD polymer might be due to the decrease in thermodynamic activity by inclusion complex formation, whereas enhanced release of the lipophilic ketoprofen by the beta-CyD polymer might be due to prevention of recrystallization occurring after contacting the film with aqueous solution. Thus, effects of low-molecular-weight beta-CyD polymer to the drug release rate from film dosage forms would vary according to the strength of interaction with and the solubility of active ingredient.

  8. Validation of HPLC and UV spectrophotometric methods for the determination of meropenem in pharmaceutical dosage form.

    Science.gov (United States)

    Mendez, Andreas S L; Steppe, Martin; Schapoval, Elfrides E S

    2003-12-04

    A high-performance liquid chromatographic method and a UV spectrophotometric method for the quantitative determination of meropenem, a highly active carbapenem antibiotic, in powder for injection were developed in present work. The parameters linearity, precision, accuracy, specificity, robustness, limit of detection and limit of quantitation were studied according to International Conference on Harmonization guidelines. Chromatography was carried out by reversed-phase technique on an RP-18 column with a mobile phase composed of 30 mM monobasic phosphate buffer and acetonitrile (90:10; v/v), adjusted to pH 3.0 with orthophosphoric acid. The UV spectrophotometric method was performed at 298 nm. The samples were prepared in water and the stability of meropenem in aqueous solution at 4 and 25 degrees C was studied. The results were satisfactory with good stability after 24 h at 4 degrees C. Statistical analysis by Student's t-test showed no significant difference between the results obtained by the two methods. The proposed methods are highly sensitive, precise and accurate and can be used for the reliable quantitation of meropenem in pharmaceutical dosage form.

  9. Biowaiver monograph for immediate-release solid oral dosage forms: fluconazole.

    Science.gov (United States)

    Charoo, Naseem; Cristofoletti, Rodrigo; Graham, Alexandra; Lartey, Paul; Abrahamsson, Bertil; Groot, D W; Kopp, Sabine; Langguth, Peter; Polli, James; Shah, Vinod P; Dressman, Jennifer

    2014-12-01

    Literature data pertaining to the decision to allow a waiver of in vivo bioequivalence (BE) testing requirements for the approval of immediate release (IR) solid oral dosage forms containing fluconazole as the only active pharmaceutical ingredient (API) are reviewed. The decision is based on solubility, dissolution, permeability, therapeutic index, pharmacokinetic parameters, pharmacodynamic properties, and other relevant data. BE/bioavailability (BA) problems and drug-excipients interaction data were also reviewed and taken into consideration. According to the biopharmaceutics classification system (BCS), fluconazole in polymorphic forms II and III is a BCS class I drug and has a wide therapeutic index. BE of test formulations from many different manufacturers containing different excipients confirmed that the risk of bioinequivalence because of formulation and manufacturing factors is low. It was inferred that risk can be further reduced if in vitro studies are performed according to biowaiver guidelines. Thus, it is concluded that a biowaiver can be recommended for fluconazole IR dosage forms if (a) fluconazole is present as polymorphic form II or III or any other form/mixture showing high solubility, (b) the selection of excipients be limited to those found in IR drug products approved in International Conference on Harmonisation (ICH) countries for the same dosage form and used in their usual amounts, and (c) both the test and comparator dosage form are very rapidly dissolving, or, rapidly dissolving throughout the shelf life with similar dissolution profiles at pH 1.2, 4.5, and 6.8. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association.

  10. New Form of Hypertonic Solution for Nebulization Therapy

    Directory of Open Access Journals (Sweden)

    Olga I. Simonova

    2016-01-01

    Full Text Available Mucolytic, expectorative and antitussive drugs are traditionally used in acute or chronic respiratory episodes affected by acute respiratory infections. Today, preference is given to drugs in a form of solutions for nebulization therapy. The article presents data on the new dosage form of 7% inhalation hypertonic solution in combination with hyaluronic acid used in mucostasis therapy for chronic respiratory diseases. The information on the properties and the favorable effect of hyaluronic acid is provided. We discuss the evidence base of inhalation of the hypertonic solution in combination with hyaluronic acid in cystic fibrosis.

  11. Bilayered buccal films as child-appropriate dosage form for systemic administration of propranolol.

    Science.gov (United States)

    Abruzzo, Angela; Nicoletta, Fiore Pasquale; Dalena, Francesco; Cerchiara, Teresa; Luppi, Barbara; Bigucci, Federica

    2017-10-05

    Buccal mucosa has emerged as an attractive site for systemic administration of drug in paediatric patients. This route is simple and non-invasive, even if the saliva wash-out effect and the relative permeability of the mucosa can reduce drug absorption. Mucoadhesive polymers represent a common employed strategy to increase the contact time of the formulation at the application site and to improve drug absorption. Among the different mucoadhesive dosage forms, buccal films are particularly addressed for paediatric population since they are thin, adaptable to the mucosal surface and able to offer an exact and flexible dose. The objective of the present study was to develop bilayered buccal films for the release of propranolol hydrochloride. A primary polymeric layer was prepared by casting and drying of solutions of film-forming polymers, such as polyvinylpyrrolidone (PVP) or polyvinylalcohol (PVA), added with different weight ratios of gelatin (GEL) or chitosan (CH). In order to achieve unidirectional drug delivery towards buccal mucosa, a secondary ethylcellulose layer was applied onto the primary layer. Bilayered films were characterized for their physico-chemical (morphology, thickness, drug content and solid state) and functional (water uptake, mucoadhesion, drug release and permeation) properties. The inclusion of CH into PVP and PVA primary layer provided the best mucoadhesion ability. Films containing CH provided a lower drug release with respect to films containing GEL and increased the amount of permeated drug through buccal mucosa, thanks to its ability of interfering with the lipid organization. The secondary ethylcellulose layer did not interfere with drug permeation, but it could limit drug release in the buccal cavity. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Artificial Neural Networks in Evaluation and Optimization of Modified Release Solid Dosage Forms

    Directory of Open Access Journals (Sweden)

    Zorica Djurić

    2012-10-01

    Full Text Available Implementation of the Quality by Design (QbD approach in pharmaceutical development has compelled researchers in the pharmaceutical industry to employ Design of Experiments (DoE as a statistical tool, in product development. Among all DoE techniques, response surface methodology (RSM is the one most frequently used. Progress of computer science has had an impact on pharmaceutical development as well. Simultaneous with the implementation of statistical methods, machine learning tools took an important place in drug formulation. Twenty years ago, the first papers describing application of artificial neural networks in optimization of modified release products appeared. Since then, a lot of work has been done towards implementation of new techniques, especially Artificial Neural Networks (ANN in modeling of production, drug release and drug stability of modified release solid dosage forms. The aim of this paper is to review artificial neural networks in evaluation and optimization of modified release solid dosage forms.

  13. A Validated RP-HPLC Method for the Determination of Atazanavir in Pharmaceutical Dosage Form

    Directory of Open Access Journals (Sweden)

    K. Srinivasu

    2011-01-01

    Full Text Available A validated RP HPLC method for the estimation of atazanavir in capsule dosage form on YMC ODS 150 × 4.6 mm, 5 μ column using mobile phase composition of ammonium dihydrogen phosphate buffer (pH 2.5 with acetonitrile (55:45 v/v. Flow rate was maintained at 1.5 mL/min with 288 nm UV detection. The retention time obtained for atazanavir was at 4.7 min. The detector response was linear in the concentration range of 30 - 600 μg/mL. This method has been validated and shown to be specific, sensitive, precise, linear, accurate, rugged, robust and fast. Hence, this method can be applied for routine quality control of atazanavir in capsule dosage forms as well as in bulk drug.

  14. Semi-Solid and Solid Dosage Forms for the Delivery of Phage Therapy to Epithelia

    Science.gov (United States)

    Petrovski, Steve; Chan, Hiu Tat; Angove, Michael J.; Tucci, Joseph

    2018-01-01

    The delivery of phages to epithelial surfaces for therapeutic outcomes is a realistic proposal, and indeed one which is being currently tested in clinical trials. This paper reviews some of the known research on formulation of phages into semi-solid dosage forms such as creams, ointments and pastes, as well as solid dosage forms such as troches (or lozenges and pastilles) and suppositories/pessaries, for delivery to the epithelia. The efficacy and stability of these phage formulations is discussed, with a focus on selection of optimal semi-solid bases for phage delivery. Issues such as the need for standardisation of techniques for formulation as well as for assessment of efficacy are highlighted. These are important when trying to compare results from a range of experiments and across different delivery bases. PMID:29495355

  15. Particle Engineering Via Mechanical Dry Coating in the Design of Pharmaceutical Solid Dosage Forms.

    Science.gov (United States)

    Qu, Li; Morton, David A V; Zhou, Qi Tony

    2015-01-01

    Cohesive powders are problematic in the manufacturing of pharmaceutical solid dosage forms because they exhibit poor flowability, fluidization and aerosolization. These undesirable bulk properties of cohesive powders represent a fundamental challenge in the design of efficient pharmaceutical manufacturing processes. Recently, mechanical dry coating has attracted increasing attention as it can improve the bulk properties of cohesive powders in a cheaper, simpler, safer and more environment-friendly way than the existing solvent-based counterparts. In this review, mechanical dry coating techniques are outlined and their potential applications in formulation and manufacturing of pharmaceutical solid dosage forms are discussed. Reported data from the literature have shown that mechanical dry coating holds promise for the design of superior pharmaceutical solid formulations or manufacturing processes by engineering the interfaces of cohesive powders in an efficient and economical way.

  16. Development and characterization of a gastroretentive dosage form composed of chitosan and hydroxyethyl cellulose for alendronate

    OpenAIRE

    Chen YC; Ho HO; Chiu CC; Sheu MT

    2013-01-01

    Ying-Chen Chen,1,* Hsiu-O Ho,1,* Chiao-Chi Chiu,1 Ming-Thau Sheu1,2 1School of Pharmacy, College of Pharmacy, Taipei Medical University, 2Clinical Research Center and Traditional Herbal Medicine Research Center, Taipei Medical University Hospital, Taipei, Taiwan*These authors contributed equally to this workAbstract: In this study, alendronate, the most commonly used biphosphonate for treating osteoporosis, was formulated as gastroretentive dosage form (GRDF) tablets to enhance its oral bioav...

  17. ANALYTICAL STUDY OF CURCUMIN CONTENT IN DIFFERENT DOSAGE FORMS CONTAINING TURMERIC EXTRACT POWDER AND TURMERIC OLEORESIN

    OpenAIRE

    Rane Rajashree; Gangolli Divya; Patil Sushma; Ingawale Kanchan; Kundalwal Sachin

    2013-01-01

    Different dosage forms namely tablets, capsules, creams and syrups were analysed for curcumin content, by the well-known spectrophotometric method. Turmeric extract powder was used as a source of curcumin in capsule and tablet formulations. Turmeric oleoresin was used as a source of curcumin in cream formulation. Additionally, syrup formulations containing turmeric extract powder as well as turmeric oleoresin, separately, were also tested for their curcumin contents. Analytical results for cu...

  18. Preparation and evaluation of doxycycline hydrochloride and bromhexine hydrochloride dosage forms for pigeons / Marga le Roux

    OpenAIRE

    Le Roux, Marga

    2004-01-01

    Objective: To prepare and evaluate three different dosage forms, containing doxycycline hydrochloride (HCI) and bromhexine hydrochloride (HCI) respectively and in combination, for the treatment of respiratory diseases in pigeons. Background: Birds have held a place in man's affection since the ancient Egyptians and Romans kept birds. Europeans have successfully bred birds, especially smaller birds and pigeons, for centuries. Only in recent years, however, have science and me...

  19. Influence of Postprandial Intragastric Pressures on Drug Release from Gastroretentive Dosage Forms.

    Science.gov (United States)

    Schneider, Felix; Hoppe, Melanie; Koziolek, Mirko; Weitschies, Werner

    2018-05-29

    Despite extensive research in the field of gastroretentive dosage forms, this "holy grail" of oral drug delivery yet remained an unmet goal. Especially under fasting conditions, the reproducible retention of dosage forms in the stomach seems to be an impossible task. This is why such systems are often advised to be taken together with food. But also the postprandial motility can contribute significantly to the failure of gastroretentive dosage forms. To investigate the influence of postprandial pressure conditions on drug release from such systems, we used a novel in vitro dissolution tool, the dissolution stress test device. With the aid of this device, we simulated three different intragastric pressure profiles that may occur after postprandial intake. These transit scenarios were based on recently obtained, postprandial SmartPill® data. The tested systems, Glumetza® 1000 and Madopar® HBS 125, are marketed dosage forms that are based on different approaches to achieve proper gastric retention. All three transit scenarios revealed a highly pressure-sensitive drug release behavior, for both drugs. For Madopar® HBS 125, nearly complete drug release was observed even after early occurring pressures. Glumetza® 1000 seemed to be more resistant to these, most likely due to incomplete wetting of the system. On the contrary to these findings, data from standard dissolution tests using the paddle apparatus displayed controlled drug release for both systems for about 6 h. Based on these results, it can be doubted that established gastroretentive systems stay intact over a longer period of time, even under postprandial conditions.

  20. Spectrophotometric simultaneous determination of Rabeprazole Sodium and Itopride Hydrochloride in capsule dosage form

    Science.gov (United States)

    Sabnis, Shweta S.; Dhavale, Nilesh D.; Jadhav, Vijay. Y.; Gandhi, Santosh V.

    2008-03-01

    A new simple, economical, rapid, precise and accurate method for simultaneous determination of rabeprazole sodium and itopride hydrochloride in capsule dosage form has been developed. The method is based on ratio spectra derivative spectrophotometry. The amplitudes in the first derivative of the corresponding ratio spectra at 231 nm (minima) and 260 nm were selected to determine rabeprazole sodium and itopride hydrochloride, respectively. The method was validated with respect to linearity, precision and accuracy.

  1. New applications to computerized tomography: analysis of solid dosage forms produced by pharmaceutical industry

    International Nuclear Information System (INIS)

    Oliveira Junior, Jose Martins de; Martins, Antonio Cesar Germano

    2009-01-01

    Full text: In recent years, computerized tomography (CT) has been used as a new probe to study solid dosage forms (tablets) produced by pharmaceutical industry. This new approach to study tablet and powder, or granulation, properties used in pharmaceutical industry is very suitable. First because CT can generate information that traditional technologies used in this kind of analysis can not, such as, density distribution of internal structures and tablet dimensions, pore size distribution, particle shape information, and also investigation of official and unofficial (counterfeit) copies of solid dosage forms. Second because CT is a nondestructive technique, allowing the use of tablets or granules in others analysis. In this work we discus how CT can be used to acquire and reconstruct internal microstructure of tablets and granules. CT is a technique that is based on attenuation of X-rays passing through matter. Attenuation depends on the density and atomic number of the material that is scanned. In this work, a micro-CT X-ray scanner (manufactured by the group of Applied Nuclear Physics at University of Sorocaba) was used to obtain three-dimensional images of the tablets and granules for nondestructive analysis. These images showed a non uniform density distribution of material inside some tablets, the morphology of some granules analyzed, the integrity of the liquid-filled soft-gelatin capsule and so on. It could also be observed that the distribution of different constituents presents an osmotic controlled-release dosage form. The present work shows that it is possible to use X-ray microtomography to obtain useful qualitative and quantitative information on the structure of pharmaceutical dosage forms. (author)

  2. Materials for Pharmaceutical Dosage Forms: Molecular Pharmaceutics and Controlled Release Drug Delivery Aspects

    Directory of Open Access Journals (Sweden)

    Patrick P. DeLuca

    2010-09-01

    Full Text Available Controlled release delivery is available for many routes of administration and offers many advantages (as microparticles and nanoparticles over immediate release delivery. These advantages include reduced dosing frequency, better therapeutic control, fewer side effects, and, consequently, these dosage forms are well accepted by patients. Advances in polymer material science, particle engineering design, manufacture, and nanotechnology have led the way to the introduction of several marketed controlled release products and several more are in pre-clinical and clinical development.

  3. Discrete element method (DEM) simulations of stratified sampling during solid dosage form manufacturing.

    Science.gov (United States)

    Hancock, Bruno C; Ketterhagen, William R

    2011-10-14

    Discrete element model (DEM) simulations of the discharge of powders from hoppers under gravity were analyzed to provide estimates of dosage form content uniformity during the manufacture of solid dosage forms (tablets and capsules). For a system that exhibits moderate segregation the effects of sample size, number, and location within the batch were determined. The various sampling approaches were compared to current best-practices for sampling described in the Product Quality Research Institute (PQRI) Blend Uniformity Working Group (BUWG) guidelines. Sampling uniformly across the discharge process gave the most accurate results with respect to identifying segregation trends. Sigmoidal sampling (as recommended in the PQRI BUWG guidelines) tended to overestimate potential segregation issues, whereas truncated sampling (common in industrial practice) tended to underestimate them. The size of the sample had a major effect on the absolute potency RSD. The number of sampling locations (10 vs. 20) had very little effect on the trends in the data, and the number of samples analyzed at each location (1 vs. 3 vs. 7) had only a small effect for the sampling conditions examined. The results of this work provide greater understanding of the effect of different sampling approaches on the measured content uniformity of real dosage forms, and can help to guide the choice of appropriate sampling protocols. Copyright © 2011 Elsevier B.V. All rights reserved.

  4. Formulation and process considerations affecting the stability of solid dosage forms formulated with methacrylate copolymers.

    Science.gov (United States)

    Petereit, H U; Weisbrod, W

    1999-01-01

    General considerations concerning the stability of coated dosage forms are discussed, in order to avoid predictable interactions which may cause long-term stability problems. As polymers themselves maintain a high chemical stability and a low reactivity, instability phenomena mainly have to be explained by interactions of low molecular weight substances or physical changes. Possible interactions of functional groups can be predicted easily and insulating subcoates are proper countermeasures. Impurities, remaining in the polymeric material from the manufacturing process, may accelerate the hydrolysis of sensitive drugs. Instabilities of coated dosage forms are mainly based on physical interactions, caused by improper formulations of coating suspensions (i.e. plasticizers or pigments) or the film coating process. Residual moisture or solvents, probably enclosed in the core and migrating over time, may increase the permeability of coatings, due to plasticizing effects. The functionality of coatings from aqueous dispersions is linked to coalescence of latex particles. Thus any incomplete film formation, caused by too high or too low coating temperatures, may result in high permeable coatings. During storage, preferably under stress conditions this process will continue and thus change the release profile. Therefore bed temperatures of 10-20 degrees C above MFT must ensure the formation of homogeneous polymer layers during the coating process. Stability test procedures and packaging materials also need to be adapted to the physicochemical properties of the dosage form, in order to get meaningful results in stability tests.

  5. Development and Validation of a HPLC Method for the Determination of Lacidipine in Pure Form and in Pharmaceutical Dosage Form

    International Nuclear Information System (INIS)

    Vinodh, M.; Vinayak, M.; Rahul, K.; Pankaj, P.

    2012-01-01

    A simple and reliable high-performance liquid chromatography (HPLC) method was developed and validated for Lacidipine in pure form and pharmaceutical dosage form. The method was developed on X bridge C-18 column (150 mm x 4.6 mm, 5 μm) with a mobile phase gradient system of ammonium acetate and acetonitrile. The effluent was monitored by PDA detector at 240 nm. Calibration curve was linear over the concentration range of 50-250 μg/ml. For Intra-day and inter-day precision % RSD values were found to be 0.83 % and 0.41 % respectively. Recovery of Lacidipine was found to be in the range of 99.78-101.76 %. The limits of detection (LOD) and quantification (LOQ) were 1.0 and 7.3 μg/ml respectively. The developed RP-HPLC method was successfully applied for the quantitative determination of lacidipine in pharmaceutical dosage. (author)

  6. The effect of miscellaneous oral dosage forms on the environmental pollution of sulfonamides in pig holdings.

    Science.gov (United States)

    Stahl, Jessica; Zessel, Katrin; Schulz, Jochen; Finke, Jan Henrik; Müller-Goymann, Christel Charlotte; Kietzmann, Manfred

    2016-04-01

    Due to antibiotic treatment of humans and animals, the prevalence of bacterial resistances increases worldwide. Especially in livestock farming, large quantities of faeces contaminated with antibiotics pose a risk of the carryover of the active ingredient to the environment. Accordingly, the aim of the present study was the evaluation of the benefit of different oral dosage forms (powder, pellets, granula) in pigs concerning the environmental pollution of sulfadiazine. Two subtherapeutic dosages were evaluated in powder mixtures to gain information about their potential to pollute the pig barn. Furthermore, a new group of pigs was kept in the stable after powder feeding of another pig group to determine the possible absorption of environmentally distributed antibiotics. Pigs were orally treated with three dosage forms. Simultaneously, sedimentation and airborne dust were collected and plasma and urine levels were determined. All formulations result in comparable plasma and urine levels, but massive differences in environmental pollution (powder > pellets, granula). Pigs housing in a contaminated barn exhibit traces of sulfadiazine in plasma and urine. Using pharmaceutical formulations like pellets or granula, the environmental pollution of sulfonamides can significantly be diminished due to massive dust reduction during feeding.

  7. Enhancement of bioavailability of ketoprofen using dry elixir as a novel dosage form.

    Science.gov (United States)

    Ahn, H J; Kim, K M; Kim, C K

    1998-07-01

    To enhance the dissolution rate and bioavailability of poorly water-soluble ketoprofen, a novel oral dosage form of ketoprofen, termed ketoprofen dry elixir, was developed by the spray-drying technique. Ketoprofen, dextrin, and sodium lauryl sulfate were dissolved in an ethanol-water mixture (20:25 w/w) and thereafter spray-dried to form the ketoprofen dry elixir. Comparative studies on the in vitro dissolution and in vivo adsorption of ketoprofen in the form of dry elixir and powder were carried out. Ketoprofen in the dry elixir completely dissolved within 5 min. On the other hand, only about 50.1% of ketoprofen powder alone dissolved during 60 min. The initial dissolution rate of ketoprofen in the dry elixir markedly increased in distilled water at 37 degrees C, becoming fourfold higher than that of ketoprofen powder alone. The maximal plasma concentration of ketoprofen (Cmax) and the area under the concentration-time curve from zero to 8 hr (AUC0-8 hr) after the oral administration of dry elixir increased about 3.2- (24.6 versus 7.6 micrograms/ml) and 2.2-(38.4 versus 17.3 micrograms hr/ml) fold compared with powder alone. It was obvious that ketoprofen dry elixir might be a useful solid dosage form to improve the dissolution rate and bioavailability of poorly water-soluble ketoprofen.

  8. A novel solid dosage form of rifampicin and isoniazid with improved functionality.

    Science.gov (United States)

    Gohel, Mukesh C; Sarvaiya, Krishnakant G

    2007-08-24

    The aim of the present investigation was to develop a novel dosage form of rifampicin and isoniazid to minimize degradation of rifampicin in acidic medium and to modulate the release of rifampicin in the stomach and isoniazid in the intestine. Gastroretentive tablets of rifampicin (150 mg) were prepared by the wet granulation method using hydroxypropyl methylcellulose, calcium carbonate, and polyethylene glycol 4000. The granules and tablets of rifampicin were characterized. Hard gelatin capsules (size 4) containing a compacted mass of isoniazid (150 mg) and dicalcium phosphate (75 mg) were enteric coated. Two tablets of rifampicin and 1 capsule (size 4) of isoniazid were put into a hard gelatin capsule (size 00). The in vitro drug release and in vitro drug degradation studies were performed. Rifampicin was released over 4 hours by zero-order kinetics from the novel dosage form. More than 90% of isoniazid was released in alkaline medium in 30 minutes. The results of dissolution studies with the US Pharmacopeia XXIII method revealed that a substantial amount of rifampicin was degraded from the immediate release capsule containing rifampicin and isoniazid powder owing to drug accumulation in the dissolution vessel and also to the presence of isoniazid. The degradation of rifampicin to 3-formyl rifampicin SV (3FRSV) was arrested (3.6%-4.8% degradation of rifampicin at 4 hours) because of the minimization of physical contact between the 2 drugs and controlled release of rifampicin in acidic medium in the modified Rossett-Rice apparatus. This study concludes that the problem of rifampicin degradation can be alleviated to a certain extent by this novel dosage form.

  9. Stability Indicating LC-Method for Estimation of Paracetamol and Lornoxicam in Combined Dosage Form

    OpenAIRE

    Shah, Dimal A.; Patel, Neel J.; Baldania, Sunil L.; Chhalotiya, Usman K.; Bhatt, Kashyap K.

    2011-01-01

    A simple, specific and stability indicating reversed phase high performance liquid chromatographic method was developed for the simultaneous determination of paracetamol and lornoxicam in tablet dosage form. A Brownlee C-18, 5 μm column having 250×4.6 mm i.d. in isocratic mode, with mobile phase containing 0.05 M potassium dihydrogen phosphate:methanol (40:60, v/v) was used. The flow rate was 1.0 ml/min and effluents were monitored at 266 nm. The retention times of paracetamol and lornoxicam ...

  10. Stability-indicating HPLC determination of pramipexole dihydrochloride in bulk drug and pharmaceutical dosage form

    OpenAIRE

    Panditrao, Vedavati M; Sarkate, Aniket P; Sangshetti, Jaiprakash N; Wakte, Pravin S; Shinde, Devanand B

    2011-01-01

    A novel stability-indicating high-performance liquid chromatographic assay method was developed and validated for quantitative determination of pramipexole dihydrochloride in bulk drugs and in pharmaceutical dosage form in the presence of degradation products. An isocratic, reversed phase HPLC method was developed to separate the drug from the degradation products, using an Ace5-C18 (250×4.6 mm, 5 µm) advance chromatography column, and 10 mmol L-1 ammonium acetate and acetonitrile (75:25 v/v)...

  11. Colorimetric determination of a paracetamole in raw material and in pharmaceutical dosage forms

    International Nuclear Information System (INIS)

    Usifoh, C.O; Adelusi, S.A.; Adebambo, R.F.

    2002-01-01

    A rapid, accurate and simple method is proposed for the determination of p-acetaminophen (paracetamole) in raw material, tablets and syrups. The method is based on measuring the intensity of the yellow color that developed when acute acetaminophen is allowed to react with p-dimethylaminobenzaldehyde in 2M HCl after heating. The color which absorbs in the visible region of gamma 450 nm is stable for several hours and the intensity is directly proportional to the concentration of the drug, that is, Beer lambert law is obeyed. The method can be used to analyse paracetamole in raw material and in pharmaceutical dosage forms. (author)

  12. Analytical Method Development and Validation of Solifenacin in Pharmaceutical Dosage Forms by RP-HPLC

    OpenAIRE

    Shaik, Rihana Parveen; Puttagunta, Srinivasa Babu; Kothapalli Bannoth, Chandrasekar; Challa, Bala Sekhara Reddy

    2014-01-01

    A new, accurate, precise, and robust HPLC method was developed and validated for the determination of solifenacin in tablet dosage form. The chromatographic separation was achieved on an Inertsil ODS 3V C18 (150 mm × 4.6 mm, 5 μm) stationary phase maintained at ambient temperature with a mobile phase combination of monobasic potassium phosphate (pH 3.5) containing 0.1% triethylamine and methanol (gradient mode) at a flow rate of 1.5 mL/min, and the detection was carried out by using UV detect...

  13. HPLC DETERMINATION OF FENBENDAZOLE AND IVERMECTIN SIMULTANEOUSLY IN BULK AND PHARMACEUTICAL DOSAGE FORMS

    OpenAIRE

    Battula Sreenivasa Rao, Mandapati Varaprasad Reddy*, Bhatraju Sreenivasa Rao

    2017-01-01

    In the present study, a simple, precise and accurate high performance liquid chromatography with photodiode array detector was developed for the simultaneous estimation of ivermectin & fenbendazole in bulk and tablet dosage forms. A Zorbax C8 column (250 cm × 4.6 mm × 5 μm) with mobile phase consisting of 0.1 M potassium dihydrogen orthophosphate and methanol (60:40 v/v) having pH 4.5 (adjusted with orthophosphoric acid) was used. The flow rate was 1.2 ml/min and the effluents were detected a...

  14. Dry coating of solid dosage forms: an overview of processes and applications.

    Science.gov (United States)

    Foppoli, Anastasia Anna; Maroni, Alessandra; Cerea, Matteo; Zema, Lucia; Gazzaniga, Andrea

    2017-12-01

    Dry coating techniques enable manufacturing of coated solid dosage forms with no, or very limited, use of solvents. As a result, major drawbacks associated with both organic solvents and aqueous coating systems can be overcome, such as toxicological, environmental, and safety-related issues on the one hand as well as costly drying phases and impaired product stability on the other. The considerable advantages related to solventless coating has been prompting a strong research interest in this field of pharmaceutics. In the article, processes and applications relevant to techniques intended for dry coating are analyzed and reviewed. Based on the physical state of the coat-forming agents, liquid- and solid-based techniques are distinguished. The former include hot-melt coating and coating by photocuring, while the latter encompass press coating and powder coating. Moreover, solventless techniques, such as injection molding and three-dimensional printing by fused deposition modeling, which are not purposely conceived for coating, are also discussed in that they would open new perspectives in the manufacturing of coated-like dosage forms.

  15. Biowaiver Monographs for Immediate-Release Solid Oral Dosage Forms: Folic Acid.

    Science.gov (United States)

    Hofsäss, Martin A; Souza, Jacqueline de; Silva-Barcellos, Neila M; Bellavinha, Karime R; Abrahamsson, Bertil; Cristofoletti, Rodrigo; Groot, D W; Parr, Alan; Langguth, Peter; Polli, James E; Shah, Vinod P; Tajiri, Tomokazu; Mehta, Mehul U; Dressman, Jennifer B

    2017-12-01

    This work presents a review of literature and experimental data relevant to the possibility of waiving pharmacokinetic bioequivalence studies in human volunteers for approval of immediate-release solid oral pharmaceutical forms containing folic acid as the single active pharmaceutical ingredient. For dosage forms containing 5 mg folic acid, the highest dose strength on the World Health Organization Essential Medicines List, the dose/solubility ratio calculated from solubility studies was higher than 250 mL, corresponding to a classification as "not highly soluble." Small, physiological doses of folic acid (≤320 μg) seem to be absorbed completely via active transport, but permeability data for higher doses of 1-5 mg are inconclusive. Following a conservative approach, folic acid is classified as a Biopharmaceutics Classification System class IV compound until more reliable data become available. Commensurate with its solubility characteristics, the results of dissolution studies indicated that none of the folic acid products evaluated showed rapid dissolution in media at pH 1.2 or 4.5. Therefore, according to the current criteria of the Biopharmaceutics Classification System, the biowaiver approval procedure cannot be recommended for immediate-release solid oral dosage forms containing folic acid. Copyright © 2017 American Pharmacists Association®. All rights reserved.

  16. Preparation and characterization of solid oral dosage forms containing soy isoflavones

    Directory of Open Access Journals (Sweden)

    Stela R. de Oliveira

    2013-02-01

    Full Text Available Soy isoflavones have been extensively used for menopausal symptoms and prevention of hormone-related cancer, osteoporosis and cardiovascular diseases. Commercially available forms of isoflavones include supplements, capsules and tablets. However, the non-standardization of soy isoflavones extracts and different dissolution profiles of these solid dosage forms highlight the need of additional studies on the development of well characterized pharmaceutical dosage forms of isoflavones. In this work, immediate release oral tablets of soy isoflavones were obtained and evaluated. Genistein and daidzein, were the main constituents of the dried soy extract. Preparation of the tables was accomplished in a rotary tableting machine following either a dry mixture for direct compression or wet granulation with different excipients. Powder, granules and tablets were evaluated for several parameters, including flow properties, Carr and Hausner indexes, hardness, friability, disintegration time and drug release profile. Also, a fast and validated HPLC analytical method for both genistein and daidzein was developed. Formulations containing sodium croscarmellose and sodium dodecyl sulfate resulted in better flowability as indicated by the flow rate and angle of repose, faster disintegration time and immediate release dissolution profile.

  17. Spectrophotometric methods for the simultaneous estimation of ofloxacin and tinidazole in bulk and pharmaceutical dosage form

    Directory of Open Access Journals (Sweden)

    Kareti Srinivasa Rao

    2011-01-01

    Full Text Available Aim: This work deals with the simultaneous estimation of Ofloxacin (OFL and Tinidazole (TNZ in in bulk and pharmaceutical dosage form, without prior separation, by three different techniques (Simultaneous equation, Absorbance ratio method and First order derivative method. Materials and Methods: The present work was carried out on Shimadzu electron UV1800 double beam UV-Visible spectrophotometer. The absorption spectra of reference and test solutions were carried out in 1 cm matched quartz cell over the range of 200 - 400 nm. Standard gift sample of OFL and TNZ obtain from Torrent pharmaceuticals Ltd., Baddi, Himachal Pradesh. Combined OFL and TNZ tablets were purchased from local market. Methanol from Merck Ltd and distilled water are used as solvent. Results: The first method is the application of simultaneous equation. Where the linearity ranges for OFL and TNZ were 5-30 μg/ml and 10-50 μg/ml respectively. The second method is the determination of ratio of absorbance at 278nm, the maximum absorption of TNZ and isobestic wavelength 283 nm, the linearity ranges for OFL and TNZ were 5-30 μg/ml and 10-50μg/ml respectively. The third method is the first order derivative method, where the linearity ranges for OFL and TNZ were 5-30 μg/ml and 10-50 μg/ml respectively. The results of the analysis have been validated statistically and by recovery studies, where the percentage recovery was found to be 100.9±0.49 and 97.30±0.20 using the simultaneous equation method, 98±0.45 and 100.4±0.48 using the graphical absorbance ratio method and 99.10±0.40 and 84.70±0.70 using first derivative method, for OFL and TNZ respectively. Conclusions: The proposed procedures are rapid, simple, require no preliminary separation steps and can be used for routine analysis of both drugs in quality control laboratories.

  18. Determination of some histamine H1-receptor antagonists in dosage forms.

    Science.gov (United States)

    Gazy, Azza A; Mahgoub, Hoda; El-Yazbi, F A; El-Sayed, M A; Youssef, Rasha M

    2002-10-15

    Three simple and accurate methods are presented for determination of Cetirizine, Fexofenadine, Loratadine and Acrivastine in pure form and commercial dosage forms. The first method is based on the reaction of the above cited drugs with bromocresol purple dye to form ion-pair complex extractable with chloroform and subsequently measured spectrophotometrically. Secondly, eosin gives with these drugs ion-pair complex, measurable directly without extraction both spectrophotometrically and spectrofluorimetrically. The last method involves the base-catalysed condensation of mixed anhydrides of organic acids (citric acid/acetic anhydride) where as the tertiary amino group in the above-cited drugs acts as the basic catalyst. The product of condensation is measured spectrophotometrically. All the reaction conditions for the proposed methods have been studied. Copyright 2002 Elsevier Science B.V.

  19. A Novel Disintegration Tester for Solid Dosage Forms Enabling Adjustable Hydrodynamics.

    Science.gov (United States)

    Kindgen, Sarah; Rach, Regine; Nawroth, Thomas; Abrahamsson, Bertil; Langguth, Peter

    2016-08-01

    A modified in vitro disintegration test device was designed that enables the investigation of the influence of hydrodynamic conditions on disintegration of solid oral dosage forms. The device represents an improved derivative of the compendial PhEur/USP disintegration test device. By the application of a computerized numerical control, a variety of physiologically relevant moving velocities and profiles can be applied. With the help of computational fluid dynamics, the hydrodynamic and mechanical forces present in the probe chamber were characterized for a variety of device moving speeds. Furthermore, a proof of concept study aimed at the investigation of the influence of hydrodynamic conditions on disintegration times of immediate release tablets. The experiments demonstrated the relevance of hydrodynamics for tablet disintegration, especially in media simulating the fasted state. Disintegration times increased with decreasing moving velocity. A correlation between experimentally determined disintegration times and computational fluid dynamics predicted shear stress on tablet surface was established. In conclusion, the modified disintegration test device is a valuable tool for biorelevant in vitro disintegration testing of solid oral dosage forms. Copyright © 2016 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  20. Development and Statistical Validation of Spectrophotometric Methods for the Estimation of Nabumetone in Tablet Dosage Form

    Directory of Open Access Journals (Sweden)

    A. R. Rote

    2010-01-01

    Full Text Available Three new simple, economic spectrophotometric methods were developed and validated for the estimation of nabumetone in bulk and tablet dosage form. First method includes determination of nabumetone at absorption maxima 330 nm, second method applied was area under curve for analysis of nabumetone in the wavelength range of 326-334 nm and third method was First order derivative spectra with scaling factor 4. Beer law obeyed in the concentration range of 10-30 μg/mL for all three methods. The correlation coefficients were found to be 0.9997, 0.9998 and 0.9998 by absorption maxima, area under curve and first order derivative spectra. Results of analysis were validated statistically and by performing recovery studies. The mean percent recoveries were found satisfactory for all three methods. The developed methods were also compared statistically using one way ANOVA. The proposed methods have been successfully applied for the estimation of nabumetone in bulk and pharmaceutical tablet dosage form.

  1. RP-HPLC Method for the Estimation of Nebivolol in Tablet Dosage Form

    Directory of Open Access Journals (Sweden)

    M. K. Sahoo

    2009-01-01

    Full Text Available A reverse phase HPLC method is described for the determination of nebivolol in tablet dosage form. Chromatography was carried on a Hypersil ODS C18 column using a mixture of methanol and water (80:20 v/v as the mobile phase at a flow rate of 1.0 mL/min with detection at 282 nm. Chlorzoxazone was used as the internal standard. The retention times were 3.175 min and 4.158 min for nebivolol and chlorzoxazone respectively. The detector response was linear in the concentration of 1-400 μg/mL. The limit of detection and limit of quantification was 0.0779 and 0.2361 μg/mL respectively. The percentage assay of nebivolol was 99.974%. The method was validated by determining its sensitivity, accuracy and precision. The proposed method is simple, fast, accurate and precise and hence can be applied for routine quality control of nebivolol in bulk and tablet dosage form.

  2. Design of a gastroretentive mucoadhesive dosage form of furosemide for controlled release

    Directory of Open Access Journals (Sweden)

    Sharad S. Darandale

    2012-10-01

    Full Text Available The aim of the present study was to develop and characterize a gastroretentive dosage form suitable for controlled drug release. It consists of a drug loaded polymeric film made up of a bilayer of immediate (IR and controlled release (CR layers folded into a hard gelatin capsule. Gastroretention results from unfolding and swelling of the film and its bioadhesion to the gastric mucosa. Furosemide, a drug with a narrow absorption window, was selected as the model drug. Inclusion of hydroxypropyl β-cyclodextrin in both layers and Carbopol® 971P NF in the CR layer of the bilayer film resulted in optimum drug release, bioadhesion and mechanical properties. The film with zig-zag folding in the capsule was shown to unfold and swell under acidic conditions and provide IR of drug over 1 h and CR for up to 12 h in acidic medium. X-ray diffraction, differential scanning calorimetry and scanning electron microscopy revealed uniform dispersion of furosemide in the polymeric matrices. The results indicate the dosage form is gastroretentive and can provide controlled release of drugs with narrow therapeutic windows.

  3. Dropwise additive manufacturing of pharmaceutical products for melt-based dosage forms.

    Science.gov (United States)

    Içten, Elçin; Giridhar, Arun; Taylor, Lynne S; Nagy, Zoltan K; Reklaitis, Gintaras V

    2015-05-01

    The US Food and Drug Administration introduced the quality by design approach and process analytical technology guidance to encourage innovation and efficiency in pharmaceutical development, manufacturing, and quality assurance. As part of this renewed emphasis on the improvement of manufacturing, the pharmaceutical industry has begun to develop more efficient production processes with more intensive use of online measurement and sensing, real-time quality control, and process control tools. Here, we present dropwise additive manufacturing of pharmaceutical products (DAMPP) as an alternative to conventional pharmaceutical manufacturing methods. This mini-manufacturing process for the production of pharmaceuticals utilizes drop on demand printing technology for automated and controlled deposition of melt-based formulations onto edible substrates. The advantages of drop-on-demand technology, including reproducible production of small droplets, adjustable drop sizing, high placement accuracy, and flexible use of different formulations, enable production of individualized dosing even for low-dose and high-potency drugs. In this work, DAMPP is used to produce solid oral dosage forms from hot melts of an active pharmaceutical ingredient and a polymer. The dosage forms are analyzed to show the reproducibility of dosing and the dissolution behavior of different formulations. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association.

  4. A progressive review of Sandhana kalpana (Biomedical fermentation): An advanced innovative dosage form of Ayurveda

    Science.gov (United States)

    Chaudhary, Anand; Singh, Neetu; Dalvi, Madhuri; Wele, Asmita

    2011-01-01

    Sandhana kalpana (biomedical fermented formulations) are one of the best dosage forms of Ayurveda in practice since thousands of years. In order to prepare these medicaments, certain sets of conditions are prearranged, which lead to fermentation. Thus, products bequeath with self-generated ethyl alcohol, which potentiate these preparations (Asava–Arishta), pharmaceutically and therapeutically. Commonly, medicinal and commercial components of these formulations are prompting many researchers to contribute in manufacturing, quality control, safety, and efficacy of these formulations. To cope up with this, literature related to Asava–Arishta has been surveyed from the Vedic period to recent publications of Government of India, ie, Ayurvedic Formulary of India, and presented briefly here. In this review paper, we have discussed pioneering facts such as nature and amount of carbohydrate, type of containers, optimum temperature, variety and relevance of initiator of fermentation, manufacturing, regulatory rules, and business aspects of Asava-Arishta. After going through this basic information, any academician or researcher may show a way to further strengthen this dosage form. PMID:22529661

  5. Development of polymer film dosage forms of lidocaine for buccal administration: II. Comparison of preparation methods.

    Science.gov (United States)

    Okamoto, Hirokazu; Nakamori, Takahiko; Arakawa, Yotaro; Iida, Kotaro; Danjo, Kazumi

    2002-11-01

    In previous studies, we prepared film dosage forms of lidocaine (LC) with hydroxypropylcellulose (HPC) as a film base using the solvent evaporation (SE) method. However, from the viewpoint of environmental issues, a reduction in organic solvent use in pharmaceutical and other industries is required. In this study, we prepared the LC films by direct compression of the physical mixture (DCPM method) and direct compression of the spray dried powder (DCSD method). Magnesium stearate, which was required as a lubricant for direct compression, showed no effect on the LC release rate. The LC release rate (%/h) was independent of the compression pressure, but a higher pressure was preferable to easily remove the film from the punches. An increase in the film weight decreased the LC release rate expressed in %/h, whereas no significant effect of film weight was observed on the LC release rate from unit surface area expressed in mg/h/cm(2). The LC release rate (%/h) was independent of the LC content, suggesting that the LC release rate (mg/h) can be quantitatively controlled by changing the LC content in the formulation. The LC release rate and penetration rate were affected by the preparation method; that is, DCPM method dosage form. Copyright 2002 Wiley-Liss, Inc. and the American Pharmaceutical Association J Pharm Sci 91:2424-2432, 2002

  6. Consumer Preferences and Perceptions towards the use Colored Oral Solid Dosage Forms in Baghdad

    Directory of Open Access Journals (Sweden)

    Inas Rifaat Ibrahim,*, Mohamed Izham M.I & Mahmoud Al-Haddad

    2010-10-01

    Full Text Available Objective: The main aims of this study were to determine consumers’ preferences and perceptions in Baghdad towards the color of Oral Solid Dosage Form.Materials and Methods: A cross sectional study was conducted using a self–administered questionnaire. A convenient sampling method was adopted to approach the consumers visiting the community pharmacies in Baghdad.The data collected was analyzed using SPSS version 16 ®. Anon-parametric statistics i.e [Chi-square, Mann-Whitney and Kruskal-Wallis tests] were used to evaluate the association of demographic variables with respondents perceptions toward physical characteristics of Oral Solid Dosage Form.Results: Colored OSDF was preferred by 76.4% of consumers.Significant differences in this preference were found among genders (P=0.029; age (P<0.001; educational level (P=0.001;and monthly income level (0.007. Further, consumers perceived that color of OSDF is related with the therapeutic activity of medicine. Significant differences in this perception were found to be influenced by gender (P=0.016; age group(P<0.001; and educational level (P<0.001.Conclusion: In a conclusion, color was the most preferred characteristic of OSDF by Baghdadi consumers with the perceptions that color is related to therapeutic activity of medicines. Gender, age, educational level, and monthly income are important factors that are associated with the preferences and perceptions toward colored OSDF.

  7. Spectrophotometric method for simultaneous estimation of atazanavir sulfate and ritonavir in tablet dosage form

    Directory of Open Access Journals (Sweden)

    Disha A Patel

    2015-01-01

    Full Text Available Background: Ritonavir (RTV and atazanavir sulfate (ATV are protease inhibitor and RTV mostly used as a booster for increasing the bioavailability of other protease inhibitors like ATV. Aims: Quality assessment of the new dosage form of RTV and ATV i.e., tablets is very essential and hence this work deals with to develop sensitive, simple and precise method for simultaneous estimation of ATV and RTV in tablet dosage form by absorbance correction method. Materials and Methods: The present work was carried out on Shimadzu Ultraviolate(UV-1700 double beam spectrophotometer with 1 cm path length supported by S Shimadzu, model-1700(Japan, UV-Probe software, version 2.31 was used for spectral measurements with 10 mm matched quartz cells. Standard ATV and RTV were supplied by Cipla Pharmaceutical Ltd. Methanol was purchased from Finar Chemicals Pvt. Ltd. Results and Conclusion: The λmax or the absorption maxima for ATV and RTV were found to be 279 and 240 nm, respectively in methanol as solvent. The drugs follow Beer-Lambert′s law in the concentration range 30-90 and 10-30 μg/mL for ATV and RTV, respectively. The percentage recovery was found to be 100-100.33% and 100-101.5% for ATV and RTV, respectively. The method was validated for different parameters as per the International Conference for Harmonization Guidelines.

  8. Continuous powder feeding for pharmaceutical solid dosage form manufacture: a short review.

    Science.gov (United States)

    Blackshields, Caroline A; Crean, Abina M

    2018-07-01

    There has been a noticeable shift from pharmaceutical batch processing towards a more continuous mode of manufacture for solid oral dosage forms. Continuous solid oral dose processes would not be possible in the absence of a highly accurate feeding system. The performance of feeders defines the content of formulations and is therefore a critical operation in continuous manufacturing of solid dosage forms. It was the purpose of this review to review the role of the initial powder feeding step in a continuous manufacturing process. Different feeding mechanisms are discussed with a particular emphasis on screw controlled loss in weight (LIW) feeding. The importance of understanding the physical properties of the raw materials and its impact on the feeding process is reviewed. Prior knowledge of materials provides an initial indication of how the powders will behave through processing and facilitates in the selection of the most suitable (i) feeder (capacity), (ii) feeding mechanism, and (iii) in the case of screw feeder - screw type. The studies identified in this review focus on the impact of material on powder feeding performance.

  9. Development and characterization of a gastroretentive dosage form composed of chitosan and hydroxyethyl cellulose for alendronate

    Directory of Open Access Journals (Sweden)

    Chen YC

    2013-12-01

    Full Text Available Ying-Chen Chen,1,* Hsiu-O Ho,1,* Chiao-Chi Chiu,1 Ming-Thau Sheu1,2 1School of Pharmacy, College of Pharmacy, Taipei Medical University, 2Clinical Research Center and Traditional Herbal Medicine Research Center, Taipei Medical University Hospital, Taipei, Taiwan*These authors contributed equally to this workAbstract: In this study, alendronate, the most commonly used biphosphonate for treating osteoporosis, was formulated as gastroretentive dosage form (GRDF tablets to enhance its oral bioavailability. GRDF tablets were characterized with the effects of different molecular weights (MWs of chitosan (CS and hydroxyethyl cellulose (HEC at various ratios on swelling, floating, and physical integrity. The CS component was formed using various acids: acetic, lactic, malic, succinic, and citric, and a high viscosity grade of HEC was selected. The results demonstrated that the swelling ratios of the formulations comprising high MW CS were lower than those of low or medium MW CS when salts were formed with any countering acids except for acetic acid. The decreasing ranking of the swelling rates was: CS-citrate > CS-malate > CS-lactate > CS-succinate > CS-acetate. A negative correlation was found between the pKa of the respective countering acid and the swelling rate. The swelling rate was promoted if an acidic salt of CS with a lower water content was incorporated, while it became slower when tablet hardness was higher or the compression force to form tablets was increased. Although HEC did not contribute to swelling or floating, it played a role in maintaining structural integrity. A prolonged dissolution profile of alendronate GRDF tablets developed in this study was observed.Keywords: gastroretentive dosage form, chitosan, hydrogel, hydroxyethyl cellulose, swelling, alendronate

  10. The Dosage Form of Aragh in Treatment, from the Iranian Traditional Medicine Perspective.

    Science.gov (United States)

    Adl, Mehdi; Emtiazi, Majid

    2016-05-01

    The Iranian traditional medicine is one of the branches of complementary medicine and it is based on using the dosage forms of plants. One of the most common forms of pharmaceutical plants is Aragh. Due to ease-of-use, distillate is a more acceptable form among the public. In this article, it is attempted to study the usage forms and effects of Aragh according to the valid traditional medicine resources. This article is a review of Iranian traditional medicine textbooks such as Makhzan-ul-dawiah, Gharabadin Kabir, Cannon of Medicine, and other recent texts on medical plants. According to the traditional medicine, the process of getting Aragh is a kind of distillation, which is performed by using Ghar and Alembic (the equipment that are used in distillation). Distillation is the process of extracting and refining the fluid of a plant. Aragh of the plants is much more effective on the body than the plant itself. Traditional medicine regards Aragh as a new kind of drug (medicine) that is rarely mentioned in older texts (except for golab). However, the modern medicine regards it as a dosage form of essence, which is dissolved in water. The more the essence, the better the distillate gets. According to the traditional medicine sources, since the time of Hakim Aghil Khorasani, Aragh was used more and more every day. About 100 kinds of Araghs are mentioned in ancient texts, which are extracted from simple plants. Considering the distillation process and the way it performs, and by knowing that Aragh is a plant's softest and the most influential entity, it seems that it has a huge effect on Arvah and Ghova, the main parts like heart and brain and nervous parts.

  11. Antioxidant activity evaluation of new dosage forms as vehicles for dehydrated vegetables.

    Science.gov (United States)

    Romero-de Soto, María Dolores; García-Salas, Patricia; Fernández-Arroyo, Salvador; Segura-Carretero, Antonio; Fernández-Campos, Francisco; Clares-Naveros, Beatriz

    2013-06-01

    A dehydrated vegetables mixture loaded in four pharmaceutical dosage forms as powder, effervescent granulate, sugar granulate and gumdrops were investigated for their antioxidant capacity using 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) radical scavenging capacity assay, oxygen radical absorbance capacity assay and ferric reducing antioxidant potential assay. Total phenolic content of dehydrated vegetables powder mixture was also measured by the Folin-Ciocalteu method, so as to evaluate its contribution to their total antioxidant function. The effect of different temperatures on stability of these systems after 90 days storage was also evaluated. These formulations presented strong antioxidant properties and high phenolic content (279 mg gallic acid equivalent/g of sample) and thus could be potential rich sources of natural antioxidants. Antioxidant properties differed significantly among selected formulations (p forms are new and innovative approach for vegetable intakes in population with special requirements providing an improvement in the administration of vegetables and fruits.

  12. Development and Validation of UV Spectrophotometric Method For Determination of Bisoprolol Fumarate in Bulk and Pharmaceutical Dosage Forms

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    Shahinaz Mohammed

    2017-10-01

    Full Text Available In this study a simple, accurate and precise UV- spectrophotometric method was developed for the estimation of bisoprolol fumarate (BF in bulk and tablet dosage form. The method was based on measurement of absorbance of BF aqueous solution at 225 nm. Validation was conducted in accordance to ICH guidelines. The calibration curve was linear in the concentration range 5.0-30.0 µg/mL with correlation coefficient not less than 0.996. The limit of detection and limit of quantification were 0.22 μg/ml and 0.66 μg/ml, respectively. Intraday and intermediate precision of the developed method were reflected by the low RSD% values (1.19 and 0.854, respectively. The recovery percentage was 100.6 ± 0.6%, n=3. The proposed method was applied for the assay of BF in three different brands.

  13. Development of polymer film dosage forms of lidocaine for buccal administration. I. Penetration rate and release rate.

    Science.gov (United States)

    Okamoto, H; Taguchi, H; Iida, K; Danjo, K

    2001-12-13

    We examined the penetration rate of lidocaine (LC) through excised oral mucosa from hamster cheek pouch and the in vitro release rate of LC from film dosage forms with hydroxypropylcellulose (HPC) as a film base. Addition of glycyrrhizic acid (GL) to the HPC films increased the LC release rate almost GL-content-dependently, while an optimum GL content was observed for the LC penetration rate. No LC penetration was observed from an acidic aqueous solution (pH 3.4) of LC, suggesting only unionized LC can substantially penetrate through the mucosa. A significant relationship between the penetration rate of LC and the release rate of unionized LC was found, suggesting that the in vitro dissolution study is a useful tool to predict the penetration rate taking the unionized drug fraction into consideration.

  14. GC Method Validation for the Analysis of Menthol in Suppository Pharmaceutical Dosage Form

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    Murad N. Abualhasan

    2017-01-01

    Full Text Available Menthol is widely used as a fragrance and flavor in the food and cosmetic industries. It is also used in the medical and pharmaceutical fields for its various biological effects. Gas chromatography (GC is considered to be a sensitive method for the analysis of menthol. GC chromatographic separation was developed using capillary column (VF-624 and a flame ionization detector (FID. The method was validated as per ICH guidelines for various parameters such as precision, linearity, accuracy, solution stability, robustness, limit of detection, and quantification. The tested validation parameters were found to be within acceptable limits. The method was successfully applied for the quantification of menthol in suppositories formulations. Quality control departments and official pharmacopeias can use our developed method in the analysis of menthol in pharmaceutical dosage formulation and raw material.

  15. A Simple RP-HPLC Method for Quantitation of Itopride HCl in Tablet Dosage Form.

    Science.gov (United States)

    Thiruvengada, Rajan Vs; Mohamed, Saleem Ts; Ramkanth, S; Alagusundaram, M; Ganaprakash, K; Madhusudhana, Chetty C

    2010-10-01

    An isocratic reversed phase high-performance liquid chromatographic method with ultraviolet detection at 220 nm has been developed for the quantification of itopride hydrochloride in tablet dosage form. The quantification was carried out using C(8) column (250 mm × 4.6 mm), 5-μm particle size SS column. The mobile phase comprised of two solvents (Solvent A: buffer 1.4 mL ortho-phosphoric acid adjusted to pH 3.0 with triethyl amine and Solvent B: acetonitrile). The ratio of Solvent A: Solvent B was 75:25 v/v. The flow rate was 1.0 mL (-1)with UV detection at 220 nm. The method has been validated and proved to be robust. The calibration curve was linear in the concentration range of 80-120% with coefficient of correlation 0.9995. The percentage recovery for itopride HCl was 100.01%. The proposed method was validated for its selectivity, linearity, accuracy, and precision. The method was found to be suitable for the quality control of itopride HCl in tablet dosage formulation.

  16. A Study of Method Development, Validation, and Forced Degradation for Simultaneous Quantification of Paracetamol and Ibuprofen in Pharmaceutical Dosage Form by RP-HPLC Method

    OpenAIRE

    Jahan, Md. Sarowar; Islam, Md. Jahirul; Begum, Rehana; Kayesh, Ruhul; Rahman, Asma

    2014-01-01

    A rapid and stability-indicating reversed phase high-performance liquid chromatography (RP-HPLC) method was developed for simultaneous quantification of paracetamol and ibuprofen in their combined dosage form especially to get some more advantages over other methods already developed for this combination. The method was validated according to United States Pharmacopeia (USP) guideline with respect to accuracy, precision, specificity, linearity, solution stability, robustness, sensitivity, and...

  17. Non-Conventional Applications of Computerized Tomography: Analysis of Solid Dosage Forms Produced by Pharmaceutical Industry

    International Nuclear Information System (INIS)

    Martins de Oliveira, Jose Jr.; Germano Martins, Antonio Cesar

    2010-01-01

    X-ray computed tomography (CT) refers to the cross-sectional imaging of an object measuring the transmitted radiation at different directions. In this work, we describe a non-conventional application of computerized tomography: visualization and improvements in the understanding of some internal structural features of solid dosage forms. A micro-CT X-ray scanner, with a minimum resolution of 30 μm was used to characterize some pharmaceutical tablets, granules, controlled-release osmotic tablet and liquid-filled soft-gelatin capsules. The analysis presented in this work are essentially qualitative, but quantitative parameters, such as porosity, density distribution, tablets dimensions, etc. could also be obtained using the related CT techniques.

  18. Thermal and Isothermal Methods in Development of Sustained Release Dosage Forms of Ketorolac Tromethamine

    Directory of Open Access Journals (Sweden)

    Dimple Chopra

    2008-01-01

    Full Text Available Differential scanning calorimetry (DSC is a rapid and convenient and conclusive method of screening drug-polymer blend during preformulation studies as it allows polymer incompatibility to be established instantaneously. Various batches of matrix tablets of ketorolac tromethamine (KTM with a series of compatible polymers were prepared. Batches of tablets which gave desired sustained release profile were subjected to stability testing according to ICH guidelines. The analysis for drug content was done using high performance liquid chromatography (HPLC method. The results revealed that there was no statistically significant change in drug content after storage of matrix tablets at elevated temperature of 40°C and 75% relative humidity. From our study we conclude that with careful selection of different polymers and their combinations, a stable sustained release oral dosage form of ketorolac tromethamine can be achieved.

  19. [Study on dosage form design for improving oral bioavailability of traditional Chinese medicines].

    Science.gov (United States)

    Xia, Hai-Jian; Zhang, Zhen-Hai; Yao, Dong-Dong; Jia, Xiao-Bin

    2013-09-01

    Both chemical drugs and traditional Chinese medicines have the problem of low bioavailability. However, as traditional Chinese medicines are a multi-component complex, their dosage forms are required to be designed in line with their characteristics, in order to improve the bioavailability of traditional Chinese medicines. Traditional Chinese medicines are mostly prepared into pill, powder, paste, elixir and decoction, but with such drawbacks as high administration dose and poor efficacy. With the process of modernization of traditional Chinese medicines, new-type preparations have be developed and made outstanding achievements. However, they fail to make an organic integration between traditional Chinese medicine theories and modern preparation theories. Characteristics of traditional Chinese medicines are required to be taken into account during the development of traditional Chinese medicines. In the article, multi-component preparation technology was adopted to establish a multi-component drug release system of traditional Chinese medicines on the basis of multiple components of traditional Chinese medicines.

  20. PAT: From Western solid dosage forms to Chinese materia medica preparations using NIR-CI.

    Science.gov (United States)

    Zhou, Luwei; Xu, Manfei; Wu, Zhisheng; Shi, Xinyuan; Qiao, Yanjiang

    2016-01-01

    Near-infrared chemical imaging (NIR-CI) is an emerging technology that combines traditional near-infrared spectroscopy with chemical imaging. Therefore, NIR-CI can extract spectral information from pharmaceutical products and simultaneously visualize the spatial distribution of chemical components. The rapid and non-destructive features of NIR-CI make it an attractive process analytical technology (PAT) for identifying and monitoring critical control parameters during the pharmaceutical manufacturing process. This review mainly focuses on the pharmaceutical applications of NIR-CI in each unit operation during the manufacturing processes, from the Western solid dosage forms to the Chinese materia medica preparations. Finally, future applications of chemical imaging in the pharmaceutical industry are discussed. Copyright © 2015 John Wiley & Sons, Ltd.

  1. Simultaneous UV Spectrophotometric Determination of Cetrizine and Dextromethorphan in Tablet Dosage Form

    Directory of Open Access Journals (Sweden)

    R. Vijayalakshmi

    2010-01-01

    Full Text Available Two accurate, precise, sensitve and economical procedures for simultaneous estimation of cetrizine and dextromethorphan in tablet dosage forms have been developed. First method employs formation and solving of simultaneous equations using 230 nm and 280 nm as two analytical wavelengths for both drugs in methanol. The second method is Q-analysis based on measurement of absorptivity at 224 nm (as isobestic point and 280 nm (λmax of CTZ. Cetrizine and dextromethorphan at their respective λmax 280 nm and 230 nm and at 224 nm (isobestic point shows linearity in a concentration range of 10-30 mcg/mL for both the drugs. The recovery studies confirmed accuracy of the proposed methods and low values of standard deviation confirmed precision of the methods. The methods were validated as per ICH guidelines.

  2. A Rapid Determination of Cinnarizine in Bulk and Pharmaceutical Dosage Form by LC

    Directory of Open Access Journals (Sweden)

    A. A. Heda

    2010-01-01

    Full Text Available A simple, selective, rapid and precise reverse phase high pressure liquid chromatographic method has been developed for the estimation of cinnarizine from pharmaceutical formulation. The method was developed using MICRA-NPS C18 (length×OD×ID =33×8.0×6.0 mm, 1.5 μm column with a mobile phase consisting of acetonitrile, triethylamine buffer (adjusted to pH 4.5 with 10% w/v potassium hydroxide and tetrahydrofuran in the ratio 30:66:4 respectively, at a flow rate of 0.5 mL/min. Wavelength was fixed at 253 nm. The developed method was validated for linearity, accuracy, precision, limit of detection and limit of quantitation. The proposed method can be used for the routine estimation of cinnarizine in pharmaceutical dosage form.

  3. Chemometric simultaneous determination of Sofosbuvir and Ledipasvir in pharmaceutical dosage form

    Science.gov (United States)

    Khalili, Mahsa; Sohrabi, Mahmoud Reza; Mirzabeygi, Vahid; Torabi Ziaratgahi, Nahid

    2018-04-01

    Partial least squares (PLS), different families of continuous wavelet transform (CWT), and first derivative spectrophotometry (DS) techniques were studied for quantification of Sofosbuvir (SFB) and Ledipasvir (LDV) simultaneously without separation step. The components were dissolved in Acetonitrile and the spectral behaviors were evaluated in the range of 200 to 400 nm. The ultraviolet (UV) absorbance of LDV exhibits no interferences between 300 and 400 nm and it was decided to predict the LDV amount through the classic spectrophotometry (CS) method in this spectral region as well. Data matrix of concentrations and calibrated models were developed, and then by applying a validation set the accuracy and precision of each model were studied. Actual concentrations versus predicted concentrations plotted and good correlation coefficients by each method resulted. Pharmaceutical dosage form was quantified by developed methods and the results were compared with the High Performance Liquid Chromatography (HPLC) reference method. Analysis Of Variance (ANOVA) in 95% confidence level showed no significant differences among methods.

  4. Multicomponent chemical imaging of pharmaceutical solid dosage forms with broadband CARS microscopy.

    Science.gov (United States)

    Hartshorn, Christopher M; Lee, Young Jong; Camp, Charles H; Liu, Zhen; Heddleston, John; Canfield, Nicole; Rhodes, Timothy A; Hight Walker, Angela R; Marsac, Patrick J; Cicerone, Marcus T

    2013-09-03

    We compare a coherent Raman imaging modality, broadband coherent anti-Stokes Raman scattering (BCARS) microscopy, with spontaneous Raman microscopy for quantitative and qualitative assessment of multicomponent pharmaceuticals. Indomethacin was used as a model active pharmaceutical ingredient (API) and was analyzed in a tabulated solid dosage form, embedded within commonly used excipients. In comparison with wide-field spontaneous Raman chemical imaging, BCARS acquired images 10× faster, at higher spatiochemical resolution and with spectra of much higher SNR, eliminating the need for multivariate methods to identify chemical components. The significant increase in spatiochemical resolution allowed identification of an unanticipated API phase that was missed by the spontaneous wide-field method and bulk Raman spectroscopy. We confirmed the presence of the unanticipated API phase using confocal spontaneous Raman, which provided spatiochemical resolution similar to BCARS but at 100× slower acquisition times.

  5. HPLC-DAD stability indicating determination of nizatidine in bulk and capsules dosage form

    Directory of Open Access Journals (Sweden)

    Tarek S. Belal

    2013-12-01

    Full Text Available This work describes the stability-indicating determination of the H2-receptor antagonist nizatidine in its bulk and capsules dosage form using high performance liquid chromatography coupled with diode array detector (HPLC-DAD. The developed method involved the use of Thermo Hypersil BDS-C8 (4.6 × 250 mm, 5 μm particle size column and a mobile phase composed of 0.05 M phosphoric acid and acetonitrile (50:50, v/v. The mobile phase was pumped at a flow rate of 1 mL/min. Quantification of nizatidine was based on measuring its peak area at 320 nm. The retention time for nizatidine was about 3.61 min. The reliability and analytical performance of the proposed HPLC procedure were statistically validated with respect to linearity, range, precision, accuracy, specificity, robustness, detection and quantification limits. Calibration curve of nizatidine was linear in the range of 5–50 μg/mL with correlation coefficient >0.9999. The drug was subjected to forced-degradation conditions of acidic and basic hydrolysis, oxidation, dry heat and UV photolysis where it showed considerable degradation in basic and oxidative conditions. The proposed method proved to be specific and stability-indicating by resolution of the drug from its forced-degradation products. The validated HPLC method was applied to the analysis of nizatidine in capsules dosage form where it was quantified with recoveries not less than 98.2%. Assay results were statistically compared to USP 2011 pharmacopeial method where no significant difference was observed between the proposed and reference methods.

  6. Kinetic spectrophotometric method for the determination of perindopril erbumine in pure and commercial dosage forms

    Directory of Open Access Journals (Sweden)

    Nafisur Rahman

    2017-02-01

    Full Text Available A kinetic spectrophotometric method has been developed for the determination of perindopril erbumine in pure and commercial dosage forms. The method is based on the reaction of drug with potassium permanganate in alkaline medium at room temperature (30 ± 1 °C. The reaction was followed spectrophotometrically by measuring the increase in absorbance with time at 603 nm and the initial rate, fixed time (at 8.0 min and equilibrium time (at 90.0 min methods were adopted for constructing the calibration graphs. All the calibration graphs are linear in the concentration range of 5.0–50.0 μg/ml. The limits of detection for initial rate, fixed time and equilibrium time methods were 0.752, 0.882 and 1.091 μg/ml, respectively. The activation parameters such as Ea, ΔH‡, ΔS‡ and ΔG‡ were also determined for the reaction and found to be 60.93 kJ/mol, 56.45 kJ/mol, 74.16 J/K mol and −6.53 kJ/mol, respectively. The variables were optimized and the proposed methods are validated as per ICH guidelines. The method has been further applied to the determination of perindopril erbumine in commercial dosage forms. The analytical results of the proposed methods when compared with those of the reference method show no significant difference in accuracy and precision and have acceptable bias.

  7. Optimization and validation of spectrophotometric methods for determination of finasteride in dosage and biological forms

    Science.gov (United States)

    Amin, Alaa S.; Kassem, Mohammed A.

    2012-01-01

    Aim and Background: Three simple, accurate and sensitive spectrophotometric methods for the determination of finasteride in pure, dosage and biological forms, and in the presence of its oxidative degradates were developed. Materials and Methods: These methods are indirect, involve the addition of excess oxidant potassium permanganate for method A; cerric sulfate [Ce(SO4)2] for methods B; and N-bromosuccinimide (NBS) for method C of known concentration in acid medium to finasteride, and the determination of the unreacted oxidant by measurement of the decrease in absorbance of methylene blue for method A, chromotrope 2R for method B, and amaranth for method C at a suitable maximum wavelength, λmax: 663, 528, and 520 nm, for the three methods, respectively. The reaction conditions for each method were optimized. Results: Regression analysis of the Beer plots showed good correlation in the concentration ranges of 0.12–3.84 μg mL–1 for method A, and 0.12–3.28 μg mL–1 for method B and 0.14 – 3.56 μg mL–1 for method C. The apparent molar absorptivity, Sandell sensitivity, detection and quantification limits were evaluated. The stoichiometric ratio between the finasteride and the oxidant was estimated. The validity of the proposed methods was tested by analyzing dosage forms and biological samples containing finasteride with relative standard deviation ≤ 0.95. Conclusion: The proposed methods could successfully determine the studied drug with varying excess of its oxidative degradation products, with recovery between 99.0 and 101.4, 99.2 and 101.6, and 99.6 and 101.0% for methods A, B, and C, respectively. PMID:23781478

  8. Development and characterization of a gastroretentive dosage form composed of chitosan and hydroxyethyl cellulose for alendronate.

    Science.gov (United States)

    Chen, Ying-Chen; Ho, Hsiu-O; Chiu, Chiao-Chi; Sheu, Ming-Thau

    2014-01-01

    In this study, alendronate, the most commonly used biphosphonate for treating osteoporosis, was formulated as gastroretentive dosage form (GRDF) tablets to enhance its oral bioavailability. GRDF tablets were characterized with the effects of different molecular weights (MWs) of chitosan (CS) and hydroxyethyl cellulose (HEC) at various ratios on swelling, floating, and physical integrity. The CS component was formed using various acids: acetic, lactic, malic, succinic, and citric, and a high viscosity grade of HEC was selected. The results demonstrated that the swelling ratios of the formulations comprising high MW CS were lower than those of low or medium MW CS when salts were formed with any countering acids except for acetic acid. The decreasing ranking of the swelling rates was: CS-citrate > CS-malate > CS-lactate > CS-succinate > CS-acetate. A negative correlation was found between the pKa of the respective countering acid and the swelling rate. The swelling rate was promoted if an acidic salt of CS with a lower water content was incorporated, while it became slower when tablet hardness was higher or the compression force to form tablets was increased. Although HEC did not contribute to swelling or floating, it played a role in maintaining structural integrity. A prolonged dissolution profile of alendronate GRDF tablets developed in this study was observed.

  9. In vivo evaluation of dosage forms: application of gamma scintigraphy to non-enteral routes of administration.

    Science.gov (United States)

    Meseguer, G; Gurny, R; Buri, P

    1994-01-01

    The trend to deliver drugs to defined areas of the body involves sophisticated carriers systems. In addition to the in vitro drug release profile one must be aware of the in vivo behaviour of the dosage form and the drug. Gamma scintigraphy is an elegant way to gain insights of the actual in vivo distribution pattern of dosage forms. This technique relies on the use of radioactive tracers included into the medicament and selected so as to enable an optimum detection by a gamma ray camera. The choice of a convenient label enables the in vivo determination of the targeting of the formulation administered through a large number of routes. The present paper reviews applications of gamma scintigraphy for the evaluation of dosage forms administered by the parenteral, rectal, buccal, nasal, pulmonary, and ophthalmic routes.

  10. [Ascolong: a new buccal dosage form of acetylsalicylic acid to be used and antiaggregant].

    Science.gov (United States)

    Kokurina, E V; Suslina, Z A; Khromov, G L; Davydo, A B; Metelitsa, V I; Ionova, V G; Tanashian, M M; Demina, E G; Bochkareva, E V; Belolipetskaia, V G; Deev, A D; Kucheriaeva, N G; Zidra, S I; Gorin, N N; Rumiantsev, D O

    1998-01-01

    Study of the tolerance and pharmacodynamic and pharmacokinetic characteristics of ascolong, a new buccal dosage form of aspirin containing a very low dose of acetylsalicylic acid (ASA): 12.5 mg. The study was carried out in 43 healthy men (assessment of the drug tolerance) and 19 male patients with coronary disease or cerebrovascular disorders. In 10 patients the antiaggregant efficacy of ascolong administered once or regularly (for 2 weeks) in a dose of 12.5 mg was compared with placebo, in 9 patients a random cross study of 2-week courses of ascolong and Russian aspirin tablets in a dose of 100 mg was carried out. Platelet aggregation was assessed on days 1 and 14 of each course before and 2, 4, and 24 h after the drug intake. Ascolong containing a very low dose of ASA exerts a reliable antiaggregant effect after a single and regular intake, although this effect is less manifest than after aspirin tablets. Profiles of ASA concentrations in the blood were studied. Transbuccal entry of ASA in systemic circulation decelerated its metabolism into a less active metabolite, salicylic acid, due to which fact the ASA microdose had an expressed antiaggregant effect. The drug was sufficiently well tolerated. The new buccal film form of aspirin containing a very low dose of ASA possesses a good antiaggregant effect and is promising in subjects with contraindications to oral intake of aspirin.

  11. Spectrofluorimetric protocol for antidepressant drugs in dosage forms and human plasma through derivatization with dansyl chloride

    Directory of Open Access Journals (Sweden)

    Mahmoud A. Omar

    2017-05-01

    Full Text Available A reliable, sensitive and selective spectrofluorimetric method has been developed for the determination of certain antidepressant drugs namely sertraline hydrochloride, fluoxetine hydrochloride, paroxetine hydrochloride, amineptine hydrochloride and bupropion hydrochloride in pure forms, pharmaceutical formulation and human plasma. The method is based on the reaction of investigated drugs with 5-(dimethylamino naphthalene-1-sulfonyl chloride (dansyl chloride in the presence of 0.5 M sodium carbonate to yield highly fluorescent derivatives, measured at 450 nm (excitation at 347 nm. The different experimental parameters affecting the development and stability of the reaction products were carefully studied and optimized. The calibration plots were constructed over the range of 0.02–0.14 μg mL−1. The proposed method was successfully applied for analysis of cited drugs in dosage forms. The high sensitivity of the proposed method allows the determination of investigated drugs in spiked and real human plasma. Statistical comparisons of the results with the reference methods show an excellent agreement and indicate no significant difference in accuracy and precision.

  12. How to stabilize cilazapril-containing solid dosage forms? The optimization of a final drug formulation

    Directory of Open Access Journals (Sweden)

    Katarzyna Regulska

    2017-03-01

    Full Text Available Cilazapril, a moisture-sensitive compound, is known to undergo rapid degradation which could be additionally facilitated by the presence of excipients that contain or absorb moisture. Hence we investigated the stability of cilazapril in two commercially-available dosage forms and in binary mixtures with the selected excipients used in the studied commercial formulations i.e.: hypromellose, lactose monohydrate, maize starch and talc in order to detect any possible, stability-affecting incompatibilities. Also the impact of the blister made of oriented polyamide/aluminum/polyvinyl chloride//aluminum on cilazapril-containing tablets was researched. A validated HPLC and HPLC-MS methods were used for analysis and the isothermal stress testing conditions were applied (temperature range 318–343 K, relative humidity 76.4% for tablets and temperature 333 K, relative humidity range 50.9–76.4% for binary mixtures. It was shown that the degradation of cilazapril in both, model mixtures and tablets follows the autocatalytic model kinetics and it is more rapid than that observed for pure substance, evidenced by higher degradation rate constants. The immediate packaging protects cilazapril in tablets from degradation only in case of the original drug while in its blistered generic counterpart a slight but statistically insignificant increase of cilazapril decay occurs when compared to bare tablets (p < 0.05. The degradation product of cilazapril in tablets and binary mixtures was identified as cilazaprilat. It was also observed that the increase of relative humidity or the presence of hypromellose, lactose and talc significantly impairs the stability of cilazapril in the aforementioned order. Only maize starch exhibited a positive effect on cilazapril stability (10.8% loss of cilazapril in binary mixture after 360 days of stressing compared to 35% loss of pure cilazapril in analogous test conditions probably thanks to its moisture-scavenging properties

  13. Biowaiver monograph for immediate-release solid oral dosage forms: acetylsalicylic acid.

    Science.gov (United States)

    Dressman, Jennifer B; Nair, Anita; Abrahamsson, Bertil; Barends, Dirk M; Groot, D W; Kopp, Sabine; Langguth, Peter; Polli, James E; Shah, Vinod P; Zimmer, Markus

    2012-08-01

    A biowaiver monograph for acetylsalicylic acid (ASA) is presented. Literature and experimental data indicate that ASA is a highly soluble and highly permeable drug, leading to assignment of this active pharmaceutical ingredient (API) to Class I of the Biopharmaceutics Classification System (BCS). Limited bioequivalence (BE) studies reported in the literature indicate that products that have been tested are bioequivalent. Most of the excipients used in products with a marketing authorization in Europe are not considered to have an impact on gastrointestinal motility or permeability. Furthermore, ASA has a wide therapeutic index. Thus, the risks to the patient that might occur if a nonbioequivalent product were to be incorrectly deemed bioequivalent according to the biowaiver procedure appear to be minimal. As a result, the BCS-based biowaiver procedure can be recommended for approval of new formulations of solid oral dosage forms containing ASA as the only API, including both multisource and reformulated products, under the following conditions: (1) excipients are chosen from those used in ASA products already registered in International Conference on Harmonization and associated countries and (2) the dissolution profiles of the test and the comparator products comply with the BE guidance. Copyright © 2012 Wiley Periodicals, Inc.

  14. Biowaiver Monograph for Immediate-Release Solid Oral Dosage Forms: Amoxicillin Trihydrate.

    Science.gov (United States)

    Thambavita, Dhanusha; Galappatthy, Priyadarshani; Mannapperuma, Uthpali; Jayakody, Lal; Cristofoletti, Rodrigo; Abrahamsson, Bertil; Groot, Dirk W; Langguth, Peter; Mehta, Mehul; Parr, Alan; Polli, James E; Shah, Vinod P; Dressman, Jennifer

    2017-10-01

    Literature and experimental data relevant to waiver of in vivo bioequivalence (BE) testing for the approval of immediate-release solid oral dosage forms containing amoxicillin trihydrate are reviewed. Solubility and permeability characteristics according to the Biopharmaceutics Classification System (BCS), therapeutic uses, therapeutic index, excipient interactions, as well as dissolution and BE and bioavailability studies were taken into consideration. Solubility and permeability studies indicate that amoxicillin doses up to 875 mg belong to BCS class I, whereas 1000 mg belongs to BCS class II and doses of more than 1000 mg belong to BCS class IV. Considering all aspects, the biowaiver procedure can be recommended for solid oral products of amoxicillin trihydrate immediate-release preparations containing amoxicillin as the single active pharmaceutical ingredient at dose strengths of 875 mg or less, provided (a) only the excipients listed in this monograph are used, and only in their usual amounts, (b) the biowaiver study is performed according to the World Health Organization-, U.S. Food and Drug Administration-, or European Medicines Agency-recommended method using the innovator as the comparator, and (c) results comply with criteria for "very rapidly dissolving" or "similarly rapidly dissolving." Products containing other excipients and those containing more than 875 mg amoxicillin per unit should be subjected to an in vivo BE study. Copyright © 2017 American Pharmacists Association®. All rights reserved.

  15. Approaches for Establishing Clinically Relevant Dissolution Specifications for Immediate Release Solid Oral Dosage Forms.

    Science.gov (United States)

    Hermans, Andre; Abend, Andreas M; Kesisoglou, Filippos; Flanagan, Talia; Cohen, Michael J; Diaz, Dorys A; Mao, Y; Zhang, Limin; Webster, Gregory K; Lin, Yiqing; Hahn, David A; Coutant, Carrie A; Grady, Haiyan

    2017-11-01

    This manuscript represents the perspective of the Dissolution Analytical Working Group of the IQ Consortium. The intent of this manuscript is to highlight the challenges of, and to provide a recommendation on, the development of clinically relevant dissolution specifications (CRS) for immediate release (IR) solid oral dosage forms. A roadmap toward the development of CRS for IR products containing active ingredients with a non-narrow therapeutic window is discussed, within the context of mechanistic dissolution understanding, supported by in-human pharmacokinetic (PK) data. Two case studies present potential outcomes of following the CRS roadmap and setting dissolution specifications. These cases reveal some benefits and challenges of pursuing CRS with additional PK data, in light of current regulatory positions, including that of the US Food and Drug Administration (FDA), who generally favor this approach, but with the understanding that both industry and regulatory agency perspectives are still evolving in this relatively new field. The CRS roadmap discussed in this manuscript also describes a way to develop clinically relevant dissolution specifications based primarily on dissolution data for batches used in pivotal clinical studies, acknowledging that not all IR product development efforts need to be supported by additional PK studies, albeit with the associated risk of potentially unnecessarily tight manufacturing controls. Recommendations are provided on what stages during the life cycle investment into in vivo studies may be valuable. Finally, the opportunities for CRS within the context of post-approval changes, Modeling and Simulation (M&S), and the application of biowaivers, are briefly discussed.

  16. Biopharmaceutical evaluation of transnasal, sublingual, and buccal disk dosage forms of butorphanol.

    Science.gov (United States)

    Shyu, W C; Mayol, R F; Pfeffer, M; Pittman, K A; Gammans, R E; Barbhaiya, R H

    1993-07-01

    A series of three-way crossover randomized studies were conducted to evaluate the absolute bioavailability of butorphanol, a potent agonist-antagonist analgesic, from transnasal, sublingual, and buccal disk formulations in order to identify a practical alternative to oral administration. In each study, healthy male volunteers received 2 mg doses of butorphanol tartrate intravenously and either transnasally, sublingually or buccally. Serial blood samples were collected over 12 h and butorphanol plasma concentrations were determined by radioimmunoassay. The plasma concentration data were subjected to non-compartmental pharmacokinetic analysis. The elimination half-life of butorphanol was about 3-5 h and was independent of the route of administration. Absorption of butorphanol following transnasal administration was faster than that observed following sublingual or buccal administration. Mean absolute bioavailabilities of sublingual tablet and buccal disk formulation were only 19 per cent and 29 per cent, respectively, but for transnasal administration the value rose significantly, to 70 per cent. Based on the results of these studies, transnasal dosage form of butorphanol was selected for further clinical trials of treatment of moderate to severe pain.

  17. Simultaneous HPTLC Determination of Rabeprazole and Itopride Hydrochloride From Their Combined Dosage Form.

    Science.gov (United States)

    Suganthi, A; John, Sofiya; Ravi, T K

    2008-01-01

    A simple, precise, sensitive, rapid and reproducible HPTLC method for the simultaneous estimation of the rabeprazole and itopride hydrochloride in tablets was developed and validated. This method involves separation of the components by TLC on precoated silica gel G60F254 plate with solvent system of n-butanol, toluene and ammonia (8.5:0.5:1 v/v/v) and detection was carried out densitometrically using a UV detector at 288 nm in absorbance mode. This system was found to give compact spots for rabeprazole (Rf value of 0.23 0.02) and for itopride hydrochloride (Rf value of 0.75+/-0.02). Linearity was found to be in the range of 40-200 ng/spot and 300-1500 ng/spot for rabeprazole and itopride hydrochloride. The limit of detection and limit of quantification for rabeprazole were 10 and 20 ng/spot and for itopride hydrochloride were 50 and 100 ng/spot, respectively. The method was found to be beneficial for the routine analysis of combined dosage form.

  18. Development and evaluation of new multiple-unit levodopa sustained-release floating dosage forms.

    Science.gov (United States)

    Goole, J; Vanderbist, F; Amighi, K

    2007-04-04

    This work relates to the development and the in vitro evaluation of sustained-release minitablets (MT), prepared by melt granulation and subsequent compression, which are designed to float over an extended period of time. Levodopa was used as a model drug. The importance of the composition and manufacturing parameters of the MT on their floating and dissolution properties was then examined. The investigation showed that MT composition and MT diameter had the greatest influence on drug release, which was sustained for more than 8h. By using the same formulation, the best floating properties were obtained with 3mm MT prepared at low compression forces ranging between 50 and 100N. Their resultant-weight (RW) values were always higher than those obtained with a marketed HBS dosage form within 13h. When they were filled into gelatin capsules, no sticking was observed. By evaluating the dissolution profiles of levodopa at different pH values, it was found that dissolution profiles depend more on the prolonged-release ability of Methocel K15M than on the pH-dependent solubility of levodopa. Finally, the robustness of the floating MT was assessed by testing the drug release variability in function of the stirring conditions during dissolution tests.

  19. Transmission FTIR derivative spectroscopy for estimation of furosemide in raw material and tablet dosage form

    Directory of Open Access Journals (Sweden)

    Máximo Gallignani

    2014-10-01

    Full Text Available A Fourier transform infrared derivative spectroscopy (FTIR-DS method has been developed for determining furosemide (FUR in pharmaceutical solid dosage form. The method involves the extraction of FUR from tablets with N,N-dimethylformamide by sonication and direct measurement in liquid phase mode using a reduced path length cell. In general, the spectra were measured in transmission mode and the equipment was configured to collect a spectrum at 4 cm−1 resolution and a 13 s collection time (10 scans co-added. The spectra were collected between 1400 cm−1 and 450 cm−1. Derivative spectroscopy was used for data processing and quantitative measurement using the peak area of the second order spectrum of the major spectral band found at 1165 cm−1 (SO2 stretching of FUR with baseline correction. The method fulfilled most validation requirements in the 2 mg/mL and 20 mg/mL range, with a 0.9998 coefficient of determination obtained by simple calibration model, and a general coefficient of variation <2%. The mean recovery for the proposed assay method resulted within the (100±3% over the 80%–120% range of the target concentration. The results agree with a pharmacopoeial method and, therefore, could be considered interchangeable.

  20. Biowaiver Monographs for Immediate-Release Solid Oral Dosage Forms: Enalapril.

    Science.gov (United States)

    Verbeeck, Roger K; Kanfer, Isadore; Löbenberg, Raimar; Abrahamsson, Bertil; Cristofoletti, Rodrigo; Groot, D W; Langguth, Peter; Polli, James E; Parr, Alan; Shah, Vinod P; Mehta, Mehul; Dressman, Jennifer B

    2017-08-01

    Literature data relevant to the decision to allow a waiver of in vivo bioequivalence testing for the marketing authorization of immediate-release, solid oral dosage forms containing enalapril maleate are reviewed. Enalapril, a prodrug, is hydrolyzed by carboxylesterases to the active angiotensin-converting enzyme inhibitor enalaprilat. Enalapril as the maleate salt is shown to be highly soluble, but only 60%-70% of an orally administered dose of enalapril is absorbed from the gastrointestinal tract into the enterocytes. Consequently, enalapril maleate is a Biopharmaceutics Classification System class III substance. Because in situ conversion of the maleate salt to the sodium salt is sometimes used in production of the finished drug product, not every enalapril maleate-labeled finished product actually contains the maleate salt. Enalapril is not considered to have a narrow therapeutic index. With this background, a biowaiver-based approval procedure for new generic products or after major revisions to existing products is deemed acceptable, provided the in vitro dissolution of both test and reference preparation is very rapid (at least 85% within 15 min at pH 1.2, 4.5, and 6.8). Additionally, the test and reference product must contain the identical active drug ingredient. Copyright © 2017 American Pharmacists Association®. All rights reserved.

  1. Biowaiver Monographs for Immediate Release Solid Oral Dosage Forms: Proguanil Hydrochloride.

    Science.gov (United States)

    Plöger, Gerlinde F; Abrahamsson, Bertil; Cristofoletti, Rodrigo; Groot, Dirk W; Langguth, Peter; Mehta, Mehul U; Parr, Alan; Polli, James E; Shah, Vinod P; Tajiri, Tomokazu; Dressman, Jennifer B

    2018-07-01

    Literature data relevant to the decision to waive in vivo bioequivalence testing for the approval of generic immediate release solid oral dosage forms of proguanil hydrochloride are reviewed. To elucidate the Biopharmaceutics Classification System (BCS) classification, experimental solubility and dissolution studies were also carried out. The antimalarial proguanil hydrochloride, effective via the parent compound proguanil and the metabolite cycloguanil, is not considered to be a narrow therapeutic index drug. Proguanil hydrochloride salt was shown to be highly soluble according to the U.S. Food and Drug Administration, World Health Organization, and European Medicines Agency guidelines, but data for permeability are inconclusive. Therefore, proguanil hydrochloride is conservatively classified as a BCS class 3 substance. In view of this information and the assessment of risks associated with a false positive decision, a BCS-based biowaiver approval procedure can be recommended for orally administered solid immediate release products containing proguanil hydrochloride, provided well-known excipients are used in usual amounts and provided the in vitro dissolution of the test and reference products is very rapid (85% or more are dissolved in 15 min at pH 1.2, 4.5, and 6.8) and is performed according to the current requirements for BCS-based biowaivers. Copyright © 2018 American Pharmacists Association®. All rights reserved.

  2. Spectrophotometric Quantification of Vilazodone Hydrochloride in Pharmaceutical Dosage Form Using Quality by Design Approach

    International Nuclear Information System (INIS)

    Panda, S.S.; Kumar, B.V.V.R.K.; Beg, S.; Behera, S.

    2015-01-01

    The present work deals with development and validation of a novel, robust, precise and accurate spectrophotometric method, for the estimation of vilazodone hydrochloride in tablets using the principle of Quality by Design (QbD). A fractional factorial design (FFD) was employed for initial parameter screening. Further the screened parameters were subjected to central composite design (CCD) for evaluating method robustness and method optimization. Different statistical parameters were evaluated to decide appropriateness of experimental data. Vilazodone shows absorption maximum at 285 nm using methanol. Factor screening slit width and sampling interval were identified as critical method variables, which were further evaluated by a CCD. Good linearity was obtained for vilazodone in the range of 5-60 μg/ mL with R"2 > 0.999. The method was found to be accurate with good average % recovery (more than 100 %). Developed method was validated as per ICH guidelines. Based on QbD development of spectrophotometric method ensured that quality is built into the method. The method was robust and can be applied for determination of the vilazodone in pharmaceutical dosage form. (author)

  3. Validated spectrophotometric methods for simultaneous determination of troxerutin and carbazochrome in dosage form

    Science.gov (United States)

    Khattab, Fatma I.; Ramadan, Nesrin K.; Hegazy, Maha A.; Al-Ghobashy, Medhat A.; Ghoniem, Nermine S.

    2015-03-01

    Four simple, accurate, sensitive and precise spectrophotometric methods were developed and validated for simultaneous determination of Troxerutin (TXN) and Carbazochrome (CZM) in their bulk powders, laboratory prepared mixtures and pharmaceutical dosage forms. Method A is first derivative spectrophotometry (D1) where TXN and CZM were determined at 294 and 483.5 nm, respectively. Method B is first derivative of ratio spectra (DD1) where the peak amplitude at 248 for TXN and 439 nm for CZM were used for their determination. Method C is ratio subtraction (RS); in which TXN was determined at its λmax (352 nm) in the presence of CZM which was determined by D1 at 483.5 nm. While, method D is mean centering of the ratio spectra (MCR) in which the mean centered values at 300 nm and 340.0 nm were used for the two drugs in a respective order. The two compounds were simultaneously determined in the concentration ranges of 5.00-50.00 μg mL-1 and 0.5-10.0 μg mL-1 for TXN and CZM, respectively. The methods were validated according to the ICH guidelines and the results were statistically compared to the manufacturer's method.

  4. Microbiological assay for the determination of meropenem in pharmaceutical dosage form.

    Science.gov (United States)

    Mendez, Andreas S L; Weisheimer, Vanessa; Oppe, Tércio P; Steppe, Martin; Schapoval, Elfrides E S

    2005-04-01

    Meropenem is a highly active carbapenem antibiotic used in the treatment of a wide range of serious infections. The present work reports a microbiological assay, applying the cylinder-plate method, for the determination of meropenem in powder for injection. The validation method yielded good results and included linearity, precision, accuracy and specificity. The assay is based on the inhibitory effect of meropenem upon the strain of Micrococcus luteus ATCC 9341 used as the test microorganism. The results of assay were treated statistically by analysis of variance (ANOVA) and were found to be linear (r=0.9999) in the range of 1.5-6.0 microg ml(-1), precise (intra-assay: R.S.D.=0.29; inter-assay: R.S.D.=0.94) and accurate. A preliminary stability study of meropenem was performed to show that the microbiological assay is specific for the determination of meropenem in the presence of its degradation products. The degraded samples were also analysed by the HPLC method. The proposed method allows the quantitation of meropenem in pharmaceutical dosage form and can be used for the drug analysis in routine quality control.

  5. A validated stability-indicating UPLC method for desloratadine and its impurities in pharmaceutical dosage forms.

    Science.gov (United States)

    Rao, Dantu Durga; Satyanarayana, N V; Malleswara Reddy, A; Sait, Shakil S; Chakole, Dinesh; Mukkanti, K

    2010-02-05

    A novel stability-indicating gradient reverse phase ultra-performance liquid chromatographic (RP-UPLC) method was developed for the determination of purity of desloratadine in presence of its impurities and forced degradation products. The method was developed using Waters Aquity BEH C18 column with mobile phase containing a gradient mixture of solvents A and B. The eluted compounds were monitored at 280nm. The run time was 8min within which desloratadine and its five impurities were well separated. Desloratadine was subjected to the stress conditions of oxidative, acid, base, hydrolytic, thermal and photolytic degradation. Desloratadine was found to degrade significantly in oxidative and thermal stress conditions and stable in acid, base, hydrolytic and photolytic degradation conditions. The degradation products were well resolved from main peak and its impurities, thus proved the stability-indicating power of the method. The developed method was validated as per ICH guidelines with respect to specificity, linearity, limit of detection, limit of quantification, accuracy, precision and robustness. This method was also suitable for the assay determination of desloratadine in pharmaceutical dosage forms.

  6. Microbiological assay for the analysis of certain macrolides in pharmaceutical dosage forms.

    Science.gov (United States)

    Mahmoudi, A; Fourar, R E-A; Boukhechem, M S; Zarkout, S

    2015-08-01

    Clarithromycin (CLA) and roxithromycin (ROX) are macrolide antibiotics with an expanded spectrum of activity that are commercially available as tablets. A microbiological assay, applying the cylinder-plate method and using a strain of Micrococcus luteus ATCC 9341 as test organism, has been used and validated for the quantification of two macrolide drugs; CLA and ROX in pure and pharmaceutical formulations. The validation of the proposed method was carried out for linearity, precision, accuracy and specificity. The linear dynamic ranges were from 0.1 to 0.5μg/mL for both compounds. Logarithmic calibration curve was obtained for each macrolide (r>0.989) with statistically equal slopes varying from 3.275 to 4.038, and a percentage relative standard deviation in the range of 0.24-0.92%. Moreover, the method was applied successfully for the assay of the studied drugs in pharmaceutical tablet dosage forms. Recovery from standard addition experiments in commercial products was 94.71-96.91% regarding clarithromycin and 93.94-98.12% regarding roxithromycin, with a precision (%RSD) 1.32-2.11%. Accordingly, this microbiological assay can be used for routine quality control analysis of titled drugs in tablet formulations. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Study of free acidity determinations in aqueous solution; Etude des dosages d'acidite libre en solution aqueuse

    Energy Technology Data Exchange (ETDEWEB)

    Kergreis, A [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1966-04-01

    The object of this work is the study of the principal methods which can be applied to the measurement of 'free' acidity. In the first part, we define the various types of acidity which can exist in aqueous solution; then, after having studied some hydrolysis reactions, we compare the value of the neutralisation pH of the hydrated cation and that of the precipitation of the hydroxide. In the second part we have started to study the determination of the acidity of an aqueous solution. After having rapidly considered the 'total' acidity determination, we deal with the problem of the 'free' acidity titration. We have considered in particular certain methods: extrapolation of the equivalent point, colorimetric titrations with or without a complexing agent, and finally the use of ion-exchange resins with mixed aqueous and solvent solutions. (author) [French] Le but de ce travail est l'etude des principales methodes de determination de l'acidite 'libre'. Dans une premiere partie nous avons defini les differentes sortes d'acidites pouvant exister en solution aqueuse, puis apres avoir etudie quelques reactions d'hydrolyse, nous avons compare la valeur de pH de neutralisation du cation hydrate et celle de precipitation de l'hydroxyde. Dans la seconde partie nous avons aborde l'etuce des dosages de l'acidite d'une solution aqueuse. Apres avoir envisage assez rapidement la determination de l'acidite 'totale', nous traitons du probleme du titrage de l'acidite 'libre'. Nous avons porte notre attention sur certaines methodes: extrapolation du point equivalent, titrimetrie colorimetrique avec ou sans complexant, et enfin utilisation des resines echangeuses d'ions en milieu aqueux et solvant mixte.

  8. Sensitive spectrophotometric determination of metoclopramide hydrochloride in dosage forms and spiked human urine using vanillin

    Directory of Open Access Journals (Sweden)

    O. Zenita Devi

    2016-09-01

    Full Text Available A new spectrophotometric method which is simple, sensitive, selective and rapid is described for the determination of metoclopramide hydrochloride (MCP in bulk drug and in dosage forms using vanillin as the chromogenic agent. The method is based on the condensation reaction between primary aromatic amine group present in MCP with aromatic aldehyde, vanillin to produce an intense yellow colored product. The resulting Schiff’s base shows an absorption maximum at 410 nm and the reaction product is stable for more than one day. The reaction was carried out in acetic acid and perchloric acid medium. Beer’s law was obeyed in the concentration range 1.5–15.0 μg ml−1 MCP with a molar absorptivity of 1.89 × 104 l mol−1 cm−1. The limit of detection (LOD and limit of quantification (LOQ were found to be 0.51 and 1.55 μg ml−1, respectively. The method was statistically evaluated by calculating percent relative error (% RE for accuracy and percent relative standard deviation (% RSD for precision, and was applied successfully to the determination of MCP in tablets, in injection and also in spiked human urine. No interference was observed from common additives found in pharmaceutical preparations. The results obtained by the proposed method were validated statistically by comparing the results with those of the reference method by applying the Student’s t-test and F-test. The accuracy and reliability of the method were further ascertained by performing recovery tests via standard-addition technique.

  9. Cathodic adsorptive stripping voltammetric determination of Ribavirin in pharmaceutical dosage form, urine and serum

    Directory of Open Access Journals (Sweden)

    Ahmed A. Abdel Gaber

    2017-05-01

    Full Text Available A sensitive, simple and rapid square-wave adsorptive stripping voltammetric method was developed and validated for the determination of Ribavirin in pharmaceutical formulations. The proposed method was based on the electrochemical reduction of Ribavirin at a hanging mercury drop electrode in Britton Robinson buffer at pH 10. A well-defined peak was observed at 880 mV with 30 s of accumulation time and 50 mV of accumulation potential. Under these optimized conditions, the square-wave adsorptive stripping voltammetric peak current showed a linear correlation on drug concentration over the range of 1 × 10−10–2 × 10−7 mol L−1 with a correlation coefficient of 0.9995 for the proposed method. The detection and quantitation limits for this method were 2.02 × 10−10 and 6.80 × 10−10 mol L−1, respectively. The results obtained for intra-day and inter-day precision (as RSD % were between 0.447% and 1.024%. This method was applied successfully for the determination of Ribavirin in its pharmaceutical dosage forms with mean recoveries of 99.68 ± 0.13 with RSD % of 0.81% and 99.20 ± 0.24 with RSD % of 0.49% for two concentrations 5 × 10−9 and 5 × 10−8 mol L−1, respectively for 200 mg capsules. The results obtained from the developed square-wave adsorptive stripping voltammetric method were compared with those obtained by the analytical method reported in the literature.

  10. Development of theophylline sustained release dosage form based on Kollidon SR.

    Science.gov (United States)

    Reza, Md Selim; Quadir, Mohiuddin Abdul; Haider, Syed Shabbir

    2002-01-01

    Sustained release theophylline matrix tablets constituting Kollidon SR (Polyvinyl acetate and povidone based matrix retarding polymer) were developed in this study in an attempt to design a dosage form that manifests desirable release profile and thorough adherence to official monographs. Four matrix tablet formulations were prepared by dry blending and direct compression of Kollidon SR and HPMC-15cps (hydroxypropylmethylcellulose) in varying proportion with fixed percentage of theophylline. Tablets containing only Kollidon SR with the active ingredient demonstrated a rapid rate of drug release with an initial burst effect. Incorporation of HPMC-15cps in the matrix tablet prolonged the release of drug with subsequent minimization of burst effect as confirmed by mean dissolution time, T50 and Higuchi release rate data. Among the batches containing HPMC-15 cps, a direct relationship was obtained between release rate and the percentage of HPMC used. A suitable controlled release profile was obtained with the matrix tablets containing 20% Kollidon SR and 30% HPMC-15cps. The formulation showed close resemblance to commercial products and compliance with USP specification. The results were explored and explained by the difference of physico-chemical property and hydration characteristics of the polymers. In addition to this result, the exponential model was applied to characterize the drug release behaviour from polymeric systems. It was found that, Fickian release is predominant in tablets containing Kollidon SR alone and non-Fickian mechanism plays an important role in the release of drug from HPMC containing tablets with a trend towards zero-order or case II release. In vitro release profile of two commercial brands were also undertaken for comparison and modulation of the experimental batches.

  11. Development of alternative methods for the determination of raloxifene hydrochloride in tablet dosage form

    Directory of Open Access Journals (Sweden)

    Fernanda Rodrigues Salazar

    2015-06-01

    Full Text Available Three methods are proposed for the quantitative determination of raloxifene hydrochloride in pharmaceutical dosage form: ultraviolet method (UV high performance liquid chromatography (HPLC and micellar capillary electrophoresis (MEKC. These methods were developed and validated and showed good linearity, precision and accuracy. Also they demonstrated to be specific and robust. The HPLC and MEKC methods were tested in regards to be stability indicating methods and they showed to have this attribute. The UV method used methanol as solvent and optimal wavelength at 284 nm, obeying Lambert-Beer law in these conditions. The chromatographic conditions for the HPLC method included: NST column C18 (250 x 4.6 mm x 5 µm, mobile phase water:acetonitrile:triethylamine (67:33:0,3 v/v, pH 3.5, flow rate 1.0 mL min-1, injection volume 20.0 µl, UV detection 287 nm and analysis temperature 30 °C. The MEKC method was performed on a fused-silica capillary (40 cm effective length x 50 µm i.d. using as background electrolyte 35.0 mmol L-1 borate buffer and 50.0 mmol L-1 anionic detergent sodium dodecyl sulfate (SDS at pH 8.8. The capillary temperature was 32°C, applied voltage 25 kV, UV detection at 280 nm and injection was perfomed at 45 mBar for 4 s, hydrodimanic mode. In this MEKC method, potassium diclofenac (200.0 µg mL-1 was used as internal standard. All these methods were statistically analyzed and demonstrated to be equivalent for quantitative analysis of RLX in tablets and were successfully applied for the determination of the drug.

  12. Stability of Dosage Forms in the Pharmaceutical Payload Aboard Space Missions

    Science.gov (United States)

    Du, Brian J.; Daniels, Vernie; Boyd, Jason L.; Crady, Camille; Satterfield, Rick; Younker, Diane R.; Putcha, Lakshmi

    2009-01-01

    Efficacious pharmaceuticals with adequate shelf lives are essential for successful space medical operations. Stability of pharmaceuticals, therefore, is of paramount importance for assuring the health and wellness of astronauts on future space exploration missions. Unique physical and environmental factors of space missions may contribute to the instability of pharmaceuticals, e.g., radiation, humidity and temperature variations. Degradation of pharmaceutical formulations can result in inadequate efficacy and/or untoward toxic effects, which could compromise astronaut safety and health. Methods: Four identical pharmaceutical payload kits containing 31 medications in different dosage forms (liquid, tablet, capsule, ointment and suppository) were transported to the International Space Station aboard the Space Shuttle (STS-121). One of the 4 kits was stored on the Shuttle and the other 3 were stored on the International Space Station (ISS) for return to Earth at 6-month interval aboard a pre-designated Shuttle flight for each kit. The kit stored on the Shuttle was returned to Earth aboard STS-121 and 2 kits from ISS were returned on STS 117 and STS-122. Results: Analysis of standard physical and chemical parameters of degradation was completed for pharmaceuticals returned by STS-121 after14 days, STS - 117 after11 months and STS 122 after 19 months storage aboard ISS. Analysis of all flight samples along with ground-based matching controls was completed and results were compiled. Conclusion: Evaluation of results from the shuttle (1) and ISS increments (2) indicate that the number of formulations degraded in space increased with duration of storage in space and was higher in space compared to their ground-based counterparts. Rate of degradation for some of the formulations tested was faster in space than on Earth. Additionally, some of the formulations included in the medical kits were unstable, more so in space than on the ground. These results indicate that the

  13. A systematic review of the use of dosage form manipulation to obtain required doses to inform use of manipulation in paediatric practice.

    Science.gov (United States)

    Richey, Roberta H; Hughes, Clare; Craig, Jean V; Shah, Utpal U; Ford, James L; Barker, Catrin E; Peak, Matthew; Nunn, Anthony J; Turner, Mark A

    2017-02-25

    This study sought to determine whether there is an evidence base for drug manipulation to obtain the required dose, a common feature of paediatric clinical practice. A systematic review of the data sources, PubMed, EMBASE, CINAHL, IPA and the Cochrane database of systematic reviews, was used. Studies that considered the dose accuracy of manipulated medicines of any dosage form, evidence of safety or harm, bioavailability, patient experience, tolerability, contamination and comparison of methods of manipulation were included. Case studies and letters were excluded. Fifty studies were eligible for inclusion, 49 of which involved tablets being cut, split, crushed or dispersed. The remaining one study involved the manipulation of suppositories of one drug. No eligible studies concerning manipulation of oral capsules or liquids, rectal enemas, nebuliser solutions, injections or transdermal patches were identified. Twenty four of the tablet studies considered dose accuracy using weight and/or drug content. In studies that considered weight using adapted pharmacopoeial specifications, the percentage of halved tablets meeting these specifications ranged from 30% to 100%. Eighteen studies investigated bioavailability, pharmacokinetics or clinical outcomes following manipulations which included nine delayed or modified release formulations. In each of these nine studies the entirety of the dosage form was administered. Only one of the 18 studies was identified where drugs were manipulated to obtain a proportion of the dosage form, and that proportion administered. The five studies that considered patient perception found that having to manipulate the tablets did not have a negative impact on adherence. Of the 49 studies only two studies reported investigating children. This review yielded limited evidence to support manipulation of medicines for children. The results cannot be extrapolated between dosage forms, methods of manipulation or between different brands of the same

  14. 75 FR 20268 - Implantation or Injectable Dosage Form New Animal Drugs; Change of Sponsor; Propofol

    Science.gov (United States)

    2010-04-19

    ... 21 CFR Part 522 Animal drugs. Therefore, under the Federal Food, Drug, and Cosmetic Act and under... use in dogs and cats--(1) Amount. The drug is administered by intravenous injection as follows: (i) Dogs. For induction of general anesthesia without the use of preanesthetics the dosage is 5.5 to 7.0 mg...

  15. New Spectrophotometric and Conductometric Methods for Macrolide Antibiotics Determination in Pure and Pharmaceutical Dosage Forms Using Rose Bengal

    Directory of Open Access Journals (Sweden)

    Rania A. Sayed

    2013-01-01

    Full Text Available Two Simple, accurate, precise, and rapid spectrophotometric and conductometric methods were developed for the estimation of erythromycin thiocyanate (I, clarithromycin (II, and azithromycin dihydrate (III in both pure and pharmaceutical dosage forms. The spectrophotometric procedure depends on the reaction of rose bengal and copper with the cited drugs to form stable ternary complexes which are extractable with methylene chloride, and the absorbances were measured at 558, 557, and 560 nm for (I, (II, and (III, respectively. The conductometric method depends on the formation of an ion-pair complex between the studied drug and rose bengal. For the spectrophotometric method, Beer's law was obeyed. The correlation coefficient ( for the studied drugs was found to be 0.9999. The molar absorptivity (, Sandell’s sensitivity, limit of detection (LOD, and limit of quantification (LOQ were also calculated. The proposed methods were successfully applied for the determination of certain pharmaceutical dosage forms containing the studied drugs

  16. Klucel™ EF and ELF polymers for immediate-release oral dosage forms prepared by melt extrusion technology.

    Science.gov (United States)

    Mohammed, Noorullah Naqvi; Majumdar, Soumyajit; Singh, Abhilasha; Deng, Weibin; Murthy, Narasimha S; Pinto, Elanor; Tewari, Divya; Durig, Thomas; Repka, Michael A

    2012-12-01

    The objective of this research work was to evaluate Klucel™ hydroxypropylcellulose (HPC) EF and ELF polymers, for solubility enhancement as well as to address some of the disadvantages associated with solid dispersions. Ketoprofen (KPR), a Biopharmaceutics Classification System class II drug with poor solubility, was utilized as a model compound. Preliminary thermal studies were performed to confirm formation of a solid solution/dispersion of KPR in HPC matrix and also to establish processing conditions for hot-melt extrusion. Extrudates pelletized and filled into capsules exhibited a carrier-dependent release with ELF polymer exhibiting a faster release. Tablets compressed from milled extrudates exhibited rapid release owing to the increased surface area of the milled extrudate. Addition of mannitol (MNT) further enhanced the release by forming micro-pores and increasing the porosity of the extrudates. An optimized tablet formulation constituting KPR, MNT, and ELF in a 1:1:1 ratio exhibited 90% release in 15 min similar to a commercial capsule formulation. HPC polymers are non-ionic hydrophilic polymers that undergo polymer-chain-length-dependent solubilization and can be used to enhance solubility or dissolution rate of poorly soluble drugs. Dissolution/release rate could be tailored for rapid-release applications by selecting a suitable HPC polymer and altering the final dosage form. The release obtained from pellets was carrier-dependent and not drug-dependent, and hence, such a system can be effectively utilized to address solubility or precipitation issues with poorly soluble drugs in the gastrointestinal environment.

  17. Image charges revisited: a closed form solution

    International Nuclear Information System (INIS)

    Choy, T. C.

    2000-01-01

    We demonstrate that the corrections to the classical Kelvin image theory due to finite electron screening length )λ, recently discussed by Roulet and Saint Jean, Am. J. Phys. 68(4) 319, is amenable to an exact closed form solution in terms of an integral involving Bessel functions. An error arising from an incorrect choice of boundary conditions is rectified as well, enabling also a complete solution for all potentials - both inside and outside the metal surface

  18. Micropellets coated with Kollicoat® Smartseal 30D for taste masking in liquid oral dosage forms.

    Science.gov (United States)

    Dashevskiy, Andriy; Mohylyuk, Valentyn; Ahmed, Abid Riaz; Kolter, Karl; Guth, Felicitas; Bodmeier, Roland

    2017-09-01

    The objective of this study was to develop delivery systems for taste masking based on multiparticulates coated with Kollicoat ® Smartseal 30D formulated as liquid oral suspensions. Coating of particles containing bitter drugs with Kollicoat ® Smartseal reduced drug leaching into aqueous medium, especially when increasing pH, therefore can be used for the formulation of liquid dosage forms. Application of an intermediate layer of ion exchange resins between drug layer and coating can further decrease drug leaching into aqueous vehicle that is beneficial in terms of taste masking. Using optimized compositions of liquid vehicles such as addition of sugar alcohols and ion exchange resin, reconstitutable or ready-to-use liquid dosage forms with micropellets can be developed with bitter taste protection after redispersion lasting longer than 3 weeks, which exceeds the usual period of application.

  19. Laūq: A Sustained-Release Dosage Form for Respiratory Disorders in Traditional Persian Medicine.

    Science.gov (United States)

    Karegar-Borzi, Hossein; Salehi, Mehdi; Rahimi, Roja

    2016-01-01

    Laūq is a pharmaceutical dosage form that had been mainly used for the treatment of various respiratory disorders in traditional Persian medicine. It is important from 2 aspects: a dosage form with efficient and optimum delivery of drugs to the respiratory tract and biological effects of its ingredients. Natural medicine in laūq has been demonstrated to act in respiratory disorders by their antitussive, antiallergic, anti-inflammatory, antioxidant, spasmolytic, and antibacterial activities. Some of these natural remedies act by most of the mentioned mechanisms such as Cydonia oblonga, Glycyrrhiza glabra, Crocus sativus, Hyssopus officinalis, Foeniculum vulgare, and honey. However, the evidence is limited including Cassia fistula, Papaver somniferum, and Drimia maritima. According to positive pharmacokinetic and pharmacodynamic aspects of laūqs, they may be considered as efficient dosage forms for delivery of drugs to the respiratory tract. For better compatibility of patients, it could be substituted laūqs with newer drug delivery systems like lozenges. © The Author(s) 2015.

  20. 75 FR 54492 - Ophthalmic and Topical Dosage Form New Animal Drugs; Gentamicin and Betamethasone Ophthalmic...

    Science.gov (United States)

    2010-09-08

    ... Ophthalmic Solution AGENCY: Food and Drug Administration, HHS. ACTION: Final rule; technical amendment... acetate ophthalmic solution. This action is being taken to comply with the Federal Food, Drug, and... GENTOCIN DURAFILM (gentamicin sulfate and betamethasone acetate) Ophthalmic Solution, sponsored by Intervet...

  1. Simultaneous in vivo visualization and localization of solid oral dosage forms in the rat gastrointestinal tract by magnetic resonance imaging (MRI).

    Science.gov (United States)

    Christmann, V; Rosenberg, J; Seega, J; Lehr, C M

    1997-08-01

    Bioavailability of orally administered drugs is much influenced by the behavior, performance and fate of the dosage form within the gastrointestinal (GI) tract. Therefore, MRI in vivo methods that allow for the simultaneous visualization of solid oral dosage forms and anatomical structures of the GI tract have been investigated. Oral contrast agents containing Gd-DTPA were used to depict the lumen of the digestive organs. Solid oral dosage forms were visualized in a rat model by a 1H-MRI double contrast technique (magnetite-labelled microtablets) and a combination of 1H- and 19F-MRI (fluorine-labelled minicapsules). Simultaneous visualization of solid oral dosage forms and the GI environment in the rat was possible using MRI. Microtablets could reproducibly be monitored in the rat stomach and in the intestines using a 1H-MRI double contrast technique. Fluorine-labelled minicapsules were detectable in the rat stomach by a combination of 1H- and 19F-MRI in vivo. The in vivo 1H-MRI double contrast technique described allows solid oral dosage forms in the rat GI tract to be depicted. Solid dosage forms can easily be labelled by incorporating trace amounts of non-toxic iron oxide (magnetite) particles. 1H-MRI is a promising tool for observing such pharmaceutical dosage forms in humans. Combined 1H- and 19F-MRI offer a means of unambiguously localizing solid oral dosage forms in more distal parts of the GI tract. Studies correlating MRI examinations with drug plasma levels could provide valuable information for the development of pharmaceutical dosage forms.

  2. Potential application of surfactant systems in formulation of dosage forms with slightly soluble substances

    Directory of Open Access Journals (Sweden)

    Ibrić Svetlana R.

    2012-01-01

    Full Text Available In order to achieve fast release of ibuprofen, slightly soluble model substance (0.52104 mol/l, surfactant systems for oral use with different PEG-40 hydrogenated castor oil (C/diethylene glycol monoethyl ether (T ratios were investigated. Comparison between dissolution profiles for ibuprofen from formulated systems and from two commercial products, film tablets and soft capsules, is presented in this paper. Photon correlation spectroscopy has shown that after high dilution with water, surfactant systems were able to form micellar solutions. The size of micelles varies from 14.8 ± 0,075 nm to 16.2 ± 0,021 nm with increasing C/T ratio from 1:2 to 2:1. Although with increasing content of PEG-40 hydrogenated castor oil larger micelles have formed, lower values of polydispersity index indicated that more homogeneous distribution of micelles size was gained. Conductometric analysis has demonstrated that system composing of C/T ratio 2:1, has shown most pronounced interaction between droplets, which can be seen as high rise of electrical conductivity with increasing water content (% (wwater/wtotal in the sample. No significant difference in percolation threshold between formulations with different C/T ratios was observed. Different surfactant systems were adsorbed on magnesium aluminometasilicate, as adsorbent with high specific active surface (≈300 m2/g, in order to investigate potential influence of adsorbent on ibuprofen dissolution rate. Formulated systems, with or without adsorbent were filled in hard gelatin capsules. The dissolution profiles of ibuprofen from different formulations were obtained in 30 minutes by dissolution apparatus with rotating baskets and compared with dissolution profiles of ibuprofen from commercial products. For formulations without adsorbent faster release of ibuprofen in first minutes of dissolution test, showed formulations with C/T ratio 2:1 and 1:1. Magnesium aluminometasilicate, as adsorbent with high specific

  3. Development and validation of a dissolution test with reversed-phase liquid chromatography analysis for rupatadine in tablet dosage forms

    Directory of Open Access Journals (Sweden)

    Sérgio Luiz Dalmora

    2010-01-01

    Full Text Available A dissolution test for in vitro evaluation of tablet dosage forms containing 10 mg of rupatadine was developed and validated by RP-LC. A discriminatory dissolution method was established using apparatus paddle at a stirring rate of 50 rpm with 900 mL of deaerated 0.01 M hydrochloric acid. The proposed method was validated yielding acceptable results for the parameters evaluated, and was applied for the quality control analysis of rupatadine tablets, and to evaluate the formulation during an accelerated stability study. Moreover, quantitative analyses were also performed, to compare the applicability of the RP-LC and the LC-MS/MS methods.

  4. New Stability Indicating RP-HPLC Method for the Estimation of Cefpirome Sulphate in Bulk and Pharmaceutical Dosage Forms

    OpenAIRE

    Rao, Kareti Srinivasa; Kumar, Keshar Nargesh; Joydeep, Datta

    2011-01-01

    A simple stability indicating reversed-phase HPLC method was developed and subsequently validated for estimation of Cefpirome sulphate (CPS) present in pharmaceutical dosage forms. The proposed RP-HPLC method utilizes a LiChroCART-Lichrosphere100, C18 RP column (250 mm ? 4mm ? 5 ?m) in an isocratic separation mode with mobile phase consisting of methanol and water in the proportion of 50:50 % (v/v), at a flow rate 1ml/min, and the effluent was monitored at 270 nm. The retention time of CPS wa...

  5. Utility of eosin Y as a complexing reagent for the determination of citalopram hydrobromide in commercial dosage forms by fluorescence spectrophotometry.

    Science.gov (United States)

    Azmi, Syed Najmul Hejaz; Al-Fazari, Ahlam; Al-Badaei, Munira; Al-Mahrazi, Ruqiya

    2015-12-01

    An accurate, selective and sensitive spectrofluorimetric method was developed for the determination of citalopram hydrobromide in commercial dosage forms. The method was based on the formation of a fluorescent ion-pair complex between citalopram hydrobromide and eosin Y in the presence of a disodium hydrogen phosphate/citric acid buffer solution of pH 3.4 that was extractable in dichloromethane. The extracted complex showed fluorescence intensity at λem = 554 nm after excitation at 259 nm. The calibration curve was linear over at concentrations of 2.0-26.0 µg/mL. Under optimized experimental conditions, the proposed method was validated as per ICH guidelines. The effect of common excipients used as additives was tested and the tolerance limit calculated. The limit of detection for the proposed method was 0.121 μg/mL. The proposed method was successfully applied to the determination of citalopram hydrobromide in commercial dosage forms. The results were compared with the reference RP-HPLC method. Copyright © 2015 John Wiley & Sons, Ltd.

  6. Simple and Inexpensive Methods Development for Determination of Venlafaxine Hydrochloride from Its Solid Dosage Forms by Visible Spectrophotometry

    Directory of Open Access Journals (Sweden)

    K. Raghubabu

    2012-01-01

    Full Text Available Two simple, sensitive and cost effective visible spectrophotometric methods (M1 and M2 have been developed for the determination of venlafaxine hydrochloride from bulk and tablet dosage forms. The method M1 is based on the formation of green colored coordination complex by the drug with cobalt thiocyanate which is quantitatively extractable into nitro benzene with an absorption maximum of 626.4 nm. The method M2 involves internal salt formation of aconitic anhydride, dehydration product of citric acid [CIA] with acetic anhydride [Ac2O] to form colored chromogen with an absorption maximum of 561.2 nm. The calibration graph is linear over the concentration range of 10-50 µg/mL and 8-24 µg/mL for method M1 and M2 respectively. The proposed methods are applied to commercial available tablets and the results are statistically compared with those obtained by the reference method and validated by recovery studies. The results are found satisfactory and reproducible. These methods are applied successfully for the estimation of the venlafaxine hydrochloride in the presence of other ingredients that are usually present in dosage forms.

  7. Spectrophotometric methods for the determination of benazepril hydrochloride in its single and multi-component dosage forms.

    Science.gov (United States)

    El-Yazbi, F A; Abdine, H H; Shaalan, R A

    1999-06-01

    Three sensitive and accurate methods are presented for the determination of benazepril in its dosage forms. The first method uses derivative spectrophotometry to resolve the interference due to formulation matrix. The second method depends on the color formed by the reaction of the drug with bromocresol green (BCG). The third one utilizes the reaction of benazepril, after alkaline hydrolysis, with 3-methylbenzothialozone (MBTH) hydrazone where the produced color is measured at 593 nm. The latter method was extended to develop a stability-indicating method for this drug. Moreover, the derivative method was applied for the determination of benazepril in its combination with hydrochlorothiazide. The proposed methods were applied for the analysis of benazepril in the pure form and in tablets. The coefficient of variation was less than 2%.

  8. 76 FR 72619 - Ophthalmic and Topical Dosage Form New Animal Drugs; Eprinomectin

    Science.gov (United States)

    2011-11-25

    ... (eprinomectin) Pour-On for Beef and Dairy Cattle, a topical solution used for the treatment and control of internal and external parasites of cattle on pasture with persistent effectiveness. The supplemental NADA...

  9. Development and Validation of RP-HPLC Method for Simultaneous Estimation of Aspirin and Esomeprazole Magnesium in Tablet Dosage Form

    Directory of Open Access Journals (Sweden)

    Dipali Patel

    2013-01-01

    Full Text Available A simple, specific, precise, and accurate reversed-phase HPLC method was developed and validated for simultaneous estimation of aspirin and esomeprazole magnesium in tablet dosage forms. The separation was achieved by HyperChrom ODS-BP C18 column (200 mm × 4.6 mm; 5.0 μm using acetonitrile: methanol: 0.05 M phosphate buffer at pH 3 adjusted with orthophosphoric acid (25 : 25 : 50, v/v as eluent, at a flow rate of 1 mL/min. Detection was carried out at wavelength 230 nm. The retention times of aspirin and esomeprazole magnesium were 4.29 min and 6.09 min, respectively. The linearity was established over the concentration ranges of 10–70 μg/mL and 10–30 μg/mL with correlation coefficients (r2 0.9986 and 0.9973 for aspirin and esomeprazole magnesium, respectively. The mean recoveries were found to be in the ranges of 99.80–100.57% and 99.70–100.83% for aspirin and esomeprazole magnesium, respectively. The proposed method has been validated as per ICH guidelines and successfully applied to the estimation of aspirin and esomeprazole magnesium in their combined tablet dosage form.

  10. Overview of PAT process analysers applicable in monitoring of film coating unit operations for manufacturing of solid oral dosage forms.

    Science.gov (United States)

    Korasa, Klemen; Vrečer, Franc

    2018-01-01

    Over the last two decades, regulatory agencies have demanded better understanding of pharmaceutical products and processes by implementing new technological approaches, such as process analytical technology (PAT). Process analysers present a key PAT tool, which enables effective process monitoring, and thus improved process control of medicinal product manufacturing. Process analysers applicable in pharmaceutical coating unit operations are comprehensibly described in the present article. The review is focused on monitoring of solid oral dosage forms during film coating in two most commonly used coating systems, i.e. pan and fluid bed coaters. Brief theoretical background and critical overview of process analysers used for real-time or near real-time (in-, on-, at- line) monitoring of critical quality attributes of film coated dosage forms are presented. Besides well recognized spectroscopic methods (NIR and Raman spectroscopy), other techniques, which have made a significant breakthrough in recent years, are discussed (terahertz pulsed imaging (TPI), chord length distribution (CLD) analysis, and image analysis). Last part of the review is dedicated to novel techniques with high potential to become valuable PAT tools in the future (optical coherence tomography (OCT), acoustic emission (AE), microwave resonance (MR), and laser induced breakdown spectroscopy (LIBS)). Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Development and Validation of Spectrophotometric Methods for Simultaneous Estimation of Valsartan and Hydrochlorothiazide in Tablet Dosage Form

    Directory of Open Access Journals (Sweden)

    Monika L. Jadhav

    2014-01-01

    Full Text Available Two UV-spectrophotometric methods have been developed and validated for simultaneous estimation of valsartan and hydrochlorothiazide in a tablet dosage form. The first method employed solving of simultaneous equations based on the measurement of absorbance at two wavelengths, 249.4 nm and 272.6 nm, λmax for valsartan and hydrochlorothiazide, respectively. The second method was absorbance ratio method, which involves formation of Q-absorbance equation at 258.4 nm (isoabsorptive point and also at 272.6 nm (λmax of hydrochlorothiazide. The methods were found to be linear between the range of 5–30 µg/mL for valsartan and 4–24 μg/mL for hydrochlorothiazide using 0.1 N NaOH as solvent. The mean percentage recovery was found to be 100.20% and 100.19% for the simultaneous equation method and 98.56% and 97.96% for the absorbance ratio method, for valsartan and hydrochlorothiazide, respectively, at three different levels of standard additions. The precision (intraday, interday of methods was found within limits (RSD<2%. It could be concluded from the results obtained in the present investigation that the two methods for simultaneous estimation of valsartan and hydrochlorothiazide in tablet dosage form are simple, rapid, accurate, precise and economical and can be used, successfully, in the quality control of pharmaceutical formulations and other routine laboratory analysis.

  12. Alternative Manufacturing Concepts for Solid Oral Dosage Forms From Drug Nanosuspensions Using Fluid Dispensing and Forced Drying Technology.

    Science.gov (United States)

    Bonhoeffer, Bastian; Kwade, Arno; Juhnke, Michael

    2018-03-01

    Flexible manufacturing technologies for solid oral dosage forms with a continuous adjustability of the manufactured dose strength are of interest for applications in personalized medicine. This study explored the feasibility of using microvalve technology for the manufacturing of different solid oral dosage form concepts. Hard gelatin capsules filled with excipients, placebo tablets, and polymer films, placed in hard gelatin capsules after drying, were considered as substrates. For each concept, a basic understanding of relevant formulation parameters and their impact on dissolution behavior has been established. Suitable matrix formers, present either on the substrate or directly in the drug nanosuspension, proved to be essential to prevent nanoparticle agglomeration of the drug nanoparticles and to ensure a fast dissolution behavior. Furthermore, convection and radiation drying methods were investigated for the fast drying of drug nanosuspensions dispensed onto polymer films, which were then placed in hard gelatin capsules. Changes in morphology and in drug and matrix former distribution were observed for increasing drying intensity. However, even fast drying times below 1 min could be realized, while maintaining the nanoparticulate drug structure and a good dissolution behavior. Copyright © 2018 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  13. High performance liquid chromatography for simultaneous determination of xipamide, triamterene and hydrochlorothiazide in bulk drug samples and dosage forms.

    Science.gov (United States)

    Abd El-Hay, Soad S; Hashem, Hisham; Gouda, Ayman A

    2016-03-01

    A novel, simple and robust high-performance liquid chromatography (HPLC) method was developed and validated for simultaneous determination of xipamide (XIP), triamterene (TRI) and hydrochlorothiazide (HCT) in their bulk powders and dosage forms. Chromatographic separation was carried out in less than two minutes. The separation was performed on a RP C-18 stationary phase with an isocratic elution system consisting of 0.03 mol L(-1) orthophosphoric acid (pH 2.3) and acetonitrile (ACN) as the mobile phase in the ratio of 50:50, at 2.0 mL min(-1) flow rate at room temperature. Detection was performed at 220 nm. Validation was performed concerning system suitability, limits of detection and quantitation, accuracy, precision, linearity and robustness. Calibration curves were rectilinear over the range of 0.195-100 μg mL(-1) for all the drugs studied. Recovery values were 99.9, 99.6 and 99.0 % for XIP, TRI and HCT, respectively. The method was applied to simultaneous determination of the studied analytes in their pharmaceutical dosage forms.

  14. Geometry of modified release formulations during dissolution--influence on performance of dosage forms with diclofenac sodium.

    Science.gov (United States)

    Dorożyński, Przemysław; Kulinowski, Piotr; Jamróz, Witold; Juszczyk, Ewelina

    2014-12-30

    The objectives of the work included: presentation of magnetic resonance imaging (MRI) and fractal analysis based approach to comparison of dosage forms of different composition, structure, and assessment of the influence of the compositional factors i.e., matrix type, excipients etc., on properties and performance of the dosage form during drug dissolution. The work presents the first attempt to compare MRI data obtained for tablet formulations of different composition and characterized by distinct differences in hydration and drug dissolution mechanisms. The main difficulty, in such a case stems from differences in hydration behavior and tablet's geometry i.e., swelling, cracking, capping etc. A novel approach to characterization of matrix systems i.e., quantification of changes of geometrical complexity of the matrix shape during drug dissolution has been developed. Using three chosen commercial modified release tablet formulations with diclofenac sodium we present the method of parameterization of their geometrical complexity on the base of fractal analysis. The main result of the study is the correlation between the hydrating tablet behavior and drug dissolution - the increase of geometrical complexity expressed as fractal dimension relates to the increased variability of drug dissolution results. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. 75 FR 1274 - Implantation or Injectable Dosage Form New Animal Drugs; Florfenicol and Flunixin

    Science.gov (United States)

    2010-01-11

    ... flunixin meglumine), a combination injectable solution, for treatment of bovine respiratory disease (BRD... treatment of bovine respiratory disease (BRD) associated with Mannheimia haemolytica, Pasteurella multocida... female dairy cattle 20 months of age or older. Use of florfenicol in this class of cattle may cause milk...

  16. 77 FR 4227 - Implantation or Injectable Dosage Form New Animal Drugs; Gonadotropin Releasing Factor Analog...

    Science.gov (United States)

    2012-01-27

    ... Factor Analog-Diphtheria Toxoid Conjugate AGENCY: Food and Drug Administration, HHS. ACTION: Final rule... extends the slaughter interval for intact male swine injected with gonadotropin releasing factor analog...-322 for IMPROVEST (gonadotropin releasing factor analog-diphtheria toxoid conjugate) Sterile Solution...

  17. Tailoring controlled-release oral dosage forms by combining inkjet and flexographic printing techniques

    DEFF Research Database (Denmark)

    Genina, Natalja; Fors, Daniela; Vakili, Hossein

    2012-01-01

    substrates: A (uncoated woodfree paper), B (triple-coated inkjet paper) and C (double-coated sheet fed offset paper) were used as porous model carriers for drug delivery. Active pharmaceutical ingredient (API) containing solutions were printed onto 1 cm × 1 cm substrate areas using an inkjet printer...

  18. Spectrophotometric method for estimation of amiloride in bulk and tablet dosage form

    Directory of Open Access Journals (Sweden)

    Aitha Vijaya Lakshmi

    2015-01-01

    Full Text Available Introduction: Amiloride chemically, 3,5-diamino-6-chloro-N-(diaminomethylene pyrazine-2-carboxamide. It is used in the management of congestive heart failure, available as Amifru tab, Amimide. It causes adverse effects like Nausea, diarrhea and dizziness. Materials: 0.1 N Hydrochloric acid, 0.1 N Sodium hydroxide and 1 mg/ml amiloride drug solution were required. Spectral and absorbance measurements were made using ELICO UV-160 double beam Spectrophotometer. Method: Amiloride drug solution concentration range of 25 to 125ug/ml in 0.1N HCl medium was scanned over the wave length range of 235-320 against blank prepared in 0.1N NaOH solution. Two wavelengths are selected one at positive peak 245 nm and another at negative peak 290 nm, the amplitude is calculated from these values. Results and Discussion: The sum of the absolute values at these wavelengths is called amplitude. The amplitude is proportional to the amount of drug. High accuracy, reproducibility and low t-values were reported from the calibration curve plotted with the amplitude verses amount of drug. So the proposed method is simple, less time consuming and it can be successfully adopted for the estimation of amiloride.

  19. Stability Indicating RP-HPLC Method for Simultaneous Determination of Aspirin and Clopidrogel in Dosage Form

    International Nuclear Information System (INIS)

    Mohd Gousuddin; Sengupta, P.; Tripathi, V.D.; Das, A.

    2016-01-01

    Stability-indicating High Performance Liquid Chromatographic (HPLC) method was developed for simultaneous Aspirin and Clopidogrel, A Phenomenex Gemini C-18, 5 μm column having 250 mm x 4.6 mm i.d. in isocratic mode, with mobile phase containing buffer solution 0.3 % orthophosphoric acid : acetonitrile (65:35, v/v). The flow rate was 1 ml/ min and effluents were monitored at 266 nm. For linearity seven points calibration curve were obtained in a concentration range from 0.030-0.120 mg/ ml for aspirin and 0.015-0.060 mg/ ml for clopidogrel with correlation coefficient 0.9999. In the present study stability indicating HPLC method for the combination was tested by degrading the drugs together under various stress conditions like acid hydrolysis, base hydrolysis, oxidation, thermal and photolytic stress which is recommended by ICH guideline. (author)

  20. Spectrophotometric Determination of Metoprolol Tartrate in Pharmaceutical Dosage Forms on Complex Formation with Cu(II

    Directory of Open Access Journals (Sweden)

    Mustafa Cesme

    2011-06-01

    Full Text Available A new, simple, sensitive and accurate spectrophotometric method has been developed for the assay of metoprolol tartrate (MPT, which is based on the complexation of drug with copper(II [Cu(II] at pH 6.0, using Britton-Robinson buffer solution, to produce a blue adduct. The latter has a maximum absorbance at 675 nm and obeys Beer’s law within the concentration range 8.5-70 mg/mL. Regression analysis of the calibration data showed a good correlation coefficient (r = 0.998 with a limit of detection of 5.56 mg/mL. The proposed procedure has been successfully applied to the determination of this drug in its tablets. In addition, the spectral data and stability constant for the binuclear copper(II complex of MPT (Cu2MPT2Cl2 have been reported.

  1. Simultaneous Estimation and Validation of Atorvastatin Calcium and Aspirin in Combined Capsule Dosage Form by RP HPLC Method

    Directory of Open Access Journals (Sweden)

    B. V. Suma

    2012-01-01

    Full Text Available A new simple, specific, precise and accurate revere phase liquid chromatography method has been developed for estimation of atorvastatin calcium (AST and ASPIRIN (ASP simultaneously in a combined capsule dosage forms. The chromatographic separation was achieved on a 5 – micron C 18 column (250x 4.6mm using a mobile phase consisting of a mixture of Acetonitrile: Ammonium Acetate buffer 0.02M (68:32 pH 4.5. The flow rate was maintained at 0.8 ml/min. The detection of the constituents was done using UV detector at 245 nm for AST and ASP. The retention time of AST and ASP were found be 4.5915 ± 0.0031 min and 3.282 ±0.0024 min respectively. The developed method was validated for accuracy, linearity, precision, limit of detection (LOD and limit of quantification (LOQ and robustness as per the ICH guidelines.

  2. Determination of glibenclamide, metformin hydrochloride and rosiglitazone maleate by reversed phase liquid chromatographic technique in tablet dosage form

    Directory of Open Access Journals (Sweden)

    Havele Shweta S.

    2014-01-01

    Full Text Available A simple, precise and accurate high performance liquid chromatography (HPLC method was developed for the simultaneous estimation of metformin hydrochloride, rosiglitazone maleate, glibenclamide present in multicomponent dosage forms. Chromatography was performed on a 25 cm × 4.6 mm i.d., 5-μm particle, C18 column with 78:22 (v/v methanol: 20 mM potassium dihydrogen phosphate buffer as mobile phase at a flow rate of 1.0 ml/min and UV detection at 238 nm for metformin hydrochloride, rosiglitazone maleate, and glibenclamide. The total elution time was shorter than 9 min. This method was found to be precise and reproducible. This proposed method was successfully applied for the analysis of metformin hydrochloride, rosiglitazone maleate, glibenclamide as a bulk drug and in pharmaceutical formulation without any interference from the excipients.

  3. Toward Higher QA: From Parametric Release of Sterile Parenteral Products to PAT for Other Pharmaceutical Dosage Forms.

    Science.gov (United States)

    Hock, Sia Chong; Constance, Neo Xue Rui; Wah, Chan Lai

    2012-01-01

    Pharmaceutical products are generally subjected to end-product batch testing as a means of quality control. Due to the inherent limitations of conventional batch testing, this is not the most ideal approach for determining the pharmaceutical quality of the finished dosage form. In the case of terminally sterilized parenteral products, the limitations of conventional batch testing have been successfully addressed with the application of parametric release (the release of a product based on control of process parameters instead of batch sterility testing at the end of the manufacturing process). Consequently, there has been an increasing interest in applying parametric release to other pharmaceutical dosage forms, beyond terminally sterilized parenteral products. For parametric release to be possible, manufacturers must be capable of designing quality into the product, monitoring the manufacturing processes, and controlling the quality of intermediates and finished products in real-time. Process analytical technology (PAT) has been thought to be capable of contributing to these prerequisites. It is believed that the appropriate use of PAT tools can eventually lead to the possibility of real-time release of other pharmaceutical dosage forms, by-passing the need for end-product batch testing. Hence, this literature review attempts to present the basic principles of PAT, introduce the various PAT tools that are currently available, present their recent applications to pharmaceutical processing, and explain the potential benefits that PAT can bring to conventional ways of processing and quality assurance of pharmaceutical products. Last but not least, current regulations governing the use of PAT and the manufacturing challenges associated with PAT implementation are also discussed. Pharmaceutical products are generally subjected to end-product batch testing as a means of quality control. Due to the inherent limitations of conventional batch testing, this is not the most

  4. Estimation of Rabeprazole Sodium and Itopride Hydrochloride in Tablet Dosage Form Using Reverse Phase High Performance Liquid Chromatography

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    Shaik Harum Rasheed

    2011-01-01

    Full Text Available A reversed phase high performance liquid chromatography (RP-HPLC method was developed, validated and used for the quantitative determination of rabeprazole sodium (RP and itopride hydrochloride (IH, from its tablet dosage form. Chromatographic separation was performed on a Phenomenex C18 column (250 mm × 4.6 mm, 5 μm, with a mobile phase comprising of a mixture of 50 mM ammonium acetate buffer and methanol (20:80v/v, pH 4.5 adjusted with acetic acid, at a flow rate of 1.3 mL/min with detection at 286 nm. Separation was completed in less than 10 min. As per International Conference on Harmonization (ICH guidelines the method was validated for linearity, accuracy, precision, limit of quantitation and limit of detection. Linearity of RP was found to be in the range of 37.5-375 μg/mL and IH was found to be in the range of 5-50 μg/mL. The correlation coefficients were 0.9997 and 0.9995 for RB and IH respectively. The accuracy of the developed method was found to be 98.6-100.7 for RP and 99.42 -100.81 for IH. The experiment shows the developed method is free from interference of excipients. It indicates the developed RP-HPLC method is simple, linear, precise and accurate and it can be conveniently adopted for the routine quality control analysis of the tablet dosage form.

  5. Attitude and perception of patients and health care practitioners toward oral sustained release dosage forms in Palestine.

    Science.gov (United States)

    Zaid, Abdel Naser

    2010-10-01

    To evaluate the knowledge of health professionals in Palestine regarding the advantages of sustained release dosage forms (SRDFs) over conventional therapy. Data were gathered from a questionnaire that was handed out to community pharmacists, physicians and patients. Pharmaceutical industry decision makers were enrolled in this study. Data were analyzed using the SPSS. Pharmacists (92.9%) and 89.2% of physicians thought that SRDFs improve patient compliance. 81.5% of pharmacists and 77% of physicians were in agreement regarding the capacity of SRDFs to maintain therapeutic activity during night. In this study, 81.5% of pharmacists and 81% of physicians believed that SRDFs provide further advantage with psychiatric patients who forget to take their medications. Pharmacists (63.1%) and only 63.5% of physicians believed that SRDFs yield a time saving for nurses who use SRDFs in hospital. Only 45.3% of physicians and 43.4% of pharmacists thought that SRDFs result in cost saving due to better disease management. Pharmacists (95.2%) and 95.9% of physicians agreed that SRDFs could be the right choice for faith patient's who must take their medication during the month of Ramadan. Pharmacists (66.7%) and 50.7% of physicians recognize that SRDFs may be unsafe if they are improperly formulated. Bad swallowing was also recognized as inconveniences of SRDFs by 67.9% of pharmacists and 57.3% of physicians. Given the above advantages, 75% of patients showed economical problems regarding the cost of the single course therapy of SRDFs and 100% of interviewed patients were enthusiastic about the advantage of SRDFs during Ramadan. The advantages of SRDFs are not completely understood by Palestinian health professionals. Pharmaceutical industries should pay more attention to the development and advertising of SRDFs due to the valuable advantages of these dosage forms.

  6. Stability-Indicating RP-HPLC Method for Determination of Guanfacine Hydrochloride in Bulk Drugs and in Pharmaceutical Dosage Form

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    Vinod K. Ahirrao

    2011-04-01

    Full Text Available A novel stability-indicating RP-HPLC method was developed and validated for quantitative determination of guanfacine hydrochloride in bulk drug and in pharmaceutical dosage form. An isocratic, reversed phase HPLC method was developed to separate the drug from the degradation products, using Apollo, C18 (250mm x 4.6mm, 5µm column with mobile phase of 50mM Ammonium acetate (volatile buffer and acetonitrile (65:35, v/v. UV detection has been done at wavelength 220 nm. The guanfacine hydrochloride was subjected to the stress conditions of hydrolysis (acid, base, oxidation, photolysis and thermal degradation. The stressed samples were analyzed by the proposed method. The analyte peak shape was excellent. The described method shows excellent linearity over a range of 30 – 450 µg/mL. The correlation coefficient for guanfacine hydrochloride was 0.999. The limit of detection for Guanfacine hydrochloride is 0.011 µg/mL and the limit of quantification is 0.038 µg/mL respectively.Degradation was observed for guanfacine hydrochloride in base, thermal and in 30% H2O2 conditions. The drug was found to be stable in the other stress conditions attempted. The degradation products were well resolved from main peak. The percentage recovery of guanfacine hydrochloride was ranged from (99.2% to 100.5% in pharmaceutical dosage form. The developed method was validated with respect to the linearity, accuracy (recovery, precision, specificity and robustness. The forced degradation studies prove the stability indicating power of the method.

  7. Evaluation of the impact of sodium lauryl sulfate source variability on solid oral dosage form development.

    Science.gov (United States)

    Qiang, Dongmei; Gunn, Jocelyn A; Schultz, Leon; Li, Z Jane

    2010-12-01

    The objective of this study was to investigate the effects of sodium lauryl sulfate (SLS) from different sources on solubilization/wetting, granulation process, and tablet dissolution of BILR 355 and the potential causes. The particle size distribution, morphology, and thermal behaviors of two pharmaceutical grades of SLS from Spectrum and Cognis were characterized. The surface tension and drug solubility in SLS solutions were measured. The BILR 355 tablets were prepared by a wet granulation process and the dissolution was evaluated. The critical micelle concentration was lower for Spectrum SLS, which resulted in a higher BILR 355 solubility. During wet granulation, less water was required to reach the same end point using Spectrum than Cognis SLS. In general, BILR 355 tablets prepared with Spectrum SLS showed a higher dissolution than the tablets containing Cognis SLS. Micronization of SLS achieved the same improved tablet dissolution as micronized active pharmaceutical ingredient. The observed differences in wetting and solubilization were likely due to the different impurity levels in SLS from two sources. This study demonstrated that SLS from different sources could have significant impact on wet granulation process and dissolution. Therefore, it is critical to evaluate SLS properties from different suppliers, and then identify optimal formulation and process parameters to ensure robustness of drug product manufacture process and performance.

  8. A new insight about pharmaceutical dosage forms for benzathine penicillin G

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    K. G. Holanda e Silva

    2009-01-01

    Full Text Available

    In this work, a micellar system of benzathine penicillin G (BPG in sodium deoxycholate (NaDC was developed and evaluated physicochemically. The solubility profile of the drug in water and buffer solutions at various pH was determined, as well as its n-octanol/water partition coefficient. The Critical Micellar Concentration of NaDC and its ability to incorporate BPG were also assessed. The study was carried out at low and high ionic strength which was adjusted by the addition of sodium chloride. The results demonstrated the ability of the micellar system to incorporate BPG, as well as to increase its apparent solubility in water. The enhancement of the solubility of BPG by the presence of NaDC micelles could be analyzed quantitatively within the framework of the pseudo-phase model. Concentration analysis showed that the micellar system could attain up to 90% incorporation of BPG. The incorporated drug is expected to exhibit improved stability, since the antibiotic enclosed in the hydrophobic core of micelles is rather shielded from the aqueous external environment. Keywords: Benzathine Penicillin G; micellar solubilization; micelles; pre-formulation; sodium deoxycholate.

  9. Preparation and Characterization of a Gastric Floating Dosage Form of Capecitabine

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    Ehsan Taghizadeh Davoudi

    2013-01-01

    Full Text Available Gastrointestinal disturbances, such as nausea and vomiting, are considered amongst the main adverse effects associated with oral anticancer drugs due to their fast release in the gastrointestinal tract (GIT. Sustained release formulations with proper release profiles can overcome some side effects of conventional formulations. The current study was designed to prepare sustained release tablets of Capecitabine, which is approved by the Food and Drug Administration (FDA for the treatment of advanced breast cancer, using hydroxypropyl methylcellulose (HPMC, carbomer934P, sodium alginate, and sodium bicarbonate. Tablets were prepared using the wet granulation method and characterized such that floating lag time, total floating time, hardness, friability, drug content, weight uniformity, and in vitro drug release were investigated. The sustained release tablets showed good hardness and passed the friability test. The tablets’ floating lag time was determined to be 30–200 seconds, and it floated more than 24 hours and released the drug for 24 hours. Then, the stability test was done and compared with the initial samples. In conclusion, by adjusting the right ratios of the excipients including release-retarding gel-forming polymers like HPMC K4M, Na alginate, carbomer934P, and sodium bicarbonate, sustained release Capecitabine floating tablet was formulated.

  10. Preparation and characterization of a gastric floating dosage form of capecitabine.

    Science.gov (United States)

    Taghizadeh Davoudi, Ehsan; Ibrahim Noordin, Mohamed; Kadivar, Ali; Kamalidehghan, Behnam; Farjam, Abdoreza Soleimani; Akbari Javar, Hamid

    2013-01-01

    Gastrointestinal disturbances, such as nausea and vomiting, are considered amongst the main adverse effects associated with oral anticancer drugs due to their fast release in the gastrointestinal tract (GIT). Sustained release formulations with proper release profiles can overcome some side effects of conventional formulations. The current study was designed to prepare sustained release tablets of Capecitabine, which is approved by the Food and Drug Administration (FDA) for the treatment of advanced breast cancer, using hydroxypropyl methylcellulose (HPMC), carbomer934P, sodium alginate, and sodium bicarbonate. Tablets were prepared using the wet granulation method and characterized such that floating lag time, total floating time, hardness, friability, drug content, weight uniformity, and in vitro drug release were investigated. The sustained release tablets showed good hardness and passed the friability test. The tablets' floating lag time was determined to be 30-200 seconds, and it floated more than 24 hours and released the drug for 24 hours. Then, the stability test was done and compared with the initial samples. In conclusion, by adjusting the right ratios of the excipients including release-retarding gel-forming polymers like HPMC K4M, Na alginate, carbomer934P, and sodium bicarbonate, sustained release Capecitabine floating tablet was formulated.

  11. Porosity measurement of solid pharmaceutical dosage forms by gamma-ray transmission

    International Nuclear Information System (INIS)

    Martins de Oliveira, Jose; Andreo Filho, Newton; Vinicius Chaud, Marco; Angiolucci, Tatiana; Aranha, Norberto; Germano Martins, Antonio Cesar

    2010-01-01

    The aim of the present work is the determination of porosity in tablets by using the gamma-ray transmission technique. Tablet dissolution depends on some inherent characteristics of the manufacturing process, such as compression force, tablet volume, density and porosity, nature of excipients, preparation methods and its physical-chemical properties. Porosity is a measure of empty spaces in a material and can be determined by various techniques. In this paper, we propose the use of a gamma-ray transmission technique to obtain the porosity of experimental formulation of tablets. The results of porosity were compared with those obtained by using conventional methodology (density and mercury intrusion). The experimental setup for gamma-ray transmission consists of a gamma-ray source of 241 Am (photons of 59.6 keV and an activity of 3.7x10 9 Bq), an NaI(Tl) scintillation detector, collimators and a standard gamma-ray spectrometry electronics. Our results suggest that the gamma-ray transmission technique is a powerful tool for non-destructive porosity quantification of solid pharmaceutical forms and presents smaller errors than those obtained with conventional methodologies.

  12. Simultaneous determination of linagliptin and metformin by reverse phase-high performance liquid chromatography method: An application in quantitative analysis of pharmaceutical dosage forms

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    Prathyusha Vemula

    2015-01-01

    Full Text Available To enhance patient compliance toward treatment in diseases like diabetes, usually a combination of drugs is prescribed. Therefore, an anti-diabetic fixed-dose combination of 2.5 mg of linagliptin 500 mg of metformin was taken for simultaneous estimation of both the drugs by reverse phase-high performance liquid chromatography (RP-HPLC method. The present study aimed to develop a simple and sensitive RP-HPLC method for the simultaneous determination of linagliptin and metformin in pharmaceutical dosage forms. The chromatographic separation was designed and evaluated by using linagliptin and metformin working standard and sample solutions in the linearity range. Chromatographic separation was performed on a C 18 column using a mobile phase of 70:30 (v/v mixture of methanol and 0.05 M potassium dihydrogen orthophosphate (pH adjusted to 4.6 with orthophosphoric acid delivered at a flow rate of 0.6 mL/min and UV detection at 267 nm. Linagliptin and metformin shown linearity in the range of 2-12 μg/mL and 400-2400 μg/mL respectively with correlation co-efficient of 0.9996 and 0.9989. The resultant findings analyzed for standard deviation (SD and relative standard deviation to validate the developed method. The retention time of linagliptin and metformin was found to be 6.3 and 4.6 min and separation was complete in <10 min. The method was validated for linearity, accuracy and precision were found to be acceptable over the linearity range of the linagliptin and metformin. The method was found suitable for the routine quantitative analysis of linagliptin and metformin in pharmaceutical dosage forms.

  13. Spectrofluorimetric determination of sertraline in dosage forms and human plasma through derivatization with 9-fluorenylmethyl chloroformate

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    Belal Fathalla

    2011-10-01

    Full Text Available Abstract Background Sertraline is primarily used to treat major depression in adult outpatients as well as obsessive-compulsive, panic and social anxiety disorders in both adults and children. A survey of the literature reveals that most of the reported methods are either insufficiently sensitive or tedious and require highly sophisticated and dedicated instrumentation. The proposed method is considered to be specific for determination of SER in presence of its metabolite (deaminated form. Results A sensitive, simple and specific spectrofluorimetric method was developed for the determination of sertraline (SER in pharmaceutical formulations and biological fluids. The method is based on its reaction with 9-fluorenylmethyl chloroformate (FMOC-Cl in borate buffer of pH 8.0 to yield a highly fluorescent derivative peaking at 315 nm after excitation at 265 nm. The different experimental parameters affecting the development and stability of the reaction product were carefully studied and optimized. The fluorescence concentration plot was rectilinear over the range of 0.05-1.0 μg mL-1 with a lower detection limit of 5.34 × 10-3 μg mL-1 and limit of quantitation of 0.016 μg mL-1. Conclusions The proposed method was successfully applied to the analysis of commercial tablets and the results obtained were in good agreement with those obtained using the reference method. Furthermore, the method was applied for the determination of SER in spiked and real human plasma. The mean % recovery (n = 3 was 94.33 ± 1.53 and 92.00 ± 2.65, respectively. A proposal of the reaction pathway was postulated.

  14. Stability Indicating Reverse Phase HPLC Method for Estimation of Rifampicin and Piperine in Pharmaceutical Dosage Form.

    Science.gov (United States)

    Shah, Umang; Patel, Shraddha; Raval, Manan

    2018-01-01

    High performance liquid chromatography is an integral analytical tool in assessing drug product stability. HPLC methods should be able to separate, detect, and quantify the various drug-related degradants that can form on storage or manufacturing, plus detect any drug-related impurities that may be introduced during synthesis. A simple, economic, selective, precise, and stability-indicating HPLC method has been developed and validated for analysis of Rifampicin (RIFA) and Piperine (PIPE) in bulk drug and in the formulation. Reversed-phase chromatography was performed on a C18 column with Buffer (Potassium Dihydrogen Orthophosphate) pH 6.5 and Acetonitrile, 30:70), (%, v/v), as mobile phase at a flow rate of 1 mL min-1. The detection was performed at 341 nm and sharp peaks were obtained for RIFA and PIPE at retention time of 3.3 ± 0.01 min and 5.9 ± 0.01 min, respectively. The detection limits were found to be 2.385 ng/ml and 0.107 ng/ml and quantification limits were found to be 7.228ng/ml and 0.325ng/ml for RIFA and PIPE, respectively. The method was validated for accuracy, precision, reproducibility, specificity, robustness, and detection and quantification limits, in accordance with ICH guidelines. Stress study was performed on RIFA and PIPE and it was found that these degraded sufficiently in all applied chemical and physical conditions. Thus, the developed RP-HPLC method was found to be suitable for the determination of both the drugs in bulk as well as stability samples of capsule containing various excipients. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  15. An integrated system for dissolution studies and magnetic resonance imaging of controlled release, polymer-based dosage forms-a tool for quantitative assessment of hydrogel formation processes.

    Science.gov (United States)

    Kulinowski, Piotr; Dorozyński, Przemysław; Jachowicz, Renata; Weglarz, Władysław P

    2008-11-04

    Controlled release (CR) dosage forms are often based on polymeric matrices, e.g., sustained-release tablets and capsules. It is crucial to visualise and quantify processes of the hydrogel formation during the standard dissolution study. A method for imaging of CR, polymer-based dosage forms during dissolution study in vitro is presented. Imaging was performed in a non-invasive way by means of the magnetic resonance imaging (MRI). This study was designed to simulate in vivo conditions regarding temperature, volume, state and composition of dissolution media. Two formulations of hydrodynamically balanced systems (HBS) were chosen as model CR dosage forms. HBS release active substance in stomach while floating on the surface of the gastric content. Time evolutions of the diffusion region, hydrogel formation region and "dry core" region were obtained during a dissolution study of L-dopa as a model drug in two simulated gastric fluids (i.e. in fed and fasted state). This method seems to be a very promising tool for examining properties of new formulations of CR, polymer-based dosage forms or for comparison of generic and originator dosage forms before carrying out bioequivalence studies.

  16. Thermal Analysis by Structural Characterization as a Method for Assessing Heterogeneity in Complex Solid Pharmaceutical Dosage Forms.

    Science.gov (United States)

    Alhijjaj, Muqdad; Reading, Mike; Belton, Peter; Qi, Sheng

    2015-11-03

    Characterizing inter- and intrasample heterogeneity of solid and semisolid pharmaceutical products is important both for rational design of dosage forms and subsequent quality control during manufacture; however, most pharmaceutical products are multicomponent formulations that are challenging in this regard. Thermal analysis, in particular differential scanning calorimetry, is commonly used to obtain structural information, such as degree of crystallinity, or identify the presence of a particular polymorph, but the results are an average over the whole sample; it cannot directly provide information about the spatial distribution of phases. This study demonstrates the use of a new thermo-optical technique, thermal analysis by structural characterization (TASC), that can provide spatially resolved information on thermal transitions by applying a novel algorithm to images acquired by hot stage microscopy. We determined that TASC can be a low cost, relatively rapid method of characterizing heterogeneity and other aspects of structure. In the examples studied, it was found that high heating rates enabled screening times of 3-5 min per sample. In addition, this study demonstrated the higher sensitivity of TASC for detecting the metastable form of polyethylene glycol (PEG) compared to conventional differential scanning calorimetry (DSC). This preliminary work suggests that TASC will be a worthwhile additional tool for characterizing a broad range of materials.

  17. Development and Validation of a UV Spectrophotometric and a RP-HPLC Methods for Moexipril Hydrochloride in Pure Form and Pharmaceutical Dosage Form

    International Nuclear Information System (INIS)

    Mastiholimath, V.S.; Gupte, P.P.; Mannur, V.S.

    2012-01-01

    A simple and reliable UV spectrophotometric and high-performance liquid chromatography (HPLC) methods were developed and validated for Moexipril hydrochloride in pure form and pharmaceutical dosage form. The RP-HPLC method was developed on agilant eclipse C 18 , (150 mm x 4.6 mm, 5 μm) with a mobile phase gradient system of 60 % (methanol:acetonitrile (70:30 % v/v)) : 40 % 20 mM ammonium acetate buffer pH 4.5 (v/v) and UV spectrophotometric method was developed in phosphate buffer pH 6.8. The effluent was monitored by SPD-M20A, prominence PDA detector at 210 nm. Calibration curve was linear over the concentration range of 10-35 μg/ml and 1-9 μg/ml for RP-HPLC and UV with a regression coefficient of 0.999. For RP-HPLC method Inter-day and intra-day precision % RSD values were found to be 1.00078 % and 1.49408 % respectively. For UV method 0.73386 % to 1.44111 % for inter day 0.453864 to 1.15542 intra-day precision. Recovery of Moexipril hydrochloride was found to be in the range of 99.8538 % to 101.5614 % and 100.5297586 % to 100.6431587 % for UV and RP-HPLC respectively. The limits of detection (LOD) and quantification (LOQ) for HPLC were 0.98969 and 2.99907 μg/ml, respectively. The developed RP-HPLC and UV spectrophotometric method was successfully applied for the quantitative determination of Moexipril hydrochloride in pharmaceutical dosage. (author)

  18. Comparative pharmacokinetic study of dosage forms with morpholinium 2-[5-(pyridin-4-yl-1,2,4-triazol-3-ylthio] acetate

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    I. V. Bushueva

    2014-12-01

    Full Text Available Using mathematical models of income distribution and excretion of drugs greatly enhances the interpretation of the results of biopharmaceutical research. Pharmacokinetic modeling makes it possible to quantify the biological assessment of pharmaceutical factors, opens the possibility of a science-based regulation of the kinetics of substances introduced through targeted changesof pharmaceutical factors. Results of the study of kinetic models are used to solve some practical problems associated with pharmacological and clinical trials of medicines. Morpholinium 2-[5-(pyridin-4-yl-1,2,4-triazol-3-ylthio] acetate is new organic compound from the 1,2,4-triazole group obtained at the Department of Inorganic Chemistry, Zaporozhye State Medical University. The substance has antioxidant and anti-ischemic action, low toxicity. Aim of this work is to study the kinetics of absorption of morpholinium 2-[5-(pyridin-4-yl-1,2,4-triazol-3-ylthio] acetate developed formulations. MATERIALS AND METHODS Pharmacokinetic studies of oral and rectal dosage forms of morpholinium 2-[5-(pyridin-4-yl-1,2,4-triazol-3-ylthio] acetate was performed on Chinchilla rabbits weighing an average of 2.5 kg, divided into three groups. The third group for comparison was administered a 1% injectable solution of morpholinium 2-[5-(pyridin-4-yl-1,2,4-triazol-3-ylthio] acetate intravenously. Substance dose was 0.1 g and 0.5 g per kg of animal body weight, which were administered once. Sampling from the auricular vein of the rabbits was performed at 5, 10, 15, 30, 45, 60, 75, 90, 120, 150 and 180 minutes after oral administration and rectal dosage forms of morpholinium 2-[5-(pyridin-4-yl-1,2,4-triazol-3-ylthio] acetate and after 3, 5, 10, 15, 20, 30, 40, 50 and 60 minutes after intravenous injection. Morpholinium 2-[5-(pyridin-4-yl-1,2,4-triazol-3-ylthio] acetate concentration in serum was adjusted spectrophotometrically. Results.Morpholinium 2-[5-(pyridin-4-yl-1,2,4-triazol-3-ylthio

  19. Utility of Charge Transfer and Ion-Pair Complexation for Spectrophotometric Determination of Eletriptan Hydrobromide in Pure and Dosage Forms

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    Ayman A. Gouda

    2013-01-01

    Full Text Available Three simple, sensitive, and accurate spectrophotometric methods have been developed for the determination of eletriptan hydrobromide (ELT in pure and dosage forms. The first two methods are based on charge transfer complex formation between ELT and chromogenic reagents quinalizarin (Quinz and alizarin red S (ARS producing charge transfer complexes which showed an absorption maximum at 569 and 533 nm for Quinz and ARS, respectively. The third method is based on the formation of ion-pair complex between ELT with molybdenum(V-thiocyanate inorganic complex in hydrochloric acid medium followed by extraction of the colored ion-pair with dichloromethane and measured at 470 nm. Different variables affecting the reactions were studied and optimized. Beer's law is obeyed in the concentration ranges 2.0–18, 1.0–8.0, and 2.0–32 μg mL−1 for Quinz, ARS, and Mo(V-thiocyanate, respectively. The molar absorptivity, Sandell sensitivity, detection, and quantification limits are also calculated. The correlation coefficients were ≥0.9994 with a relative standard deviation (R.S.D%. of ≤0.925. The proposed methods were successfully applied for simultaneous determination of ELT in tablets with good accuracy and precision and without interferences from common additives, and the validity is assessed by applying the standard addition technique, which is compared with those obtained using the reported method.

  20. Separation and determination of impurities in paracetamol, codeine and pitophenone in the presence of fenpiverinium in combined suppository dosage form.

    Science.gov (United States)

    Vojta, Jiří; Hanzlík, Pavel; Jedlička, Aleš; Coufal, Pavel

    2015-01-01

    A new HPLC method for separation and determination of impurities in paracetamol, codeine phosphate hemihydrate and pitophenone hydrochloride in the presence of fenpiverinium bromide in combined suppository dosage form was developed and validated. The separation of paracetamol and its impurities 4-aminophenol, 4-nitrophenol, 4-chloracetanilid; codeine and its impurities methylcodeine, morphine, codeine dimer and 10-hydroxycodeine; pitophenone and its impurities 2-[4-[2-(1-piperidinyl)ethoxy]benzoyl] benzoic acid, 2-[4-[2-(1-piperidinyl)ethoxy]benzoyl]benzoic acid 2-(1-piperidinyl)-ethyl ester, methyl ester of 2-(4-hydroxybenzoyl) benzoic acid and fenpiverinium was achieved by using ion-pair reversed phase liquid chromatography with UV detection. Validation parameters such as the precision, accuracy, linearity, limit of detection (LOD), limit of quantification (LOQ) and robustness were verified for all the mentioned impurities of codeine phosphate hemihydrate and 4-aminophenol and 2-[4-[2-(1-piperidinyl)ethoxy]benzoyl] benzoic acid as the main degradation products of paracetamol and pitophenone hydrochloride, respectively. The described method was found to be useful for analysis of the stability samples and therefore suitable for routine purity testing of the drug product. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Simultaneous Estimation of Ibuprofen and Phenylephrine Hydrochloride in Bulk and Combined Dosage Form by First Derivative UV Spectrophotometry Method

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    Mehul Patel

    2013-01-01

    Full Text Available A simple, precise, rapid, and economic method was developed for the simultaneous determination of Ibuprofen and Phenylephrine HCl in bulk and combined dosage form. This method involves first-order derivative spectroscopy using 248 nm and 237 nm as zero crossing points for Ibuprofen and Phenylephrine HCl, respectively. For spectrophotometric method 0.1 N NaOH was used as a solvent. The linearity was established over the concentration range of 12–72 μg/mL and 1.5–22 μg/mL for Ibuprofen and Phenylephrine HCl with correlation coefficient (r2 of 0.9972 and 0.9981, respectively. The mean % recoveries were found to be in the range of 98.88% and 98.54% for Ibuprofen and Phenylephrine HCl, respectively. Interday and intraday studies showed repeatability of the method. The method was found to be specific and robust. The method was successfully applied to pharmaceutical formulation, with no interference from excipients as indicated by the recovery study. Results of analysis were validated statistically and by recovery studies.

  2. Stability-Indicating Validated HPLC Method for Analysis of Berberine Hydrochloride and Trimethoprim in Pharmaceutical Dosage Form

    Directory of Open Access Journals (Sweden)

    Jing-Chun Wang

    2013-01-01

    Full Text Available A stability-indicating HPLC method was developed and validated for the determination of berberine hydrochloride and trimethoprim in pharmaceutical dosage form in the presence of degradation products. The proposed RP-HPLC method utilizes an Agilent TC-C18, 4.6 mm × 250 mm, 5 μm, column using a mobile phase consisting of acetonitrile-50 mM potassium dihydrogen phosphate (30 : 70, v/v, pH adjusted to 3 with orthophosphoric acid at a flow rate of 1.0 mL/min and UV detection at 271 nm. The linearity of berberine hydrochloride and trimethoprim was in the range of 2 to 60 μg/mL (r=0.9996 and 1 to 30 μg/mL (r=0.9995, respectively. Repeatability and intermediate precisions were also determined with percentage relative standard deviation (% RSD less than 2.0%. The limits of detection were found to be 9.8 ng/mL for berberine hydrochloride and 2.5 ng/mL for trimethoprim. The mean recoveries for berberine hydrochloride and trimethoprim were 99.8 and 98.8%, respectively. The stability of the two drugs was determined under different conditions and the proposed method has shown effective separation for their degradation products. And the proposed assays method can thus be considered stability-indicating.

  3. Spectrophotometric and Spectrofluorimetric Methods for the Determination of Dothiepin Hydrochloride in its Pure and Dosage Forms using Eosin

    Science.gov (United States)

    Walash, M. I.; Belal, F.; El-Enany, N.; Elmansi, H.

    2010-01-01

    Spectrophotometric and spectrofluorimetric methods were developed for the determination of dothiepin hydrochloride (DOP) in different dosage forms. The spectrophotometric method (Method I) is based on formation of a binary complex with eosin at 540 nm in acetate buffer of pH3.7. The absorbance-concentration plot is rectilinear over the range 1–10 μg/mL with LOD of 0.18 μg/mL and LOQ of 0.54 μg/mL. The spectroflurimetric method (Method II) is based on the quantitative quenching effect of Dothiepin on the native fluorescence of eosin at the same pH. The quenching of the fluorescence of eosin was measured at 543 nm after excitation at 304 nm. The fluorescence-concentration plot is rectilinear over the range 0.3–8 μg/ mL with LOD of 0.11 μg/mL and LOQ of 0.34 μg/mL. The proposed methods were successfully applied to the analysis of commercial tablets and capsules containing the drug. Statistical comparison of the results with those of the reference method revealed good agreement and proved that there were no significant differences in the accuracy and precision between the two methods respectively. PMID:23675210

  4. Stability indicating RP-LC-PDA method for the quantitative analysis of saxagliptin in pharmaceutical dosage form

    Directory of Open Access Journals (Sweden)

    Laís Engroff Scheeren

    2015-06-01

    Full Text Available Saxagliptin is a potent and selective inhibitor of the enzyme dipeptidyl peptidase 4. It is effective in the treatment of type 2 diabetes mellitus because it stimulates the pancreas to produce insulin. In the present study, a liquid chromatography method was developed and validated to quantify the drug in tablets. This method was based on the isocratic elution of saxagliptin, using a mobile phase consisting of 0.1% phosphoric acid at pH 3.0 - methanol (70: 30, v/v at a flow rate of 1 mL.min-1 with UV detection at 225 nm. The chromatographic separation was achieved in 8 minutes on a Waters XBridge C18 column (250 mm x 4.6 mm, 5µm maintained at ambient temperature. The proposed method proved to be specific and robust for the quality control of saxagliptin in pharmaceutical dosage forms, showing good linearity in the range of 15.0 - 100.0 µg.mL-1 (r>0.999, precision (RSD

  5. Simultaneous Estimation of Gemcitabine Hydrochloride and Capecitabine Hydrochloride in Combined Tablet Dosage Form by RP-HPLC Method

    Directory of Open Access Journals (Sweden)

    V. Rajesh

    2011-01-01

    Full Text Available A new reverse phase high performance liquid chromatography (RP-HPLC method has been developed for the simultaneous estimation of gemcitabine hydrochloride and capecitabine hydrochloride in combined tablet dosage form. An inertsil ODS-3 C-18 column having dimensions of 250×4.6 mm and particle size of 5 µm, with mobile phase containing a mixture of acetonitrile : water : triethyelamine in the ratio of (70 : 28 : 2v/v was used. The pH of mobile phase was adjusted to 4.0 with ortho-phosphoric acid. The flow rate was 1 mL/min and the column effluents were monitored at 260 nm. The retention time for gemcitabine hydrochloride and capecitabine hydrochloride was found to be 2.76 and 2.3 min respectively. The proposed method was validated in terms of linearity, accuracy, precision, limit of detection, limit of quantitation and robustness. The method was found to be linear in the range of 10-50 µg/mL and 4-24 µg/mL for gemcitabine hydrochloride and capecitabine hydrochloride, with regression coefficient r = 0.999 and r = 0.999, respectively.

  6. Challenges and opportunities of using liquid chromatography and mass spectrometry methods to develop complex vaccine antigens as pharmaceutical dosage forms.

    Science.gov (United States)

    Hickey, John M; Sahni, Neha; Toth, Ronald T; Kumru, Ozan S; Joshi, Sangeeta B; Middaugh, C Russell; Volkin, David B

    2016-10-01

    Liquid chromatographic methods, combined with mass spectrometry, offer exciting and important opportunities to better characterize complex vaccine antigens including recombinant proteins, virus-like particles, inactivated viruses, polysaccharides, and protein-polysaccharide conjugates. The current abilities and limitations of these physicochemical methods to complement traditional in vitro and in vivo vaccine potency assays are explored in this review through the use of illustrative case studies. Various applications of these state-of-the art techniques are illustrated that include the analysis of influenza vaccines (inactivated whole virus and recombinant hemagglutinin), virus-like particle vaccines (human papillomavirus and hepatitis B), and polysaccharide linked to protein carrier vaccines (pneumococcal). Examples of utilizing these analytical methods to characterize vaccine antigens in the presence of adjuvants, which are often included to boost immune responses as part of the final vaccine dosage form, are also presented. Some of the challenges of using chromatographic and LC-MS as physicochemical assays to routinely test complex vaccine antigens are also discussed. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. New Stability Indicating RP-HPLC Method for the Estimation of Cefpirome Sulphate in Bulk and Pharmaceutical Dosage Forms.

    Science.gov (United States)

    Rao, Kareti Srinivasa; Kumar, Keshar Nargesh; Joydeep, Datta

    2011-01-01

    A simple stability indicating reversed-phase HPLC method was developed and subsequently validated for estimation of Cefpirome sulphate (CPS) present in pharmaceutical dosage forms. The proposed RP-HPLC method utilizes a LiChroCART-Lichrosphere100, C18 RP column (250 mm × 4mm × 5 μm) in an isocratic separation mode with mobile phase consisting of methanol and water in the proportion of 50:50 % (v/v), at a flow rate 1ml/min, and the effluent was monitored at 270 nm. The retention time of CPS was 2.733 min and its formulation was exposed to acidic, alkaline, photolytic, thermal and oxidative stress conditions, and the stressed samples were analyzed by the proposed method. The described method was linear over a range of 0.5-200μg/ml. The percentage recovery was 99.46. F-test and t-test at 95% confidence level were used to check the intermediate precision data obtained under different experimental setups; the calculated value was found to be less than the critical value.

  8. Zein as a Pharmaceutical Excipient in Oral Solid Dosage Forms: State of the Art and Future Perspectives.

    Science.gov (United States)

    Berardi, Alberto; Bisharat, Lorina; AlKhatib, Hatim S; Cespi, Marco

    2018-05-07

    Zein is the main storage protein of corn and it has several industrial applications. Mainly in the last 10-15 years, zein has emerged as a potential pharmaceutical excipient with unique features. Zein is a natural, biocompatible and biodegradable material produced from renewable sources. It is insoluble, yet due to its amphiphilic nature, it has self-assembling properties, which have been exploited for the formation of micromicroparticle and nanoparticle and films. Moreover, zein can hydrate so it has been used in swellable matrices for controlled drug release. Other pharmaceutical applications of zein in oral drug delivery include its incorporation in solid dispersions of poorly soluble drugs and in colonic drug delivery systems. This review describes the features of zein significant for its use as a pharmaceutical excipient for oral drug delivery, and it summaries the literature relevant to macroscopic zein-based oral dosage forms, i.e. tablets, capsules, beads and powders. Particular attention is paid to the most novel formulations and applications of zein. Moreover, gaps of knowledge as well as possible venues for future investigations on zein are highlighted.

  9. Predicting the oral pharmacokinetic profiles of multiple-unit (pellet) dosage forms using a modeling and simulation approach coupled with biorelevant dissolution testing: case example diclofenac sodium.

    Science.gov (United States)

    Kambayashi, Atsushi; Blume, Henning; Dressman, Jennifer B

    2014-07-01

    The objective of this research was to characterize the dissolution profile of a poorly soluble drug, diclofenac, from a commercially available multiple-unit enteric coated dosage form, Diclo-Puren® capsules, and to develop a predictive model for its oral pharmacokinetic profile. The paddle method was used to obtain the dissolution profiles of this dosage form in biorelevant media, with the exposure to simulated gastric conditions being varied in order to simulate the gastric emptying behavior of pellets. A modified Noyes-Whitney theory was subsequently fitted to the dissolution data. A physiologically-based pharmacokinetic (PBPK) model for multiple-unit dosage forms was designed using STELLA® software and coupled with the biorelevant dissolution profiles in order to simulate the plasma concentration profiles of diclofenac from Diclo-Puren® capsule in both the fasted and fed state in humans. Gastric emptying kinetics relevant to multiple-units pellets were incorporated into the PBPK model by setting up a virtual patient population to account for physiological variations in emptying kinetics. Using in vitro biorelevant dissolution coupled with in silico PBPK modeling and simulation it was possible to predict the plasma profile of this multiple-unit formulation of diclofenac after oral administration in both the fasted and fed state. This approach might be useful to predict variability in the plasma profiles for other drugs housed in multiple-unit dosage forms. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Unveiling multiple solid-state transitions in pharmaceutical solid dosage forms using multi-series hyperspectral imaging and different curve resolution approaches

    DEFF Research Database (Denmark)

    Alexandrino, Guilherme L; Amigo Rubio, Jose Manuel; Khorasani, Milad Rouhi

    2017-01-01

    Solid-state transitions at the surface of pharmaceutical solid dosage forms (SDF) were monitored using multi-series hyperspectral imaging (HSI) along with Multivariate Curve Resolution – Alternating Least Squares (MCR-ALS) and Parallel Factor Analysis (PARAFAC and PARAFAC2). First, the solid-stat...

  11. [Pharmaceutical counseling of non-conventional dosage forms concerning the health-literacy and the patient adherence in public medication dispensing -Questionnaire surveys in Hungarian community pharmacies.

    Science.gov (United States)

    Somogyi, O; Zelko, R

    Although the non-conventional dosage forms (e.g. modified release per oral systems or transdermal patches) have more significant advantages than other conventional dosage forms, the pa- tients have to apply them correctly in their home medicine using to reach the effective and safe therapy. A guideline of relevant application instructions contribute to development of an effective pharmaceutical counseling in community pharmacies. The counseling and advices can improve the patients' knowledge concerning application rules of different new dosage forms (health- literacy) with patient adherence. Finally it will result more effective and safer therapies. The aim of our Hungarian questionnaire surveys was to explore the patients' drug application habits or application errors and improve special verbal counseling of mentioned non-conventional dosage forms in community pharmacies. Understandable patient information leaflets were developed about application rules and besides the levels of patients' reading comprehension was evaluated in case of the leaflet of medicinal patches. The results show that a properly developed text is useful for the majority of patients but they need the verbal explanation as well, moreover there is a demand for the verbal counseling in community pharmacies. The most common application errors were explored and the most effective instructions or application rules were collected for the pharmacists and patients concerning the modified release tablets or capsules and transdermal patches.

  12. The knowledge, attitudes and beliefs of patients and their healthcare professionals around oral dosage form modification: A systematic review of the qualitative literature.

    Science.gov (United States)

    Mc Gillicuddy, Aoife; Kelly, Maria; Crean, Abina M; Sahm, Laura J

    The objective of this systematic review was to synthesize the available qualitative evidence on the knowledge, attitudes and beliefs of adult patients, healthcare professionals and carers about oral dosage form modification. A systematic review and synthesis of qualitative studies was undertaken, utilising the thematic synthesis approach. The following databases were searched from inception to September 2015: PubMed, Medline (EBSCO), EMBASE, CINAHL, PsycINFO, Web of Science, ProQuest Databases, Scopus, Turning Research Into Practice (TRIP), Cochrane Central Register of Controlled Trials (CENTRAL) and the Cochrane Database of Systematic Reviews (CDSR). Citation tracking and searching the references lists of included studies was also undertaken. Grey literature was searched using the OpenGrey database, internet searching and personal knowledge. An updated search was undertaken in June 2016. Studies meeting the following criteria were eligible for inclusion; (i) used qualitative data collection and analysis methods; (ii) full-text was available in English; (iii) included adult patients who require oral dosage forms to be modified to meet their needs or; (iv) carers or healthcare professionals of patients who require oral dosage forms to be modified. Two reviewers independently appraised the quality of the included studies using the Critical Appraisal Skills Programme Checklist. A thematic synthesis was conducted and analytical themes were generated. Of 5455 records screened, seven studies were eligible for inclusion; three involved healthcare professionals and the remaining four studies involved patients. Four analytical themes emerged from the thematic synthesis: (i) patient-centred individuality and variability; (ii) communication; (iii) knowledge and uncertainty and; (iv) complexity. The variability of individual patient's requirements, poor communication practices and lack of knowledge about oral dosage form modification, when combined with the complex and multi

  13. Novel potentiometric application for the determination of pantoprazole sodium and itopride hydrochloride in their pure and combined dosage form.

    Science.gov (United States)

    Ragab, Mona T; Abd El-Rahman, Mohamed K; Ramadan, Nesrin K; El-Ragehy, Nariman A; El-Zeany, Badr A

    2015-06-01

    Three sensitive and selective polyvinyl chloride (PVC) matrix membrane electrodes were developed and investigated. Sensor I was developed using tetraheptylammonium bromide (THB) as an anion exchanger with 2-nitrophenyl octyl ether (2-NPOE) as a plasticizer for the determination of the anionic drug pantoprazole sodium sesquihydrate (PAN). To determine the cationic drug itopride hydrochloride (ITH), two electrodes (sensors II and III) were developed using potassium tetrakis(4-chlorophenyl) borate (KTCPB) as a cation exchanger with dioctyl phthalate (DOP) as a plasticizer. Selective molecular recognition components, 2-hydroxypropyl-β-cyclodextrin (2-HP βCD) and 4-tert-butylcalix[8]arene (tBC8), were used as ionophores to improve the selectivity of sensors II and III, respectively. The proposed sensors had a linear dynamic range of 1×10(-5) to 1×10(-2) mol L(-1) with Nernstian slopes of -54.83±0.451, 56.90±0.300, and 51.03±1.909 mV/decade for sensors I, II and III, respectively. The Nernstian slopes were also estimated over the pH ranges of 11-13, 3.5-8 and 4-7 for the three sensors, respectively. The proposed sensors displayed useful analytical characteristics for the determination of PAN and ITH in bulk powder, in laboratory prepared mixtures and in combined dosage forms with clear discrimination from several ions, sugars and some common drug excipients. The method was validated according to ICH guidelines. Statistical comparison between the results from the proposed method and the results from the reference methods showed no significant difference regarding accuracy and precision. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Development and validation of spectrophotometric methods for simultaneous estimation of citicoline and piracetam in tablet dosage form

    Directory of Open Access Journals (Sweden)

    Akhila Sivadas

    2013-01-01

    Full Text Available Context: Citicoline (CN and piracetam (PM combination in tablet formulation is newly introduced in market. It is necessary to develop suitable quality control methods for rapid and accurate determination of these drugs. Aim: The study aimed to develop the methods for simultaneous determination of CN and PM in combined dosage form. Materials and Methods: The first method was developed by formation and solving simultaneous equations using 280.3 and 264.1 nm as two analytical wavelengths. Second method was absorbance ratio in which wavelengths selected were 256.6 nm as its absorptive point and 280.3 nm as λmax of CN. According to International Conference on Harmonization (ICH norm, the parameters - linearity, precision, and accuracy were studied. The methods were validated statistically and by recovery studies. Results: Both the drugs obeyed Beer-Lambert′s law at the selected wavelengths in concentration range of 5-13 μg/ml for CN and 10-22 μg/ml for PM. The percentage of CN and PM in marketed tablet formulation was found to be 99.006 ± 0.173 and 99.257 ± 0.613, respectively; by simultaneous equation method. For Q-Absorption ratio method the percentage of CN and PM was found to be 99.078 ± 0.158 and 99.708 ± 0.838, respectively. Conclusions: The proposed methods were simple, reproducible, precise and robust. The methods can be successfully applied for routine analysis of tablets.

  15. Development and Validation of a Rapid RP-HPLC Method for the Determination of Venlafaxine Hydrochloride in Pharmaceutical Dosage forms using Experimental Design

    Directory of Open Access Journals (Sweden)

    Vanita Somasekhar

    2009-01-01

    Full Text Available The objective of the current study was to develop a simple, accurate, precise and rapid reversed-phase HPLC method and subsequent validation as per ICH guidelines for the determination of venlafaxine hydrochloride in pharmaceutical dosage forms. The proposed RP-HPLC method utilizes a 5 μm Varian® Microsorb-MV 100 C18 column (250 mmx4.6 mm at ambient temperature. A 23 factorial design consisting of 3 factors at 2 levels was set up to standardize the chromatographic conditions. A numerical optimization technique employing the desirability approach was used to locate the optimum chromatographic conditions. The optimum mobile phase consisted of acetonitrile, 0.04 M potassium dihydrogen phosphate buffer and methanol (45:25:30, v/v, with pH adjusted to 5.5 using 10% phosphoric acid solution. The mobile phase was delivered isocratically at a flow rate of 1 mL/min with UV detection at 224 nm. The calibration plots constructed using the optimized chromatographic conditions displayed good linear relationship in the concentration range of 1-50 μg/mL with r=0.9992. The method was validated for precision, accuracy, robustness and recovery. The minimum detectable and minimum quantifiable amounts were found to be 0.568 and 1.72 μg/mL, respectively and the method was found to be reproducible from the statistical data generated. Venlafaxine hydrochloride was eluted at 3.43 min

  16. Optimization of Forced Degradation Using Experimental Design and Development of a Stability-Indicating Liquid Chromatographic Assay Method for Rebamipide in Bulk and Tablet Dosage Form

    Directory of Open Access Journals (Sweden)

    Sandeep SONAWANE

    2016-09-01

    Full Text Available A novel stability-indicating RP-HPLC assay method was developed and validated for quantitative determination of rebamipide in bulk and tablet dosage form. Rebamipide (drug and drug product solutions were exposed to acid and alkali hydrolysis, thermal stress, oxidation by hydrogen peroxide and photodegradation. Experimental design has been used during forced degradation to determine significant factors responsible for degradation and to obtain optimal degradation conditions. In addition, acid and alkali hydrolysis was performed using a microwave oven. The chromatographic method employed the HiQ sil C-18HS (250 × 4.6 mm; 5 μm column with mobile phase consisting of 0.02 M potassium phosphate (pH adjusted to 6.8 and methanol (40:60, v/v and the detection was performed at 230 nm. The procedure was validated for specificity, linearity, accuracy, precision and robustness. There was no interference observed of excipients and degradation products in the determination of the active pharmaceutical ingredient. The method showed good accuracy and precision (intra and inter day and the response was linear in a range from 0.5 to 5 μg mL−1. The method was found to be simple and fast with less trial and error experimentation by making use of experimental design. Also, it proved that microwave energy can be used to expedite hydrolysis of rebamipide.

  17. Optimal Mortgage Refinancing: A Closed Form Solution.

    Science.gov (United States)

    Agarwal, Sumit; Driscoll, John C; Laibson, David I

    2013-06-01

    We derive the first closed-form optimal refinancing rule: Refinance when the current mortgage interest rate falls below the original rate by at least [Formula: see text] In this formula W (.) is the Lambert W -function, [Formula: see text] ρ is the real discount rate, λ is the expected real rate of exogenous mortgage repayment, σ is the standard deviation of the mortgage rate, κ/M is the ratio of the tax-adjusted refinancing cost and the remaining mortgage value, and τ is the marginal tax rate. This expression is derived by solving a tractable class of refinancing problems. Our quantitative results closely match those reported by researchers using numerical methods.

  18. Optimal Mortgage Refinancing: A Closed Form Solution

    Science.gov (United States)

    Agarwal, Sumit; Driscoll, John C.; Laibson, David I.

    2013-01-01

    We derive the first closed-form optimal refinancing rule: Refinance when the current mortgage interest rate falls below the original rate by at least 1ψ[ϕ+W(−exp(−ϕ))]. In this formula W(.) is the Lambert W-function, ψ=2(ρ+λ)σ,ϕ=1+ψ(ρ+λ)κ∕M(1−τ), ρ is the real discount rate, λ is the expected real rate of exogenous mortgage repayment, σ is the standard deviation of the mortgage rate, κ/M is the ratio of the tax-adjusted refinancing cost and the remaining mortgage value, and τ is the marginal tax rate. This expression is derived by solving a tractable class of refinancing problems. Our quantitative results closely match those reported by researchers using numerical methods. PMID:25843977

  19. Validated sensitive spectrofluorimetric method for determination of antihistaminic drug azelastine HCl in pure form and in pharmaceutical dosage forms: application to stability study.

    Science.gov (United States)

    El-Masry, Amal A; Hammouda, Mohammed E A; El-Wasseef, Dalia R; El-Ashry, Saadia M

    2017-03-01

    A highly sensitive, simple and rapid spectrofluorimetric method was developed for the determination of azelastine HCl (AZL) in either its pure state or pharmaceutical dosage form. The proposed method was based on measuring the native fluorescence of the studied drug in 0.2 M H 2 SO 4 at λ em  = 364 nm after excitation at λ ex  = 275 nm. Different experimental parameters were studied and optimized carefully to obtain the highest fluorescence intensity. The proposed method showed a linear dependence of the fluorescence intensity on drug concentration over a concentration range of 10-250 ng/mL, with a limit of detection of 1.52 ng/mL and limit of quantitation of 4.61 ng/mL. Moreover, the method was successfully applied to pharmaceutical preparations, with percent recovery values (± SD) of 99.96 (± 0.4) and 100.1 (± 0.52) for nasal spray and eye drops, respectively. The results were in good agreement with those obtained by the comparison method, as revealed by Student's t-test and the variance ratio F-test. The method was extended to study the stability of AZL under stress conditions, where the drug was exposed to neutral, acidic, alkaline, oxidative and photolytic degradation according to International Conference on Harmonization (ICH) guidelines. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  20. Potentiometric determination of free nitric-acid in trilaurylamine solutions containing plutonium nitrate; Dosage potentiometrique de l'acidite nitrique libre dans les solutions organiques de trilaurylamine

    Energy Technology Data Exchange (ETDEWEB)

    Perez, J J; Saey, J C [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1965-07-01

    A potentiometric method of determination of the free nitric acid in trilaurylamine solutions containing plutonium or thorium nitrates is described. The potentiometric titration is carried out in a mixture of benzene and 1,2-dichloro ethane with a standard solution of trilaurylamine as the titrant. When thorium nitrate is present the metal complex is not dissociated then the titration has a single end-point. In the case of plutonium nitrate the partial dissociation of the plutonium complex corresponds to a second point. The experimental error in duplicate analyses of 50 samples is about 1 per cent for free acid concentrations in the range of 0,03 to 0,1 N and plutonium concentrations between 1 to 5 g/l. (authors) [French] Une methode potentiometrique de dosage de l'acidite nitrique libre dans les solutions de trilaurylamine contenant un complexe de plutonium ou de thorium est decrite. La potentiometrie est effectuee en prenant comme base titrante la trilaurylamine et comme milieu de dilution un melange de benzene et de 1,2 dichloroethane. Dans le cas du thorium, le complexe organometallique n'est pas deplace et la courbe de titrage presente un seul point d'inflexion. Dans le cas du plutonium le complexe est partiellement dissocie ce qui correspond a un second saut de potentiel. La moyenne des erreurs experimentales sur 50 echantillons doses a ete d'environ {+-} 1 pour cent sur l'acide libre. Les solutions experimentees contenaient de 0,03 a 0,1 N en acide et de 1 a 5 g/l en plutonium. (auteurs)

  1. Development and Validation of RP-HPLC Method for the Simultaneous Determination of Rabeprazole Sodium and Itopride Hydrochloride in Solid Dosage Form

    Directory of Open Access Journals (Sweden)

    Rajesh Sharma

    2010-01-01

    Full Text Available A simple, sensitive, precise, accurate, rapid and reproducible reverse phase high performance liquid chromatographic procedure is developed for simultaneous determination of rabeprazole sodium and itopride hydrochloride in solid dosage form. The mobile phase used was a combination of acetonitrile: buffer (35:65 v/v and the pH was adjusted to 7.0 ± 0.1 by addition of triethylamine. The detection of the capsule dosage form was carried out at 266 nm and a flow rate employed was 1 mL/min. Linearity was obtained in the concentration range of 2 to 16 μg/mL of rabeprazole sodium and 5 to 55 μg/mL of itopride hydrochloride with a correlation coefficient of 0.9992 and 0.9996 respectively. The results of the analysis were validated statistically and recovery studies confirmed the accuracy of the proposed method.

  2. A novel once daily microparticulate dosage form comprising lansoprazole to prevent nocturnal acid breakthrough in the case of gastro-esophageal reflux disease: preparation, pharmacokinetic and pharmacodynamic evaluation.

    Science.gov (United States)

    Alai, Milind; Lin, Wen Jen

    2013-01-01

    The objective of this study was to formulate and evaluate the lansoprazole (LPZ)-loaded microparticles to prevent nocturnal acid breakthrough in the case of gastro-esophageal reflux disease (GERD). The microparticulate delivery system was prepared by solvent evaporation method using Eudragit RS100 as a matrix polymer followed by enteric coated with Eudragit S100 and hydroxypropyl methylcellulose phthalate HP55 using spray drying method. The enteric coated microparticles were stable in gastric pH condition. In vivo pharmacokinetic and pharmacodynamic studies in male Wistar rats demonstrated that enteric coated microparticles sustained release of LPZ and promoted ulcer healing activity. In other words, the microparticulate dosage form provided effective drug concentration for a longer period as compared to conventional extended release dosage form, and showed sufficient anti-acid secretion activity to treat acid related disorders including the enrichment of nocturnal acid breakthrough event based on a once daily administration.

  3. Development and Validation of UV-Visible Spectrophotometric Methods for Simultaneous Estimation of Thiocolchicoside and Dexketoprofen in Bulk and Tablet Dosage Form

    OpenAIRE

    M. T. Harde; S. B. Jadhav; D. L. Dharam; P. D. Chaudhari

    2012-01-01

    Development and validation of two simple, accurate, precise and economical UV Spectrophotometric methods for simultaneous estimation of Thiocolchicoside and Dexketoprofen in bulk and in tablet dosage form. The methods employed were Method-1 Absorbance correction method and Method-2 First order derivative spectroscopic method. In method-1 Absorbance is measured at two wavelengths 370nm at which Dexketoprofen has no absorbance and 255nm at which both the drug have considerable absorbance. In me...

  4. Development and Validation of a Precise, Single HPLC Method for the Determination of Tolperisone Impurities in API and Pharmaceutical Dosage Forms

    OpenAIRE

    Raju, Thummala Veera Raghava; Seshadri, Raja Kumar; Arutla, Srinivas; Mohan, Tharlapu Satya Sankarsana Jagan; Rao, Ivaturi Mrutyunjaya; Nittala, Someswara Rao

    2012-01-01

    A novel, sensitive, stability-indicating HPLC method has been developed for the quantitative estimation of Tolperisone-related impurities in both bulk drugs and pharmaceutical dosage forms. Effective chromatographic separation was achieved on a C18 stationary phase with a simple mobile phase combination delivered in a simple gradient programme, and quantitation was by ultraviolet detection at 254 nm. The mobile phase consisted of a buffer and acetonitrile delivered at a flow rate 1.0 ml/min. ...

  5. Semi-quantitative prediction of a multiple API solid dosage form with a combination of vibrational spectroscopy methods.

    Science.gov (United States)

    Hertrampf, A; Sousa, R M; Menezes, J C; Herdling, T

    2016-05-30

    Quality control (QC) in the pharmaceutical industry is a key activity in ensuring medicines have the required quality, safety and efficacy for their intended use. QC departments at pharmaceutical companies are responsible for all release testing of final products but also all incoming raw materials. Near-infrared spectroscopy (NIRS) and Raman spectroscopy are important techniques for fast and accurate identification and qualification of pharmaceutical samples. Tablets containing two different active pharmaceutical ingredients (API) [bisoprolol, hydrochlorothiazide] in different commercially available dosages were analysed using Raman- and NIR Spectroscopy. The goal was to define multivariate models based on each vibrational spectroscopy to discriminate between different dosages (identity) and predict their dosage (semi-quantitative). Furthermore the combination of spectroscopic techniques was investigated. Therefore, two different multiblock techniques based on PLS have been applied: multiblock PLS (MB-PLS) and sequential-orthogonalised PLS (SO-PLS). NIRS showed better results compared to Raman spectroscopy for both identification and quantitation. The multiblock techniques investigated showed that each spectroscopy contains information not present or captured with the other spectroscopic technique, thus demonstrating that there is a potential benefit in their combined use for both identification and quantitation purposes. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. PREPARATION AND CHARACTERIZATION OF CO-PROCESSED EXCIPIENT-PREGELATINIZED CASSAVA STARCH PROPIONATE AS A MATRIX IN THE GASTRORETENTIVE DOSAGE FORM

    Directory of Open Access Journals (Sweden)

    Junaedi

    2011-11-01

    Full Text Available The gastroretentive dosage form is designed to prolong the gastric residence time of the drug delivery system whichalso results in the development of an appropriate excipient. The purpose of this study is to develop and characterize coprocessedexcipient made from carrageenan (kappa-iota = 1:1 and pregelatinized cassava starch propionate (PCSP inratios of 1:1, 1:2, and 1:3. PCSP was prepared with propionic anhydride in an aqueous medium. The product was mixedwith carrageenan (kappa-iota = 1:1, as well as characterized physicochemical and functional properties. The coprocessedexcipient was then used as a mucoadhesive granule and floating tablet. The USP Basket was selected toperform the dissolution test of the granules in HCl buffer (pH 1.2 and distilled water for 8 hours each. Mucoadhesiveproperties were evaluated using bioadhesive through a vitro test and wash-off test. As for the floating tablet, the USPPaddle was selected to perform the dissolution test of the tablets in 0.1 N HCl for 10 hours. The floating lag time andfloating time were tested in 0.1 N HCl for 24 hours. The result of these studies indicated that co-processed excipientcarrageenan-PCSP can retard dosage form in gastric and drug controlled release, thus making it a suitable material forthe gastroretentive dosage form.

  7. COMPARISON OF PHYSICAL STABILITY PROPERTIES OF POMEGRANATE SEED OIL NANOEMULSION DOSAGE FORMS WITH LONG-CHAIN TRIGLYCERIDE AND MEDIUM-CHAIN TRIGLYCERIDE AS THE OIL PHASE

    Directory of Open Access Journals (Sweden)

    Sri Hartanti Yuliani

    2016-08-01

    Full Text Available Pomegranate seed oil has antioxidant, anti-inflammatory, and chemo preventive activities. Pomegranate seed oil is lipophilic substance suitable to be prepared in emulsion dosage forms. Long-chain triglyceride (LCT and medium-chain triglyceride (MCT are commonly used as oil phase in emulsion dosage forms. This research aimed to compare the use of LCT and MCT in the Nano emulsion formula of pomegranate seed oil dosage forms. Formulation of pomegranate seed oil Nano emulsion was conducted using high energy emulsification. Parameters observed were pH, Nano emulsion type, percent transmittance, viscosity, turbidity, and droplet size before and after 3 cycles of freeze-thaw. The result showed that there was no significant difference between physical properties of pomegranate oil Nano emulsion with LCT as oil phase and pomegranate oil Nano emulsion with MCT as oil phase. Moreover, physical stability of pomegranate oil Nano emulsion with LCT as oil phase was better than pomegranate oil Nano emulsion with MCT as oil phase.

  8. Pasteurization as a tool to control the bio-burden in solid herbal dosage forms: A pilot study of formulating Ashoka tablets with an industrial perspective.

    Science.gov (United States)

    Pushpalatha, Hulikal Basavarajaiah; Pramod, Kumar; Sundaram, Ramachandran; Shyam, Ramakrishnan

    2014-10-01

    Irradiation and use of preservatives are routine procedures to control bio-burden in solid herbal dosage forms. Use of steam or pasteurization is even though reported in the literature, not many studies are available with respect to its application in reducing the bio-burden in herbal drug formulations. Hence, we undertook a series of studies to explore the suitability of pasteurization as a method to reduce bio-burden during formulation and development of herbal dosage forms, which will pave the way for preparing preservative-free formulations. Optimized Ashoka (Saraca indica) tablets were formulated and developed. The optimized formula was then subjected to pasteurization during formulation, with an aim to keep the microbial count well within the limits of pharmacopoeial standards. Then, three variants of the optimized Ashoka formulation - with preservative, without preservative and formulation without preservative and subjected to pasteurization, were compared by routine in-process parameters and stability studies. The results obtained indicate that Ashoka tablets manufactured by inclusion of the pasteurization technique not only showed the bio-burden to be within the limits of pharmacopoeial standards, but also exhibited the compliance with other parameters, such as stability and quality. The outcome of this pilot study shows that pasteurization can be employed as a distinctive method for reducing bio-burden during the formulation and development of herbal dosage forms, such as tablets.

  9. Simultaneous determination of related substances of telmisartan and hydrochlorothiazide in tablet dosage form by using reversed phase high performance liquid chromatographic method

    Directory of Open Access Journals (Sweden)

    Sutirtho Mukhopadhyay

    2011-01-01

    Full Text Available Objective : Telmisartan is a potent, long-lasting, nonpeptide antagonist of the angiotensin II type-1 (AT 1 receptor that is indicated for the treatment of essential hypertension. Hydrochlorothiazide is a widely prescribed diuretic and it is indicated for the treatment of edema, control of essential hypertension and management of diabetes insipidus. In the current article a new, accurate, sensitive, precise, rapid, reversed phase high performance liquid chromatography (RP-HPLC method was developed for determination of related substances of Telmisartan and Hydrochlorthiazide in tablet dosage form. Materials and Methods : Simultaneous determination of related substances was performed on Kromasil C 18 analytical column (250 × 4.6 mm; 5΅m pertical size column at 40°C employing a gradient elution. Mobile phase consisting of solvent A (solution containing 2.0 g of potassium dihydrogen phosphate anhydrous and 1.04 g of Sodium 1- Hexane sulphonic acid monohydrate per liter of water, adjusted to pH 3.0 with orthophosphoric acid and solvent B (mixture of Acetonitrile: Methanol in the ratio 80:20 v/v was used at a flow rate of 1.0 ml min−1 . UV detection was performed at 270 nm. Results : During method validation parameter such as precision, linearity, accuracy, specificity, limit of detection and quantification were evaluated, which remained within acceptable limits. Conclusions : HPLC analytical method is linear, accurate, precise, robust and specific, being able to separate the main drug from its degradation products. It may find application for the routine analysis of the related substances of both Telmisartan and Hydrochlorthiazide in this combination tablets.

  10. A Study of Method Development, Validation, and Forced Degradation for Simultaneous Quantification of Paracetamol and Ibuprofen in Pharmaceutical Dosage Form by RP-HPLC Method

    Directory of Open Access Journals (Sweden)

    Md. Sarowar Jahan

    2014-01-01

    Full Text Available A rapid and stability-indicating reversed phase high-performance liquid chromatography (RP-HPLC method was developed for simultaneous quantification of paracetamol and ibuprofen in their combined dosage form especially to get some more advantages over other methods already developed for this combination. The method was validated according to United States Pharmacopeia (USP guideline with respect to accuracy, precision, specificity, linearity, solution stability, robustness, sensitivity, and system suitability. Forced degradation study was validated according to International Conference on Harmonisation (ICH. For this, an isocratic condition of mobile phase comprising phosphate buffer (pH 6.8 and acetonitrile in a ratio of 65:35, v/v at a flow rate of 0.7 mL/minute over RP C18 (octadecylsilane (ODS, 150 × 4.6 mm, 5 μm, Phenomenex Inc. column at ambient temperature was maintained. The method showed excellent linear response with correlation coefficient ( R 2 values of 0.999 and 1.0 for paracetamol and ibuprofen respectively, which were within the limit of correlation coefficient ( R 2 > 0.995. The percent recoveries for two drugs were found within the acceptance limit of (97.0-103.0%. Intra-and inter-day precision studies of the new method were less than the maximum allowable limit percentage of relative standard deviation (%RSD ≤ 2.0. Forced degradation of the drug product was carried out as per the ICH guidelines with a view to establishing the stability-indicating property of this method and providing useful information about the degradation pathways, degradation products, and how the quality of a drug substance and drug product changes with time under the influence of various stressing conditions. The degradation of ibuprofen was within the limit (5-20%, according to the guideline of ICH, while paracetamol showed <20% degradation in oxidation and basic condition.

  11. A Study of Method Development, Validation, and Forced Degradation for Simultaneous Quantification of Paracetamol and Ibuprofen in Pharmaceutical Dosage Form by RP-HPLC Method.

    Science.gov (United States)

    Jahan, Md Sarowar; Islam, Md Jahirul; Begum, Rehana; Kayesh, Ruhul; Rahman, Asma

    2014-01-01

    A rapid and stability-indicating reversed phase high-performance liquid chromatography (RP-HPLC) method was developed for simultaneous quantification of paracetamol and ibuprofen in their combined dosage form especially to get some more advantages over other methods already developed for this combination. The method was validated according to United States Pharmacopeia (USP) guideline with respect to accuracy, precision, specificity, linearity, solution stability, robustness, sensitivity, and system suitability. Forced degradation study was validated according to International Conference on Harmonisation (ICH). For this, an isocratic condition of mobile phase comprising phosphate buffer (pH 6.8) and acetonitrile in a ratio of 65:35, v/v at a flow rate of 0.7 mL/minute over RP C18 (octadecylsilane (ODS), 150 × 4.6 mm, 5 μm, Phenomenex Inc.) column at ambient temperature was maintained. The method showed excellent linear response with correlation coefficient (R (2)) values of 0.999 and 1.0 for paracetamol and ibuprofen respectively, which were within the limit of correlation coefficient (R (2) > 0.995). The percent recoveries for two drugs were found within the acceptance limit of (97.0-103.0%). Intra-and inter-day precision studies of the new method were less than the maximum allowable limit percentage of relative standard deviation (%RSD) ≤ 2.0. Forced degradation of the drug product was carried out as per the ICH guidelines with a view to establishing the stability-indicating property of this method and providing useful information about the degradation pathways, degradation products, and how the quality of a drug substance and drug product changes with time under the influence of various stressing conditions. The degradation of ibuprofen was within the limit (5-20%, according to the guideline of ICH), while paracetamol showed degradation in oxidation and basic condition.

  12. The Impact of Wine Style and Sugar Addition in liqueur d’expedition (dosage Solutions on Traditional Method Sparkling Wine Composition

    Directory of Open Access Journals (Sweden)

    Belinda Kemp

    2017-01-01

    Full Text Available The purpose of this study was to investigate the effect of wine style and cane sugar addition in the liqueur d’expedition (dosage solution on volatile aroma compounds (VOCs in traditional method sparkling wine. There were 24 bottles of each treatment produced. Treatments were sparkling wine zero dosage (ZD; NV sparkling wine + sugar (BS; unoaked still Chardonnay wine + sugar (UC; Pinot noir 2009 sparkling wine + sugar (PN; Niagara produced Brandy + sugar (B and Icewine (IW. The control treatment in the sensory analysis was an oaked still Chardonnay wine + sugar (OC because the zero-dosage wine was not suitable for a difference test that compared wines with sugar to one without. Standard wine chemical parameters were analysed before disgorging and after liqueur d’expedition was added and included; pH, titratable acidity (TA g/L, alcohol (v/v %, residual sugar (RS g/L, free and total SO2 and total phenolics (A.U.. Volatile aroma compounds (VOCs analysed by Headspace Solid- Phase Micro-Extraction Gas Chromatography-Mass Spectrometry (HS-SPME-GC-MS included two alcohols, and six ethyl esters. ZD wines had the highest foam height and highest dissolved oxygen level. Sugar affected VOC concentrations in all treatments at five weeks post-disgorging, but by 15 weeks after liqueur d’expedition addition, the wine with added sugar had similar VOC concentrations to the ZD wines. The type of wines used in the dosage solutions had more influence on VOC concentrations than sugar addition.

  13. Electrospun poly(ε-caprolactone) matrices containing silver sulfadiazine complexed with β-cyclodextrin as a new pharmaceutical dosage form to wound healing: preliminary physicochemical and biological evaluation.

    Science.gov (United States)

    Souza, Sarah Oliveira Lamas; Cotrim, Monique Alvarenga Pinto; Oréfice, Rodrigo Lambert; Carvalho, Suzana Gonçalves; Dutra, Jessyca Aparecida Paes; de Paula Careta, Francisco; Resende, Juliana Alves; Villanova, Janaina Cecília Oliveira

    2018-05-10

    Cooperation between researchers in the areas of medical, pharmaceutical and materials science has facilitated the development of pharmaceutical dosage forms that elicit therapeutic effects and protective action with a single product. In addition to optimizing pharmacologic action, such dosage forms provide greater patient comfort and increase success and treatment compliance. In the present work, we prepared semipermeable bioactive electrospun fibers for use as wound dressings containing silver sulfadiazine complexed with β-cyclodextrin in a poly(Ɛ-caprolactone) nanofiber matrix aiming to reduce the direct contact between silver and skin and to modulate the drug release. Wound dressings were prepared by electrospinning, and were subjected to ATR-FT-IR and TG/DTG assays to evaluate drug stability. The hydrophilicity of the fibrous nanostructure in water and PBS buffer was studied by goniometry. Electrospun fibers permeability and swelling capacity were assessed, and a dissolution test was performed. In vitro biological tests were realized to investigate the biological compatibility and antimicrobial activity. We obtained flexible matrices that were each approximately 1.0 g in weight. The electrospun fibers were shown to be semipermeable, with water vapor transmission and swelling indexes compatible with the proposed objective. The hydrophilicity was moderate. Matrices containing pure drug modulated drug release adequately during 24 h but presented a high hemolytic index. Complexation promoted a decrease in the hemolytic index and in the drug release but did not negatively impact antimicrobial activity. The drug was released predominantly by diffusion. These results indicate that electrospun PCL matrices containing β-cyclodextrin/silver sulfadiazine inclusion complexes are a promising pharmaceutical dosage form for wound healing.

  14. Development and Validation of a Stability-Indicating RP-HPLC Method for Rapid Determination of Doxycycline in Pharmaceutical Bulk and Dosage Forms

    OpenAIRE

    Shabnam Pourmoslemi, Soroush Mirfakhraee, Saeid Yaripour, Ali Mohammadi

    2016-01-01

    Background: A rapid stability-indicating RP-HPLC method for analysis of doxycycline in the presence of its degradation products was developed and validated. Methods: Forced degradation studies were carried out on bulk samples and capsule dosage forms of doxycycline using acid, base, H2O2, heat, and UV light as described by ICH for stress conditions to demonstrate the stability-indicating power of the method. Separations were performed on a Perfectsil® Target ODS column (3-5µm, 125 mm×4 mm), u...

  15. Inverse Kinematics With Closed Form Solution For Denso Robot Manipulator

    OpenAIRE

    Ikhsan Eka Prasetia; Trihastuti Agustinah

    2015-01-01

    In this paper, the forward kinematics and inverse kinematics used on the Denso robot manipulator which has a 6-DOF. The forward kinematics will result in the desired position by end-effector, while inverse kinematics produce angel on each joint. Inverse kinematics problem are very difficult, therefor to obtain the solution of inverse kinematics using closed form solution with geometry approach. The simulation result obtained from forward kinematics and inverse kinematics is determining desire...

  16. Development of a stability-indicating high performance liquid chromatography method for assay of erythromycin ethylsuccinate in powder for oral suspension dosage form

    Directory of Open Access Journals (Sweden)

    Fahimeh Kamarei

    2014-12-01

    Full Text Available In this study an effective method was developed to assay erythromycin ethylsuccinate for an oral suspension dosage form. The chromatographic separation was achieved on an X-Terra™ C18 analytical column. A mixture of acetonitrile–ammonium dihydrogen phosphate buffer (0.025 mol L-1 (60:40, V/V (pH 7.0 was used as the mobile phase, effluent flow rate monitored at 1.0 mL min−1, and UV detection at 205 nm. In forced degradation studies, the effects of acid, base, oxidation, UV light and temperature were investigated showing no interference in the peak of drug. The proposed method was validated in terms of specificity, linearity, robustness, precision and accuracy. The method was linear at concentrations ranging from 400 to 600 μg mL−1, precise (intra- and inter-day relative standard deviations <0.65, accurate (mean recovery; 99.5%. The impurities and degradation products of erythromycin ethylsuccinate were selectively determined with good resolution in both the raw material and the final suspension forms. The method could be useful for both routine analytical and quality control assays of erythromycin ethylsuccinate in commercial powder for an oral suspension dosage form and it could be a very powerful tool to investigate the chemical stability of erythromycin ethylsuccinate.

  17. Determination of dasatinib in the tablet dosage form by ultra high performance liquid chromatography, capillary zone electrophoresis, and sequential injection analysis.

    Science.gov (United States)

    Gonzalez, Aroa Garcia; Taraba, Lukáš; Hraníček, Jakub; Kozlík, Petr; Coufal, Pavel

    2017-01-01

    Dasatinib is a novel oral prescription drug proposed for treating adult patients with chronic myeloid leukemia. Three analytical methods, namely ultra high performance liquid chromatography, capillary zone electrophoresis, and sequential injection analysis, were developed, validated, and compared for determination of the drug in the tablet dosage form. The total analysis time of optimized ultra high performance liquid chromatography and capillary zone electrophoresis methods was 2.0 and 2.2 min, respectively. Direct ultraviolet detection with detection wavelength of 322 nm was employed in both cases. The optimized sequential injection analysis method was based on spectrophotometric detection of dasatinib after a simple colorimetric reaction with folin ciocalteau reagent forming a blue-colored complex with an absorbance maximum at 745 nm. The total analysis time was 2.5 min. The ultra high performance liquid chromatography method provided the lowest detection and quantitation limits and the most precise and accurate results. All three newly developed methods were demonstrated to be specific, linear, sensitive, precise, and accurate, providing results satisfactorily meeting the requirements of the pharmaceutical industry, and can be employed for the routine determination of the active pharmaceutical ingredient in the tablet dosage form. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Closed form solutions of two time fractional nonlinear wave equations

    Directory of Open Access Journals (Sweden)

    M. Ali Akbar

    2018-06-01

    Full Text Available In this article, we investigate the exact traveling wave solutions of two nonlinear time fractional wave equations. The fractional derivatives are described in the sense of conformable fractional derivatives. In addition, the traveling wave solutions are accomplished in the form of hyperbolic, trigonometric, and rational functions involving free parameters. To investigate such types of solutions, we implement the new generalized (G′/G-expansion method. The extracted solutions are reliable, useful and suitable to comprehend the optimal control problems, chaotic vibrations, global and local bifurcations and resonances, furthermore, fission and fusion phenomena occur in solitons, the relativistic energy-momentum relation, scalar electrodynamics, quantum relativistic one-particle theory, electromagnetic interactions etc. The results reveal that the method is very fruitful and convenient for exploring nonlinear differential equations of fractional order treated in theoretical physics. Keywords: Traveling wave solution, Soliton, Generalized (G′/G-expansion method, Time fractional Duffing equation, Time fractional Riccati equation

  19. Effect of surfactants, gastric emptying, and dosage form on supersaturation of dipyridamole in an in vitro model simulating the stomach and duodenum.

    Science.gov (United States)

    Mitra, A; Fadda, H M

    2014-08-04

    The purpose of this study was to investigate the influence of gastric emptying patterns, surfactants, and dosage form on the supersaturation of a poorly soluble weakly basic drug, dipyridamole, using an in vitro model mimicking the dynamic environment of the upper gastrointestinal tract, and, furthermore, to evaluate the usefulness of this model in establishing correlations to in vivo bioavailability for drugs with solubility/dissolution limited absorption. A simulated stomach duodenum model comprising four compartments was used to assess supersaturation and precipitation kinetics as a function of time. It integrates physiologically relevant fluid volumes, fluid transfer rates, and pH changes of the upper GI tract. Monoexponential gastric emptying patterns simulating the fasted state were compared to linear gastric emptying patterns simulating the fed state. The effect of different surfactants commonly used in oral preparations, specifically, sodium lauryl sulfate (SLS), poloxamer-188, and polysorbate-80, on dipyridamole supersaturation was investigated while maintaining surface tension of the simulated gastric fluids at physiological levels and without obtaining artificial micellar solubilization of the drug. The supersaturation behavior of different dose strengths of dipyridamole was explored. Significant levels of dipyridamole supersaturation were observed in the duodenal compartment under all the different in vivo relevant conditions explored. Dipyridamole supersaturation ratios of up to 11-fold have been observed, and supersaturation has been maintained for up to 120 min. Lower duodenal concentrations of dipyridamole were observed under linear gastric emptying patterns compared to mononexponential gastric emptying. The mean duodenal area under concentration-time curves (AUC60min) for the dipyridamole concentration profile in the duodenal compartment is significantly different for all the surfactants explored (P stomach duodenum model can provide a reliable and

  20. A Stability-Indicating HPLC Method for the Determination of Memantine Hydrochloride in Dosage Forms through Derivatization with 1-Fluoro-2,4-dinitrobenzene

    Science.gov (United States)

    Jalalizadeh, Hassan; Raei, Mahdi; Tafti, Razieh Fallah; Farsam, Hassan; Kebriaeezadeh, Abbas; Souri, Effat

    2014-01-01

    Memantine is chemically a tricyclic amine and is used for Parkinson’s disease and movement disorders. Although several HPLC methods with different derivatization reagents have been developed for the determination of memantine in biological fluids, there are some complications which limit the use of these methods in routine analysis of memantine in in vitro tests. We established a simple, sensitive, precise, and accurate HPLC method for the quantification of memantine in dosage forms. Pre-column derivatization of memantine was performed with 1-fluoro-2,4-dinitrobenzene and the reaction product was separated on a Nova-Pak C18 column. A mixture of acetonitrile and sodium dihydrogenphosphate (pH 2.5; 0.05 M) (70: 30, v/v) was used as the mobile phase. UV detection was performed at 360 nm. Forced degradation studies were performed on a powdered tablet sample of memantine hydro-chloride using acidic (0.1 M hydrochloric acid), basic (0.1 M sodium hydroxide), oxidative (10% hydrogen peroxide), thermal (105°C), photolytic, and humidity conditions. Good linearity (r2=0.999) was obtained over the range of 1–12 μg mL−1 of memantine hydrochloride with acceptable within-day and between-day precision values in the range of 0.05–0.95%. The proposed method was used for the assay determination and dissolution rate study of memantine dosage forms with excellent specificity. PMID:24959398

  1. Development and Validation of a Stability-Indicating RP-HPLC Method for Rapid Determination of Doxycycline in Pharmaceutical Bulk and Dosage Forms

    Directory of Open Access Journals (Sweden)

    Shabnam Pourmoslemi, Soroush Mirfakhraee, Saeid Yaripour, Ali Mohammadi

    2016-06-01

    Full Text Available Background: A rapid stability-indicating RP-HPLC method for analysis of doxycycline in the presence of its degradation products was developed and validated. Methods: Forced degradation studies were carried out on bulk samples and capsule dosage forms of doxycycline using acid, base, H2O2, heat, and UV light as described by ICH for stress conditions to demonstrate the stability-indicating power of the method. Separations were performed on a Perfectsil® Target ODS column (3-5µm, 125 mm×4 mm, using a mobile phase consisting of methanol-50 mM ammonium acetate buffer (containing 0.1% v/v trifluoroacetic acid and 0.1% v/v triethylamine, pH 2.5 (50:50 v/v at room temperature. The flow rate was 0.8 mL/min. Results: The method linearity was investigated in the range of 25–500 µg/mL (r > 0.9999. The LOD and LOQ were 5 and 25 µg/mL, respectively. The method selectivity was evaluated by peak purity test using a diode array detector. There was no interference among detection of doxycycline and its stressed degradation products. Total peak purity numbers were in the range of 0.94-0.99, indicating the homogeneity of DOX peaks. Conclusion: These data show the stability-indicating nature of the method for quality control of doxycycline in bulk samples and capsule dosage forms.

  2. Utility of Hantzsch reaction for development of highly sensitive spectrofluorimetric method for determination of alfuzosin and terazosin in bulk, dosage forms and human plasma.

    Science.gov (United States)

    Hammad, Mohamed A; Omar, Mahmoud A; Salman, Baher I

    2017-09-01

    A highly sensitive, cheap, simple and accurate spectrofluorimetric method has been developed and validated for the determination of alfuzosin hydrochloride and terazosin hydrochloride in their pharmaceutical dosage forms and in human plasma. The developed method is based on the reaction of the primary amine moiety in the studied drugs with acetylacetone and formaldehyde according to the Hantzsch reaction, producing yellow fluorescent products that can be measured spectrofluorimetrically at 480 nm after excitation at 415 nm. Different experimental parameters affecting the development and stability of the reaction products were carefully studied and optimized. The fluorescence-concentration plots of alfuzosin and terazosin were rectilinear over a concentration range of 70-900 ng ml -1 , with quantitation limits 27.1 and 32.2 ng ml -1 for alfuzosin and terazosin, respectively. The proposed method was validated according to ICH guidelines and successfully applied to the analysis of the investigated drugs in dosage forms, content uniformity test and spiked human plasma with high accuracy. Copyright © 2017 John Wiley & Sons, Ltd.

  3. Stability-indicating UPLC method for determination of Valsartan and their degradation products in active pharmaceutical ingredient and pharmaceutical dosage forms.

    Science.gov (United States)

    Krishnaiah, Ch; Reddy, A Raghupathi; Kumar, Ramesh; Mukkanti, K

    2010-11-02

    A simple, precise, accurate stability-indicating gradient reverse phase ultra-performance liquid chromatographic (RP-UPLC) method was developed for the quantitative determination of purity of Valsartan drug substance and drug products in bulk samples and pharmaceutical dosage forms in the presence of its impurities and degradation products. The method was developed using Waters Aquity BEH C18 (100 mm x 2.1 mm, 1.7 microm) column with mobile phase containing a gradient mixture of solvents A and B. The eluted compounds were monitored at 225 nm, the run time was within 9.5 min, which Valsartan and its seven impurities were well separated. Valsartan was subjected to the stress conditions of oxidative, acid, base, hydrolytic, thermal and photolytic degradation. Valsartan was found to degrade significantly in acid and oxidative stress conditions and stable in base, hydrolytic and photolytic degradation conditions. The degradation products were well resolved from main peak and its impurities, proving the stability-indicating power of the method. The developed method was validated as per international conference on harmonization (ICH) guidelines with respect to specificity, linearity, limit of detection, limit of quantification, accuracy, precision and robustness. This method was also suitable for the assay determination of Valsartan in pharmaceutical dosage forms.

  4. A Validated Stability Indicating RP-HPLC Method for the Determination of Emtricitabine, Tenofovir Disoproxil Fumarate, Elvitegravir and Cobicistat in Pharmaceutical Dosage Form

    Science.gov (United States)

    Runja, Chinnalalaiah; Ravi Kumar, Pigili; Avanapu, Srinivasa Rao

    2016-01-01

    A new simple, rapid stability indicating assay method has been developed and validated for the determination of emtricitabine, tenofovir disoproxil fumarate, elvitegravir and cobicistat using reverse-phase high-performance liquid chromatography in their pharmaceutical dosage form. The chromatographic separation was performed on an ODS column (250 × 4.6 mm, 5 µm) using mobile phase A (potassium dihydrogen orthophosphate, pH adjusted to 2.5) and mobile phase B (acetonitrile) in the ratio of 55:45% v/v at a flow rate of 1 mL/min. The analytes were detected at 250 nm. The method was found to be linear in the concentration range of 2–12 µg/mL for EMT, 3–18 µg/mL for TNDF, 1.5–9 µg/mL for ELV and COB, with the coefficient value (R2) of >0.9990. The accuracy was measured via recovery studies and found to be acceptable, and the percentage recoveries were found in the range of 99.93–100.08 ± 0.5%. Forced degradation studies were also conducted, and the drugs were subjected to various stress conditions such as acid hydrolysis, base hydrolysis, oxidative, photolytic and thermal degradation. The proposed method was successfully validated and applied for the quantitative estimation of these drugs in both bulk and tablet dosage forms. PMID:26865655

  5. Minimal solution of linear formed fuzzy matrix equations

    Directory of Open Access Journals (Sweden)

    Maryam Mosleh

    2012-10-01

    Full Text Available In this paper according to the structured element method, the $mimes n$ inconsistent fuzzy matrix equation $Ailde{X}=ilde{B},$ which are linear formed by fuzzy structured element, is investigated. The necessary and sufficient condition for the existence of a fuzzy solution is also discussed. some examples are presented to illustrate the proposed method.

  6. Inverse Kinematics With Closed Form Solution For Denso Robot Manipulator

    Directory of Open Access Journals (Sweden)

    Ikhsan Eka Prasetia

    2015-03-01

    Full Text Available In this paper, the forward kinematics and inverse kinematics used on the Denso robot manipulator which has a 6-DOF. The forward kinematics will result in the desired position by end-effector, while inverse kinematics produce angel on each joint. Inverse kinematics problem are very difficult, therefor to obtain the solution of inverse kinematics using closed form solution with geometry approach. The simulation result obtained from forward kinematics and inverse kinematics is determining desired position by Denso robot manipulator. Forward kinematics produce the desired position by the end-effector. Inverse kinematics produce joint angle, where the inverse kinematics produce eight conditions obtained from closed form solution with geometry approach to reach the desired position by the end-effector.

  7. Closed form solutions of two time fractional nonlinear wave equations

    Science.gov (United States)

    Akbar, M. Ali; Ali, Norhashidah Hj. Mohd.; Roy, Ripan

    2018-06-01

    In this article, we investigate the exact traveling wave solutions of two nonlinear time fractional wave equations. The fractional derivatives are described in the sense of conformable fractional derivatives. In addition, the traveling wave solutions are accomplished in the form of hyperbolic, trigonometric, and rational functions involving free parameters. To investigate such types of solutions, we implement the new generalized (G‧ / G) -expansion method. The extracted solutions are reliable, useful and suitable to comprehend the optimal control problems, chaotic vibrations, global and local bifurcations and resonances, furthermore, fission and fusion phenomena occur in solitons, the relativistic energy-momentum relation, scalar electrodynamics, quantum relativistic one-particle theory, electromagnetic interactions etc. The results reveal that the method is very fruitful and convenient for exploring nonlinear differential equations of fractional order treated in theoretical physics.

  8. Ultrasound-assisted powder-coating technique to improve content uniformity of low-dose solid dosage forms

    DEFF Research Database (Denmark)

    Genina, Natalja; Räikkönen, Heikki; Antikainen, Osmo

    2010-01-01

    An ultrasound-assisted powder-coating technique was used to produce a homogeneous powder formulation of a low-dose active pharmaceutical ingredient (API). The powdered particles of microcrystalline cellulose (MCC; Avicel® PH-200) were coated with a 4% m/V aqueous solution of riboflavin sodium...

  9. Radiation dosage

    Energy Technology Data Exchange (ETDEWEB)

    Finston, Roland [Health Physics, Stanford University, Stanford, CA (United States)

    1986-07-01

    Radiation dosage at Bikini Atoll is the result of current soil contamination, a relic of the nuclear weapons testing program of some 30 years ago. The principal contaminants today and some of their physical properties are listed: cesium-137, strontium-90, plutonium -239, 240 and americium-241. Cobalt-60 contributes less than 1 to the dose and is not considered significant. A resident of the atoll would accumulate radiation dose (rem) in two ways -- by exposure to radiation emanating from the ground and vegetation, and by exposure to radiation released in the spontaneous decay of radionuclides that have entered his body during the ingestion of locally grown foods. The latter process would account for some 90% of the dose; cesium-137 would be responsible for 0 90% of it. Since BARC's method of estimating dosage differs in some respects from that employed by the Lawrence Livermore National Laboratory (LLNL), (Ref.1, LLNL 1982) we are presenting our method in detail. The differences have two sources. First, the numbers used by BARC for the daily ingestion of radionuclides via the diet are higher than LLNL's. Second, BARC's calculation of dose from radionuclide intake utilizes the ICRP system. The net result is that BARC doses are consistently higher than LLNL doses, and in this respect are more conservative.

  10. Radiation dosage

    International Nuclear Information System (INIS)

    Finston, Roland

    1986-01-01

    Radiation dosage at Bikini Atoll is the result of current soil contamination, a relic of the nuclear weapons testing program of some 30 years ago. The principal contaminants today and some of their physical properties are listed: cesium-137, strontium-90, plutonium -239, 240 and americium-241. Cobalt-60 contributes less than 1 to the dose and is not considered significant. A resident of the atoll would accumulate radiation dose (rem) in two ways -- by exposure to radiation emanating from the ground and vegetation, and by exposure to radiation released in the spontaneous decay of radionuclides that have entered his body during the ingestion of locally grown foods. The latter process would account for some 90% of the dose; cesium-137 would be responsible for 0 90% of it. Since BARC's method of estimating dosage differs in some respects from that employed by the Lawrence Livermore National Laboratory (LLNL), (Ref.1, LLNL 1982) we are presenting our method in detail. The differences have two sources. First, the numbers used by BARC for the daily ingestion of radionuclides via the diet are higher than LLNL's. Second, BARC's calculation of dose from radionuclide intake utilizes the ICRP system. The net result is that BARC doses are consistently higher than LLNL doses, and in this respect are more conservative

  11. Development and validation of new analytical methods for simultaneous estimation of Drotaverine hydrochloride in combination with Omeprazole in a pharmaceutical dosage form

    Directory of Open Access Journals (Sweden)

    Smita Sharma

    2017-02-01

    Full Text Available A rapid and precise method (in accordance with ICH guidelines is developed for the quantitative simultaneous determination of Drotaverine hydrochloride and Omeprazole in a combined pharmaceutical dosage form. Three methods are described for the simultaneous determination of Drotaverine hydrochloride and Omeprazole in a binary mixture. The first method was based on UV-Spectrophotometric determination of two drugs, using Vierordt!s simultaneous equation method. It involves absorbance measurement at 226.8 nm (λmax of Drotaverine hydrochloride and 269.4 nm (λmax of Omeprazole in methanol; linearity was obtained in the range of 5–30 μg ml−1 for both the drugs. The second method was based on HPLC separation of the two drugs using potassium dihydrogen phosphate buffer pH 5.0: Acetonitrile: Triethylamine (60:40:0.5, v/v as a mobile phase. Areas were recorded at 260 nm for both the drugs and retention time was found to be 2.71 min. and 3.87 min for Drotaverine hydrochloride and Omeprazole, respectively at 1.0 mL/min flow rate. The selected chromatographic conditions were found to determine Drotaverine hydrochloride and Omeprazole quantitatively in a combined dosage form without any physical separation. The method has been validated for linearity, accuracy and precision. Linearity was found over the range of 5–30 μg mL−1 for both drugs. The third method was based on HPTLC method for simultaneous quantification of these compounds in pharmaceutical dosage forms. Precoated silica gel 60 F254 plate was used as stationary phase. The separation was carried out using Glacial acetic acid:Cyclohexane:Methanol:(80:15:5 v/v/v as mobile phase. The proposed method was found to be fast, accurate, precise, reproducible and rugged and can be used for a simultaneous analysis of these drugs in combined formulations.

  12. Closed Form Solution of Synchronous Machine Short Circuit Transients

    Directory of Open Access Journals (Sweden)

    Gibson H.M. Sianipar

    2010-05-01

    Full Text Available This paper presents the closed form solution of the synchronous machine transients undergoing short circuit. That analytic formulation has been derived based on linearity and balanced conditions of the fault. Even though restrictive, the proposed method will serve somehow or other as a new resource for EMTP productivity. Indisputably superior, the closed-form formulation has some features inimitable by discretization such as continuity, accuracy and absolute numerical stability. Moreover, it enables us to calculate states at one specific instant independent of previous states or a snapshot, which any discretization methods cannot do.

  13. A Closed Form Solution for an Unorthodox Trigonometric Integral

    Science.gov (United States)

    Wu, Yan

    2009-01-01

    A closed form solution for the trigonometric integral [integral]sec[superscript 2k+1]xdx, k=0,1,2,..., is presented in this article. The result will fill the gap in another trigonometric integral [integral]sec[superscript 2m+1] x tan[superscript 2n]xdx, which is neglected by most of the calculus textbooks due to its foreseeable unorthodox solution…

  14. Exact Closed-form Solutions for Lamb's Problem

    Science.gov (United States)

    Feng, X.

    2017-12-01

    In this work, we report on an exact closedform solution for the displacement at the surfaceof an elastic halfspace elicited by a buried point source that acts at some point underneath thatsurface. This is commonly referred to as the 3D Lamb's problem, for which previous solutionswere restricted to sources and receivers placed at the free surface. By means of the reciprocitytheorem, our solution should also be valid as a means to obtain the displacements at interior pointswhen the source is placed at the free surface. We manage to obtain explicit results by expressingthe solution in terms of elementary algebraic expression as well as elliptic integrals. We anchorour developments on Poissons ratio 0.25 starting from Johnson's numerical, integral transformsolutions. Furthermore, the spatial derivatives of our solutions can be easily acquired in termsof our methods. In the end, our closed-form results agree perfectly with the numerical results ofJohnson, which strongly conrms the correctness of our explicit formulas. It is hoped that in duetime, these formulas may constitute a valuable canonical solution that will serve as a yardstickagainst which other numerical solutions can be compared and measured.In addition, we abstract some terms from our solutions as the generator of the Rayleigh waves.Some basic properties of the Rayleigh waves in the time domain will be indicated in terms of thegenerator. The fareld radiation patterns of P-wave and S-wave elicited by the double-couple forcein the uniform half-space medium could also be acquired from our results.

  15. A simple spectrophotometric determination of diclofenac sodium in commercial dosage forms using 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ)

    International Nuclear Information System (INIS)

    Raza, A.; Ansari, T.M.; Niazi, S.B.; Bukhari, S.I.H.

    2005-01-01

    A rapid, simple and sensitive spectrophotometric method has been developed for the determination of diclofenac sodium in pure and tablet formulations. The method depends on the charge-transfer complexation between diclofenac sodium as n-electron donor with 2,3-dichloro-,6-dicyano-1,4-benzoquinone (DDQ) in acetonitrile medium as pi-acceptor to give a colored complex which absorbs maximally at 545 nm. Beer's law has been obeyed in the concentration range of 13-275 micro gram ml/sup -1/ with molar absorptivity of 2.5 x 10/sup 3/L mole/sup -1/cm/sup -1/. The proposed method is precise, accurate and specific for routine quantitative analysis of the drug in bulk and dosage forms. (author)

  16. Simultaneous determination of atorvastatin calcium and ramipril in capsule dosage forms by high-performance liquid chromatography and high-performance thin layer chromatography.

    Science.gov (United States)

    Panchal, Hiral J; Suhagia, Bhanubhai N

    2010-01-01

    Two simple and accurate methods to determine atorvastatin calcium and ramipril in capsule dosage forms were developed and validated using HPLC and HPTLC. The HPLC separation was achieved on a Phenomenex Luna C18 column (250 x 4.6 mm id, 5 microm) in the isocratic mode using 0.1% phosphoric acid-acetonitrile (38 + 62, v/v), pH 3.5 +/- 0.05, mobile phase at a flow rate of 1 ml/min. The retention times were 6.42 and 2.86 min for atorvastatin calcium and ramipril, respectively. Quantification was achieved with a photodiode array detector set at 210 nm over the concentration range of 0.5-5 microg/mL for each, with mean recoveries (at three concentration levels) of 100.06 +/- 0.49% and 99.95 +/- 0.63% RSD for atorvastatin calcium and ramipril, respectively. The HPTLC separation was achieved on silica gel 60 F254 HPTLC plates using methanol-benzene-glacial acetic acid (19.6 + 80.0 + 0.4, v/v/v) as the mobile phase. The Rf values were 0.40 and 0.20 for atorvastatin calcium and ramipril, respectively. Quantification was achieved with UV densitometry at 210 nm over the concentration range of 50-500 ng/spot for each, with mean recoveries (at three concentration levels) of 99.98 +/- 0.75% and 99.87 +/- 0.83% RSD for atorvastatin calcium and ramipril, respectively. Both methods were validated according to International Conference on Harmonization guidelines and found to be simple, specific, accurate, precise, and robust. The mean assay percentages for atorvastatin calcium and ramipril were 99.90 and 99.55% for HPLC and 99.91 and 99.47% for HPTLC, respectively. The methods were successfully applied for the determination of atorvastatin calcium and ramipril in capsule dosage forms without any interference from common excipients.

  17. Pharmaceutical optimization of lipid-based dosage forms for the improvement of taste-masking, chemical stability and solubilizing capacity of phenobarbital.

    Science.gov (United States)

    Monteagudo, Ezequiel; Langenheim, Mariana; Salerno, Claudia; Buontempo, Fabián; Bregni, Carlos; Carlucci, Adriana

    2014-06-01

    Microemulsions (MEs) and self-emulsifying drug delivery systems (SEEDS) containing phenobarbital (Phe) were developed to improve its chemical stability, solubilizing capacity and taste-masking in oral liquid dosage forms. Cremophor® RH40 and Labrasol® were used as surfactants for the screening of ME regions, Capmul® MCM L, Captex® 355, Imwitor® 408, Myglyol® 840 and Isopropyl myristate were the oil phases assayed; Transcutol® P, Polyethylene-glycol 400, glycerol, Propylene-glycol and ethanol the cosurfactants. Phe stability assay was carried out (20:4:20:56% and 20:4:35:41% (w/w); surfactant:oily phase:cosurfactant:water) for both surfactants; only one containing ethanol showed significant dismissing in its drug content. Solubility capacity for these selected formulations were also evaluated, an amount between 17 and 58 mg/mL of Phe could be loaded. At last, an optimized ME formulation with Cremophor® RH40 20%, Capmul® MCM L 4%, PEG 400 35% and sucralose 2% (w/w) was chosen in order to optimize taste-masking using an electronic tongue. Strawberry along with banana and tutti-frutti flavors plus mint flavor proved to be the best ones. Labrasol-based pre-concentrates were tested for (micro)emulsifying properties; all of them resulted to behave as SEDDS. In summary, a rationale experimental design conducted to an optimized ME for Phe oral pediatric administration which was able to load 5-fold times the currently used dose (4 mg/mL), with no sign of physical or chemical instability and with improved taste; SEDDS for capsule filling were also obtained. The biopharmaceutical advantages described for these dosage forms encourage furthering in vivo evaluation.

  18. Azeotropic mixture used for development and validation of Lornoxicam in bulk and its tablet dosage form by spectrophotometric method

    Directory of Open Access Journals (Sweden)

    Prajesh Prajapati

    2012-08-01

    Full Text Available A novel, safe, economic and sensitive method of spectrophotometric estimation has been developed using Azeoptropic mixture (water:methanol: 60:40, v/v for the quantitative determination of Lornoxicam, a practically water-insoluble drug. Hence, Lornoxicam stock solution was prepared in Azeoptropic mixture. Lornoxicam showed maximum absorbance at 383 nm. Beer's law was obeyed in the concentration range 4–24 μg/mL with regression coefficient of 0.999. The method was validated in terms of linearity (R2=0.999, precision (CV for intra-day and inter-day was 0.28–0.68 and 0.12–0.92, respectively, accuracy (98.03–100.59% w/w and specificity. This method is simple, precise, accurate, sensitive and reproducible and can be used for the routine quality control testing of the marketed formulations. Keywords: Analgesic, Chlortenoxicam, Lornoxicam, Oxicam, Spectrophotometric, Azeotropic mixture

  19. Delay chemical master equation: direct and closed-form solutions.

    Science.gov (United States)

    Leier, Andre; Marquez-Lago, Tatiana T

    2015-07-08

    The stochastic simulation algorithm (SSA) describes the time evolution of a discrete nonlinear Markov process. This stochastic process has a probability density function that is the solution of a differential equation, commonly known as the chemical master equation (CME) or forward-Kolmogorov equation. In the same way that the CME gives rise to the SSA, and trajectories of the latter are exact with respect to the former, trajectories obtained from a delay SSA are exact representations of the underlying delay CME (DCME). However, in contrast to the CME, no closed-form solutions have so far been derived for any kind of DCME. In this paper, we describe for the first time direct and closed solutions of the DCME for simple reaction schemes, such as a single-delayed unimolecular reaction as well as chemical reactions for transcription and translation with delayed mRNA maturation. We also discuss the conditions that have to be met such that such solutions can be derived.

  20. A Stability-Indicating HPLC-DAD Method for Determination of Stiripentol: Development, Validation, Kinetics, Structure Elucidation and Application to Commercial Dosage Form

    Directory of Open Access Journals (Sweden)

    Hany W. Darwish

    2014-01-01

    Full Text Available A rapid, simple, sensitive, and accurate isocratic reversed-phase stability-indicating high performance liquid chromatography method has been developed and validated for the determination of stiripentol and its degradation product in its bulk form and pharmaceutical dosage form. Chromatographic separation was achieved on a Symmetry C18 column and quantification was achieved using photodiode array detector (DAD. The method was validated in accordance with the ICH requirements showing specificity, linearity (r2=0.9996, range of 1–25 μg/mL, precision (relative standard deviation lower than 2%, accuracy (mean recovery 100.08±1.73, limits of detection and quantitation (LOD = 0.024 and LOQ = 0.081 μg/mL, and robustness. Stiripentol was subjected to various stress conditions and it has shown marked stability under alkaline hydrolytic stress conditions, thermal, oxidative, and photolytic conditions. Stiripentol degraded only under acidic conditions, forming a single degradation product which was well resolved from the pure drug with significantly different retention time values. This degradation product was characterized by 1H-NMR and 13C-NMR spectroscopy as well as ion trap mass spectrometry. The results demonstrated that the method would have a great value when applied in quality control and stability studies for stiripentol.

  1. Determination of methadone hydrochloride in a maintenance dosage formulation.

    Science.gov (United States)

    Hoffmann, T J; Thompson, R D

    1975-07-01

    A colorimetric method for direct quantitative assay of methadone hydrochloride in liquid oral dosage forms is presented. The procedure involves the formation of a dye complex with bromothymol blue buffer solution. The resultant complex is extracted with benzene and measured spectrophotometrically. Duplicate tests on the formulation showed 99.2% of the labeled amount of methadone.

  2. Decoupled Closed-Form Solution for Humanoid Lower Limb Kinematics

    Directory of Open Access Journals (Sweden)

    Alejandro Said

    2015-01-01

    Full Text Available This paper presents an explicit, omnidirectional, analytical, and decoupled closed-form solution for the lower limb kinematics of the humanoid robot NAO. The paper starts by decoupling the position and orientation analysis from the overall Denavit-Hartenberg (DH transformation matrices. Here, the joint activation sequence for the DH matrices is based on the geometry of a triangle. Furthermore, the implementation of a forward and a reversed kinematic analysis for the support and swing phase equations is developed to avoid matrix inversion. The allocation of constant transformations allows the position and orientation end-coordinate systems to be aligned with each other. Also, the redefinition of the DH transformations and the use of constraints allow decoupling the shared DOF between the legs and the torso. Finally, a geometric approach to avoid the singularities during the walking process is indicated. Numerical data is presented along with an experimental implementation to prove the validity of the analytical results.

  3. Closed form analytic solutions describing glow discharge plasma

    International Nuclear Information System (INIS)

    Pai, S.T.; Guo, X.M.; Zhou, T.D.

    1996-01-01

    On the basis of an analytic model developed previously [S. T. Pai, J. Appl. Phys. 71, 5820 (1992)], an improved version of the model for the description of dc glow discharge plasma was successfully developed. A set of closed form solutions was obtained from the governing equations. The two-dimensional, analytic solutions are functional and completely satisfy the governing equations, the actual boundary conditions, and Maxwell equations. They can be readily used to carry out numerical calculations without the necessity of employing any assumed boundary conditions. Results obtained from the model reveal that as the discharge gap spacing or pressure increases the maximum value in the electron density distribution moves toward the cathode. At a sufficiently large value of gap spacing, the positive column phenomenon begins to appear in the discharge region. The model has the capability of treating the positive column and negative glow as a continuous system without the necessity of studying them separately. The model also predicts a sharp rise of the positive ion density near the cathode and field reversal in the anode region. Variation of the electrode radius produces little effect on the axial spatial distribution of physical quantities studied. copyright 1996 American Institute of Physics

  4. Glycine phases formed from frozen aqueous solutions: Revisited

    Energy Technology Data Exchange (ETDEWEB)

    Surovtsev, N. V. [Institute of Automation and Electrometry, Siberian Branch of Russian Academy of Sciences, Novosibirsk 630090 (Russian Federation); Novosibirsk State University, Novosibirsk 630090 (Russian Federation); Adichtchev, S. V.; Malinovsky, V. K. [Institute of Automation and Electrometry, Siberian Branch of Russian Academy of Sciences, Novosibirsk 630090 (Russian Federation); Ogienko, A. G.; Manakov, A. Yu. [Novosibirsk State University, Novosibirsk 630090 (Russian Federation); Nikolaev Institute of Inorganic Chemistry, Siberian Branch of Russian Academy of Sciences, Novosibirsk 630090 (Russian Federation); Drebushchak, V. A. [Novosibirsk State University, Novosibirsk 630090 (Russian Federation); Institute of Geology and Mineralogy, Siberian Branch of Russian Academy of Sciences, Novosibirsk 630090 (Russian Federation); Ancharov, A. I.; Boldyreva, E. V. [Novosibirsk State University, Novosibirsk 630090 (Russian Federation); Institute of Solid Chemistry and Mechanochemistry, Siberian Branch of Russian Academy of Sciences, Novosibirsk 630090 (Russian Federation); Yunoshev, A. S. [Novosibirsk State University, Novosibirsk 630090 (Russian Federation); Lavrentiev Institute of Hydrodynamics, Siberian Branch of Russian Academy of Sciences, Novosibirsk 630090 (Russian Federation)

    2012-08-14

    Glycine phases formed when aqueous solutions were frozen and subsequently heated under different conditions were studied by Raman scattering, x-ray diffraction, and differential scanning calorimetry (DSC) techniques. Crystallization of ice I{sub h} was observed in all the cases. On cooling at the rates of 0.5 K/min and 5 K/min, glassy glycine was formed as an intermediate phase which lived about 1 min or less only, and then transformed into {beta}-polymorph of glycine. Quench cooling of glycine solutions (15% w/w) in liquid nitrogen resulted in the formation of a mixture of crystalline water ice I{sub h} and a glassy glycine, which could be preserved at cryogenic temperatures (80 K) for an indefinitely long time. This mixture remained also quite stable for some time after heating above the cryogenic temperature. Subsequent heating under various conditions resulted in the transformation of the glycine glass into an unknown crystalline phase (glycine 'X-phase') at 209-216 K, which at 218-226 K transformed into {beta}-polymorph of glycine. The 'X-phase' was characterized by Raman spectroscopy; it could be obtained in noticeable amounts using a special preparation technique and tentatively characterized by x-ray powder diffraction (P2, a= 6.648 A, b= 25.867 A, c= 5.610 A, {beta}= 113.12 Masculine-Ordinal-Indicator ); the formation of 'X-phase' from the glycine glassy phase and its transformation into {beta}-polymorph were followed by DSC. Raman scattering technique with its power for unambiguous identification of the crystalline and glassy polymorphs without limitation on the crystallite size helped us to follow the phase transformations during quenching, heating, and annealing. The experimental findings are considered in relation to the problem of control of glycine polymorphism on crystallization.

  5. Glycine phases formed from frozen aqueous solutions: Revisited

    Science.gov (United States)

    Surovtsev, N. V.; Adichtchev, S. V.; Malinovsky, V. K.; Ogienko, A. G.; Drebushchak, V. A.; Manakov, A. Yu.; Ancharov, A. I.; Yunoshev, A. S.; Boldyreva, E. V.

    2012-08-01

    Glycine phases formed when aqueous solutions were frozen and subsequently heated under different conditions were studied by Raman scattering, x-ray diffraction, and differential scanning calorimetry (DSC) techniques. Crystallization of ice Ih was observed in all the cases. On cooling at the rates of 0.5 K/min and 5 K/min, glassy glycine was formed as an intermediate phase which lived about 1 min or less only, and then transformed into β-polymorph of glycine. Quench cooling of glycine solutions (15% w/w) in liquid nitrogen resulted in the formation of a mixture of crystalline water ice Ih and a glassy glycine, which could be preserved at cryogenic temperatures (80 K) for an indefinitely long time. This mixture remained also quite stable for some time after heating above the cryogenic temperature. Subsequent heating under various conditions resulted in the transformation of the glycine glass into an unknown crystalline phase (glycine "X-phase") at 209-216 K, which at 218-226 K transformed into β-polymorph of glycine. The "X-phase" was characterized by Raman spectroscopy; it could be obtained in noticeable amounts using a special preparation technique and tentatively characterized by x-ray powder diffraction (P2, a = 6.648 Å, b = 25.867 Å, c = 5.610 Å, β = 113.12°); the formation of "X-phase" from the glycine glassy phase and its transformation into β-polymorph were followed by DSC. Raman scattering technique with its power for unambiguous identification of the crystalline and glassy polymorphs without limitation on the crystallite size helped us to follow the phase transformations during quenching, heating, and annealing. The experimental findings are considered in relation to the problem of control of glycine polymorphism on crystallization.

  6. Transforming lipid-based oral drug delivery systems into solid dosage forms: an overview of solid carriers, physicochemical properties, and biopharmaceutical performance.

    Science.gov (United States)

    Tan, Angel; Rao, Shasha; Prestidge, Clive A

    2013-12-01

    The diversity of lipid excipients available commercially has enabled versatile formulation design of lipid-based drug delivery systems for enhancing the oral absorption of poorly water-soluble drugs, such as emulsions, microemulsions, micelles, liposomes, niosomes and various self-emulsifying systems. The transformation of liquid lipid-based systems into solid dosage forms has been investigated for several decades, and has recently become a core subject of pharmaceutical research as solidification is regarded as viable means for stabilising lipid colloidal systems while eliminating stringent processing requirements associated with liquid systems. This review describes the types of pharmaceutical grade excipients (silica nanoparticle/microparticle, polysaccharide, polymer and protein-based materials) used as solid carriers and the current state of knowledge on the liquid-to-solid conversion approaches. Details are primarily focused on the solid-state physicochemical properties and redispersion capacity of various dry lipid-based formulations, and how these relate to the in vitro drug release and solubilisation, lipid carrier digestion and cell permeation performances. Numerous in vivo proof-of-concept studies are presented to highlight the viability of these dry lipid-based formulations. This review is significant in directing future research work in fostering translation of dry lipid-based formulations into clinical applications.

  7. A Localized Surface Plasmon Resonance Sensing Method for Simultaneous Determination of Atenolol and Amiloride in Pharmaceutical Dosage Forms and Urine Samples

    Directory of Open Access Journals (Sweden)

    Marwa R. El-Zahry

    2018-01-01

    Full Text Available This contribution describes a simple, fast, and sensitive application of localized surface plasmon resonance effect of silver nanoparticles for simultaneous determination of antihypertensive drugs’ mixture atenolol and amiloride in both pharmaceutical dosage forms and in biological samples (urine. Silver nanoparticles were prepared by chemical reduction of silver nitrate using hydroxylamine HCL in an alkaline medium. Application of silver-hydroxylamine nanoparticles (SH NPs provides many advantages including reproducibility, sensitivity, and cost effective way of analyte determination. Amiloride has four amino groups which act as attachment points on the surface of silver nanoparticles resulting in a synergistic effect on the absorption intensity of atenolol, leading to increase the sensitivity of the determination of both compounds. This method shows excellent advantages comparing with the previously reported methods, including accuracy, precision, and selectivity. The linear range of atenolol is 1 × 10−5–1 × 10−4 mol·L−1 and of amiloride is 1 × 10−6–1 × 10−5 mol·L−1. The limit of detection (LOD values of atenolol and amiloride are 0.89 × 10−5 and 0.42 × 10−6 mol·L−1, respectively.

  8. A Simple and Specific Stability- Indicating RP-HPLC Method for Routine Assay of Adefovir Dipivoxil in Bulk and Tablet Dosage Form.

    Science.gov (United States)

    Darsazan, Bahar; Shafaati, Alireza; Mortazavi, Seyed Alireza; Zarghi, Afshin

    2017-01-01

    A simple and reliable stability-indicating RP-HPLC method was developed and validated for analysis of adefovir dipivoxil (ADV).The chromatographic separation was performed on a C 18 column using a mixture of acetonitrile-citrate buffer (10 mM at pH 5.2) 36:64 (%v/v) as mobile phase, at a flow rate of 1.5 mL/min. Detection was carried out at 260 nm and a sharp peak was obtained for ADV at a retention time of 5.8 ± 0.01 min. No interferences were observed from its stress degradation products. The method was validated according to the international guidelines. Linear regression analysis of data for the calibration plot showed a linear relationship between peak area and concentration over the range of 0.5-16 μg/mL; the regression coefficient was 0.9999and the linear regression equation was y = 24844x-2941.3. The detection (LOD) and quantification (LOQ) limits were 0.12 and 0.35 μg/mL, respectively. The results proved the method was fast (analysis time less than 7 min), precise, reproducible, and accurate for analysis of ADV over a wide range of concentration. The proposed specific method was used for routine quantification of ADV in pharmaceutical bulk and a tablet dosage form.

  9. Analytical Method Development and Validation for the Simultaneous Estimation of Abacavir and Lamivudine by Reversed-phase High-performance Liquid Chromatography in Bulk and Tablet Dosage Forms.

    Science.gov (United States)

    Raees Ahmad, Sufiyan Ahmad; Patil, Lalit; Mohammed Usman, Mohammed Rageeb; Imran, Mohammad; Akhtar, Rashid

    2018-01-01

    A simple rapid, accurate, precise, and reproducible validated reverse phase high performance liquid chromatography (HPLC) method was developed for the determination of Abacavir (ABAC) and Lamivudine (LAMI) in bulk and tablet dosage forms. The quantification was carried out using Symmetry Premsil C18 (250 mm × 4.6 mm, 5 μm) column run in isocratic way using mobile phase comprising methanol: water (0.05% orthophosphoric acid with pH 3) 83:17 v/v and a detection wavelength of 245 nm and injection volume of 20 μl, with a flow rate of 1 ml/min. In the developed method, the retention times of ABAC and LAMI were found to be 3.5 min and 7.4 min, respectively. The method was validated in terms of linearity, precision, accuracy, limits of detection, limits of quantitation, and robustness in accordance with the International Conference on Harmonization guidelines. The assay of the proposed method was found to be 99% - 101%. The recovery studies were also carried out and mean % recovery was found to be 99% - 101%. The % relative standard deviation from reproducibility was found to be performance liquid chromatography, UV: Ultraviolet, ICH: International Conference on Harmonization, ABAC: Abacavir, LAMI: Lamivudine, HIV: Human immunodeficiency virus, AIDS: Acquired immunodeficiency syndrome, NRTI: Nucleoside reverse transcriptase inhibitors, ARV: Antiretroviral, RSD: Relative standard deviation, RT: Retention time, SD: Standard deviation.

  10. Polymer adhesion predictions for oral dosage forms to enhance drug administration safety. Part 2: In vitro approach using mechanical force methods.

    Science.gov (United States)

    Drumond, Nélio; Stegemann, Sven

    2018-06-01

    Predicting the potential for unintended adhesion of solid oral dosage forms (SODF) to mucosal tissue is an important aspect that should be considered during drug product development. Previous investigations into low strength mucoadhesion based on particle interactions methods provided evidence that rheological measurements could be used to obtain valid predictions for the development of SODF coatings that can be safely swallowed. The aim of this second work was to estimate the low mucoadhesive strength properties of different polymers using in vitro methods based on mechanical forces and to identify which methods are more precise when measuring reduced mucoadhesion. Another aim was to compare the obtained results to the ones achieved with in vitro particle interaction methods in order to evaluate which methodology can provide stronger predictions. The combined results correlate between particle interaction methods and mechanical force measurements. The polyethylene glycol grades (PEG) and carnauba wax showed the lowest adhesive potential and are predicted to support safe swallowing. Hydroxypropyl methylcellulose (HPMC) along with high molecular grades of polyvinylpyrrolidone (PVP) and polyvinyl alcohol (PVA) exhibited strong in vitro mucoadhesive strength. The combination of rheological and force tensiometer measurements should be considered when assessing the reduced mucoadhesion of polymer coatings to support safe swallowing of SODF. Copyright © 2018 Elsevier B.V. All rights reserved.

  11. Use of Activated Carbon in Packaging to Attenuate Formaldehyde-Induced and Formic Acid-Induced Degradation and Reduce Gelatin Cross-Linking in Solid Dosage Forms.

    Science.gov (United States)

    Colgan, Stephen T; Zelesky, Todd C; Chen, Raymond; Likar, Michael D; MacDonald, Bruce C; Hawkins, Joel M; Carroll, Sophia C; Johnson, Gail M; Space, J Sean; Jensen, James F; DeMatteo, Vincent A

    2016-07-01

    Formaldehyde and formic acid are reactive impurities found in commonly used excipients and can be responsible for limiting drug product shelf-life. Described here is the use of activated carbon in drug product packaging to attenuate formaldehyde-induced and formic acid-induced drug degradation in tablets and cross-linking in hard gelatin capsules. Several pharmaceutical products with known or potential vulnerabilities to formaldehyde-induced or formic acid-induced degradation or gelatin cross-linking were subjected to accelerated stability challenges in the presence and absence of activated carbon. The effects of time and storage conditions were determined. For all of the products studied, activated carbon attenuated drug degradation or gelatin cross-linking. This novel use of activated carbon in pharmaceutical packaging may be useful for enhancing the chemical stability of drug products or the dissolution stability of gelatin-containing dosage forms and may allow for the 1) extension of a drug product's shelf-life when the limiting attribute is a degradation product induced by a reactive impurity, 2) marketing of a drug product in hotter and more humid climatic zones than currently supported without the use of activated carbon, and 3) enhanced dissolution stability of products that are vulnerable to gelatin cross-linking. Copyright © 2016 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  12. Validated RP-HPLC Method for the Assay of Etoricoxib (A Non-Steroidal Anti-Inflammatory Drug in Pharmaceutical Dosage Forms

    Directory of Open Access Journals (Sweden)

    Srinivasu Topalli

    2012-01-01

    Full Text Available A simple, accurate, sensitive and reproducible reverse phase high performance liquid chromatographic method has been developed for the quantitative determination of Etoricoxib in pharmaceutical dosage forms. The assay was performed on Hypersil ODS C-18 (250 x 4.6 mm., 5µm particle size column using acetonitrile and potassium dihydrogen phosphate buffer (pH 4.2 (46:54 % v/v as mobile phase with UV detection at 280 nm (flow rate 1.2 ml/min. Bromhexine was used as an internal standard. Quantization was achieved by measurement of the peak area ratio of the drug to the internal standard. The limit of detection (LOD and the limit of quantification (LOQ were 0.0704 µg ml-1 and 0.2134 µg ml-1 respectively. Each analysis required no longer than 10 minutes. The calibration curve was linear over the concentration range from 0.5-85.0 µg ml-1. The retention times of Etoricoxib and Bromhexine were found to be 3.083 and 7.631 minutes respectively. The proposed method was validated according to the ICH guidelines and can be used successfully to analyse marketed formulations.

  13. Stability-Indicating RP-UPLC Method for the Simultaneous Determination of Potential Degradation and Process Impurities of Amlodipine Basylate and Benazepril HCl in Pharmaceutical Dosage Form

    Directory of Open Access Journals (Sweden)

    Gajanan B. Kasawar

    2014-10-01

    Full Text Available A stability-indicating RP-UPLC method was developed for the quantification of related impurities of amlodipine basylate (AB and Benazepril hydrochloride (BH in solid pharmaceutical dosages form. The chromatographic separation employs a C18 column using a gradient elution, being solvent-A (1.36 g of potassium dihydrogen phosphate dissolved in one liter of water, adjusted to pH 3.0 with orthophosphoric acid and solvent-B (acetonitrile delivered at a flow rate of 0.3 mL min-1. The analytes were detected and quantified at 217 nm and 240 nm using photo diode-array detector. The method was validated demonstrating to be accurate and precise within the corresponding linear range of all components. The stability of the method was investigated under different stress conditions including hydrolytic, oxidative, exposed to photolytic, humidity and thermal as recommended by ICH guidelines. Relevant degradation was found under hydrolytic and oxidative conditions. Robustness against small modification in mobile phase pH, column oven temperature, flow rate and percentage of the mobile phase composition was ascertained. Lower limit of quantification and detection was also determined. The peak purity indices (purity angle < purity threshold obtained with the aid of PDA detector and satisfactory resolution between related impurities established the specificity of the determination.

  14. Matrix effect on leaching of Bisphenol A diglycidyl ether (BADGE) from epoxy resin based inner lacquer of aluminium tubes into semi-solid dosage forms.

    Science.gov (United States)

    Lipke, Uwe; Haverkamp, Jan Boris; Zapf, Thomas; Lipperheide, Cornelia

    2016-04-01

    To study the impact of different semi-solid dosage form components on the leaching of Bisphenol A (BPA) and Bisphenol A diglycidyl ether (BADGE) from the epoxy resin-based inner lacquer of aluminium tubes, the tubes were filled with different matrix preparations and stored at an elevated temperature. Despite compliance with the European Standards EN 15348 and EN 15766 on porosity and polymerisation of internal coatings of aluminium tubes, the commercially available tubes used in the study contained an increased amount of polymerisation residues, such as unbound BPA, BADGE and BADGE derivatives in the lacquer, as determined by acetonitrile extraction. Storage of Macrogol ointments in these tubes resulted in an almost quantitative migration of the unbound polymerisation residues from the coating into the ointment. In addition, due to alterations observed in the RP-HPLC chromatograms of the matrix spiked with BADGE and BADGE derivatives it is supposed that the leachates can react with formulation components. The contamination of the medicinal product by BPA, BADGE and BADGE derivatives can be precluded by using aluminium tubes with an internal lacquer with a low degree of unbound polymerisation residues. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

  15. Development and Validation of a Precise, Single HPLC Method for the Determination of Tolperisone Impurities in API and Pharmaceutical Dosage Forms.

    Science.gov (United States)

    Raju, Thummala Veera Raghava; Seshadri, Raja Kumar; Arutla, Srinivas; Mohan, Tharlapu Satya Sankarsana Jagan; Rao, Ivaturi Mrutyunjaya; Nittala, Someswara Rao

    2013-01-01

    A novel, sensitive, stability-indicating HPLC method has been developed for the quantitative estimation of Tolperisone-related impurities in both bulk drugs and pharmaceutical dosage forms. Effective chromatographic separation was achieved on a C18 stationary phase with a simple mobile phase combination delivered in a simple gradient programme, and quantitation was by ultraviolet detection at 254 nm. The mobile phase consisted of a buffer and acetonitrile delivered at a flow rate 1.0 ml/min. The buffer consisted of 0.01 M potassium dihydrogen phosphate with the pH adjusted to 8.0 by using diethylamine. In the developed HPLC method, the resolution between Tolperisone and its four potential impurities was found to be greater than 2.0. Regression analysis showed an R value (correlation coefficient) of greater than 0.999 for the Tolperisone impurities. This method was capable of detecting all four impurities of Tolperisone at a level of 0.19 μg/mL with respect to the test concentration of 1000 μg/mL for a 10 µl injection volume. The tablets were subjected to the stress conditions of hydrolysis, oxidation, photolysis, and thermal degradation. Considerable degradation was found to occur in base hydrolysis, water hydrolysis, and oxidation. The stress samples were assayed against a qualified reference standard and the mass balance was found to be close to 100%. The established method was validated and found to be linear, accurate, precise, specific, robust, and rugged.

  16. Brand versus generic dispensing trend for ciprofloxacin 500 mg, levofloxacin 500 mg, and moxifloxacin 400 mg (oral dosage forms) among pharmacies of Karachi, Pakistan.

    Science.gov (United States)

    Zehra, Fatima; Naqvi, Atta Abbas; Tasneem, Sumbul; Ahmad, Rizwan; Ahmad, Niyaz; Shamsi, Adnan Zia; Asghar, Naqiya Ali; Khan, Ghufran Ullah

    2017-01-01

    Pakistan spends 0.7% of its gross domestic product on health. The public sector health-care system provides services to 22% of population thus paving the way for a dominant private sector. Patients in Pakistan mostly pay their medical expenses directly, and 64% of the health expenditures are borne by the household. Expenditure on medicine constitutes 43% of the total household expenditure. A quantitative cross-sectional study was conducted in Karachi, Pakistan, for a month. It was aimed at gathering response from different pharmacies to understand the brand versus generic dispensing trend of ciprofloxacin 500 mg, levofloxacin 500 mg, and moxifloxacin 400 mg oral dosage forms. The study employed convenience sampling and used a survey checklist. The data gathered was entered in SPSS version 22. The mean price per tablet for ciprofloxacin brand and generic was reported at Pakistani Rupees (PKR) 48.44 and PKR 26.85, respectively. The trend for dispensing ciprofloxacin highlighted a split in the market between brand (51%) and generic (49%). For levofloxacin brand and generic, the price per tablet was reported at PKR 36.50 and PKR 36.15 respectively, and despite same price, the market was dominated by generic levofloxacin (92%). Due to a price difference between brand and generic moxifloxacin, i.e., PKR 129.44 and PKR 71.91, respectively, the market was mostly occupied by the generic form (75%). Pricing mechanism must be revisited, and the authorities should take stern actions against any illegitimate price hike. The surging burden of drug expenditure on poorer sections of the society must be addressed by the government on an urgent basis.

  17. Unphosphorylated rhabdoviridae phosphoproteins form elongated dimers in solution.

    Science.gov (United States)

    Gerard, Francine C A; Ribeiro, Euripedes de Almeida; Albertini, Aurélie A V; Gutsche, Irina; Zaccai, Guiseppe; Ruigrok, Rob W H; Jamin, Marc

    2007-09-11

    The phosphoprotein (P) is an essential component of the replication machinery of rabies virus (RV) and vesicular stomatitis virus (VSV), and the oligomerization of P, potentially controlled by phosphorylation, is required for its function. Up to now the stoichiometry of phosphoprotein oligomers has been controversial. Size exclusion chromatography combined with detection by multiangle laser light scattering shows that the recombinant unphosphorylated phosphoproteins from VSV and from RV exist as dimers in solution. Hydrodynamic analysis indicates that the dimers are highly asymmetric, with a Stokes radius of 4.8-5.3 nm and a frictional ratio larger than 1.7. Small-angle neutron scattering experiments confirm the dimeric state and the asymmetry of the structure and yield a radius of gyration of about 5.3 nm and a cross-sectional radius of gyration of about 1.6-1.8 nm. Similar hydrodynamic properties and molecular dimensions were obtained with a variant of VSV phosphoprotein in which Ser60 and Thr62 are substituted by Asp residues and which has been reported previously to mimic phosphorylation by inducing oligomerization and activating transcription. Here, we show that this mutant also forms a dimer with hydrodynamic properties and molecular dimensions similar to those of the wild type protein. However, incubation at 30 degrees C for several hours induced self-assembly of both wild type and mutant proteins, leading to the formation of irregular filamentous structures.

  18. A study of knowledge, attitude and practice regarding administration of pediatric dosage forms and allied health literacy of caregivers for children

    Directory of Open Access Journals (Sweden)

    Amrita Sil

    2017-01-01

    Full Text Available Context: Caregivers of sick children have to be careful with medicine dosing and giving medicines to a reluctant child can be challenging. Aim: To assess the knowledge, attitude, and practices of caregivers regarding pediatric medicine administration and health literacy allied to this task. Settings and Design: This cross-sectional study was carried out on outpatient and inpatient basis in the pediatrics department of a teaching hospital over 6 months. Subjects and Methods: Data regarding sociodemographic profile of patient and caregiver, idea regarding pediatric dosage forms, dosing of medicines, and medication errors during administration were recorded from 377 caregivers. Reconstitution of dry powder and measurement of 5 mL liquid medicine using measuring cup of the medicine phial was demonstrated by the caregivers. Statistical Analysis: Association assessed by point biserial correlation and Spearman's rank correlation. Results: Majority of the primary caregivers surveyed were young, educated, homemaker mothers. Liquid medicines were used maximally (88.9%. Majority (87.3% of the caregivers used standardized dosing instruments to measure liquids and reconstitution (85.9%, and teaspoon measurement task (91% was performed satisfactorily by most. Some potentially wrong practices (e.g., adding medicine to milk, redilution of reconstituted medicine, and storing beyond the recommended period were recorded. Medication errors were reported by 44.5% caregivers, significantly more in the outpatient setting. Although the statistical correlation was weak, the chance of medication error was less, and the precision of measurement was better with increasing education of the caregiver. Conclusions: Physicians need to be aware of the limitations of knowledge and the possibility of wrong administration practices among caregivers of children. Remedial measures in this regard can reduce the risk of medication errors.

  19. Stability indicating RP-HPLC method development and validation for the simultaneous determination of aminexil and minoxidil in pharmaceutical dosage form.

    Science.gov (United States)

    Siddiraju, S; Sahithi, M

    2015-03-01

    The objective of the present work is to develop stability indicating high-performance liquid chromatographic method for the simultaneous determination of aminexil and minoxidil in pharmaceutical dosage form. The chromatographic separation was achieved with BDS Hypersil C18 column (250 mm×4.6 mm×5 μ) as stationary phase and phosphate buffer and acetonitrile (78:22) as mobile phase. The method was employed by using a flow rate of 1.1 mL/min kept at 30°C. The detection wavelength was kept at 238 nm by using photo-diode array detector. The retention times of the aminexil and minoxidil were found to be 2.3 min and 3.9 min, respectively. The method developed was validated in accordance with ICH guidelines with respect to the stability indicating capacity of the method including system suitability, accuracy, precision, linearity, range, limit of detection, limit of quantification and robustness. The linearity responses of aminexil and minoxidil were found to be in the concentration ranges of 18.75-112.5 μg/mL and 25-150 μg/mL, respectively. The LOD and LOQ values for aminexil were found to be 0.31 and 0.92 μg/mL and minoxidil were found to be 0.03 and 0.10 μg/mL respectively. The percentage recoveries for both the drugs were found in the range of 98-101%. This method is accurate, precise and sensitive; hence, it can be employed for routine quality control of aminexil and minoxidil in pharmaceutical industries and drug testing laboratories. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  20. Simultaneous determination of nortriptyline hydrochloride and fluphenazine hydrochloride in microgram quantities from low dosage forms by liquid chromatography–UV detection

    Directory of Open Access Journals (Sweden)

    Safwan Ashour

    2012-12-01

    Full Text Available A novel method for the simultaneous high-performance liquid chromatographic determination of nortriptyline hydrochloride and fluphenazine hydrochloride was developed and validated. Fluvastatin sodium was used as internal standard. The determination was performed on a Hypersil Gold C8 column (250 mm × 4.6 mm i.d., 5 μm particle size at 25 °C; the mobile phase, consisting of a mixture of formic acid (0.1 M, pH 2.16-methanol (33:67, v/v, was delivered at a flow rate of 1.1 mL/min and detector wavelength at 251 nm. The retention time of nortriptyline, fluphenazine and fluvastatin was found to be 5.11, 8.05 and 11.38 min, respectively. Linearity ranges were 5.0–1350.0 and 10.0–1350.0 μg/mL with limit of detection values of 0.72 and 0.31 μg/mL, for nortriptyline and fluphenazine, respectively. Results of assay and recovery studies were statistically evaluated for its accuracy and precision. Correlation coefficients (r2 of the regression equations were greater than 0.999 in all cases. According to the validation results, the proposed method was found to be specific, accurate, precise and could be applied to the simultaneous quantitative analysis of nortriptyline and fluphenazine. Keywords: Nortriptyline hydrochloride, Fluphenazine hydrochloride, Liquid chromatography, Pharmaceutical dosage form

  1. Development and validation of RP-HPLC method for determination of famotidine and its application in quality control of different pharmaceutical dosage forms

    International Nuclear Information System (INIS)

    Hassan, S.S.; Ayub, M.; Ishtiaq, S.; Ahmad; I; Khalid, N.

    2013-01-01

    A precise and fast novel high-performance liquid chromatography method was developed and validated for the quantitative determination of Famotidine (FMT) in commercially available pharmaceutical dosage forms. An Agilent 1200 Series High Performance Liquid Chromatography (HPLC) system having the column C 1 8 (5 micro m particle size, 150*4.6 mm) was used in this study and detection (diode array detector) was made at 280 nm. The mobile phase was acetonitrile, distilled water, triethylamine and phosphoric acid (49.9:49.9:0.1:0.1, v/v), isocratic elution under ambient temperature at flow rate of 1.5 mL min/sup -1/ with injection volume 5 micro L. In this method, the retention times for FMT pure, tablets and suspension were 0.787 min, 0.789 min and 0.839 minutes respectively. The new method was validated by different validation parameters. The procedure provided a linear response over the concentration range of 0.1-1.0 mg mL/sup -1/ (r/sup 2/ =0.998) and equation was y=3902.6+18.651. The mean % recovery for inter-day (96.56%) and intra-day (97.36%) assuring a good precision and accuracy was 96-98%. The method was found to be very rapid and the overall assay time was less than 2 minutes and the results obtained were accurate, precise and selective enough to allow the determination of FMT in the presence of certain excipients. (author)

  2. Development of a stability-indicating UPLC method for determining olanzapine and its associated degradation products present in active pharmaceutical ingredients and pharmaceutical dosage forms.

    Science.gov (United States)

    Krishnaiah, Ch; Vishnu Murthy, M; Kumar, Ramesh; Mukkanti, K

    2011-03-25

    A simple, sensitive and reproducible ultra performance liquid chromatography (UPLC) coupled with a photodiode array detector method was developed for the quantitative determination of olanzapine (OLN) in API and pharmaceutical dosage forms. The method is applicable to the quantification of related substances and assays of drug substances. Chromatographic separation was achieved on Acquity UPLC BEH 100-mm, 2.1-mm, and 1.7-μm C-18 columns, and the gradient eluted within a short runtime, i.e., within 10.0 min. The eluted compounds were monitored at 250 nm, the flow rate was 0.3 mL/min, and the column oven temperature was maintained at 27°C. The resolution of OLN and eight (potential, bi-products and degradation) impurities was greater than 2.0 for all pairs of components. The high correlation coefficient (r(2)>0.9991) values indicated clear correlations between the investigated compound concentrations and their peak areas within the test ranges. The repeatability and intermediate precision, expressed by the RSD, were less than 2.4%. The accuracy and validity of the method were further ascertained by performing recovery studies via a spike method. The accuracy of the method expressed as relative error was satisfactory. No interference was observed from concomitant substances normally added to the tablets. The drug was subjected to the International Conference on Harmonization (ICH)-prescribed hydrolytic, oxidative, photolytic and thermal stress conditions. The performance of the method was validated according to the present ICH guidelines for specificity, limit of detection, limit of quantification, linearity, accuracy, precision, ruggedness and robustness. Copyright © 2010 Elsevier B.V. All rights reserved.

  3. Solving the AKNS Hierarchy by Its Bilinear Form: Generalized Double Wronskian Solutions

    International Nuclear Information System (INIS)

    Yin Fumei; Sun Yepeng; Cai Fuqing; Chen Dengyuan

    2008-01-01

    Through the Wronskian technique, a simple and direct proof is presented that the AKNS hierarchy in the bilinear form has generalized double Wronskian solutions. Moreover, by using a unified way, soliton solutions, rational solutions, Matveev solutions and complexitons in double Wronskian form for it are constructed.

  4. Low cost technology for the rapid and safe in-house (hospital-based) preparation of dual - radiotherapeutic (Rx) and radiodiagnostic (Dx) - dosage forms of high specific activity 131I-mIBG for clinical application

    International Nuclear Information System (INIS)

    Noronha, O.P.D.; Sonawane, G.A.; Samuel, A.M.

    1998-01-01

    Radioiodinated mIBG is finding increasing utility in nuclear medicine. However, its widespread use in developing countries is precluded by logistic constraints owing to the relative instability of the labelled molecule with respect to time and temp., and high costs. This prompted us to develop a low cost in-house batch process technology that could be used for the small-scale preparation of 131 I-mIBG even in a less equipped hospital-based radiopharmacy. The production of large amounts of 131 I-mIBG for clinical use requires sophisticated infrastructure (a scarce resource) to contain / safeguard against internal and external radiation exposures. We have indigenously designed a semi-automated, self-shielded, remote-controlled and safe microplant + process assemblies using easily accessible and cheap inputs, and developed the complete technology for the rapid and safe production of dual dosage forms of 131 I-mIBG, a radiotherapeutic (R x ) single dosage form of high activity along with 1-3 low activity radiodiagnostics (D x ) as multidosage forms. The radioiodide exchange reaction was effected in the solid / melt phase at 190 deg. C in 1.0 h. The radiolabelling yield was ∼80.0-86.0%, and the radiochemical purity > 99.5% and specific activity of R x /D x =900-1300/60-800 MBq ( x dosage forms at 3 weeks. The dosage forms (especially R x ) were only made against firm patient appointment(s). Thus far we have prepared 14 R x (49.0 GBq) and 70 + 14 batches (43.43 GBq) of (∼150 nos.) D x forms, and used them in 14 and > 1100 patients respectively. (author)

  5. Microporous uranyl chromates successively formed by evaporation from acidic solution

    Energy Technology Data Exchange (ETDEWEB)

    Siidra, Oleg I.; Nazarchuk, Evgeny V.; Bocharov, Sergey N.; Kayukov, Roman A. [St. Petersburg State Univ. (Russian Federation). Dept. of Crystallography; Depmeier, Wulf [Kiel Univ. (Germany). Inst. fuer Geowissenschaften

    2018-04-01

    The first microporous framework structures containing uranium and chromium have been synthesized and characterized. Rb{sub 2}[(UO{sub 2}){sub 2}(CrO{sub 4}){sub 3}(H{sub 2}O){sub 2}](H{sub 2}O){sub 3} (1) was crystallized from uranyl chromate solution by evaporation. Further evaporation led to increased viscosity of the solution and overgrowing of Rb{sub 2}[(UO{sub 2}){sub 2}(CrO{sub 4}){sub 3}(H{sub 2}O)](H{sub 2}O) (2) on the crystals of 1. With respect to 1, the framework of 2 is partially dehydrated. Both frameworks differ compositionally by only one water molecule, but this seemingly small difference affects significantly the pore size and overall structural topology of the frameworks, which present very different flexibility of the U-O-Cr links. These are rigid in the pillared framework of 1, in contrast to 2 where the U-O-Cr angles range from 126.3 to 168.2 , reflecting the substantial flexibility of Cr-O-U connections which make them comparable to the corresponding Mo-O-U links in uranyl molybdates.

  6. Dosage of trace carbon in sodium (1963); Dosage de traces de carbone dans le sodium (1963)

    Energy Technology Data Exchange (ETDEWEB)

    Sannier, J; Vasseur, A [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1963-07-01

    A wet method for dosing carbon in sodium has been developed. The carbon is oxidised in a vacuum using Van SLYKE'S solution. The carbonic acid formed is measured volumetrically; its purity can be controlled by chromatographic analysis. The results obtained show that this method makes it possible to measure carbon in concentrations of about 10 ppm. (authors) [French] Une methode de dosage par voie humide du carbone dans le sodium a ete mise au point. L'oxydation du carbone par la solution de Van SLYKE est realisee sous vide. Le gaz carbonique forme est dose volumetriquement; sa purete peut etre controlee par analyse chromatographique. Les resultats obtenus montrent que cette methode permet de doser des teneurs en carbone de l'ordre de 10 ppm. (auteurs)

  7. Development of the fast, simple and fully validated high performance liquid chromatographic method with diode array detector for quantification of testosterone esters in an oil-based injectable dosage form.

    Science.gov (United States)

    Kozlik, Petr; Tircova, Barbora

    2016-11-01

    Counterfeit steroids are available on the black market, ultimately to consumers who believe they are buying a legitimate pharmaceutical item from the labeled company. In many cases, counterfeit steroids can contain lower doses or some products can be overdosed. This can unwittingly expose users to a significant health risks. The mixture of testosterone propionate, phenylpropionate, isocaproate and decanoate in an oil-based injectable dosage form belongs to the one of the most misused illicit drugs by a variety of athletes. This study developed a new, fast, simple and reliable HPLC method combined with a simple sample preparation step to determine testosterone propionate, phenylpropionate, isocaproate and decanoate in an oil-based injectable dosage form without the use of sophisticated and expensive instrumentation. The developed analytical procedure provides high throughput of samples where LC analysis takes only 6min and sample preparation of oil matrix in one step takes approximately 10min with precision ranging from 1.03 to 3.38% (RSD), and accuracy (relative error %) within ±2.01%. This method was found to be precise, linear, accurate, sensitive, selective and robust for routine application in screening of commercial pharmaceutical products based on content of mentioned testosterone esters in their oil-based injectable dosage form for counterfeit drugs. This method was successfully applied to the analysis of nine samples of commercial testosterone mixtures purchased from various sources and will be further used as an effective screening method for determination of previously mentioned testosterone esters in samples confiscated by Institute of Forensic Science (Slovakia) during the illegal trade. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Comprehensive evaluation of cesium removal by CuFC adsorption. The effects of initial concentration, CuFC dosage and co-existing ions in solution

    International Nuclear Information System (INIS)

    Yao Xu; Ping Gu; Guang-Hui Zhang; Jun Zhao; Lu Wang; Xiang-Zhu Xiao; Fei Han

    2017-01-01

    To use copper ferrocyanide (CuFC) more efficiently in wastewater treatment, the method of isotope carrying used in "1"3"7Cs removal was investigated. A calculation model based on Freundlich isotherm was established to determine the optimum initial cesium concentration, at which the highest decontamination factor (DF) could be obtained at a certain CuFC dosage. An accurate DF prediction model was developed to describe synergistic effects of sodium and potassium. A novel index called volumetric distribution coefficient (K_v_d) was proposed to evaluate adsorption performance in terms of DF and concentration factor. (author)

  9. Magnetohydrodynamic viscous flow over a nonlinearly moving surface: Closed-form solutions

    Science.gov (United States)

    Fang, Tiegang

    2014-05-01

    In this paper, the magnetohydrodynamic (MHD) flow over a nonlinearly (power-law velocity) moving surface is investigated analytically and solutions are presented for a few special conditions. The solutions are obtained in closed forms with hyperbolic functions. The effects of the magnetic, the wall moving, and the mass transpiration parameters are discussed. These solutions are important to show the flow physics as well as to be used as bench mark problems for numerical validation and development of new solution schemes.

  10. Polymer adhesion predictions for oral dosage forms to enhance drug administration safety. Part 3: Review of in vitro and in vivo methods used to predict esophageal adhesion and transit time.

    Science.gov (United States)

    Drumond, Nélio; Stegemann, Sven

    2018-05-01

    The oral cavity is frequently used to administer pharmaceutical drug products. This route of administration is seen as the most accessible for the majority of patients and supports an independent therapy management. For current oral dosage forms under development, the prediction of their unintended mucoadhesive properties and esophageal transit profiles would contribute for future administration safety, as concerns regarding unintended adhesion of solid oral dosage forms (SODF) during oro-esophageal transit still remain. Different in vitro methods that access mucoadhesion of polymers and pharmaceutical preparations have been proposed over the years. The same methods might be used to test non-adhesive systems and contribute for developing safe-to-swallow technologies. Previous works have already investigated the suitability of non-animal derived in vitro methods to assess such properties. The aim of this work was to review the in vitro methodology available in the scientific literature that used animal esophageal tissue to evaluate mucoadhesion and esophageal transit of pharmaceutical preparations. Furthermore, in vivo methodology is also discussed. Since none of the in vitro methods developed are able to mimic the complex swallowing process and oro-esophageal transit, in vivo studies in humans remain as the gold standard. Copyright © 2018 Elsevier B.V. All rights reserved.

  11. Differences between Solution and Membrane Forms of Chitosan on the In Vitro Activity of Fibroblasts

    Directory of Open Access Journals (Sweden)

    Bahar Uslu

    2015-03-01

    Full Text Available Background: Chitosan, a linear polysaccharide, has been recently used in biomedical applications. In vitro studies have demonstrated its effect on cellular growth and its stimulatory action on cellular layer formation. Aims: The present study aims to compare the proliferative effects of chitosan in two forms, membranous and solution forms, on Swiss 3T3 mouse embryonic fibroblasts. Study Design: In vitro study. Methods: Three experimental groups were formed: cells were cultured in a normal medium without chitosan (Control Group; cells were cultured either in a medium containing 2.0% chitosan in membranous form (Membrane Group or chitosan solution at a concentration of 2.0% (Solution Group.Two different methods were used in the experiments: cells cultured on the medium containing chitosan in solution or membranous forms (method 1; and chitosan solution or membranous forms were added into the medium containing previously cultured cells (method 2. Results: Scanning electron microscopic investigations of the experimental groups revealed cells with well-defined cellular projections, intact cellular membranes and tight intercellular junctions. They were especially prominent in the membrane group of method 1 and in the membrane and solution groups of method 2. Mouse monoclonal anti-collagen 1 primary antibody was used to indicate collagen synthesis. Prominent collagen synthesis was detected in the membrane groups on the 10th day of culture for both methods. Bromodeoxyuridine (BrdU and MTT assays were performed in order to assess cellular proliferation and viability, respectively. BrdU labelling tests indicated a higher proliferation index in the membrane group of method 1 on the 5th and 10th days. For the second method, the membranous form on the 10th day and solution form on the 5th day were the most effective groups in terms of cellular proliferation. MTT results reflected a high cellular viability in method 1 on the 5th day of treatment with the

  12. In Situ Monitoring and Modeling of the Solution-Mediated Polymorphic Transformation of Rifampicin: From Form II to Form I.

    Science.gov (United States)

    Guo, Nannan; Hou, Baohong; Wang, Na; Xiao, Yan; Huang, Jingjing; Guo, Yanmei; Zong, Shuyi; Hao, Hongxun

    2018-01-01

    In this article, the solution-mediated polymorphic transformation of rifampicin was investigated and simulated in 3 solvents at 30°C. The solid-state form I and form II of rifampicin was characterized by powder X-ray diffraction, scanning electron microscopy, thermogravimetric analysis, Raman spectroscopy, and Fourier transform infrared spectroscopy (FTIR). To explore the relative stability, solubility data of form I and form II of rifampicin in butan-1-ol were determined using a dynamical method. In addition, Raman spectroscopy and focused beam reflectance measurement were used to in situ monitor the transformation of rifampicin from form II to form I. The liquid state concentration of rifampicin was measured by UV spectroscopic method. To investigate the effect of solvent on transformation, the transformation experiments were carried out in 3 solvents. Furthermore, a mathematical model was built to describe the kinetics of dissolution, nucleation, and growth processes during transformation by using experimental data. By combination of experimental and simulation results, it was found that the transformation process of rifampicin is controlled by dissolution of form II in heptane, whereas the transformation in hexane and octane was firstly controlled by dissolution of solid-state form and then controlled by growth of form I. Copyright © 2018 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  13. Closed form solution to a second order boundary value problem and its application in fluid mechanics

    International Nuclear Information System (INIS)

    Eldabe, N.T.; Elghazy, E.M.; Ebaid, A.

    2007-01-01

    The Adomian decomposition method is used by many researchers to investigate several scientific models. In this Letter, the modified Adomian decomposition method is applied to construct a closed form solution for a second order boundary value problem with singularity

  14. Growth behavior of anodic porous alumina formed in malic acid solution

    Science.gov (United States)

    Kikuchi, Tatsuya; Yamamoto, Tsuyoshi; Suzuki, Ryosuke O.

    2013-11-01

    The growth behavior of anodic porous alumina formed on aluminum by anodizing in malic acid solutions was investigated. High-purity aluminum plates were electropolished in CH3COOH/HClO4 solutions and then anodized in 0.5 M malic acid solutions at 293 K and constant cell voltages of 200-350 V. The anodic porous alumina grew on the aluminum substrate at voltages of 200-250 V, and a black, burned oxide film was formed at higher voltages. The nanopores of the anodic oxide were only formed at grain boundaries of the aluminum substrate during the initial stage of anodizing, and then the growth region extended to the entire aluminum surface as the anodizing time increased. The anodic porous alumina with several defects was formed by anodizing in malic acid solution at 250 V, and oxide cells were approximately 300-800 nm in diameter.

  15. Low resolution solution structure of the Apo form of Escherichia coli haemoglobin protease Hbp.

    NARCIS (Netherlands)

    scott, D.J.; Grossman, J.G.; Tame, J.R.H.; Byron, O.; Wilson, K.S.; Otto, B.R.

    2002-01-01

    We have studied the solution properties of the apo form of the haemoglobin protease or "haemoglobinase", Hbp, a principal component of an important iron acquisition system in pathogenic Escherichia coli. Experimental determination of secondary structure content from circular dichroism (CD)

  16. Electrooxidation of Indomethacin at Multiwalled Carbon Nanotubes-Modified GCE and Its Determination in Pharmaceutical Dosage Form and Human Biological Fluids

    OpenAIRE

    Sataraddi, Sanjeevaraddi R.; Patil, Shreekant M.; Bagoji, Atmanand M.; Pattar, Vijay P.; Nandibewoor, Sharanappa T.

    2014-01-01

    A simple, rapid, selective, and sensitive electrochemical method for the direct determination of indomethacin was developed. The electrochemical behavior of indomethacin was carried at multiwalled carbon nanotube- (MWCNTs-) modified glassy carbon electrode (GCE). The cyclic voltammetric results indicated that MWCNT-modified glassy carbon electrode remarkably enhanced electrocatalytic activity towards the oxidation of indomethacin in slightly acidic solutions. It led to a considerable improvem...

  17. Intercavitary implants dosage calculation

    International Nuclear Information System (INIS)

    Rehder, B.P.

    The use of spacial geometry peculiar to each treatment for the attainment of intercavitary and intersticial implants dosage calculation is presented. The study is made in patients with intercavitary implants by applying a modified Manchester technique [pt

  18. XPS study of the passive layers formed on lead in aqueous nitrate solutions

    International Nuclear Information System (INIS)

    Uchida, Miho; Okuwaki, Akitsugu

    1997-01-01

    The analysis of the lead surface immersed in aqueous nitrate solutions by X-ray photoelectron spectroscopy (XPS) shows the formation of passive oxide layer containing nitrogen compound. The oxide layer formed on the lead surface in aqueous ammonium nitrate solution was hydrolyzed and cracked. (author)

  19. A Closed-Form Solution to Tensor Voting: Theory and Applications

    OpenAIRE

    Wu, Tai-Pang; Yeung, Sai-Kit; Jia, Jiaya; Tang, Chi-Keung; Medioni, Gerard

    2016-01-01

    We prove a closed-form solution to tensor voting (CFTV): given a point set in any dimensions, our closed-form solution provides an exact, continuous and efficient algorithm for computing a structure-aware tensor that simultaneously achieves salient structure detection and outlier attenuation. Using CFTV, we prove the convergence of tensor voting on a Markov random field (MRF), thus termed as MRFTV, where the structure-aware tensor at each input site reaches a stationary state upon convergence...

  20. Evaluation of two different dosages of local anesthetic solution used for ultrasound-guided femoral nerve block for pain relief and positioning for central neuraxial block in patients of fracture neck of the femur

    Directory of Open Access Journals (Sweden)

    Abhijit A Karmarkar

    2017-01-01

    Full Text Available Introduction: Surgical management of the fracture femur is preferred so as to prevent complications associated with prolonged immobilization. Central neuraxial blockade (CNB is an attractive option for these patients, and an optimal positioning of the patient is a definite requirement. Owing to the pain associated with movement of the fractured limb, it becomes difficult for the patients to give suitable positioning. Femoral nerve block (FNB features as a rescue analgesia so as to provide adequate analgesia for facilitation of satisfactory positioning. Aim: This study aims to compare analgesic effect of two different dosages of local anesthetic (LA solution administered for ultrasonography (USG-guided FNB given to facilitate optimal positioning for conduct of CNB. Materials and Methods: After taking permission from the institutional review board, eighty patients were enrolled in the study to find out the efficacy of dosage of LA solution for FNB in providing pain relief caused by movement of fractured limb during conduct of regional anesthesia. Informed consent was taken. All patients were given USG-guided FNB. Patients were randomized using a computer-generated random number table, into two groups of forty patients each. Group A patients received USG-guided 12 ml of LA solution containing 10 ml lignocaine solution without preservative (2% plus 2 ml normal saline (NS, while Group B patients received USG-guided 15 ml of LA solution containing 13 ml lignocaine solution without preservative (2% plus 2 ml NS for positioning before combined spinal epidural. Results: A total of eighty patients, divided randomly into two groups, were enrolled in the study. Demographics (age, sex, weight, and American Society of Anesthesiologists grades were similar in both groups. No statistical significance was found in the numeric rating scale scores at baseline, zero minutes, 5, and 15 min in both the groups. Conclusion: USG-guided FNB with 12 ml of LA solution was

  1. An efficient closed-form solution for acoustic emission source location in three-dimensional structures

    Directory of Open Access Journals (Sweden)

    Xibing Li

    2014-02-01

    Full Text Available This paper presents an efficient closed-form solution (ECS for acoustic emission(AE source location in three-dimensional structures using time difference of arrival (TDOA measurements from N receivers, N ≥ 6. The nonlinear location equations of TDOA are simplified to linear equations. The unique analytical solution of AE sources for unknown velocity system is obtained by solving the linear equations. The proposed ECS method successfully solved the problems of location errors resulting from measured deviations of velocity as well as the existence and multiplicity of solutions induced by calculations of square roots in existed close-form methods.

  2. Determination of a closed-form solution for the multidimensional transport equation using a fractional derivative

    International Nuclear Information System (INIS)

    Zabadal, J.; Vilhena, M.T.; Segatto, C.F.; Pazos, R.P.Ruben Panta.

    2002-01-01

    In this work we construct a closed-form solution for the multidimensional transport equation rewritten in integral form which is expressed in terms of a fractional derivative of the angular flux. We determine the unknown order of the fractional derivative comparing the kernel of the integral equation with the one of the Riemann-Liouville definition of fractional derivative. We report numerical simulations

  3. Determination of a closed-form solution for the multidimensional transport equation using a fractional derivative

    Energy Technology Data Exchange (ETDEWEB)

    Zabadal, J. E-mail: jorge.zabadal@ufrgs.br; Vilhena, M.T. E-mail: vilhena@mat.ufrgs.br; Segatto, C.F. E-mail: cynthia@mat.ufrgs.br; Pazos, R.P.Ruben Panta. E-mail: rpp@mat.pucrgs.br

    2002-07-01

    In this work we construct a closed-form solution for the multidimensional transport equation rewritten in integral form which is expressed in terms of a fractional derivative of the angular flux. We determine the unknown order of the fractional derivative comparing the kernel of the integral equation with the one of the Riemann-Liouville definition of fractional derivative. We report numerical simulations.

  4. In vitro dissolution of generic immediate-release solid oral dosage forms containing BCS class I drugs: comparative assessment of metronidazole, zidovudine, and amoxicillin versus relevant comparator pharmaceutical products in South Africa and India.

    Science.gov (United States)

    Reddy, Nallagundla H S; Patnala, Srinivas; Löbenberg, Raimar; Kanfer, Isadore

    2014-10-01

    Biowaivers are recommended for immediate-release solid oral dosage forms using dissolution testing as a surrogate for in vivo bioequivalence studies. Several guidance are currently available (the World Health Organization (WHO), the US FDA, and the EMEA) where the conditions are described. In this study, definitions, criteria, and methodologies according to the WHO have been applied. The dissolution performances of immediate-release metronidazole, zidovudine, and amoxicillin products purchased in South African and Indian markets were compared to the relevant comparator pharmaceutical product (CPP)/reference product. The dissolution performances were studied using US Pharmacopeia (USP) apparatus 2 (paddle) set at 75 rpm in each of three dissolution media (pH1.2, 4.5, and 6.8). Concentrations of metronidazole, zidovudine, and amoxicillin in each dissolution media were determined by HPLC. Of the 11 metronidazole products tested, only 8 could be considered as very rapidly dissolving products as defined by the WHO, whereas 2 of those products could be considered as rapidly dissolving products but did not comply with the f 2 acceptance criteria in pH 6.8. All 11 zidovudine products were very rapidly dissolving, whereas in the case of the 14 amoxicillin products tested, none of those products met any of the WHO criteria. This study indicates that not all generic products containing the same biopharmaceutics classification system (BCS) I drug and in similar strength and dosage form are necessarily in vitro equivalent. Hence, there is a need for ongoing market surveillance to determine whether marketed generic products containing BCS I drugs meet the release requirements to confirm their in vitro bioequivalence to the respective reference product.

  5. UPLC and LC-MS studies on degradation behavior of irinotecan hydrochloride and development of a validated stability-indicating ultra-performance liquid chromatographic method for determination of irinotecan hydrochloride and its impurities in pharmaceutical dosage forms.

    Science.gov (United States)

    Kumar, Navneet; Sangeetha, Dhanaraj; Reddy, Sunil P

    2012-10-01

    The objective of the current investigation was to study the degradation behavior of irinotecan hydrochloride under different International Conference on Harmonization (ICH) recommended stress conditions using ultra-performance liquid chromatography and liquid chromatography-mass spectrometry and to establish a validated stability-indicating reverse-phase ultra-performance liquid chromatographic method for the quantitative determination of irinotecan hydrochloride and its seven impurities and degradation products in pharmaceutical dosage forms. Irinotecan hydrochloride was subjected to the stress conditions of oxidative, acid, base, hydrolytic, thermal and photolytic degradation. Irinotecan hydrochloride was found to degrade significantly in oxidative and base hydrolysis and photolytic degradation conditions. The degradation products were well resolved from the main peak and its impurities, thus proving the stability-indicating power of the method. Chromatographic separation was achieved on a Waters Acquity BEH C8 (100 × 2.1 mm) 1.7-µm column with a mobile phase containing a gradient mixture of solvent A (0.02M KH(2)PO(4) buffer, pH 3.4) and solvent B (a mixture of acetonitrile and methanol in the ratio of 62:38 v/v). The mobile phase was delivered at a flow rate of 0.3 mL/min with ultraviolet detection at 220 nm. The run time was 8 min, within which irinotecan and its seven impurities and degradation products were satisfactorily separated. The developed method was validated as per ICH guidelines with respect to specificity, linearity, limit of detection, limit of quantification, accuracy, precision and robustness. This method was also suitable for the assay determination of irinotecan hydrochloride in pharmaceutical dosage forms.

  6. A validated stability indicating high-performance liquid chromatographic method for simultaneous estimation of cefuroxime sodium and sulbactam sodium in injection dosage form

    Directory of Open Access Journals (Sweden)

    Falguni M Patel

    2012-01-01

    Full Text Available Background: A fixed dose combination of cefuroxime sodium (β lactam antibiotic and sulbactam sodium (β Lactamase inhibitor is used in ratio of 2:1 as powder for injection for the treatment of resistant lower respiratory tract and other infections. Aims: A simple, precise, and accurate ion-pair reverse-phase high-performance liquid chromatography (RP-HPLC method was developed and validated for determination of cefuroxime Na(CEF and sulbactam Na(SUL in injection. Materials and Methods: Isocratic RP-HPLC separation was achieved on an ACE C 18 column (150×4.6 mm id, 5 μm particle size using the mobile phase 0.002 M tetrabutylammonium hydroxide sulfate (TBAH in 10 mm potassium di-hydrogen phosphate buffer-acetonitrile (86:14 v/v, pH 3.7 at a flow rate of 1.0 ml/min. Results and Conclusion: The retention time of sulbactam Na and cefuroxime Na were 3.2 min and 10.2 min, respectively. The ion-pairing reagent improved the retention of highly polar sulbactam Na on reverse-phase column. The detection was performed at 210 nm. The method was validated for linearity, precision, accuracy, robustness, solution stability, and specificity. The method was validated for linearity, precision, accuracy, robustness, solution stability, and specificity. The method was linear in the concentration range of 10-100 μg/ml for cefuroxime Na and 5-50 μg/ml for sulbactam Na, with a correlation coefficient of 0.9999 and 0.9998 for the respective drugs. The intraday precision was 0.13-0.21% and 0.48-0.65%, and the interday precision was 0.32-0.81% and 0.60-0.83% for cefuroxime Na and sulbactam Na, respectively. The accuracy (recovery was found to be in the range of 98.76-100.61% and 98.99-100.30% for cefuroxime Na and sulbactam Na, respectively. The drugs were found to degrade under hydrolytic and oxidative conditions. The drugs could be effectively separated from different degradation products, and hence the method can be used for stability analysis.

  7. Identification of different shapes, colors and sizes of standard oral dosage forms in diabetes type 2 patients-A pilot study.

    Science.gov (United States)

    Stegemann, Sven; Riedl, Regina; Sourij, Harald

    2017-01-30

    The clear identification of drug products by the patients is essential for a safe and effective medication management. In order to understand the impact of shape, size and color on medication identification a study was performed in subjects with type 2 diabetes mellitus (T2D). Ten model drugs differentiated by shape, size and color were evaluated using a mixed method of medication schedule preparation by the participants followed by a semi-structured interview. Detection times were fastest for the large round tablet shape and the bi-chromatic forms. Larger size was easier to identify than the smaller sizes except for the bi-chromatic forms. The shape was the major source of errors, followed by the size and the color dimension. The results from this study suggests that color as a single dimension are perceived more effectively by subjects with T2D compared to shape and size, which requires a more demanding processing of three dimension and is dependent on the perspective. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Development of iron phosphate ceramic waste form to immobilize radioactive waste solution

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jongkwon [Division of Advanced Nuclear Engineering, Pohang University of Science and Technology (POSTECH), San 31, Hyoja-Dong, Pohang (Korea, Republic of); Um, Wooyong, E-mail: wooyong.um@pnnl.gov [Division of Advanced Nuclear Engineering, Pohang University of Science and Technology (POSTECH), San 31, Hyoja-Dong, Pohang (Korea, Republic of); Pacific Northwest National Laboratory, Richland, WA 99354 (United States); Choung, Sungwook [Division of Advanced Nuclear Engineering, Pohang University of Science and Technology (POSTECH), San 31, Hyoja-Dong, Pohang (Korea, Republic of)

    2014-09-15

    The objective of this research was to develop an iron phosphate ceramic (IPC) waste form using converter slag obtained as a by-product of the steel industry as a source of iron instead of conventional iron oxide. Both synthetic off-gas scrubber solution containing technetium-99 (or Re as a surrogate) and LiCl–KCl eutectic salt, a final waste solution from pyrochemical processing of spent nuclear fuel, were used as radioactive waste streams. The IPC waste form was characterized for compressive strength, reduction capacity, chemical durability, and contaminant leachability. Compressive strengths of the IPC waste form prepared with different types of waste solutions were 16 MPa and 19 MPa for LiCl–KCl eutectic salt and the off-gas scrubber simulant, respectively, which meet the minimum compressive strength of 3.45 MPa (500 psi) for waste forms to be accepted into the radioactive waste repository. The reduction capacity of converter slag, a main dry ingredient used to prepare the IPC waste form, was 4136 meq/kg by the Ce(IV) method, which is much higher than those of the conventional Fe oxides used for the IPC waste form and the blast furnace slag materials. Average leachability indexes of Tc, Li, and K for the IPC waste form were higher than 6.0, and the IPC waste form demonstrated stable durability even after 63-day leaching. In addition, the Toxicity Characteristic Leach Procedure measurements of converter slag and the IPC waste form with LiCl–KCl eutectic salt met the universal treatment standard of the leachability limit for metals regulated by the Resource Conservation and Recovery Act. This study confirms the possibility of development of the IPC waste form using converter slag, showing its immobilization capability for radionuclides in both LiCl–KCl eutectic salt and off-gas scrubber solutions with significant cost savings.

  9. The application dosage of Azolla pinnata in fresh and powder form as organic fertilizer on soil chemical properties, growth and yield of rice plant

    Science.gov (United States)

    Setiawati, Mieke Rochimi; Damayani, Maya; Herdiyantoro, Diyan; Suryatmana, Pujawati; Anggraini, Derisfha; Khumairah, Fiqriah Hanum

    2018-02-01

    The yield of rice plants is strongly influenced by N fertilizer. Nitrogen in rice plants has roles in vegetative growth, tiller formation and increasing yield through rice protein formation. Nitrogen supplied from organic fertilizers is better than inorganic fertilizers that may have environmental problem effects. Organic fertilizers from Azolla pinnata water fern contain higher N than other organic fertilizers. Symbiosis between A. pinnata and the N-fixing cyanobacteria results in high content of nitrogen, 3 to 5%. A. pinnata can be added to the rice field as organic fertilizer in form of fresh biomass or composted. Composted form can be ground into powder which passes through 100 mesh sieve. Preparation of compost powder of A. pinnata is done to reduce the constraints of voluminous application of organic fertilizers and to improve the efficiency of its use. The objective of this research was to compare the effect of the use of fresh A. pinnata and compost powder of A. pinnata on some soil and plant chemical properties and rice yield. The treatments applied were fresh A. pinnata at the dose of 0, 10 and 20 ton ha-1 and A. pinnata compost powder at 12.5 and 25 kg ha-1. The results showed that incorporation of fresh A. pinnata at 20 tons ha-1 and its compost powder at 25 kg ha-1 increased the available P of soil, plant P content and tiller number, but did not affect the content of organic-C, total soil N, plant N content and rice yield. This study suggested the benefits of A. pinnata compost powder technology in organic fertilization of soil to increase the nutrient content of soil and rice plants.

  10. Development and application of a validated stability-indicating HPLC method for simultaneous determination of granisetron hydrochloride, benzyl alcohol and their main degradation products in parenteral dosage forms.

    Science.gov (United States)

    Hewala, Ismail; El-Fatatre, Hamed; Emam, Ehab; Mubrouk, Mokhtar

    2010-06-30

    A simple, rapid and sensitive reversed phase high performance liquid chromatographic method using photodiode array detection was developed and validated for the simultaneous determination of granisetron hydrochloride, benzyl alcohol, 1-methyl-1H-indazole-3-carboxylic acid (the main degradation product of granisetron) and benzaldehyde (the main degradation product of benzyl alcohol) in granisetron injections. The separation was achieved on Hypersil BDS C8 (250 mm x 4.6 mm i.d., 5 microm particle diameter) column using a mobile phase consisted of acetonitrile:0.05 M KH(2)PO(4):triethylamine (22:100:0.15) adjusted to pH 4.8. The column was maintained at 25 degrees C and 20 microL of solutions was injected. Photodiode array detector was used to test the peak purity and the chromatograms were extracted at 210 nm. Naphazoline hydrochloride was used as internal standard. The method was validated with respect to specificity, linearity, accuracy, precision, limit of quantitation and limit of detection. The validation acceptance criteria were met in all cases. Identification of the pure peaks was carried out using library match programmer and wavelengths of derivative optima of the spectrograms of the peaks. The method was successfully applied to the determination of the investigated drugs and their degradation products in different batches of granisetron injections. The method was proved to be sensitive for the determination down to 0.03 and 0.01% of granisetron degradation product and benzaldehyde, respectively, which are far below the compendia limits for testing these degradation products in their corresponding intact drugs. Copyright 2010 Elsevier B.V. All rights reserved.

  11. Unsteady free convection flow of a micropolar fluid with Newtonian heating: Closed form solution

    Directory of Open Access Journals (Sweden)

    Hussanan Abid

    2017-01-01

    Full Text Available This article investigates the unsteady free convection flow of a micropolar fluid over a vertical plate oscillating in its own plane with Newtonian heating condition. The problem is modelled in terms of partial differential equations with some physical conditions. Closed form solutions in terms of exponential and complementary error functions of Gauss are obtained by using the Laplace transform technique. They satisfy the governing equations and impose boundary and initial conditions. The present solution in the absence of microrotation reduces to well-known solutions of Newtonian fluid. Graphs are plotted to study the effects of various physical parameters on velocity and microrotation. Numerical results for skin friction and wall couple stress is computed in tables. Apart from the engineering point of view, the present article has strong advantage over the published literature as the exact solutions obtained here can be used as a benchmark for comparison with numerical/ approximate solutions and experimental data.

  12. Optimization of headspace solid-phase microextraction for analysis of {beta}-caryophyllene in a nanoemulsion dosage form prepared with copaiba (Copaifera multijuga Hayne) oil

    Energy Technology Data Exchange (ETDEWEB)

    Dias, Daiane de O; Colombo, Mariana; Kelmann, Regina G. [Programa de Pos-Graduacao em Ciencias Farmaceuticas, Faculdade de Farmacia, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Av. Ipiranga, 2752, CEP 90610-000 (Brazil); De Souza, Tatiane P. [Programa de Pos-Graduacao em Ciencias Farmaceuticas, Universidade Federal do Amazonas, Manaus, Amazonas (Brazil); Bassani, Valquiria L.; Teixeira, Helder F. [Programa de Pos-Graduacao em Ciencias Farmaceuticas, Faculdade de Farmacia, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Av. Ipiranga, 2752, CEP 90610-000 (Brazil); Veiga, Valdir F. [Departamento de Quimica, Instituto de Ciencias Exatas, UFAM, Av. Gal. Rodrigo Octavio, 6.200 - Japiim, 69.079-000, Manaus - AM (Brazil); Limberger, Renata P. [Programa de Pos-Graduacao em Ciencias Farmaceuticas, Faculdade de Farmacia, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Av. Ipiranga, 2752, CEP 90610-000 (Brazil); and others

    2012-04-06

    Highlights: Black-Right-Pointing-Pointer A SPME-CG method is proposed for {beta}-caryophyllene assay in nanoemulsions containing copaiba oil. Black-Right-Pointing-Pointer SPME parameters were optimized for efficient {beta}-caryophyllene extraction. Black-Right-Pointing-Pointer The stability-indicating capability and specificity of the method were satisfied. Black-Right-Pointing-Pointer Nanoemulsions partially protected {beta}-caryophyllene under stressing conditions. Black-Right-Pointing-Pointer The proposed method presents linearity, lows LOD and LOQ, good precision, accuracy and robustness. - Abstract: Recent studies have shown the anti-inflammatory activity of Copaiba oils may be addressed to the high content of {beta}-caryophyllene, the most common sesquiterpene detected, especially in the Copaifera multijuga Hayne species. In the present study, nanoemulsions were proposed as a delivery system for copaiba oil in view to treat locally inflamed skin. This article describes the optimization and validation of a stability-indicating SPME-GC method, for {beta}-caryophyllene analysis in the nanoemulsions produced by high pressure homogenization. SPME methods are performed with PDMS (polydimethylsiloxane) fiber (100 {mu}m). Three SPME parameters were evaluated by a three-level-three-factor Box-Behnken factorial design as potentially affecting the technique efficiency. According to the results obtained, the best conditions to extract {beta}-caryophyllene were: (i) sampling temperature of 45 Degree-Sign C, (ii) sampling time of 20 min and (iii) no NaCl addition. Results coming from the forced degradation tests showed a reduction of {beta}-caryophyllene peak area when both caryophyllene methanolic solution and nanoemulsions were exposed to acid hydrolysis, UV-A irradiation, oxidative (H{sub 2}O{sub 2}) and thermolitic (60 Degree-Sign C) conditions. Such reduction occurred in lower extent in the nanoemulsions, suggesting a protective effect of the formulation to {beta

  13. Optimization of headspace solid-phase microextraction for analysis of β-caryophyllene in a nanoemulsion dosage form prepared with copaiba (Copaifera multijuga Hayne) oil

    International Nuclear Information System (INIS)

    Dias, Daiane de O; Colombo, Mariana; Kelmann, Regina G.; De Souza, Tatiane P.; Bassani, Valquiria L.; Teixeira, Helder F.; Veiga, Valdir F.; Limberger, Renata P.

    2012-01-01

    Highlights: ► A SPME-CG method is proposed for β-caryophyllene assay in nanoemulsions containing copaiba oil. ► SPME parameters were optimized for efficient β-caryophyllene extraction. ► The stability-indicating capability and specificity of the method were satisfied. ► Nanoemulsions partially protected β-caryophyllene under stressing conditions. ► The proposed method presents linearity, lows LOD and LOQ, good precision, accuracy and robustness. - Abstract: Recent studies have shown the anti-inflammatory activity of Copaiba oils may be addressed to the high content of β-caryophyllene, the most common sesquiterpene detected, especially in the Copaifera multijuga Hayne species. In the present study, nanoemulsions were proposed as a delivery system for copaiba oil in view to treat locally inflamed skin. This article describes the optimization and validation of a stability-indicating SPME-GC method, for β-caryophyllene analysis in the nanoemulsions produced by high pressure homogenization. SPME methods are performed with PDMS (polydimethylsiloxane) fiber (100 μm). Three SPME parameters were evaluated by a three-level-three-factor Box–Behnken factorial design as potentially affecting the technique efficiency. According to the results obtained, the best conditions to extract β-caryophyllene were: (i) sampling temperature of 45 °C, (ii) sampling time of 20 min and (iii) no NaCl addition. Results coming from the forced degradation tests showed a reduction of β-caryophyllene peak area when both caryophyllene methanolic solution and nanoemulsions were exposed to acid hydrolysis, UV-A irradiation, oxidative (H 2 O 2 ) and thermolitic (60 °C) conditions. Such reduction occurred in lower extent in the nanoemulsions, suggesting a protective effect of the formulation to β-caryophyllene content. Since no degradation products were detected in the same retention time of β-caryophyllene, the specificity of the method was demonstrated. The method was linear in

  14. Development and validation of a reversed-phase HPLC method for simultaneous estimation of clotrimazole and beclomethasone dipropionate in lotion and cream dosage form

    Directory of Open Access Journals (Sweden)

    Komal R Dhudashia

    2013-01-01

    Full Text Available Background: The combination of Clotrimazole and Beclomethasone dipropionate is used as anti-fungal and anti-inflammatory for external use in the form of cream and lotion. Aim: A simple, specific, economic, precise, and accurate reversed-phase high performance liquid chromatographic method development for the simultaneous estimation of clotrimazole (CT and beclomethasone dipropionate (BD in lotion and cream formulations. Materials and Methods: The chromatographic separation was achieved on a Kromasil C18 (150 mm × 4.6 mm, 5 μm analytical column. A mixture of acetonitrile-water (70:30, v/v was used as the mobile phase, at a flow rate of 1 ml/min and detector wavelength at 254 nm. The validation of the proposed method was carried out for specificity, linearity, accuracy, precision, limit of detection, limit of quantitation, and system suitability test as per ICH guideline. Results: The retention time of CT and BD was found to be 5.4 and 4 min, respectively. The linear dynamic ranges were from 2-16 μg/ml and 80-640 μg/ml for BD and CT, respectively. Limit of detection and quantification for BD were 0.039 and 0.12 μg/ml, for CT 1.24 and 3.77 μg/ml, respectively. Conclusions: The developed method was validated and found to be simple, specific, accurate and precise and can be used for routine quality control analysis of titled drugs in combination in lotion and cream formulation.

  15. Development of a validated HPLC method for the quantitative determination of trelagliptin succinate and its related substances in pharmaceutical dosage forms.

    Science.gov (United States)

    Luo, Zhiqiang; Chen, Xinjing; Wang, Guopeng; Du, Zhibo; Ma, Xiaoyun; Wang, Hao; Yu, Guohua; Liu, Aoxue; Li, Mengwei; Peng, Wei; Liu, Yang

    2018-01-01

    Trelagliptin succinate is a dipeptidyl peptidase IV (DPP-4) inhibitor which is used as a new long-acting drug for once-weekly treatment of type 2 diabetes mellitus (DM). In the present study, a rapid, sensitive and accurate high-performance liquid chromatography (HPLC) method was developed and validated for separation and determination of trelagliptin succinate and its eight potential process-related impurities. The chromatographic separation was achieved on a Waters Xselect CSH™ C 18 (250mm×4.6mm, 5.0μm) column. The mobile phases comprised of 0.05% trifluoroacetic acid in water as well as acetonitrile containing 0.05% trifluoroacetic acid. The compounds of interest were monitored at 224nm and 275nm. The stability-indicating capability of this method was evaluated by performing stress test studies. Trelagliptin succinate was found to degrade significantly in acid, base, oxidative and thermal stress conditions and only stable in photolytic degradation condition. The degradation products were well resolved from the main peak and its impurities. In addition, the major degradation impurities formed under acid, base, oxidative and thermal stress conditions were characterized by ultra-high-performance liquid chromatography coupled with linear ion trap-Orbitrap tandem mass spectrometry (UHPLC-LTQ-Orbitrap). The method was validated to fulfill International Conference on Harmonisation (ICH) requirements and this validation included specificity, linearity, limit of detection (LOD), limit of quantification (LOQ), accuracy, precision and robustness. The developed method in this study could be applied for routine quality control analysis of trelagliptin succinate tablets, since there is no official monograph. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Continuous production of controlled release dosage forms based on hot-melt extruded gum arabic: Formulation development, in vitro characterization and evaluation of potential application fields.

    Science.gov (United States)

    Kipping, Thomas; Rein, Hubert

    2016-01-30

    Controlled release matrices based on gum arabic are prepared by applying a continuous hot-melt extrusion technology: the pre-mixture consisting of gum arabic and the incorporated API is plasticized by a co-rotating twin-screw extruder, an intermediate strand is formed by a round nozzle. Single dosed matrices are prepared by cutting the semi elastic strand with a rotary fly cutter. Paracetamol and phenazone are used as model drug substances. High drug loadings up to 70% can be realized. Matrices are characterized concerning their crystalline structure, in vitro dissolution, disintegration time and various physical parameters including glass transition temperature (Tg). Release characteristic behavior is mainly influenced by erosion of the matrices. At higher drug loadings also diffusion based transport gain importance. The solubility of the API shows an influence on the erosion rate of the matrix and should therefore be considered during formulation development. Tg is mainly influenced by the solubility of the API in the surrounding matrix. High soluble phenazone shows a decrease, whereas paracetamol addition has nearly no influence on the Tg of the polymeric system. Activation energy (EA) of the glass transition is determined via dynamic mechanical analysis. The addition of APIs leads to a reduction of EA indicating an increased molecular movement at Tg region compared to placebo extrudates. X-ray diffraction is used to determine the crystalline state of the extruded matrices and interaction between matrix and incorporated APIs. The production of thin layer matrices is an interesting option to provide a fast drug delivery to the oral cavity. High mechanical strength combined with fast disintegration times can be a great advantage for the development of oro-dispersible tablets. A great benefit of the evaluated processing technology is the simple adaption of the final dose by varying either the cutting length or the diameter of the nozzle resulting in a cost

  17. Comments on "A closed-form solution to Tensor voting: theory and applications"

    OpenAIRE

    Maggiori, Emmanuel; Lotito, Pablo Andres; Manterola, Hugo Luis; del Fresno, Mariana

    2017-01-01

    We comment on a paper that describes a closed-form formulation to Tensor Voting, a technique to perceptually group clouds of points, usually applied to infer features in images. The authors proved an analytic solution to the technique, a highly relevant contribution considering that the original formulation required numerical integration, a time-consuming task. Their work constitutes the first closed-form expression for the Tensor Voting framework. In this work we first observe that the propo...

  18. The preparation method of solid boron solution in silicon carbide in the form of micro powder

    International Nuclear Information System (INIS)

    Pampuch, R.; Stobierski, L.; Lis, J.; Bialoskorski, J.; Ermer, E.

    1993-01-01

    The preparation method of solid boron solution in silicon carbide in the form of micro power has been worked out. The method consists in introducing mixture of boron, carbon and silicon and heating in the atmosphere of inert gas to the 1573 K

  19. Exact closed-form solutions of a fully nonlinear asymptotic two-fluid model

    Science.gov (United States)

    Cheviakov, Alexei F.

    2018-05-01

    A fully nonlinear model of Choi and Camassa (1999) describing one-dimensional incompressible dynamics of two non-mixing fluids in a horizontal channel, under a shallow water approximation, is considered. An equivalence transformation is presented, leading to a special dimensionless form of the system, involving a single dimensionless constant physical parameter, as opposed to five parameters present in the original model. A first-order dimensionless ordinary differential equation describing traveling wave solutions is analyzed. Several multi-parameter families of physically meaningful exact closed-form solutions of the two-fluid model are derived, corresponding to periodic, solitary, and kink-type bidirectional traveling waves; specific examples are given, and properties of the exact solutions are analyzed.

  20. Solitary Wave Solutions of the Boussinesq Equation and Its Improved Form

    Directory of Open Access Journals (Sweden)

    Reza Abazari

    2013-01-01

    Full Text Available This paper presents the general case study of previous works on generalized Boussinesq equations, (Abazari, 2011 and (Kılıcman and Abazari, 2012, that focuses on the application of G′/G-expansion method with the aid of Maple to construct more general exact solutions for the coupled Boussinesq equations. In this work, the mentioned method is applied to construct more general exact solutions of Boussinesq equation and improved Boussinesq equation, which the French scientist Joseph Valentin Boussinesq (1842–1929 described in the 1870s model equations for the propagation of long waves on the surface of water with small amplitude. Our work is motivated by the fact that the G′/G-expansion method provides not only more general forms of solutions but also periodic, solitary waves and rational solutions. The method appears to be easier and faster by means of a symbolic computation.

  1. Effects of molecular interactions and the existence of different molecular forms of sodium fluoresceinate in solutions

    International Nuclear Information System (INIS)

    Golubeva, N.G.

    1989-01-01

    The results of measurement of fluorescence and absorption spectra of sodium fluoresceinate (FLNa) in different solutions and blood plasma are presented. The influence of solvent nature, its polarity, medium concentration and acidity on frequency, intensity and shape of fluorescence and absorption lines was analyzed. A general medium effect on fluorescence line spectral absorption was calculated from Lippert's equation. The influence of specific interactions has been analyzed on the example of acid-base interactions and hydrogen bonds in two- and multicomponent solutions. Computer processing of the spectra obtained allows to separate some forms of existing fluorophor molecules and to get data on the dynamics of their changes in different solutions. A special attention was given to the analysis of absorption and fluorescence bands of FLNa at its interaction with different proteins and lipids in solutions. From the analysis of data obtained a number of conclusions was drawn on the state of fluophor at its interactions with biological media. (author)

  2. Foreign matter identification from solid dosage forms

    DEFF Research Database (Denmark)

    Pekka Pajander, Jari; Haugshøj, Kenneth Brian; Bjørneboe, Kathrine

    2013-01-01

    Despite the increased request for robust quality systems, the end product may contain unidentified defects or discoloured regions. The foreign matter has to be monitored, identified and its source defined in order to prevent further contamination. However, the identification task can be complicated......, since the origin and nature of foreign matter are various. The aim of this study is to provide an efficient foreign matter identification procedure for various substances possibly originating from pharmaceutical manufacturing environment. The surface or cross-section of the uncoated and coated tablets...... was analysed by utilization of different analytical techniques, such as light microscopy (LM), scanning electron microscopy in combination with energy dispersive X-ray microanalysis (SEM/EDX), Fourier transform infrared spectroscopy (FT-IR) and time-of-flight secondary ion mass spectrometry (To...

  3. Tooling solutions for sheet metal forming and punching of lean duplex stainless steel

    DEFF Research Database (Denmark)

    Wadman, Boel; Madsen, Erik; Bay, Niels

    2012-01-01

    .4509 and lean duplex EN1.4162 in a production designed for austenitic stainless steels, such as EN1.4301 and 1.4401. The result is a guideline that summarizes how stainless material properties may affect tool degradation, and suggests tool solutions for reduced production disturbances and tool maintenance cost.......For producers of advanced stainless components the choice of stainless material influences not only the product properties, but also the tooling solution for sheet metal stamping. This work describes how forming and punching tools will be affected when introducing the stainless alloys ferritic EN1...

  4. On Conservation Forms and Invariant Solutions for Classical Mechanics Problems of Liénard Type

    Directory of Open Access Journals (Sweden)

    Gülden Gün Polat

    2014-01-01

    Full Text Available In this study we apply partial Noether and λ-symmetry approaches to a second-order nonlinear autonomous equation of the form y′′+fyy′+g(y=0, called Liénard equation corresponding to some important problems in classical mechanics field with respect to f(y and g(y functions. As a first approach we utilize partial Lagrangians and partial Noether operators to obtain conserved forms of Liénard equation. Then, as a second approach, based on the λ-symmetry method, we analyze λ-symmetries for the case that λ-function is in the form of λ(x,y,y′=λ1(x,yy′+λ2(x,y. Finally, a classification problem for the conservation forms and invariant solutions are considered.

  5. Closed-Form Solutions for Gradient Elastic Beams with Geometric Discontinuities by Laplace Transform

    Directory of Open Access Journals (Sweden)

    Mustafa Özgür Yayli

    2013-01-01

    Full Text Available The static bending solution of a gradient elastic beam with external discontinuities is presented by Laplace transform. Its utility lies in the ability to switch differential equations to algebraic forms that are more easily solved. A Laplace transformation is applied to the governing equation which is then solved for the static deflection of the microbeam. The exact static response of the gradient elastic beam with external discontinuities is obtained by applying known initial conditions when the others are derived from boundary conditions. The results are given in a series of figures and compared with their classical counterparts. The main contribution of this paper is to provide a closed-form solution for the static deflection of microbeams under geometric discontinuities.

  6. Constructing soliton solutions and super-bilinear form of lattice supersymmetric KdV equation

    International Nuclear Information System (INIS)

    Carstea, A S

    2015-01-01

    The Hirota bilinear form and multisoliton solution for semidiscrete and fully discrete (difference–difference) versions of the supersymmetric Korteweg–de Vries (KdV) equation found by Xue et al (2013 J. Phys. A: Math. Theor 46 502001) are presented. The solitonic interaction term displays a fermionic dressing factor as in the continuous supersymmetric case. Using bilinear equations it is also shown that a new integrable semidiscrete (and fully discrete) version of supersymmetric KdV can be constructed with a simpler bilinear form but a more complicated interaction dressing. Its continuum limit is also computed. (paper)

  7. Antimicrobial Activity of Chitosan Film Forming Solution Enriched with Essential Oils; an in Vitro Assay.

    Science.gov (United States)

    Raphaël, Kana Jean; Meimandipour, Amir

    2017-01-01

    Background: The resistance of the bacteria and fungi to the innumerous antimicrobial agents is a major challenge in the treatment of the infections demands to the necessity for searching and finding new sources of substances with antimicrobial properties. The incorporation of the essential oils (EOs) in chitosan film forming solution may enhance antimicrobial properties. However, its use as the feeding additive in the poultry nutrition needs to clarify the product's activity against both pathogen and the useful microbes in the gastrointestinal tract. Objectives: In the present study, we carried out an in vitro investigation and evaluated the antimicrobial activity of chitosan film forming solution incorporated with essential oils (CFs+EOs) against microbial strains including Staphylococcus aureus, Escherichia coli, Enterococcus faecium, Lactobacillus rahmnosus, Aspergillus niger and Alternaria alternate . Material and Methods: In three replicates, the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) of different treatments including: 1- essential oils (EOs), 2- chitosan film solution (CFs), and 3-chitosan film solution enriched with EOs (CFs+EOs) were determined against above mentioned microbes. Results: The results indicated that the chitosan solution enriched with essential oils (CFs+EOs) is capable of inhibiting the bacterial and fungal growth even at the lowest concentrations. The MIC and MBC for all the antimicrobial agents against Escherichia coli and Staphylococcus aureus were very low compared to the concentrations needed to inhibit the growth of useful bacteria, Lactobacillus rahmnosu and Enterococcus faecium . The antifungal activity of chitosan was enhanced as the concentration of EOs increased in the film solution. Conclusion: Chitosan-EOs complexes are the promising candidate for novel contact antimicrobial agents that can be used in animal feeds.

  8. Closed-form solutions for linear regulator design of mechanical systems including optimal weighting matrix selection

    Science.gov (United States)

    Hanks, Brantley R.; Skelton, Robert E.

    1991-01-01

    Vibration in modern structural and mechanical systems can be reduced in amplitude by increasing stiffness, redistributing stiffness and mass, and/or adding damping if design techniques are available to do so. Linear Quadratic Regulator (LQR) theory in modern multivariable control design, attacks the general dissipative elastic system design problem in a global formulation. The optimal design, however, allows electronic connections and phase relations which are not physically practical or possible in passive structural-mechanical devices. The restriction of LQR solutions (to the Algebraic Riccati Equation) to design spaces which can be implemented as passive structural members and/or dampers is addressed. A general closed-form solution to the optimal free-decay control problem is presented which is tailored for structural-mechanical system. The solution includes, as subsets, special cases such as the Rayleigh Dissipation Function and total energy. Weighting matrix selection is a constrained choice among several parameters to obtain desired physical relationships. The closed-form solution is also applicable to active control design for systems where perfect, collocated actuator-sensor pairs exist.

  9. Comments on "A Closed-Form Solution to Tensor Voting: Theory and Applications".

    Science.gov (United States)

    Maggiori, Emmanuel; Lotito, Pablo; Manterola, Hugo Luis; del Fresno, Mariana

    2014-12-01

    We comment on a paper that describes a closed-form formulation to Tensor Voting, a technique to perceptually group clouds of points, usually applied to infer features in images. The authors proved an analytic solution to the technique, a highly relevant contribution considering that the original formulation required numerical integration, a time-consuming task. Their work constitutes the first closed-form expression for the Tensor Voting framework. In this work we first observe that the proposed formulation leads to unexpected results which do not satisfy the constraints for a Tensor Voting output, hence they cannot be interpreted. Given that the closed-form expression is said to be an analytic equivalent solution, unexpected outputs should not be encountered unless there are flaws in the proof. We analyzed the underlying math to find which were the causes of these unexpected results. In this commentary we show that their proposal does not in fact provide a proper analytic solution to Tensor Voting and we indicate the flaws in the proof.

  10. Formulation and Development of Metered Dose Inhalations of Salbutamol in Solution Form

    Science.gov (United States)

    Khale, Anubha; Bajaj, Amrita

    2011-01-01

    In the present study attempts were made to prepare metered dose inhalation of salbutamol in solution form and compared it with the marketed metered dose inhalation in suspension form. Solution form of the drug was found better than marketed suspension formulation with respect to homogeneity and content uniformity. Propellant blend P-11 and P-12 in the proportion 30:70 was selected as it gave optimum vapour pressure. Surfactant oleic acid in concentration 10 mg per can was selected as it gave best results with clarity, spray pattern, vapour pressure, content per spray and rate of evaporation. Ethyl alcohol 2 ml per can was used as a cosolvent to give a clear solution, optimum vapour pressure, maximum content per spray and fair rate of evaporation. The selected formulation was subjected to the physico-chemical evaluation tests as per the standard pharmacopoeial procedures and the characteristics of the formulations were further compared with a conventional marketed formulation. In vitro study reveled the net respirable fraction was better than marketed preparation. PMID:22923867

  11. Spectrophotometric Determination of Trimipramine in Tablet Dosage ...

    African Journals Online (AJOL)

    Purpose: To develop and validate simple, rapid and sensitive spectrophotometric procedures for determination of trimipramine in tablet dosage form. Methods: The methods were based on the interaction of trimipramine as n-electron donor with the ο-acceptor, iodine and various π-acceptors, namely: chloranil (CH), ...

  12. Dosage of cesium 137 in radioactive wastes by the application of sodium tetraphenylborate; Dosage du cesium 137 dans les effluents radioactifs par le tetraphenylborate de sodium

    Energy Technology Data Exchange (ETDEWEB)

    Testemale, G; Girault, J [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1967-07-01

    A simple technique of the dosage of {sup 137}Cs has been developed. The technique consists in the formation of cesium tetraphenyl borate, followed by a double extraction with isoamyl acetate, and washing of the organic phase. The counting of known parts of the cesium solution assaying of its purity by {gamma} spectrometry enable the determination of the {sup 137}Cs. The yield is about 98 per cent. (authors) [French] Une technique simple du dosage du {sup 137}Cs a ete mise au point. Elle consiste en une double extraction du tetraphenylborate de cesium forme par l'acetate d'isoamyle suivie d'un lavage de la phase organique. Des comptages sur des parties aliquotes de la solution de cesium et un controle de purete par spectrometrie {gamma} permettent la determination de cet element. Rendement: environ 98 pour cent. (auteurs)

  13. Closed-form kinetic parameter estimation solution to the truncated data problem

    International Nuclear Information System (INIS)

    Zeng, Gengsheng L; Kadrmas, Dan J; Gullberg, Grant T

    2010-01-01

    In a dedicated cardiac single photon emission computed tomography (SPECT) system, the detectors are focused on the heart and the background is truncated in the projections. Reconstruction using truncated data results in biased images, leading to inaccurate kinetic parameter estimates. This paper has developed a closed-form kinetic parameter estimation solution to the dynamic emission imaging problem. This solution is insensitive to the bias in the reconstructed images that is caused by the projection data truncation. This paper introduces two new ideas: (1) it includes background bias as an additional parameter to estimate, and (2) it presents a closed-form solution for compartment models. The method is based on the following two assumptions: (i) the amount of the bias is directly proportional to the truncated activities in the projection data, and (ii) the background concentration is directly proportional to the concentration in the myocardium. In other words, the method assumes that the image slice contains only the heart and the background, without other organs, that the heart is not truncated, and that the background radioactivity is directly proportional to the radioactivity in the blood pool. As long as the background activity can be modeled, the proposed method is applicable regardless of the number of compartments in the model. For simplicity, the proposed method is presented and verified using a single compartment model with computer simulations using both noiseless and noisy projections.

  14. Identification of precipitates formed on zero-valent iron in anaerobic aqueous solutions

    International Nuclear Information System (INIS)

    Schuhmacher, T.; Odziemkowski, M.S.; Reardon, E.J.; Gillham, R.W.

    1997-01-01

    The formation of precipitates has been identified as a possible limitation in the use of granular iron for in situ remediation of groundwater. This study was undertaken to identify the precipitates that form on the iron surfaces under conditions of differing water chemistry. Two laboratory column tests were performed using 100 mesh, 99% pure electrolytic iron. A 120 mg/L calcium carbonate (CaCO 3 ) solution passed through one column and a 40 mg/L potassium bromide (KBr) solution through the other. The CaCO, treated iron formed a whitish gray coating on the first centimeter of the column but the KBr treated iron did not display any visible precipitates. X-ray diffraction, Raman spectroscopy, and scanning electron microscopy were used to identify the precipitates. Calcium carbonate and ferrous carbonate (FeCO 3 ) phases were only present on the surface of the iron removed from the influent end of the column treated with a CaCO 3 solution. Iron surfaces analyzed from both the influent and the effluent end of the KBr treated iron and the effluent end of the CaCO 3 treated iron indicated the presence of magnetite (Fe 3 O 4 ) precipitates

  15. Abundant closed form solutions of the conformable time fractional Sawada-Kotera-Ito equation using (G‧ / G) -expansion method

    Science.gov (United States)

    Al-Shawba, Altaf Abdulkarem; Gepreel, K. A.; Abdullah, F. A.; Azmi, A.

    2018-06-01

    In current study, we use the (G‧ / G) -expansion method to construct the closed form solutions of the seventh order time fractional Sawada-Kotera-Ito (TFSKI) equation based on conformable fractional derivative. As a result, trigonometric, hyperbolic and rational functions solutions with arbitrary constants are obtained. When the arbitrary constants are taken some special values, the periodic and soliton solutions are obtained from the travelling wave solutions. The obtained solutions are new and not found elsewhere. The effect of the fractional order on some of these solutions are represented graphically to illustrate the behavior of the exact solutions when the parameter take some special choose.

  16. High density liquid structure enhancement in glass forming aqueous solution of LiCl

    Science.gov (United States)

    Camisasca, G.; De Marzio, M.; Rovere, M.; Gallo, P.

    2018-06-01

    We investigate using molecular dynamics simulations the dynamical and structural properties of LiCl:6H2O aqueous solution upon supercooling. This ionic solution is a glass forming liquid of relevant interest in connection with the study of the anomalies of supercooled water. The LiCl:6H2O solution is easily supercooled and the liquid state can be maintained over a large decreasing temperature range. We performed simulations from ambient to 200 K in order to investigate how the presence of the salt modifies the behavior of supercooled water. The study of the relaxation time of the self-density correlation function shows that the system follows the prediction of the mode coupling theory and behaves like a fragile liquid in all the range explored. The analysis of the changes in the water structure induced by the salt shows that while the salt preserves the water hydrogen bonds in the system, it strongly affects the tetrahedral hydrogen bond network. Following the interpretation of the anomalies of water in terms of a two-state model, the modifications of the oxygen radial distribution function and the angular distribution function of the hydrogen bonds in water indicate that LiCl has the role of enhancing the high density liquid component of water with respect to the low density component. This is in agreement with recent experiments on aqueous ionic solutions.

  17. A closed form solution for the response of a long elastic beam to dynamic loading

    International Nuclear Information System (INIS)

    Mittal, R.K.

    1989-01-01

    Closed form solutions have been obtained using Fourier transform method for the deflection, curvature and particle velocity of a long elastic beam when it is subjected to a concentrated transverse force which is varying with time. These solutions have been illustrated with the help of two force histories, i.e. a half-sine pulse and a rectangular pulse. Dimensionless parameters representing deflection, curvature and particle velocity have been plotted as functions of dimensionless distance and dimensionless time. Furthermore, the particular case of constant velocity impact which has been studied by other authors using different techniques has also been considered in the present paper and the results compare within numerical errors involved in the evaluation of integrals. (orig.) [de

  18. Electrostatics promotes molecular crowding and selects the aggregation pathway in fibril-forming protein solutions

    International Nuclear Information System (INIS)

    Raccosta, S.; Martorana, V.; Manno, M.; Blanco, M.; Roberts, C.J.

    2016-01-01

    The role of intermolecular interaction in fibril-forming protein solutions and its relation with molecular conformation are crucial aspects for the control and inhibition of amyloid structures. Here, we study the fibril formation and the protein-protein interactions for two proteins at acidic ph, lysozyme and α-chymotrypsinogen. By using light scattering experiments and the Kirkwood-Buff integral approach, we show how concentration fluctuations are damped even at moderate protein concentrations by the dominant long-ranged electrostatic repulsion, which determines an effective crowded environment. In denaturing conditions, electrostatic repulsion keeps the monomeric solution in a thermodynamically metastable state, which is escaped through kinetically populated conformational sub-states. This explains how electrostatics acts as a gatekeeper in selecting a specific aggregation pathway.

  19. Endotoxin dosage in sepsis

    Directory of Open Access Journals (Sweden)

    Vincenzo Rondinelli

    2012-03-01

    Full Text Available Introduction. Endotoxin, a component of the cell wall of Gram-negative bacteria is a major contributor to the pathogenesis of septic shock and multiple organ failure (MOF. Its entry into the bloodstream stimulates monocytes/macrophages which once activated produce and release cytokines, nitric oxide and other mediators that induce systemic inflammation, endothelial damage, organ dysfunction, hypotension (shock and MOF.The aim of this study is to evaluate the usefulness of a quantitative test for the dosage of endotoxin to determine the risk of severe Gram-negative sepsis. Materials and methods. In the period January 2009 - June 2011 we performed 897 tests for 765 patients, mostly coming from the emergency room and intensive care, of which 328 (43% women (mean age 53 and 437 (57% male (mean age 49. Fifty-nine patients, no statistically significant difference in sex, were monitored by an average of two determinations of EA.All patients had procalcitonin values significantly altered.The kit used was EAA (Endotoxin Activity Assay Estor Company, Milan, which has three ranges of endotoxin activity (EA: low risk of sepsis if <0.40 units, medium if between 0.40 and 0.59; high if 0.60. Results. 78 out of 765 patients (10% had a low risk, 447 (58% a medium risk and 240 (32% a high risk.The dosage of EA, combined with that of procalcitonin, has allowed a more targeted antibiotic therapy. Six patients in serious clinical conditions were treated by direct hemoperfusion with Toraymyxin, a device comprising a housing containing a fiber polypropylene and polystyrene with surface-bound polymyxin B, an antibiotic that removes bacterial endotoxins from the blood. Conclusions.The test is useful in risk stratification as well as Gram negative sepsis, to set and monitor targeted therapies, also based on the neutralization of endotoxin.

  20. New Families of Rational Form Solitary Wave Solutions to (2+1)-Dimensional Broer-Kaup-Kupershmidt System

    International Nuclear Information System (INIS)

    Wang Qi; Li Biao; Zhang Hongqing; Chen Yong

    2005-01-01

    Taking the (2+1)-dimensional Broer-Kaup-Kupershmidt system as a simple example, some families of rational form solitary wave solutions, triangular periodic wave solutions, and rational wave solutions are constructed by using the Riccati equation rational expansion method presented by us. The method can also be applied to solve more nonlinear partial differential equation or equations.

  1. Comparison of closed-form and finite-element solutions of thick laminated anisotropic rectangular plates

    Energy Technology Data Exchange (ETDEWEB)

    Reddy, J N; Chao, W C [Virginia Polytechnic Inst. and State Univ., Blacksburg (USA). Dept. of Engineering Science and Mechanics

    1981-04-01

    In this study the effects of reduced integration, mesh size, and element type (i.e. linear or quadratic) on the accuracy of a penalty-finite element based on the theory governing thick, laminated, anisotropic composite plates are investigated. In order to assess the accuracy of the present finite element, exact closed-form solutions are developed for cross-ply and antisymmetric angle-ply rectangular plates simply supported and subjected to sinusoidally distributed mechanical and/or thermal loadings, and free vibration.

  2. The Analysis of Closed-form Solution for Energy Detector Dynamic Threshold Adaptation in Cognitive Radio

    Directory of Open Access Journals (Sweden)

    R. Bozovic

    2017-12-01

    Full Text Available Spectrum sensing is the most important process in cognitive radio in order to ensure interference avoidance to primary users. For optimal performance of cognitive radio, it is substantial to monitor and promptly react to dynamic changes in its operating environment. In this paper, energy detector based spectrum sensing is considered. Under the assumption that detected signal can be modelled according to an autoregressive model, noise variance is estimated from that noisy signal, as well as primary user signal power. A closed-form solution for optimal decision threshold in dynamic electromagnetic environment is proposed and analyzed.

  3. The Conduct of Adjustment Term as Form Alternative to Jurisdictionalization the Solution of Conflict Environmental

    Directory of Open Access Journals (Sweden)

    Tatiana Fernandes Dias Da Silva

    2016-10-01

    Full Text Available This paper aims to demonstrate that the Conduct Adjustment Term (TAC can be an effective way to forward alternative jurisdictionalization environmental conflicts. Therefore we studied the Brazilian legislation, the national and foreign doctrine, case law and journals. The goal is to prove that given the slow pace of judicial assistance, especially in cases of environmental demands, the TAC, as extrajudicial form of dispute resolution, could be an effective solution for the preservation and protection of the environment if it were more used by legitimate environmental agencies and effectively monitored compliance by the local government.

  4. Development of clinical dosage forms for a poorly water-soluble drug II: formulation and characterization of a novel solid microemulsion preconcentrate system for oral delivery of a poorly water-soluble drug.

    Science.gov (United States)

    Li, Ping; Hynes, Sara R; Haefele, Thomas F; Pudipeddi, Madhu; Royce, Alan E; Serajuddin, Abu T M

    2009-05-01

    The solution of a poorly water-soluble drug in a liquid lipid-surfactant mixture, which served as a microemulsion preconcentrate, was converted into a solid form by incorporating it in a solid polyethylene glycol (PEG) matrix. The solid microemulsion preconcentrates thus formed consisted of Capmul PG8 (propylene glycol monocaprylate) as oil, Cremophor EL (polyoxyl 35 castor oil) as surfactant, and hydrophilic polymer PEG 3350 as solid matrix. The drug (aqueous solubility: 0.17 microg/mL at pH 1-8 and 25 degrees C) was dissolved in a melt of the mixture at 65-70 degrees C and then the hot solution was filled into hard gelatin capsules; the liquid gradually solidified upon cooling below 55 degrees C. The solid system was characterized by differential scanning calorimetry (DSC), scanning electron microscopy (SEM), confocal Raman microscopy (CRM), and the dispersion testing in water. It was confirmed that a solid microemulsion preconcentrate is a two-phase system, where clusters of crystalline PEG 3350 formed the solid structure (m.p. 55-60 degrees C) and the liquid microemulsion preconcentrate dispersed in between PEG 3350 crystals as a separate phase. The drug remained dissolved in the liquid phase. In vitro release testing showed that the preconcentrate dispersed readily in water forming a microemulsion with the drug dissolved in the oil particles (PEG 3350 did not interfere with the process of self-microemulsification.

  5. Closed-form Solution to Directly Design FACE Waveforms for Beampatterns Using Planar Array

    KAUST Repository

    Bouchoucha, Taha; Ahmed, Sajid; Al-Naffouri, Tareq Y.; Alouini, Mohamed-Slim

    2015-01-01

    In multiple-input multiple-output radar systems, it is usually desirable to steer transmitted power in the region-of-interest. To do this, conventional methods optimize the waveform covariance matrix, R, for the desired beampattern, which is then used to generate actual transmitted waveforms. Both steps require constrained optimization, therefore, use iterative algorithms. The main challenges encountered in the existing approaches are the computational complexity and the design of waveforms to use in practice. In this paper, we provide a closed-form solution to design covariance matrix for the given beampattern using the planar array, which is then used to derive a novel closed-form algorithm to directly design the finite-alphabet constant-envelope (FACE) waveforms. The proposed algorithm exploits the two-dimensional fast-Fourier-transform. The performance of our proposed algorithm is compared with existing methods that are based on semi-definite quadratic programming with the advantage of a considerably reduced complexity.

  6. Closed-form Solution to Directly Design FACE Waveforms for Beampatterns Using Planar Array

    KAUST Repository

    Bouchoucha, Taha

    2015-04-19

    In multiple-input multiple-output radar systems, it is usually desirable to steer transmitted power in the region-of-interest. To do this, conventional methods optimize the waveform covariance matrix, R, for the desired beampattern, which is then used to generate actual transmitted waveforms. Both steps require constrained optimization, therefore, use iterative algorithms. The main challenges encountered in the existing approaches are the computational complexity and the design of waveforms to use in practice. In this paper, we provide a closed-form solution to design covariance matrix for the given beampattern using the planar array, which is then used to derive a novel closed-form algorithm to directly design the finite-alphabet constant-envelope (FACE) waveforms. The proposed algorithm exploits the two-dimensional fast-Fourier-transform. The performance of our proposed algorithm is compared with existing methods that are based on semi-definite quadratic programming with the advantage of a considerably reduced complexity.

  7. A closed-form solution to tensor voting: theory and applications.

    Science.gov (United States)

    Wu, Tai-Pang; Yeung, Sai-Kit; Jia, Jiaya; Tang, Chi-Keung; Medioni, Gérard

    2012-08-01

    We prove a closed-form solution to tensor voting (CFTV): Given a point set in any dimensions, our closed-form solution provides an exact, continuous, and efficient algorithm for computing a structure-aware tensor that simultaneously achieves salient structure detection and outlier attenuation. Using CFTV, we prove the convergence of tensor voting on a Markov random field (MRF), thus termed as MRFTV, where the structure-aware tensor at each input site reaches a stationary state upon convergence in structure propagation. We then embed structure-aware tensor into expectation maximization (EM) for optimizing a single linear structure to achieve efficient and robust parameter estimation. Specifically, our EMTV algorithm optimizes both the tensor and fitting parameters and does not require random sampling consensus typically used in existing robust statistical techniques. We performed quantitative evaluation on its accuracy and robustness, showing that EMTV performs better than the original TV and other state-of-the-art techniques in fundamental matrix estimation for multiview stereo matching. The extensions of CFTV and EMTV for extracting multiple and nonlinear structures are underway.

  8. 21 CFR 524.1193 - Ivermectin topical solution.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Ivermectin topical solution. 524.1193 Section 524...) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS OPHTHALMIC AND TOPICAL DOSAGE FORM NEW ANIMAL DRUGS § 524.1193 Ivermectin topical solution. (a) Specifications. Each milliliter (mL) of solution contains 5 milligrams of...

  9. 21 CFR 524.1446 - Milbemycin oxime solution.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Milbemycin oxime solution. 524.1446 Section 524...) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS OPHTHALMIC AND TOPICAL DOSAGE FORM NEW ANIMAL DRUGS § 524.1446 Milbemycin oxime solution. (a) Specifications. Each tube contains 0.25 milliliter of a 0.1 percent solution...

  10. Analytic Closed-Form Solution of a Mixed Layer Model for Stratocumulus Clouds

    Science.gov (United States)

    Akyurek, Bengu Ozge

    Stratocumulus clouds play an important role in climate cooling and are hard to predict using global climate and weather forecast models. Thus, previous studies in the literature use observations and numerical simulation tools, such as large-eddy simulation (LES), to solve the governing equations for the evolution of stratocumulus clouds. In contrast to the previous works, this work provides an analytic closed-form solution to the cloud thickness evolution of stratocumulus clouds in a mixed-layer model framework. With a focus on application over coastal lands, the diurnal cycle of cloud thickness and whether or not clouds dissipate are of particular interest. An analytic solution enables the sensitivity analysis of implicitly interdependent variables and extrema analysis of cloud variables that are hard to achieve using numerical solutions. In this work, the sensitivity of inversion height, cloud-base height, and cloud thickness with respect to initial and boundary conditions, such as Bowen ratio, subsidence, surface temperature, and initial inversion height, are studied. A critical initial cloud thickness value that can be dissipated pre- and post-sunrise is provided. Furthermore, an extrema analysis is provided to obtain the minima and maxima of the inversion height and cloud thickness within 24 h. The proposed solution is validated against LES results under the same initial and boundary conditions. Then, the proposed analytic framework is extended to incorporate multiple vertical columns that are coupled by advection through wind flow. This enables a bridge between the micro-scale and the mesoscale relations. The effect of advection on cloud evolution is studied and a sensitivity analysis is provided.

  11. A new technique in constructing closed-form solutions for nonlinear PDEs appearing in fluid mechanics and gas dynamics

    Directory of Open Access Journals (Sweden)

    Panayotounakos D. E.

    1996-01-01

    Full Text Available We develop a new unique technique in constructing closed-form solutions for several nonlinear partial differential systems appearing in fluid mechanics and gas dynamics. The obtained solutions include fewer arbitrary functions than needed for general solutions, fact that permits us to specify them according to the initial state, or the geometry, of each specific problem under consideration. In order to apply the before mentioned technique we construct closed-form solutions concerning the gas-dynamic equations with constant pressure, the dynamic equations of an ideal gas in isentropic flow, and the two-dimensional incompressible boundary layer flow.

  12. Quercetin topical application, from conventional dosage forms to nanodosage forms.

    Science.gov (United States)

    Hatahet, T; Morille, M; Hommoss, A; Devoisselle, J M; Müller, R H; Bégu, S

    2016-11-01

    Skin is a multifunctional organ with activities in protection, metabolism and regulation. Skin is in a continuous exposure to oxidizing agents and inflammogens from the sun and from the contact with the environment. These agents may overload the skin auto-defense capacity. To strengthen skin defense mechanisms against oxidation and inflammation, supplementation of exogenous antioxidants is a promising strategy. Quercetin is a flavonoid with very pronounced effective antioxidant and antiinflammatory activities, and thus a candidate of first choice for such skin supplementation. Quercetin showed interesting actions in cellular and animal based models, ranging from protecting cells from UV irradiation to support skin regeneration in wound healing. However, due to its poor solubility, quercetin has limited skin penetration ability, and various formulation approaches were taken to increase its dermal penetration. In this article, the quercetin antioxidant and antiinflammatory activities in wound healing and supporting skin against aging are discussed in detail. In addition, quercetin topical formulations from conventional emulsions to novel nanoformulations in terms of skin penetration enhancement are also presented. This article gives a comprehensive review of quercetin for topical application from biological effects to pharmaceutical formulation design for the last 25 years of research. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Memristor Multiport Readout: A Closed-Form Solution for Sneak Paths

    KAUST Repository

    Zidan, Mohammed A.; Eltawil, Ahmed M.; Fahmy, Hossam A.H.; Kurdahi, Fadi; Salama, Khaled N.

    2014-01-01

    In this paper, we introduce for the first time, a closed-form solution for the memristor-based memory sneak paths without using any gating elements. The introduced technique fully eliminates the effect of sneak paths by reading the stored data using multiple access points and evaluating a simple addition/subtraction on the different readings. The new method requires fewer reading steps compared to previously reported techniques, and has a very small impact on the memory density. To verify the underlying theory, the proposed system is simulated using Synopsys HSPICE showing the ability to achieve a 100% sneak-path error-free memory. In addition, the effect of quantization bits on the system performance is studied.

  14. XPS characterization of the anodic oxide film formed on uranium metal in sodium hydroxide solution

    International Nuclear Information System (INIS)

    Fu Xiaoguo; Wang Xiaolin; Guo Huanjun; Wang Qingfu; Zhao Zhengping; Zhong Yongqiang

    2002-01-01

    X-ray photoelectron spectroscopy (XPS) is used to examine the anodic oxide film formed on uranium metal in 0.8 mol/L NaOH solution. The U4f 7/2 fitting spectra suggests that the anodic oxide film is composed of uranium trioxide and a small amount of UO 2+x . Under UHV condition, the U4f peak shifts to the lower binding energy, while a gradual increase in the intensity of U5f peak and the broad of U4f peak are also observed. All of these changes are due to reduction of uranium trioxide in the anodic oxide film. XPS quantitative analysis confirms the occurrence of reduction reaction

  15. Memristor Multiport Readout: A Closed-Form Solution for Sneak Paths

    KAUST Repository

    Zidan, Mohammed A.

    2014-06-18

    In this paper, we introduce for the first time, a closed-form solution for the memristor-based memory sneak paths without using any gating elements. The introduced technique fully eliminates the effect of sneak paths by reading the stored data using multiple access points and evaluating a simple addition/subtraction on the different readings. The new method requires fewer reading steps compared to previously reported techniques, and has a very small impact on the memory density. To verify the underlying theory, the proposed system is simulated using Synopsys HSPICE showing the ability to achieve a 100% sneak-path error-free memory. In addition, the effect of quantization bits on the system performance is studied.

  16. One-parameter families of supersymmetric isospectral potentials from Riccati solutions in function composition form

    Energy Technology Data Exchange (ETDEWEB)

    Rosu, Haret C., E-mail: hcr@ipicyt.edu.mx [IPICYT, Instituto Potosino de Investigacion Cientifica y Tecnologica, Camino a la presa San José 2055, Col. Lomas 4a Sección, 78216 San Luis Potosí, S.L.P. (Mexico); Mancas, Stefan C., E-mail: mancass@erau.edu [Department of Mathematics, Embry–Riddle Aeronautical University, Daytona Beach, FL 32114-3900 (United States); Chen, Pisin, E-mail: pisinchen@phys.ntu.edu.tw [Leung Center for Cosmology and Particle Astrophysics (LeCosPA) and Department of Physics, National Taiwan University, Taipei 10617, Taiwan (China)

    2014-04-15

    In the context of supersymmetric quantum mechanics, we define a potential through a particular Riccati solution of the composition form (F∘f)(x)=F(f(x)) and obtain a generalized Mielnik construction of one-parameter isospectral potentials when we use the general Riccati solution. Some examples for special cases of F and f are given to illustrate the method. An interesting result is obtained in the case of a parametric double well potential generated by this method, for which it is shown that the parameter of the potential controls the heights of the localization probability in the two wells, and for certain values of the parameter the height of the localization probability can be higher in the smaller well. -- Highlights: •Function-composition generalization of parametric isospectral potentials is presented. •Mielnik one-parameter family of harmonic potentials is obtained as a particular case. •Graphical discussion of regular and singular regions in the parameter space is given.

  17. Solitary wave solutions to the modified form of Camassa-Holm equation by means of the homotopy analysis method

    International Nuclear Information System (INIS)

    Abbasbandy, S.

    2009-01-01

    Solitary wave solutions to the modified form of Camassa-Holm (CH) equation are sought. In this work, the homotopy analysis method (HAM), one of the most effective method, is applied to obtain the soliton wave solutions with and without continuity of first derivatives at crest

  18. Evaluation of Enzymatically Modified Soy Protein Isolate Film Forming Solution and Film at Different Manufacturing Conditions.

    Science.gov (United States)

    Mohammad Zadeh, Elham; O'Keefe, Sean F; Kim, Young-Teck; Cho, Jin-Hun

    2018-04-01

    The effects of transglutaminase on soy protein isolate (SPI) film forming solution and films were investigated by rheological behavior and physicochemical properties based on different manufacturing conditions (enzyme treatments, enzyme incubation times, and protein denaturation temperatures). Enzymatic crosslinking reaction and changes in molecular weight distribution were confirmed by viscosity measurement and SDS-PAGE, respectively, compared to 2 controls: the nonenzyme treated and the deactivated enzyme treated. Films treated with both the enzyme and the deactivated enzyme showed significant increase in tensile strength (TS), percent elongation (%E), and initial contact angle of films compared to the nonenzyme control film due to the bulk stabilizers in the commercial enzyme. Water absorption property, protein solubility, Fourier transform infrared (FTIR) and X-ray diffraction (XRD) spectroscopy revealed that enzyme treated SPI film matrix in the molecular structure level, resulted in the changes in physicochemical properties. Based on our observation, the enzymatic treatment at appropriate conditions is a practical and feasible way to control the physical properties of protein based biopolymeric film for many different scientific and industrial areas. Enzymes can make bridges selectively among different amino acids in the structure of protein matrix. Therefore, protein network is changed after enzyme treatment. The behavior of biopolymeric materials is dependent on the network structure to be suitable in different applications such as bioplastics applied in food and pharmaceutical products. In the current research, transglutaminase, as an enzyme, applied in soy protein matrix in different types of forms, activated and deactivated, and different preparation conditions to investigate its effects on different properties of the new bioplastic film. © 2018 Institute of Food Technologists®.

  19. Closed-form solution for piezoelectric layer with two collinear cracks parallel to the boundaries

    Directory of Open Access Journals (Sweden)

    B. M. Singh

    2006-01-01

    Full Text Available We consider the problem of determining the stress distribution in an infinitely long piezoelectric layer of finite width, with two collinear cracks of equal length and parallel to the layer boundaries. Within the framework of reigning piezoelectric theory under mode III, the cracked piezoelectric layer subjected to combined electromechanical loading is analyzed. The faces of the layers are subjected to electromechanical loading. The collinear cracks are located at the middle plane of the layer parallel to its face. By the use of Fourier transforms we reduce the problem to solving a set of triple integral equations with cosine kernel and a weight function. The triple integral equations are solved exactly. Closed form analytical expressions for stress intensity factors, electric displacement intensity factors, and shape of crack and energy release rate are derived. As the limiting case, the solution of the problem with one crack in the layer is derived. Some numerical results for the physical quantities are obtained and displayed graphically.

  20. Bloch Modes and Evanescent Modes of Photonic Crystals: Weak Form Solutions Based on Accurate Interface Triangulation

    Directory of Open Access Journals (Sweden)

    Matthias Saba

    2015-01-01

    Full Text Available We propose a new approach to calculate the complex photonic band structure, both purely dispersive and evanescent Bloch modes of a finite range, of arbitrary three-dimensional photonic crystals. Our method, based on a well-established plane wave expansion and the weak form solution of Maxwell’s equations, computes the Fourier components of periodic structures composed of distinct homogeneous material domains from a triangulated mesh representation of the inter-material interfaces; this allows substantially more accurate representations of the geometry of complex photonic crystals than the conventional representation by a cubic voxel grid. Our method works for general two-phase composite materials, consisting of bi-anisotropic materials with tensor-valued dielectric and magnetic permittivities ε and μ and coupling matrices ς. We demonstrate for the Bragg mirror and a simple cubic crystal closely related to the Kelvin foam that relatively small numbers of Fourier components are sufficient to yield good convergence of the eigenvalues, making this method viable, despite its computational complexity. As an application, we use the single gyroid crystal to demonstrate that the consideration of both conventional and evanescent Bloch modes is necessary to predict the key features of the reflectance spectrum by analysis of the band structure, in particular for light incident along the cubic [111] direction.

  1. A semi-analytical solution for elastic analysis of rotating thick cylindrical shells with variable thickness using disk form multilayers.

    Science.gov (United States)

    Zamani Nejad, Mohammad; Jabbari, Mehdi; Ghannad, Mehdi

    2014-01-01

    Using disk form multilayers, a semi-analytical solution has been derived for determination of displacements and stresses in a rotating cylindrical shell with variable thickness under uniform pressure. The thick cylinder is divided into disk form layers form with their thickness corresponding to the thickness of the cylinder. Due to the existence of shear stress in the thick cylindrical shell with variable thickness, the equations governing disk layers are obtained based on first-order shear deformation theory (FSDT). These equations are in the form of a set of general differential equations. Given that the cylinder is divided into n disks, n sets of differential equations are obtained. The solution of this set of equations, applying the boundary conditions and continuity conditions between the layers, yields displacements and stresses. A numerical solution using finite element method (FEM) is also presented and good agreement was found.

  2. A Semi-Analytical Solution for Elastic Analysis of Rotating Thick Cylindrical Shells with Variable Thickness Using Disk Form Multilayers

    Directory of Open Access Journals (Sweden)

    Mohammad Zamani Nejad

    2014-01-01

    Full Text Available Using disk form multilayers, a semi-analytical solution has been derived for determination of displacements and stresses in a rotating cylindrical shell with variable thickness under uniform pressure. The thick cylinder is divided into disk form layers form with their thickness corresponding to the thickness of the cylinder. Due to the existence of shear stress in the thick cylindrical shell with variable thickness, the equations governing disk layers are obtained based on first-order shear deformation theory (FSDT. These equations are in the form of a set of general differential equations. Given that the cylinder is divided into n disks, n sets of differential equations are obtained. The solution of this set of equations, applying the boundary conditions and continuity conditions between the layers, yields displacements and stresses. A numerical solution using finite element method (FEM is also presented and good agreement was found.

  3. Levothyroxine liquid solution versus tablet form for replacement treatment in pregnant women.

    Science.gov (United States)

    Cappelli, Carlo; Negro, Roberto; Pirola, Ilenia; Gandossi, Elena; Agosti, Barbara; Castellano, Maurizio

    2016-01-01

    To evaluate the need and the magnitude of levothyroxine (LT4) increase in hypothyroid pregnant women on liquid compared to tablet formulations. Patients were recruited by searching our "thyroid patients" database. The selection criteria were as follows: a) pregnant women on treatment for hypothyroidism (both liquid and tablet LT4) who gave birth at our hospital between February 2012 and January 2014; b) thyroid stimulating hormone (TSH) and free thyroxine (FT4) levels obtained at least 3 months before missed menstrual cycle, with a TSH value less than 2.5 mIU/L and c) TSH and FT4 obtained within 12 weeks of pregnancy, and each month subsequently. During pregnancy, 8/31 (25.5%) of the women had to increase the dosage of LT4. Of these, 7/17 (41.2%) were on LT4 replacement therapy with tablets, and 1/14 (7.1%) with liquid formulation (p = 0.038). Daily LT4 was significantly increased in the liquid group only (52.9 ± 19.5 versus 67.5 ± 19.2 mcg/day (p = 0.013). A logistic regression analysis showed that the treatment with LT4 tablets was the only predictor of LT4 increase (OR: 0.44; 95% CI: 0.04-0.83; p = 0.031). Pregnant women on optimal replacement therapy before pregnancy require an increase of LT4 dosage more often when on a tablet than liquid formulation.

  4. Equilibrium leach tests with cobalt in the system cemented waste form/container material/aqueous solution

    International Nuclear Information System (INIS)

    Vejmelka, P.; Koester, R.; Lee, M. J.; Han, K. W.

    1991-01-01

    The equilibrium concentrations of Co in the system of cemented waste form/aqueous solutions were determined including the effect of the container material and its corrosion products under the respective conditions. The chemical conditions in the near field of the waste form were characterized by measurement of the pH and E h value. As disposal relevant solutions, saturated sodium chloride, Q-brine (main constituent MgCl 2 ) and a granitic type groundwater were used. For comparison, also experiments using deionized water were performed. In all systems investigated the cemented waste form itself has a strong influence on the chemical conditions in the near field. The pH and E h values are affected in all cases by the addition of the cemented waste form. There is no or only a slight difference between the E h values if iron powder or iron hydroxide is added to the cemented waste form/solution systems, but the E h is markedly decreased when iron powder is added to the solution free of cement. The Co concentration is decreased in all solutions by the addition of the cemented waste form, the largest effect is observed in Q-brine and this can be attributed either to the sorption of the Co-ions on the corrosion products of the cement or to the coprecipitation of Co-hydroxide and Mg-hydroxide. In the other solutions the Co concentration is decreased by precipitation of Co-hydroxide due to the high pH value of 12.5, and the concentrations are comparable for the different solutions

  5. Cesium release from ceramic waste form materials in simulated canister corrosion product containing solutions

    Energy Technology Data Exchange (ETDEWEB)

    Vittorio, Luca; Drabarek, Elizabeth; Chronis, Harriet; Griffith, Christopher S

    2004-07-01

    It has previously been demonstrated that immobilization of Cs{sup +} and/or Sr{sup 2+} sorbed on hexagonal tungsten oxide bronze (HTB) adsorbent materials can be achieved by heating the materials in air at temperatures in the range 500 - 1300 deg C. Highly crystalline powdered HTB materials formed by heating at 800 deg C show leach characteristics comparable to Cs-containing hot-pressed hollandites in the pH range from 0 to 12. As a very harsh leaching test, and also to model in a basic manner, leaching in the presence of canister corrosion products in oxidising environments, leaching of the bronzoid phases has been undertaken in Fe(NO{sub 3}){sub 3} solutions of increasing concentration. This is done in comparison with Cs -hollandite materials in order to compare the leaching characteristics of these two materials under such conditions. Both the Cs-loaded bronze and hollandite materials leach severely in Fe(NO{sub 3}){sub 3} losing virtually all of the immobilized Cs in a period of four days at 150 deg C. Total release of Cs and conversion of hollandite to titanium and iron titanium oxides begins to be observed at relatively low concentrations and is virtually complete after four days reaction in 0.5 mol/L Fe(NO{sub 3}){sub 3}. In the case of the bronze, all of the Cs is also extracted but the HTB structure is preserved. The reaction presumably involves an ion-exchange mechanism and iron oxide with a spinel structure is also observed at high Fe concentrations. (authors)

  6. Cesium release from ceramic waste form materials in simulated canister corrosion product containing solutions

    International Nuclear Information System (INIS)

    Vittorio, Luca; Drabarek, Elizabeth; Chronis, Harriet; Griffith, Christopher S.

    2004-01-01

    It has previously been demonstrated that immobilization of Cs + and/or Sr 2+ sorbed on hexagonal tungsten oxide bronze (HTB) adsorbent materials can be achieved by heating the materials in air at temperatures in the range 500 - 1300 deg C. Highly crystalline powdered HTB materials formed by heating at 800 deg C show leach characteristics comparable to Cs-containing hot-pressed hollandites in the pH range from 0 to 12. As a very harsh leaching test, and also to model in a basic manner, leaching in the presence of canister corrosion products in oxidising environments, leaching of the bronzoid phases has been undertaken in Fe(NO 3 ) 3 solutions of increasing concentration. This is done in comparison with Cs -hollandite materials in order to compare the leaching characteristics of these two materials under such conditions. Both the Cs-loaded bronze and hollandite materials leach severely in Fe(NO 3 ) 3 losing virtually all of the immobilized Cs in a period of four days at 150 deg C. Total release of Cs and conversion of hollandite to titanium and iron titanium oxides begins to be observed at relatively low concentrations and is virtually complete after four days reaction in 0.5 mol/L Fe(NO 3 ) 3 . In the case of the bronze, all of the Cs is also extracted but the HTB structure is preserved. The reaction presumably involves an ion-exchange mechanism and iron oxide with a spinel structure is also observed at high Fe concentrations. (authors)

  7. Modelling size and structure of nanoparticles formed from drying of submicron solution aerosols

    International Nuclear Information System (INIS)

    Bandyopadhyay, Arpan A.; Pawar, Amol A.; Venkataraman, Chandra; Mehra, Anurag

    2015-01-01

    Drying of submicron solution aerosols, under controlled conditions, has been explored to prepare nanoparticles for drug delivery applications. A computational model of solution drop evaporation is developed to study the evolution of solute gradients inside the drop and predict the size and shell thickness of precipitating nanoparticles. The model considers evaporation as a two-stage process involving droplet shrinkage and shell growth. It was corroborated that droplet evaporation rate controls the solute distribution within a droplet and the resulting particle structure (solid or shell type). At higher gas temperatures, rapid build-up of solute near drop surface from high evaporation rates results in early attainment of critical supersaturation solubility and a steeper solute gradient, which favours formation of larger, shell-type particles. At lower gas temperatures, formation of smaller, solid nanoparticles is indicated. The computed size and shell thickness are in good agreement with experimentally prepared lipid nanoparticles. This study indicates that solid or shell structure of precipitated nanoparticles is strongly affected by evaporation rate, while initial solute concentration in the precursor solution and atomized droplet size affect shell thickness. For the gas temperatures considered, evaporative cooling leads to droplet temperature below the melting point of the lipid solute. Thus, we conclude that control over nanoparticle size and structure, of thermolabile precursor materials suitable for drug delivery, can be achieved by controlling evaporation rates, through selection of aerosol processing conditions

  8. Modelling size and structure of nanoparticles formed from drying of submicron solution aerosols

    Energy Technology Data Exchange (ETDEWEB)

    Bandyopadhyay, Arpan A.; Pawar, Amol A.; Venkataraman, Chandra; Mehra, Anurag, E-mail: mehra@iitb.ac.in [Indian Institute of Technology Bombay, Department of Chemical Engineering (India)

    2015-01-15

    Drying of submicron solution aerosols, under controlled conditions, has been explored to prepare nanoparticles for drug delivery applications. A computational model of solution drop evaporation is developed to study the evolution of solute gradients inside the drop and predict the size and shell thickness of precipitating nanoparticles. The model considers evaporation as a two-stage process involving droplet shrinkage and shell growth. It was corroborated that droplet evaporation rate controls the solute distribution within a droplet and the resulting particle structure (solid or shell type). At higher gas temperatures, rapid build-up of solute near drop surface from high evaporation rates results in early attainment of critical supersaturation solubility and a steeper solute gradient, which favours formation of larger, shell-type particles. At lower gas temperatures, formation of smaller, solid nanoparticles is indicated. The computed size and shell thickness are in good agreement with experimentally prepared lipid nanoparticles. This study indicates that solid or shell structure of precipitated nanoparticles is strongly affected by evaporation rate, while initial solute concentration in the precursor solution and atomized droplet size affect shell thickness. For the gas temperatures considered, evaporative cooling leads to droplet temperature below the melting point of the lipid solute. Thus, we conclude that control over nanoparticle size and structure, of thermolabile precursor materials suitable for drug delivery, can be achieved by controlling evaporation rates, through selection of aerosol processing conditions.

  9. Closed-form solutions for linear regulator-design of mechanical systems including optimal weighting matrix selection

    Science.gov (United States)

    Hanks, Brantley R.; Skelton, Robert E.

    1991-01-01

    This paper addresses the restriction of Linear Quadratic Regulator (LQR) solutions to the algebraic Riccati Equation to design spaces which can be implemented as passive structural members and/or dampers. A general closed-form solution to the optimal free-decay control problem is presented which is tailored for structural-mechanical systems. The solution includes, as subsets, special cases such as the Rayleigh Dissipation Function and total energy. Weighting matrix selection is a constrained choice among several parameters to obtain desired physical relationships. The closed-form solution is also applicable to active control design for systems where perfect, collocated actuator-sensor pairs exist. Some examples of simple spring mass systems are shown to illustrate key points.

  10. 21 CFR 524.1200b - Kanamycin ophthalmic aqueous solution.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Kanamycin ophthalmic aqueous solution. 524.1200b... (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS OPHTHALMIC AND TOPICAL DOSAGE FORM NEW ANIMAL DRUGS § 524.1200b Kanamycin ophthalmic aqueous solution. (a) Specifications. The drug, which is in an aqueous...

  11. 21 CFR 524.390b - Chloramphenicol ophthalmic solution.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Chloramphenicol ophthalmic solution. 524.390b... (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS OPHTHALMIC AND TOPICAL DOSAGE FORM NEW ANIMAL DRUGS § 524.390b Chloramphenicol ophthalmic solution. (a) Specifications. Each milliliter contains 5...

  12. 21 CFR 524.1982 - Proparacaine hydrochloride ophthalmic solution.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Proparacaine hydrochloride ophthalmic solution... SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS OPHTHALMIC AND TOPICAL DOSAGE FORM NEW ANIMAL DRUGS § 524.1982 Proparacaine hydrochloride ophthalmic solution. (a) Specifications. The drug is...

  13. 21 CFR 524.1044a - Gentamicin ophthalmic solution.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Gentamicin ophthalmic solution. 524.1044a Section... (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS OPHTHALMIC AND TOPICAL DOSAGE FORM NEW ANIMAL DRUGS § 524.1044a Gentamicin ophthalmic solution. (a) Specifications. Each milliliter of sterile aqueous...

  14. Obtaining of barium sulfate from solution formed after desulfation of the active mass of scrap lead-acid batteries

    Directory of Open Access Journals (Sweden)

    O. A. Kalko

    2014-03-01

    Full Text Available Analyses of literature data about processes for solution utilization formed after desulfation of the active mass of scrap lead-acid batteries is performed. Optimal conditions for obtaining of barium sulfate sediment from ammonium sulfate solute and chemically pure Ba(OH2×8H2O и BaCl2×2H2O were found experimentally. In laboratory the commercial barium sulfate from sulfate solutions, that are waste of recycling process of battery scrap, with application of chloride and barium hydroxide was production. The possibility of using this product were discussed.

  15. The reactivity of the electron formed in the radiolysis of aerated alkaline aqueous solutions containing tetracycline hydrochloride, at 77 Ksup(+)

    International Nuclear Information System (INIS)

    Guedes, S.M.L.; Vasconcellos, M.B.A.

    1986-01-01

    The radiolysis of tetracycline hydrochloride dissolved in aerated alkaline aqueous solutions containing 0.1, 0.5 and 1M NaOH at 77 K, followed by ESR is reported. The rate constants for the reactions between the electron and physical or chemical traps which are present in these solutions are calculated. The reactivity of electrons that are formed in the radiolysis of water decreases in the following proportions: physical traps: chemical traps: molecules of water (4.8x10sup(14) : 6.5x10sup(8) : 1.0). The electrons react preferentially with the solute instead of the solvent. (author)

  16. Improving the Ability of Mathematic Representation Capabilities and Students Skills in Importing Square Forms to Square Using Variation Solutions

    Science.gov (United States)

    Nirawati, R.

    2018-04-01

    This research was conducted to see whether the variation of the solution is acceptable and easy to understand by students with different level of ability so that it can be seen the difference of students ability in facilitating the quadratic form in the upper, middle and lower groups. This research used experimental method with factorial design. Based on the result of final test analysis, there were differences of students ability in upper group, medium group, and lower group in putting squared form based on the use certain variation of solution.

  17. Modeling of Filament Deposition Rapid Prototyping Process with a Closed form Solution

    Science.gov (United States)

    Devlin, Steven Leon

    Fused Deposition Modeling (FDM(TM)) or fused filament fabrication (FFF) systems are extrusion-based technologies used to produce functional or near functional parts from a wide variety of plastic materials. First patented by S. Scott Crump and commercialized by Stratasys, Ltd in the early 1990s, this technology, like many additive manufacturing systems, offers significant opportunities for the design and production of complex part structures that are difficult if not impossible to produce using traditional manufacturing methods. Standing on the shoulders of a twenty-five year old invention, a rapidly growing open-source development community has exponentially driven interest in FFF technology. However, part quality often limits use in final product commercial markets. Development of accurate and repeatable methods for determining material strength in FFF produced parts is essential for wide adoption into mainstream manufacturing. This study builds on the empirical, squeeze flow and intermolecular diffusion model research conducted by David Grewell and Avraham Benatar, applying a combined model to predict auto adhesion or healing to FFF part samples. In this research, an experimental study and numerical modeling were performed in order to drive and validate a closed form heat transfer solution for extrusion processes to develop temperature field models. An extrusion-based 3D printing system, with the capacity to vary deposition speeds and temperatures, was used to fabricate the samples. Standardized specimens of Polylactic Acid (PLA) and Acrylonitrile Butadiene Styrene (ABS) filament were used to fabricate the samples with different speeds and temperatures. Micro-scanning of cut and lapped specimens, using an optical microscope, was performed to find the effect of the speed and the temperature on the geometry of the cross-sections. It was found that by increasing the speed of the extrusion printing, the area of the cross-section and the maximum thickness decrease

  18. Study of the confined solutions properties: case of gel formed during nuclear glass alteration

    International Nuclear Information System (INIS)

    Matar-Briman, I.

    2012-01-01

    In this study, we have investigated the thermodynamic properties, the structure and the dynamics of confined solutions in model gels and in a gel coming from glass alteration. The first step was to determine the structure and the dynamics of pure confined water in porous materials by using nuclear magnetic resonance and neutron scattering. Meso-porous silica was elaborated and grafted by sol-gel route to decrease the pore sizes from 2.7 to 2 nm and to modify pore surfaces to have Si-OH, Zr-OH and Al-OH. The second step involved determining the dynamics of water in leachate confined in the model gels and in the gel of altered glass by using neutron scattering. In the model gels and at a 10 -12 -10 -9 second timescale, two kinds of waters were highlighted: first, an interfacial water linked to the pore surfaces and second, a free water in the pore core. Their ratio depends on the pore size and pore surface composition. Whatever the pore surface, when the pore size decreases the free water ratio in the pore center also decreases. For pores smaller than 2.3 nm and pore surfaces with Zr-OH or Al-OH surfaces, water is strongly linked to the surface and few water molecules are mobile. This is due to the ability of alumina and zirconia to immobilize water molecules through chemical coordination bonds stronger than the physical bonds established between silica and water. The result also highlight that pore surface composition could be the predominant parameter affecting the fixed proton content. Moreover, the mobility of water confined in a leachate is not modified. The study of the water dynamics in a gel formed during alteration of glass constituted of SiO 2 , Al 2 O 3 and CaO, and having a porosity between 2 and 7 nm showed the same behavior as water confined in pores presenting an Al-OH surface. (author) [fr

  19. Solution exchange corrosion testing with the glass-zeolite ceramic waste form in demineralized water at 900C

    International Nuclear Information System (INIS)

    Simpson, L. J.

    1998-01-01

    A ceramic waste form of glass-bonded zeolite is being developed for the long-term disposition of fission products and transuranic elements in wastes from the U.S. Department of Energy's spent nuclear fuel conditioning activities. Solution exchange corrosion tests were performed on the ceramic waste form and its potential base constituents of glass, zeolite 5A, and sodalite as part of an effort to qualify the ceramic waste form for acceptance into the Civilian Radioactive Waste Management System. Solution exchange tests were performed at 90 C by replacing 80 to 90% of the leachate with fresh demineralized water after set time intervals. The results from these tests provide information about corrosion mechanisms and the ability of the ceramic waste form and its constituent materials to retain waste components. The results from solution exchange tests indicate that radionuclides will be preferentially retained in the zeolites without the glass matrix and in the ceramic waste form, with respect to cations like Li, K, and Na. Release results have been compared for simulated waste from candidate ceramic waste forms with zeolite 5A and its constituent materials to determine the corrosion behavior of each component

  20. A closed-form solution for steady-state coupled phloem/xylem flow using the Lambert-W function.

    Science.gov (United States)

    Hall, A J; Minchin, P E H

    2013-12-01

    A closed-form solution for steady-state coupled phloem/xylem flow is presented. This incorporates the basic Münch flow model of phloem transport, the cohesion model of xylem flow, and local variation in the xylem water potential and lateral water flow along the transport pathway. Use of the Lambert-W function allows this solution to be obtained under much more general and realistic conditions than has previously been possible. Variation in phloem resistance (i.e. viscosity) with solute concentration, and deviations from the Van't Hoff expression for osmotic potential are included. It is shown that the model predictions match those of the equilibrium solution of a numerical time-dependent model based upon the same mechanistic assumptions. The effect of xylem flow upon phloem flow can readily be calculated, which has not been possible in any previous analytical model. It is also shown how this new analytical solution can handle multiple sources and sinks within a complex architecture, and can describe competition between sinks. The model provides new insights into Münch flow by explicitly including interactions with xylem flow and water potential in the closed-form solution, and is expected to be useful as a component part of larger numerical models of entire plants. © 2013 John Wiley & Sons Ltd.

  1. Forms and lability of phosphorus in algae and aquatic macrophytes characterized by solution 31P NMR coupled with enzymatic hydrolysis

    Science.gov (United States)

    Increased information on forms and lability of phosphorus (P) in aquatic macrophytes and algae is crucial for better understanding of P biogeochemical cycling in eutrophic lakes. In this work, solution 31P nuclear magnetic resonance (NMR) spectroscopy coupled with enzymatic hydrolysis (EH) was used ...

  2. On new classes of solutions of nonlinear partial differential equations in the form of convergent special series

    Science.gov (United States)

    Filimonov, M. Yu.

    2017-12-01

    The method of special series with recursively calculated coefficients is used to solve nonlinear partial differential equations. The recurrence of finding the coefficients of the series is achieved due to a special choice of functions, in powers of which the solution is expanded in a series. We obtain a sequence of linear partial differential equations to find the coefficients of the series constructed. In many cases, one can deal with a sequence of linear ordinary differential equations. We construct classes of solutions in the form of convergent series for a certain class of nonlinear evolution equations. A new class of solutions of generalized Boussinesque equation with an arbitrary function in the form of a convergent series is constructed.

  3. INFLUENCE OF QUARTZ CERAMICS SINGLE-STAGE PROCESSING BY GEL-FORMING WATER SOLUTIONS ON ITS STRENGTH

    Directory of Open Access Journals (Sweden)

    S. K. Evstropiev

    2014-09-01

    Full Text Available The main research results of the influence of quartz ceramics processing by silicon- and aluminum-containing gel- forming water solutions on its durability and porosity are given. Aqueous-alcoholic solutions based on tetraethoxysilane (TEOS, Si(C2H5O4 with additives of aluminum nitrate are proposed for impregnation of porous quartz ceramics samples. Ceramic samples are being impregnated with solutions at the room temperature for 12 minutes. After impregnation they are being exposed to drying at the room temperature for 24 hours and heat treatment in the electric muffle furnace. The made experiments show that impregnation of quartz ceramics porous samples by gel-forming solutions leads to durability growth of not burned samples by 6-7 times even without additional heat treatment. High-temperature heat treatment of previously impregnated ceramic samples leads to decomposition of aluminum nitrate and removal of fossils, and also to hardening of the formed additional bonds between material particles. It considerably improves strength characteristics of quartz ceramics as well. Thus, the possibility of considerable hardening of porous quartz ceramics and stability growth of its strength properties by preliminary impregnation of silicon- and aluminum-bearing gel-forming solutions even without additional heat treatment is experimentally shown. It is revealed that impregnation of porous quartz ceramic samples by these solutions leads only to insignificant reduction of porosity of samples. Subsequent heat treatment of the impregnated porous ceramic samples at the temperatures, equal to 900-1200oC, results in additional significant increase in their mechanical durability.

  4. Numerical Solution of Uncertain Beam Equations Using Double Parametric Form of Fuzzy Numbers

    Directory of Open Access Journals (Sweden)

    Smita Tapaswini

    2013-01-01

    Full Text Available Present paper proposes a new technique to solve uncertain beam equation using double parametric form of fuzzy numbers. Uncertainties appearing in the initial conditions are taken in terms of triangular fuzzy number. Using the single parametric form, the fuzzy beam equation is converted first to an interval-based fuzzy differential equation. Next, this differential equation is transformed to crisp form by applying double parametric form of fuzzy number. Finally, the same is solved by homotopy perturbation method (HPM to obtain the uncertain responses subject to unit step and impulse loads. Obtained results are depicted in terms of plots to show the efficiency and powerfulness of the methodology.

  5. Closed-form analytical solutions incorporating pumping and tidal effects in various coastal aquifer systems

    Science.gov (United States)

    Wang, Chaoyue; Li, Hailong; Wan, Li; Wang, Xusheng; Jiang, Xiaowei

    2014-07-01

    Pumping wells are common in coastal aquifers affected by tides. Here we present analytical solutions of groundwater table or head variations during a constant rate pumping from a single, fully-penetrating well in coastal aquifer systems comprising an unconfined aquifer, a confined aquifer and semi-permeable layer between them. The unconfined aquifer terminates at the coastline (or river bank) and the other two layers extend under tidal water (sea or tidal river) for a certain distance L. Analytical solutions are derived for 11 reasonable combinations of different situations of the L-value (zero, finite, and infinite), of the middle layer's permeability (semi-permeable and impermeable), of the boundary condition at the aquifer's submarine terminal (Dirichlet describing direct connection with seawater and no-flow describing the existence of an impermeable capping), and of the tidal water body (sea and tidal river). Solutions are discussed with application examples in fitting field observations and parameter estimations.

  6. Copper removal from aqueous solution using Aspergillus niger mycelia in free and polyurethane-bound form

    Energy Technology Data Exchange (ETDEWEB)

    Tsekova, K.; Ilieva, S. [Inst. of Microbiology, Bulgarian Academy of Sciences, Sofia (Bulgaria)

    2001-07-01

    This study assesses the ability of mycelia of Aspergillus niger B-77 (both free and immobilized on polyurethane foam) to remove copper from single-ion solution. All experiments were conducted using 0.5 mM solutions of CuSO{sub 4}.5H{sub 2} O. Mycelia immobilized on polyurethane foam cells showed a three-fold increase in uptake, compared with that of free cells. The efficiency of copper removal (mg Cu{sup 2+} removed/mg Cu{sup 2+} added) in a column system reached more than 99% before the break-through point was attained. (orig.)

  7. FormScanner: Open-Source Solution for Grading Multiple-Choice Exams

    Science.gov (United States)

    Young, Chadwick; Lo, Glenn; Young, Kaisa; Borsetta, Alberto

    2016-01-01

    The multiple-choice exam remains a staple for many introductory physics courses. In the past, people have graded these by hand or even flaming needles. Today, one usually grades the exams with a form scanner that utilizes optical mark recognition (OMR). Several companies provide these scanners and particular forms, such as the eponymous…

  8. Experimental evidence for excess entropy discontinuities in glass-forming solutions.

    Science.gov (United States)

    Lienhard, Daniel M; Zobrist, Bernhard; Zuend, Andreas; Krieger, Ulrich K; Peter, Thomas

    2012-02-21

    Glass transition temperatures T(g) are investigated in aqueous binary and multi-component solutions consisting of citric acid, calcium nitrate (Ca(NO(3))(2)), malonic acid, raffinose, and ammonium bisulfate (NH(4)HSO(4)) using a differential scanning calorimeter. Based on measured glass transition temperatures of binary aqueous mixtures and fitted binary coefficients, the T(g) of multi-component systems can be predicted using mixing rules. However, the experimentally observed T(g) in multi-component solutions show considerable deviations from two theoretical approaches considered. The deviations from these predictions are explained in terms of the molar excess mixing entropy difference between the supercooled liquid and glassy state at T(g). The multi-component mixtures involve contributions to these excess mixing entropies that the mixing rules do not take into account. © 2012 American Institute of Physics

  9. Removal of Lead Hydroxides Complexes from Solutions Formed in Silver/Gold: Cyanidation Process

    Science.gov (United States)

    Parga, José R.; Martinez, Raul Flores; Moreno, Hector; Gomes, Andrew Jewel; Cocke, David L.

    2014-04-01

    The presence of lead hydroxides in "pregnant cyanide solution" decreases the quality of the Dore obtained in the recovery processes of gold and silver, so it is convenient to remove them. The adsorbent capacity of the low cost cow bone powder was investigated for the removal of lead ions from a solution of lead hydroxide complexes at different initial metal ion concentrations (10 to 50 mg/L), and reaction time. Experiments were carried out in batches. The maximum sorption capacity of lead determined by the Langmuir model was found to be 126.58 mg/g, and the separation factor R L was between 0 and 1, indicating a significant affinity of bone for lead. Experimental data follow pseudo-second order kinetics suggesting chemisorption. It is concluded that cow bone powder can be successfully used for the removal of lead ions, and improves the quality of the silver-gold cyanides precipitate.

  10. Dosage of DTPA administration by inhalation

    International Nuclear Information System (INIS)

    Koizumi, Akira; Fukuda, Satoshi; Yamada, Yuji; Iida, Haruzo; Shimo, Michikuni

    2000-01-01

    The administration of DTPA by inhalation was examined as an emergency medical treatment. In order to estimate the practical dosage to the human, an accurate model of the human air way was connected to a anesthetizer and respiration was simulated. Ca-DTPA, aerosolized by an ultra-sonic nebulizer, was administered by inhalation to the model. For the experiments, the respiratory volume (tidal volume) and the respiration rate was 12 per minute. Irrigation water from the model of larynx and mouth, and the air filter were collected and measured by chelate titration in order to determine the quantity of aerosolized DTPA and the amount deposited on the trachea and lang. The results indicated that the quantity of aerosolized DTPA varied with dilution of the DTPA solution in a ample. It was found that a 3 time dilution was the most practical and that 73 mg of DTPA per minute could be aerosolized. Furthermore, the results indicated that 46% of the aerosolized DTPA was taken in through inhalation and that 26% of DTPA was deposited in the trachea and lung. These results suggest that in practical application in the emergency medical treatment, 15 minutes of inhalation could delivered to approximately 500 mg of DTPA, and 130 mg could be delivered to the trachea and lung. It is considered that these quantity are enough amount to increase the effects of radioactive nuclides from the body, comparing with the recommended dosage for injection administration. (author)

  11. The Form of the Solutions of the Linear Integro-Differential Equations of Subsonic Aeroelasticity.

    Science.gov (United States)

    1979-09-01

    coefficients w (0) are given in Table 3; it V follows that, for T > 0 and (E - K v2) non-singular, the inverse transform of M- ) has the form, using (B-I) V...degree of freedom system by expanding )M- I in the form of equation (35), obtaining its inverse transform using the v -1results of Appendix A and hence...obtaining the inverse transform of M- l . The two-dimensional case, when the characteristic equation has a zero root, is not as simple. * Assuming all

  12. Photo-electrochemical analysis of passive film formed on X80 pipeline steel in bicarbonate/carbonate buffer solution

    Energy Technology Data Exchange (ETDEWEB)

    Li, D.G. [School of Materials Science and Engineering, Xi' an Jiaotong University, Xi' an 710049 (China); Tubular Goods Research Center of CNPC, Xi' an 710065 (China)], E-mail: dangguoli78@yahoo.com.cn; Feng, Y.R.; Bai, Z.Q. [Tubular Goods Research Center of CNPC, Xi' an 710065 (China); Zhu, J.W.; Zheng, M.S. [School of Materials Science and Engineering, Xi' an Jiaotong University, Xi' an 710049 (China)

    2008-02-28

    Photo-electrochemical measurement was used to explore the formation potential, formation time, chloride ions concentration, applied potential and pH value of the solution on the electronic property of passive film formed on X80 pipeline steel in 1 M NaHCO{sub 3}/0.5 M Na{sub 2}CO{sub 3} buffer solution. The results showed that the photocurrent is positive, indicating an n-type semiconductor character of the passive film, the photocurrent increased with increasing the formation potential, prolonging the formation time, decreasing chloride ions concentration, rising applied potential and decreasing the pH value of the solution. Capacitance measurement exhibited a positive slope of Mott-Schottky plot, and the slopes of Mott-Schottky plots increased with the increasing formation potential, showing a decrement of the donor density of the passive film.

  13. GPS/Galileo Multipath Detection and Mitigation Using Closed-Form Solutions

    Directory of Open Access Journals (Sweden)

    Khaled Rouabah

    2009-01-01

    Full Text Available We propose an efficient method for the detection of Line of Sight (LOS and Multipath (MP signals in global navigation satellite systems (GNSSs which is based on the use of virtual MP mitigation (VMM technique. By using the proposed method, the MP signals' delay and coefficient amplitudes can be efficiently estimated. According to the computer simulation results, it is obvious that our proposed method is a solution for obtaining high performance in the estimation and mitigation of MP signals and thus it results in a high accuracy in GNSS positioning.

  14. Identification of major degradation products of 5-aminosalicylic acid formed in aqueous solutions and in pharmaceuticals

    DEFF Research Database (Denmark)

    Jensen, J.; Cornett, Claus; Olsen, C. E.

    1992-01-01

    of polymeric species by oxidative self-coupling of 5-ASA moieties. These results indicate that the degradation of 5-ASA follows the same mechanism as observed for the autooxidation of 4-aminophenol and 1,4-phenylenediamine. Some of the identified degradation products were found in 5-ASA......The formation of four major degradation products of 5-aminosalicylic acid (5-ASA) in buffered solutions at pH 7.0 was demonstrated by gradient HPLC analysis. The isolation and structural elucidation of the resulting degradation products showed that the degradation of 5-ASA led to the formation...

  15. Electron transfer across anodic films formed on tin in carbonate-bicarbonate buffer solution

    International Nuclear Information System (INIS)

    Gervasi, C.A.; Folquer, M.E.; Vallejo, A.E.; Alvarez, P.E.

    2005-01-01

    Impedance and steady-state data were recorded in order to study the kinetics of electron transfer between passive tin electrodes and an electrolytic solution containing the K 3 Fe(CN) 6 -K 4 Fe(CN) 6 redox couple. Film thickness plays a key role in determining the type of electronic conduction of these oxide covered electrodes. Electron exchange with the oxide takes place with participation of the conduction band in the semiconducting film. A mechanism involving direct electron tunneling through the space charge barrier is the most suitable to interpret the experimental evidence

  16. Electron transfer across anodic films formed on tin in carbonate-bicarbonate buffer solution

    Energy Technology Data Exchange (ETDEWEB)

    Gervasi, C.A. [Universidad Nacional de La Plata (Argentina). Facultad de Ciencias Exactas; Universidad Nacional de La Plata (Argentina). Facultad de Ingenieria; Folquer, M.E. [Universidad Nacional de Tucaman (Argentina). Inst. de Quimica Fisica; Vallejo, A.E. [Universidad Nacional de La Plata (Argentina). Facultad de Ingenieria; Alvarez, P.E. [Universidad Nacional de Tucaman (Argentina). Inst. de Fisica

    2005-01-15

    Impedance and steady-state data were recorded in order to study the kinetics of electron transfer between passive tin electrodes and an electrolytic solution containing the K{sub 3}Fe(CN){sub 6}-K{sub 4}Fe(CN){sub 6} redox couple. Film thickness plays a key role in determining the type of electronic conduction of these oxide covered electrodes. Electron exchange with the oxide takes place with participation of the conduction band in the semiconducting film. A mechanism involving direct electron tunneling through the space charge barrier is the most suitable to interpret the experimental evidence. (Author)

  17. Aldehydes, ketones, and carboxylic acids formed radiolytically in aqueous solutions of cyanides and simple nitriles

    International Nuclear Information System (INIS)

    Negron-Mendoza, A.; Draganic, Z.D.; Navarro-Gonzalez, R.; Graganic, I.G.

    1983-01-01

    A systematic search for aldehydes, ketones, and carboxylic acids was carried out in aqueous solutions of HCN, NH 4 CN, CH 3 CN, and C 2 H 4 CN, that had received multikilogray doses of 60 Co γ radiation. About 30 radiolytic products were identified, among them a large variety of dicarboxylic and tricarboxylic acids. Some of them might be of significant interest in molecular evolution studies of prebiotic processes. They originate in the free-radical-initiated chemical reactions where the additional oligomerization processes are particularly important. Most of the radiolytic products appear in both cyanides and nitriles and point to the importance of reactions involving the carbon-nitrogen triple bond

  18. Customizable pre-printed consent forms: a solution in light of the Montgomery ruling.

    Science.gov (United States)

    Owen, Deborah; Aresti, Nick; Mulligan, Alex; Kosuge, Dennis

    2018-02-02

    This article presents an audit cycle supported quality improvement project addressing best practice in the consent process for lower limb arthroplasty which takes into account the new standard in surgical consent and the importance of material risks. 50 consecutive total hip and total knee replacement consent forms over a 3-month period were reviewed for legibility and completeness. Following the introduction of a new, pre-printed but customizable consent form the review process was repeated. The introduction of a customizable, pre-printed consent form that can be adjusted to reflect the individualized material risks of each patient increased legibility, reduced inappropriate human error variation and abolished the use of abbreviations and medical jargon. When used as part of an extended consent process, the authors feel that the use of pre-printed but customizable consent forms improves legibility, completeness and consistency and also provides the ability to highlight those complications that are of particular importance for that patient to satisfy the new accepted standard in surgical consent.

  19. Groupwork as a Form of Assessment: Common Problems and Recommended Solutions

    Science.gov (United States)

    Davies, W. Martin

    2009-01-01

    This paper reviews some of the literature on the use of groupwork as a form of assessment in tertiary institutions. It outlines the considerable advantages of groupwork but also its systemic associated problems. In discussing the problems, the paper considers issues such as "free riding" and the "sucker effect", issues associated with ethnic mix…

  20. Networks of gel-forming triblock copolymer solutions: In situ SANS and rheological measurements

    DEFF Research Database (Denmark)

    Mortensen, K.; Almdal, K.; Kleppinger, R.

    1998-01-01

    Triblock copolymers in a solvent, selective for their middle blocks provide the basis for the formation of novel physical networks where cross-links are formed by self-assembled domains of the end-blocks. Triblock copolymers of poly(styrene)-poly(ethylene,butylene)-poly(styrene) (SEBS) dissolved...

  1. The importance of functional form in optimal control solutions of problems in population dynamics

    Science.gov (United States)

    Runge, M.C.; Johnson, F.A.

    2002-01-01

    Optimal control theory is finding increased application in both theoretical and applied ecology, and it is a central element of adaptive resource management. One of the steps in an adaptive management process is to develop alternative models of system dynamics, models that are all reasonable in light of available data, but that differ substantially in their implications for optimal control of the resource. We explored how the form of the recruitment and survival functions in a general population model for ducks affected the patterns in the optimal harvest strategy, using a combination of analytical, numerical, and simulation techniques. We compared three relationships between recruitment and population density (linear, exponential, and hyperbolic) and three relationships between survival during the nonharvest season and population density (constant, logistic, and one related to the compensatory harvest mortality hypothesis). We found that the form of the component functions had a dramatic influence on the optimal harvest strategy and the ultimate equilibrium state of the system. For instance, while it is commonly assumed that a compensatory hypothesis leads to higher optimal harvest rates than an additive hypothesis, we found this to depend on the form of the recruitment function, in part because of differences in the optimal steady-state population density. This work has strong direct consequences for those developing alternative models to describe harvested systems, but it is relevant to a larger class of problems applying optimal control at the population level. Often, different functional forms will not be statistically distinguishable in the range of the data. Nevertheless, differences between the functions outside the range of the data can have an important impact on the optimal harvest strategy. Thus, development of alternative models by identifying a single functional form, then choosing different parameter combinations from extremes on the likelihood

  2. A Closed-Form Approximation Solution for an Inventory Model with Supply Disruptions and Non-ZIO Reorder Policy

    Directory of Open Access Journals (Sweden)

    David Heimann

    2007-08-01

    Full Text Available In supply chains, domestic and global, a producer must decide on an optimal quantity of items to order from suppliers and at what inventory level to place this order (the EOQ problem. We discuss how to modify the EOQ in the face of failures and recoveries by the supplier. This is the EOQ with disruption problem (EOQD. The supplier makes transitions between being capable and not being capable of filling an order in a Markov failure and recovery process. The producer adjusts the reorder point and the inventories to provide a margin of safety. Numerical solutions to the EOQD problem have been developed. In addition, a closed-form approximate solution has been developed for the zero inventory option (ZIO, where the inventory level on reordering is set to be zero. This paper develops a closed-form approximate solution for the EOQD problem when the reorder point can be non-zero, obtaining for that situation an optimal reorder quantity and optimal reorder point that represents an improvement on the optimal ZIO solution. The paper also supplies numerical examples demonstrating the cost savings against the ZIO situation, as well as the accuracy of the approximation technique.

  3. A Study on Scattered Wave Amplitude Closed-Form Solution Calculation of Torsional Wave Mode by Reciprocity Theorem

    International Nuclear Information System (INIS)

    Lee, Jaesun; Cho, Younho; Achenbach, Jan D.

    2016-01-01

    Guided waves can be used for the inspection of long range pipelines. Surface corrosion is often found as a major defect type in pipelines. The reciprocity relation is a well-established theorem by which one can simplify complicated mathematical expressions. The approach has been already applied to plate and half-space structures to obtain the closed-form solutions of scattered amplitude. However, results for the case of cylindrical structures have not been reported yet. In this paper, the scattering of torsional waves, which is widely used in commercial applications, is explored by the reciprocity theorem approach. Obtaining closed-form solutions of the amplitudes of propagating waves is much simplified by using the reciprocal relation. The scattered amplitudes for elliptical and rectangular defect shapes are calculated with respect to defect depth and width, at frequencies between 0 and 500 kHz. The amplitude shows the periodic result as a function of frequency. The derived closed-form solutions can play a significant role in quantitative signal interpretation

  4. A Study on Scattered Wave Amplitude Closed-Form Solution Calculation of Torsional Wave Mode by Reciprocity Theorem

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jaesun; Cho, Younho [Pusan National Univ., Pusan (Korea, Republic of); Achenbach, Jan D. [Northwestern Univ., Everston (United States)

    2016-07-15

    Guided waves can be used for the inspection of long range pipelines. Surface corrosion is often found as a major defect type in pipelines. The reciprocity relation is a well-established theorem by which one can simplify complicated mathematical expressions. The approach has been already applied to plate and half-space structures to obtain the closed-form solutions of scattered amplitude. However, results for the case of cylindrical structures have not been reported yet. In this paper, the scattering of torsional waves, which is widely used in commercial applications, is explored by the reciprocity theorem approach. Obtaining closed-form solutions of the amplitudes of propagating waves is much simplified by using the reciprocal relation. The scattered amplitudes for elliptical and rectangular defect shapes are calculated with respect to defect depth and width, at frequencies between 0 and 500 kHz. The amplitude shows the periodic result as a function of frequency. The derived closed-form solutions can play a significant role in quantitative signal interpretation.

  5. Occurrence forms of uranium in the production solutions in the areas of underground leaching of epigenetic uranium deposits

    International Nuclear Information System (INIS)

    Serebrennikov, V.S.; Dorofeeva, V.A.

    1980-01-01

    Redox, acid-basic features of solutions (Eh changes from + 50 to 650 mV, pH from 7.5 to 1.5) and their chemical composition are studied in the process of hydrogeochemical investigations at the areas of underground leaching (UL) of epigenetic uranium deposits. It is shown that at studied areas of UL under neutral and weakly acidic conditions up to (pH 6.0-5.8), carbonate complexes of uranyl are the prevailing form of uranium existence in the solution, and sulfate complexes prevail under more acidic conditions. A supposition is made that it is expedient to process separate ore blocks with increased carbonate contents, particularly with oxidant additions under near-neutral acid-basic conditions (pH 7.2-6.8) with the use of weakly acid pumping solutions, which act (at the expense of their interaction with carbonates of ore-containing rocks) for enrichment of working solutions with HCO 3 - and CO 3 2- ions, promoting uranium transfer into solution

  6. Detection of the electronic structure of iron-(iii)-oxo oligomers forming in aqueous solutions.

    Science.gov (United States)

    Seidel, Robert; Kraffert, Katrin; Kabelitz, Anke; Pohl, Marvin N; Kraehnert, Ralph; Emmerling, Franziska; Winter, Bernd

    2017-12-13

    The nature of the small iron-oxo oligomers in iron-(iii) aqueous solutions has a determining effect on the chemical processes that govern the formation of nanoparticles in aqueous phase. Here we report on a liquid-jet photoelectron-spectroscopy experiment for the investigation of the electronic structure of the occurring iron-oxo oligomers in FeCl 3 aqueous solutions. The only iron species in the as-prepared 0.75 M solution are Fe 3+ monomers. Addition of NaOH initiates Fe 3+ hydrolysis which is followed by the formation of iron-oxo oligomers. At small enough NaOH concentrations, corresponding to approximately [OH]/[Fe] = 0.2-0.25 ratio, the iron oligomers can be stabilized for several hours without engaging in further aggregation. Here, we apply a combination of non-resonant as well as iron 2p and oxygen 1s resonant photoelectron spectroscopy from a liquid microjet to detect the electronic structure of the occurring species. Specifically, the oxygen 1s partial electron yield X-ray absorption (PEY-XA) spectra are found to exhibit a peak well below the onset of liquid water and OH - (aq) absorption. The iron 2p absorption gives rise to signal centered between the main absorption bands typical for aqueous Fe 3+ . Absorption bands in both PEY-XA spectra are found to correlate with an enhanced photoelectron peak near 20 eV binding energy, which demonstrates the sensitivity of resonant photoelectron (RPE) spectroscopy to mixing between iron and ligand orbitals. These various signals from the iron-oxo oligomers exhibit maximum intensity at [OH]/[Fe] = 0.25 ratio. For the same ratio, we observe changes in the pH as well as in complementary Raman spectra, which can be assigned to the transition from monomeric to oligomeric species. At approximately [OH]/[Fe] = 0.3 we begin to observe particles larger than 1 nm in radius, detected by small-angle X-ray scattering.

  7. On a closed form solution of the point kinetics equations with reactivity feedback of temperature

    International Nuclear Information System (INIS)

    Silva, Jeronimo J.A.; Vilhena, Marco T.M.B.; Petersen, Claudio Z.; Bodmann, Bardo E.J.; Alvim, Antonio C.M.

    2011-01-01

    An analytical solution of the point kinetics equations to calculate reactivity as a function of time by the Decomposition method has recently appeared in the literature. In this paper, we go one step forward, by considering the neutron point kinetics equations together with temperature feedback effects. To accomplish that, we extended the point kinetics by a temperature perturbation, obtaining a second order nonlinear ordinary differential equation. This equation is then solved by the Decomposition Method, that is, by expanding the neutron density in a series and the nonlinear terms into Adomian Polynomials. Substituting these expansions into the nonlinear ordinary equation, we construct a recursive set of linear problems that can be solved by the methodology previously mentioned for the point kinetics equation. We also report on numerical simulations and comparisons against literature results. (author)

  8. Semiconducting properties of oxide films formed onto an Nb electrode in NaOH solutions

    Directory of Open Access Journals (Sweden)

    VLADIMIR D. JOVIC

    2008-03-01

    Full Text Available In this paper, the results of the potentiostatic formation of homogeneous and heterogeneous, nano-crystalline passive films of Nb2O5 onto an Nb electrode in NaOH solutions of different concentrations at potentials lower than 3.0 V vs. SCE are presented. The semiconducting properties of such films were investigated by EIS measurements. After fitting the EIS results by appropriate equivalent circuits, the space charge capacitance (Csc and space charge resistance (Rsc of these films were determined. The donor density (Nsc, flat band potential (Efb and thickness of the space charge layer (dsc for such oxide films were determined from the corresponding Mott–Schottky (M–S plots. It is shown that all oxide films were n-type semiconductors in a certain potential range.

  9. Referral letter with an attached structured reply form: Is it a solution for not getting replies

    Directory of Open Access Journals (Sweden)

    R. P. J. C. Ramanayake

    2013-01-01

    Full Text Available Background: Communication between primary care doctors and specialists/hospital doctors is vital for smooth functioning of a health care system. In many instances referral and reply letters are the sole means of communication between general practitioners and hospital doctors/specialists. Despite the obvious benefits to patient care, answers to referral letters are the exception worldwide. In Sri Lanka hand written conventional letters are used to refer patients and replies are scarce. Materials and Methods: This interventional study was designed to assess if attaching a structured reply form with the referral letter would increase the rate of replies/back-referrals. It was conducted at the Family Medicine Clinic of the Faculty of Medicine, University of Kelaniya. A structured referral letter (form was designed based on guide lines and literature and it was used for referral of patients for a period of six months. Similarly a structured reply form was also designed and both the referral letter and the reply letter were printed on A4 papers side by side and these were used for the next six months for referrals. Both letters had headings and space underneath to write details pertaining to the patient. A register was maintained to document the number of referrals and replies received during both phases. Patents were asked to return the reply letters if specialists/hospital doctors obliged to reply. Results: Total of 90 patients were referred using the structured referral form during 1st phase. 80 letters (with reply form attached were issued during the next six months. Patients were referred to eight different specialties. Not a single reply during the 1 st phase and there were six 6 (7.5% replies during the 2 nd phase. Discussion: This was an attempt to improve communication between specialists/hospital doctors and primary care doctors. Even though there was some improvement it was not satisfactory. A multicenter island wide study should be

  10. Complex crystals formed in the aqueous solution of copper(I) iodide and sodium iodide

    International Nuclear Information System (INIS)

    Sugasaka, Kazuhiko; Fujii, Ayako

    1977-01-01

    Crystals of different crystal habits were separated from the copper(I) iodide and sodium iodide solution and the thermal changes of the composition of copper(I) iodide and sodium iodide complexes were studied by chemical analysis, thermal analysis and X-ray diffractometry. Granular and columnar crystals were determined to be copper(I) iodide and sodium iodide dihydrate by X-ray diffraction analysis, respectively. Needle crystal (A) which was separated from the solution at 25 0 C was assumed to be Na 2 CuI 3 .6H 2 O. (A) was stable in its appearance in the air, but the X-ray diffraction pattern of (A) changed. Needle crystal (B) which was recrystallized at 10 0 C from mother liquor after the separation of crystal (A) was assumed to be NaCuI 2 .4H 2 O. (B) was hygroscopic and decomposed to precipitate copper(I) iodide with moisture in the air. (A) and (B) were found to change by heating and or drying, respectively, as follows: Na 2 CuI 3 .6H 2 O → (-2H 2 O, 80 0 C) → 2NaI.2H 2 O + CuI → (-4H 2 O, 160 0 C) → 2NaI + CuI → (+1/2O 2 , 450 0 C) → 2NaI + CuO + 1/2I 2 , NaCuI 2 .4H 2 O → (-4H 2 O, Dried) → NaI + CuI. (auth.)

  11. Genetics of common forms of heart failure: challenges and potential solutions.

    Science.gov (United States)

    Rau, Christoph D; Lusis, Aldons J; Wang, Yibin

    2015-05-01

    In contrast to many other human diseases, the use of genome-wide association studies (GWAS) to identify genes for heart failure (HF) has had limited success. We will discuss the underlying challenges as well as potential new approaches to understanding the genetics of common forms of HF. Recent research using intermediate phenotypes, more detailed and quantitative stratification of HF symptoms, founder populations and novel animal models has begun to allow researchers to make headway toward explaining the genetics underlying HF using GWAS techniques. By expanding analyses of HF to improved clinical traits, additional HF classifications and innovative model systems, the intractability of human HF GWAS should be ameliorated significantly.

  12. Validation of HPLC, DPPH• and nitrosation methods for mesalamine determination in pharmaceutical dosage forms Validação dos métodos de CLAE, DPPH• e nitrosação para determinação de mesalazina em formas farmacêuticas

    Directory of Open Access Journals (Sweden)

    Janice Aparecida Rafael

    2007-03-01

    Full Text Available Mesalamine (5-aminosalicylic acid, 5-ASA is used because of its local effects in the treatment of inflammatory bowel disease. Therefore, the aims of this work were to compare and validate three analytical methods for the quality control of commercial coated tablets containing 5-ASA: high performance liquid chromatography (HPLC, 1,1-diphenyl-2-picrylhydrazyl radicals (DPPH• and nitrosation. The parameters linearity, precision and accuracy were studied in this work. HPLC with ultraviolet detection at 254 nm was carried out with a C18 column and a mobile phase constituted of 30 mmol/L monobasic phosphate buffer (pH 7.0 and methanol (70:30; v/v, with 25% tetrabutylammonium hydrogen sulphate. The DPPH• method was performed at 517 nm and using 100 mmol/L acetate buffer, pH 5.5, ethanol and 250 µmol/L ethanolic solution of DPPH•. The nitrosation method was accomplished by using a platinum electrode and standard 0.1 mol/L sodium nitrite as titrant solution. Repeatability (intra-day and intermediate precision (inter-day, expressed as RSD, were lower than 3%. The experimental recoveries were between 72.5 and 99.9%. Statistical analysis by one-way ANOVA, followed by the multiple comparison test of Bonferroni showed no significant difference among the three methods. All proposed methods can be used for the reliable quantitation of 5-ASA in pharmaceutical dosage forms.Mesalazina (ácido 5-aminosalicílico, 5-ASA é utilizado devido seu efeito local no tratamento de doença inflamatória intestinal. Assim, o objetivo deste trabalho foi comparar e validar três métodos analíticos para o controle de qualidade de comprimidos comerciais revestidos contendo 5-ASA: cromatografia líquida de alta eficiência (CLAE, radical 1,1-difenil-2-picril-hidrazil (DPPH• e nitrosação. Os parâmetros linearidade, precisão e exatidão foram estudados neste trabalho. CLAE com detecção ultravioleta em 254 nm foi realizada utilizando coluna C18 e a eluição em fase m

  13. Electrochemically formed passive layers on titanium - preparation and biocompatibility assessment in Hank's balanced salt solution

    International Nuclear Information System (INIS)

    Zhao, B.; Jerkiewicz, G.

    2006-01-01

    Uniform and crack-free passive layers on Ti are prepared using AC voltage in 7.5 wt.% aq. NH 4 ·BF 4 at 25 o C. The passive layers possess coloration (wide spectrum of colors) that depends on the experimental conditions. The biocompatibility of such prepared passive layers is evaluated using corrosion science and analytical techniques. Their corrosion behavior, Ti-ion release, surface roughness, and wettability in Hank's Balanced Salt Solution (HBSS) at 37 o C are the main focus of this work. Open-circuit potential and polarization measurements demonstrate that the corrosion potential (E corr ) of the passive layers becomes more positive than that of the untreated Ti. The value of E corr increases as we increase the AC voltage (VAC). Their corrosion rate (CR) is lower than that of the untreated Ti, and they reduced the Ti-ion release level from 230 to 15 ppb. An increase in the AC voltage frequency (f) leads to a slightly higher level of the Ti-ion release (∼50 ppb). Surface profilometry, optical microscopy, and scanning electron microscopy (SEM) analyses show that prolonged exposure of the passive layers to HBSS results in changes to their surface topography. The passive layers prepared by the application of AC voltage are rougher and more hydrophilic than the untreated Ti. Our methodology of preparing biocompatible passive layers on Ti might be applied as a new surface treatment procedure for Ti implants. (author)

  14. Optical constants of anodic aluminum oxide films formed in oxalic acid solution

    Energy Technology Data Exchange (ETDEWEB)

    Wang Jian [College of Physics and Electronic Engineering, Northwest Normal University, Lanzhou 730070 (China); Wang Chengwei [College of Physics and Electronic Engineering, Northwest Normal University, Lanzhou 730070 (China); State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China)], E-mail: cwwang@nwnu.edu.cn; Li Yan [College of Physics and Electronic Engineering, Northwest Normal University, Lanzhou 730070 (China); Liu Weimin [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China)

    2008-09-01

    The anodic aluminum oxide (AAO) films with highly ordered nanopore arrays were prepared in oxalic acid solution under different anodizing voltage and time, its surface and cross section appearances were characterized by using field emission scanning electron microscopy, the transmission spectra with the interference fringes were measured at normal incidence over the wavelength range 200 to 2500 nm. Then the modified Swanepoel method was used for the determination of the optical constants and thickness of the free standing AAO films. The results indicate that the refractive index increases with the increase of anodizing voltage and the decrease of anodizing time, which is mainly due to the content of Al{sub 2}O{sub 3} with octahedron increases in the AAO films. The dispersion of the refractive index is discussed in terms of the single-oscillator Wemple-DiDomenico model, and the energy dependence of the absorption coefficient can be described using the direct transition model proposed by Tauc. Likewise, the optical energy gap E{sub g} is derived from Tauc's extrapolation, and E{sub g} increases from 4.178 to 4.256 eV with the anodizing voltage, but is weakly dependent on anodizing time. All the results are self-consistent in the paper.

  15. A closed form solution for vulnerable options with Heston’s stochastic volatility

    International Nuclear Information System (INIS)

    Lee, Min-Ku; Yang, Sung-Jin; Kim, Jeong-Hoon

    2016-01-01

    Over-the-counter stock markets in the world have been growing rapidly and vulnerability to default risks of option holders traded in the over-the-counter markets became an important issue, in particular, since the global finance crisis and Eurozone crisis. This paper studies the pricing of European-type vulnerable options when the underlying asset follows the Heston dynamics. In this paper, we obtain a closed form analytic formula of the option price as a stochastic volatility extension of the classical Heston formula and find how the stochastic volatility effect on the Black–Scholes price as well as on the decreasing speed of the option price with credit risk depends on moneyness.

  16. Closed-form solution to directly design frequency modulated waveforms for beampatterns

    KAUST Repository

    Ahmed, Sajid

    2018-03-12

    The targets image performance depends on the transmit beampattern and power-spectral-density of the probing signal. To design such probing signals for multiple-input multiple output (MIMO) radar, conventional algorithms are iterative in nature, therefore high computational complexity restricts their use in real time applications. In this paper, to achieve the desired beampattern, a novel closed-form algorithm to design frequency-modulated (FM) waveforms for MIMO radar is proposed. The proposed algorithm has negligible computational complexity and yields unity peak-to-average power ratio constant envelope waveforms. Moreover, in contrast to the narrow band algorithms, it has almost flat main and side lobes. In the proposed algorithm, a relationship between the width of symmetric beampattern and the product of initial frequency and duration of the baseband FM waveforms is developed.

  17. Solution of Urban Problems by Forming an Environment for the Development of Innovative and Small Business

    Directory of Open Access Journals (Sweden)

    Anna Zhernoklieieva

    2017-07-01

    Full Text Available The article reveals the methods of solving the problems of the modern city by stimulating new forms of innovative small business and youth entrepreneurship, using Kharkov as an example. The formation of the start-up culture of Kharkov and the state of development of co-working zones are analyzed. It was determined that the construction of an effective public-private partnership of local authorities and new forms of entrepreneurship should be based on the possibility of creating co-working zones in the areas that are not used by the city, while stimulating the social responsibility of entrepreneurs through the provision of appropriate financing. Based on the results of a comparative analysis of the number and amount of incomes of freelancers in Kharkiv with the overall data for Ukraine, it is established that Kharkov freelancers are leaders both in terms of total and specific income. Based on the analysis of the dynamics of the revenues of the single social contribution paid by the entrepreneurs of Kharkiv, a conclusion is drawn that it is possible to achieve a sustainable growth in the filling of social insurance funds by increasing the number of freelancers. The peculiarities of the Start-up of the culture of Kharkov have been singled out, namely: the orientation towards a new product, the youth character of projects, understanding of the importance of implementing socially significant projects, the innovative nature of the activity, the priority of participants' self-expression over the financial component of projects, and cooperation with local authorities.

  18. Closed-form solution of a two-dimensional fuel temperature model for TRIGA-type reactors

    Energy Technology Data Exchange (ETDEWEB)

    Rivard, J B [Sandia Laboratories (United States)

    1974-07-01

    If azimuthal power density variations are ignored, the steady-state temperature distribution within a TRIGA-type fuel element is given by the solution of the Poisson equation in two dimensions (r and z) . This paper presents a closed-form solution of this equation as a function of the axial and radial power density profiles, the conductivity of the U-ZrH, the inlet temperature, specific heat and flow rate of the coolant, and the overall heat transfer coefficient. The method begins with the development of a system of linear ordinary differential equations describing mass and energy balances in the fuel and coolant. From the solution of this system, an expression for the second derivative of the fuel temperature distribution in the axial (z) direction is found. Substitution of this expression into the Poisson equation for T(r,z) reduces it from a partial differential equation to an ordinary differential equation in r, which is subsequently solved in closed-form. The results of typical calculations using the model are presented. (author)

  19. Deforming black hole and cosmological solutions by quasiperiodic and/or pattern forming structures in modified and Einstein gravity

    Science.gov (United States)

    Bubuianu, Laurenţiu; Vacaru, Sergiu I.

    2018-05-01

    We elaborate on the anholonomic frame deformation method, AFDM, for constructing exact solutions with quasiperiodic structure in modified gravity theories, MGTs, and general relativity, GR. Such solutions are described by generic off-diagonal metrics, nonlinear and linear connections and (effective) matter sources with coefficients depending on all spacetime coordinates via corresponding classes of generation and integration functions and (effective) matter sources. There are studied effective free energy functionals and nonlinear evolution equations for generating off-diagonal quasiperiodic deformations of black hole and/or homogeneous cosmological metrics. The physical data for such functionals are stated by different values of constants and prescribed symmetries for defining quasiperiodic structures at cosmological scales, or astrophysical objects in nontrivial gravitational backgrounds some similar forms as in condensed matter physics. It is shown how quasiperiodic structures determined by general nonlinear, or additive, functionals for generating functions and (effective) sources may transform black hole like configurations into cosmological metrics and inversely. We speculate on possible implications of quasiperiodic solutions in dark energy and dark matter physics. Finally, it is concluded that geometric methods for constructing exact solutions consist an important alternative tool to numerical relativity for investigating nonlinear effects in astrophysics and cosmology.

  20. Closed-form analytical solutions for assessing the consequences of sea-level rise on unconfined sloping island aquifers

    Science.gov (United States)

    Chesnaux, R.

    2016-04-01

    Closed-form analytical solutions for assessing the consequences of sea-level rise on fresh groundwater oceanic island lenses are provided for the cases of both strip and circular islands. Solutions are proposed for directly calculating the change in the thickness of the lens, the changes in volume and the changes in travel time of fresh groundwater within island aquifers. The solutions apply for homogenous aquifers recharged by surface infiltration and discharged by a down-gradient, fixed-head boundary. They also take into account the inland shift of the ocean due to land surface inundation, this shift being determined by the coastal slope of inland aquifers. The solutions are given for two simple island geometries: circular islands and strip islands. Base case examples are presented to illustrate, on one hand, the amplitude of the change of the fresh groundwater lens thickness and the volume depletion of the lens in oceanic island with sea-level rise, and on the other hand, the shortening of time required for groundwater to discharge into the ocean. These consequences can now be quantified and may help decision-makers to anticipate the effects of sea-level rise on fresh groundwater availability in oceanic island aquifers.

  1. The Artificial Hamiltonian, First Integrals, and Closed-Form Solutions of Dynamical Systems for Epidemics

    Science.gov (United States)

    Naz, Rehana; Naeem, Imran

    2018-03-01

    The non-standard Hamiltonian system, also referred to as a partial Hamiltonian system in the literature, of the form {\\dot q^i} = {partial H}/{partial {p_i}},\\dot p^i = - {partial H}/{partial {q_i}} + {Γ ^i}(t,{q^i},{p_i}) appears widely in economics, physics, mechanics, and other fields. The non-standard (partial) Hamiltonian systems arise from physical Hamiltonian structures as well as from artificial Hamiltonian structures. We introduce the term `artificial Hamiltonian' for the Hamiltonian of a model having no physical structure. We provide here explicitly the notion of an artificial Hamiltonian for dynamical systems of ordinary differential equations (ODEs). Also, we show that every system of second-order ODEs can be expressed as a non-standard (partial) Hamiltonian system of first-order ODEs by introducing an artificial Hamiltonian. This notion of an artificial Hamiltonian gives a new way to solve dynamical systems of first-order ODEs and systems of second-order ODEs that can be expressed as a non-standard (partial) Hamiltonian system by using the known techniques applicable to the non-standard Hamiltonian systems. We employ the proposed notion to solve dynamical systems of first-order ODEs arising in epidemics.

  2. Scavenging of Tc(V) formed by I.T. in 95mTcO4- solutions

    International Nuclear Information System (INIS)

    Ianoz, E.; Colin, M.; Kosinski, M.

    1988-01-01

    The chemical effects of the I.T. of 95m Tc in 95m TcO 4 - have been studied in chelating ligand solutions. At high pH and at high concentration of 1,4,8,11-tetraazacyclotetradecane and 1,4-dithia-8, 11-diazacyclotetradecane, the retention of 95g Tc is about 20% and the unretained 95g Tc appears preponderantly (ca. 73%) as [TcO 2 L] + complexes. In glucoheptonate solution, the 95g Tc retention remains practically the same (22%) but the unretained 95g Tc is found in high proportion (73%) as [TcObis(glucoheptonate)] - . The added ligands are very good scavengers for 95g Tc(V). A comparison is made between 95g Tc species formed by the I.T. in 95m TcO 4 - and 99m Tc species resulting from the chemical reduction of 99m TcO 4 - . (orig.)

  3. Chemical composition and electronic structure of the passive layer formed on stainless steels in a glucose-oxidase solution

    Energy Technology Data Exchange (ETDEWEB)

    Marconnet, C. [Laboratoire de Genie des Procedes et des Materiaux, Ecole Centrale Paris, Grande Voie des Vignes, 92290 CHATENAY-MALABRY (France)], E-mail: cyril.marconnet@yahoo.fr; Wouters, Y. [Science et Ingenierie des Materiaux et Procedes, Institut National Polytechnique de Grenoble, F-38402 Saint-Martin d' Heres Cedex (France); Miserque, F. [Laboratoire de Reactivite des Surfaces et des Interfaces, CEA Saclay, Bat. 391, 91191 GIF-SUR-YVETTE (France); Dagbert, C. [Laboratoire de Genie des Procedes et des Materiaux, Ecole Centrale Paris, Grande Voie des Vignes, 92290 CHATENAY-MALABRY (France)], E-mail: catherine.dagbert@ecp.fr; Petit, J.-P. [Laboratoire d' Electrochimie et de Physico-chimie des Materiaux et des Interfaces, INPG, F-38402 Saint-Martin d' Heres Cedex (France); Galerie, A. [Science et Ingenierie des Materiaux et Procedes, Institut National Polytechnique de Grenoble, F-38402 Saint-Martin d' Heres Cedex (France); Feron, D. [Service de Corrosion et du Comportement des Materiaux dans leur Environnement, CEA Saclay, Bat. 458, 91191 GIF-SUR-YVETTE (France)

    2008-12-01

    This article deals with the interaction between the passive layer formed on UNS S30403 and S31254 stainless steels and an enzymatic solution containing glucose oxidase (GOx) and its substrate D-glucose. This enzymatic solution is often used to reproduce in laboratory the ennoblement occuring in non-sterile aerated aqueous environments because of the biofilm settlement on the surface of the metallic material. GOx catalyses the oxidation of D-glucose to gluconic acid by reducing oxygen to hydrogen peroxide and produces an organic acid. Thanks to photocurrent measurements, XPS analysis and Mott-Schottky diagrams, it is here shown that such an environment generates modifications in the chemical composition and electronic structure of the passive layer: it induces a relative enrichment of the n-type semi-conducting phase containing chromium (chromine Cr{sub 2}O{sub 3}) and an increase of the donors density in the space charge region.

  4. Chemical composition and electronic structure of the passive layer formed on stainless steels in a glucose-oxidase solution

    International Nuclear Information System (INIS)

    Marconnet, C.; Wouters, Y.; Miserque, F.; Dagbert, C.; Petit, J.-P.; Galerie, A.; Feron, D.

    2008-01-01

    This article deals with the interaction between the passive layer formed on UNS S30403 and S31254 stainless steels and an enzymatic solution containing glucose oxidase (GOx) and its substrate D-glucose. This enzymatic solution is often used to reproduce in laboratory the ennoblement occuring in non-sterile aerated aqueous environments because of the biofilm settlement on the surface of the metallic material. GOx catalyses the oxidation of D-glucose to gluconic acid by reducing oxygen to hydrogen peroxide and produces an organic acid. Thanks to photocurrent measurements, XPS analysis and Mott-Schottky diagrams, it is here shown that such an environment generates modifications in the chemical composition and electronic structure of the passive layer: it induces a relative enrichment of the n-type semi-conducting phase containing chromium (chromine Cr 2 O 3 ) and an increase of the donors density in the space charge region

  5. 21 CFR 524.1484e - Neomycin sulfate and polymyxin B sulfate ophthalmic solution.

    Science.gov (United States)

    2010-04-01

    ... ophthalmic solution. 524.1484e Section 524.1484e Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS OPHTHALMIC AND TOPICAL DOSAGE FORM NEW ANIMAL DRUGS § 524.1484e Neomycin sulfate and polymyxin B sulfate ophthalmic solution. (a...

  6. Non-Gaussian Closed Form Solutions for Geometric Average Asian Options in the Framework of Non-Extensive Statistical Mechanics

    Directory of Open Access Journals (Sweden)

    Pan Zhao

    2018-01-01

    Full Text Available In this paper we consider pricing problems of the geometric average Asian options under a non-Gaussian model, in which the underlying stock price is driven by a process based on non-extensive statistical mechanics. The model can describe the peak and fat tail characteristics of returns. Thus, the description of underlying asset price and the pricing of options are more accurate. Moreover, using the martingale method, we obtain closed form solutions for geometric average Asian options. Furthermore, the numerical analysis shows that the model can avoid underestimating risks relative to the Black-Scholes model.

  7. Computationally simple, analytic, closed form solution of the Coulomb self-interaction problem in Kohn Sham density functional theory

    International Nuclear Information System (INIS)

    Gonis, Antonios; Daene, Markus W.; Nicholson, Don M.; Stocks, George Malcolm

    2012-01-01

    We have developed and tested in terms of atomic calculations an exact, analytic and computationally simple procedure for determining the functional derivative of the exchange energy with respect to the density in the implementation of the Kohn Sham formulation of density functional theory (KS-DFT), providing an analytic, closed-form solution of the self-interaction problem in KS-DFT. We demonstrate the efficacy of our method through ground-state calculations of the exchange potential and energy for atomic He and Be atoms, and comparisons with experiment and the results obtained within the optimized effective potential (OEP) method.

  8. Behavior of Paramecium sp. in solutions containing Sr and Pb: Do Paramecium sp. alter chemical forms of those metals?

    International Nuclear Information System (INIS)

    Kozai, Naofumi; Ohnuki, Toshihiko; Koka, Masahi; Satoh, Takahiro; Kamiya, Tomihiro

    2011-01-01

    The behavior of Paramecium sp. (Paramecium bursaria) in aqueous solutions containing Sr and Pb was investigated to determine the role of protozoa in the migration of radionuclides in the environment. Precultured living cells of P. bursaria were exposed to aqueous solutions containing 0.01 or 0.05 mM Sr or Pb at pH 7 for 24 h. For comparison, pre-killed cells were treated with the metal solutions in the same way. Two-dimensional elemental mappings of cells were obtained by micro-PIXE. Aquatic species of Sr and Pb were analyzed by size exclusion chromatography (SEC) coupled online to ultraviolet (UV) spectroscopy and inductivity coupled plasma mass spectroscopy (ICP-MS). The amounts of Sr adsorbed or taken up by the cells surviving for 24 h and adsorbed on pre-killed cells were below the detection limit. Cells of P. bursaria adsorbed or took up a fraction of Pb. The Pb adsorbed or taken up by the cells surviving for 24 h in the Pb solution was barely detectable, while the Pb adsorbed on pre-killed cells was clearly mappable. These findings suggest that living cells of P. bursaria have functions that reduce adsorption or uptake of Pb on the cells. Quantitative and SEC-UV-ICP-MS analyses of the Sr and Pb in aqueous phases showed no clear evidences that living cells of P. bursaria alter the chemical form of Sr or Pb remaining in the aqueous phases after the cell-solution contact.

  9. Behavior of Paramecium sp. in solutions containing Sr and Pb: Do Paramecium sp. alter chemical forms of those metals?

    Science.gov (United States)

    Kozai, Naofumi; Ohnuki, Toshihiko; Koka, Masahi; Satoh, Takahiro; Kamiya, Tomihiro

    2011-10-01

    The behavior of Paramecium sp. (Paramecium bursaria) in aqueous solutions containing Sr and Pb was investigated to determine the role of protozoa in the migration of radionuclides in the environment. Precultured living cells of P. bursaria were exposed to aqueous solutions containing 0.01 or 0.05 mM Sr or Pb at pH 7 for 24 h. For comparison, pre-killed cells were treated with the metal solutions in the same way. Two-dimensional elemental mappings of cells were obtained by micro-PIXE. Aquatic species of Sr and Pb were analyzed by size exclusion chromatography (SEC) coupled online to ultraviolet (UV) spectroscopy and inductivity coupled plasma mass spectroscopy (ICP-MS). The amounts of Sr adsorbed or taken up by the cells surviving for 24 h and adsorbed on pre-killed cells were below the detection limit. Cells of P. bursaria adsorbed or took up a fraction of Pb. The Pb adsorbed or taken up by the cells surviving for 24 h in the Pb solution was barely detectable, while the Pb adsorbed on pre-killed cells was clearly mappable. These findings suggest that living cells of P. bursaria have functions that reduce adsorption or uptake of Pb on the cells. Quantitative and SEC-UV-ICP-MS analyses of the Sr and Pb in aqueous phases showed no clear evidences that living cells of P. bursaria alter the chemical form of Sr or Pb remaining in the aqueous phases after the cell-solution contact.

  10. Behavior of Paramecium sp. in solutions containing Sr and Pb: Do Paramecium sp. alter chemical forms of those metals?

    Energy Technology Data Exchange (ETDEWEB)

    Kozai, Naofumi, E-mail: kozai.naofumi@jaea.go.jp [Advanced Sciences Research Center, Japan Atomic Energy Agency (JAEA), Tokai, Ibaraki 319-1195 (Japan); Ohnuki, Toshihiko [Advanced Sciences Research Center, Japan Atomic Energy Agency (JAEA), Tokai, Ibaraki 319-1195 (Japan); Koka, Masahi; Satoh, Takahiro; Kamiya, Tomihiro [Takasaki Advanced Radiation Research Institute, JAEA, 1233 Watanuki-machi, Takasaki, Gunma 370-1292 (Japan)

    2011-10-15

    The behavior of Paramecium sp. (Paramecium bursaria) in aqueous solutions containing Sr and Pb was investigated to determine the role of protozoa in the migration of radionuclides in the environment. Precultured living cells of P. bursaria were exposed to aqueous solutions containing 0.01 or 0.05 mM Sr or Pb at pH 7 for 24 h. For comparison, pre-killed cells were treated with the metal solutions in the same way. Two-dimensional elemental mappings of cells were obtained by micro-PIXE. Aquatic species of Sr and Pb were analyzed by size exclusion chromatography (SEC) coupled online to ultraviolet (UV) spectroscopy and inductivity coupled plasma mass spectroscopy (ICP-MS). The amounts of Sr adsorbed or taken up by the cells surviving for 24 h and adsorbed on pre-killed cells were below the detection limit. Cells of P. bursaria adsorbed or took up a fraction of Pb. The Pb adsorbed or taken up by the cells surviving for 24 h in the Pb solution was barely detectable, while the Pb adsorbed on pre-killed cells was clearly mappable. These findings suggest that living cells of P. bursaria have functions that reduce adsorption or uptake of Pb on the cells. Quantitative and SEC-UV-ICP-MS analyses of the Sr and Pb in aqueous phases showed no clear evidences that living cells of P. bursaria alter the chemical form of Sr or Pb remaining in the aqueous phases after the cell-solution contact.

  11. Characterization of film-forming solutions and films incorporating free and nanoencapsulated tea polyphenol prepared by gelatins with different Bloom values

    Science.gov (United States)

    Gelatin film-forming solutions and their films incorporating tea polyphenol (TP) and chitosan nanoparticles (CSNs) were prepared from gelatins with different Bloom values (100, 150 and 225). Blank gelatin film-forming solutions and films were prepared as controls. Gelatins with higher Bloom values h...

  12. Melatonin charge transfer complex with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone: Molecular structure, DFT studies, thermal analyses, evaluation of biological activity and utility for determination of melatonin in pure and dosage forms

    Science.gov (United States)

    Mohamed, Gehad G.; Hamed, Maher M.; Zaki, Nadia G.; Abdou, Mohamed M.; Mohamed, Marwa El-Badry; Abdallah, Abanoub Mosaad

    2017-07-01

    A simple, accurate and fast spectrophotometric method for the quantitative determination of melatonin (ML) drug in its pure and pharmaceutical forms was developed based on the formation of its charge transfer complex with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) as an electron acceptor. The different conditions for this method were optimized accurately. The Lambert-Beer's law was found to be valid over the concentration range of 4-100 μg mL- 1 ML. The solid form of the CT complex was structurally characterized by means of different spectral methods. Density functional theory (DFT) and time-dependent density functional theory (TD-DFT) calculations were carried out. The different quantum chemical parameters of the CT complex were calculated. Thermal properties of the CT complex and its kinetic thermodynamic parameters were studied, as well as its antimicrobial and antifungal activities were investigated. Molecular docking studies were performed to predict the binding modes of the CT complex components towards E. coli bacterial RNA and the receptor of breast cancer mutant oxidoreductase.

  13. Carbapenems and SHV-1 β-Lactamase Form Different Acyl-Enzyme Populations in Crystals and Solution

    Science.gov (United States)

    Kalp, Matthew; Carey, Paul R.

    2009-01-01

    The reactions between single crystals of the SHV-1 β-lactamase enzyme and the carbapenems, meropenem, imipenem and ertapenem, have been studied by Raman microscopy. Aided by quantum mechanical calculations, major populations of two acyl-enzyme species, a labile Δ2-pyrroline and a more tightly bound Δ1-pyrroline, have been identified for all three compounds. These isomers differ only in the position of the double bond about the carbapenem nucleus. This discovery is consonant with X-ray crystallographic findings that also identified two populations for meropenem bound in SHV-1: one with the acyl C=O group in the oxyanion hole and the second with the acyl group rotated 180 degrees compared to its expected position [Nukaga, M., Bethel, C. R., Thomson, J. M., Hujer, A. M., Distler, A. M., Anderson, V. E., Knox, J. R., and Bonomo, R. A. (2008) Journal of the American Chemical Society]. When crystals of the Δ1 and Δ2 containing acyl-enzymes were exposed to solutions with no carbapenem, rapid deacylation of the Δ2 species was observed by kinetic Raman experiments. However, no change in the Δ1 population was observed over 1 hour, the effective lifetime of the crystal. These observations lead to the hypothesis that the stable Δ1 species is due to the form seen by X-ray with the acyl carbonyl outside the oxyanion hole, while the Δ2 species corresponds to the form with the carbonyl inside the oxyanion hole. Soak-in and soak-out Raman experiments also demonstrated that tautomeric exchange between the Δ1 and Δ2 forms does not occur on the crystalline enzyme. When meropenem or ertapenem were reacted with SHV-1 in solution, the Raman difference spectra demonstrated that only a major population corresponding to the Δ1 acyl-enzyme could be detected. The 1003 cm-1 mode of the phenyl ring positioned on the C3 side chain of ertapenem acts as an effective internal Raman intensity standard and the ratio of its intensity to that of the 1600 cm-1 feature of Δ1 provides an

  14. Physicochemical characterization of in situ drug-polymer nanocomplex formed between zwitterionic drug and ionomeric material in aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Salamanca, Constain H., E-mail: chsalamanca@icesi.edu.co [Pharmaceutical physical chemistry laboratory, Department of Pharmacy, Faculty of Natural Sciences, ICESI University, Cali (Colombia); Castillo, Duvan F.; Villada, Juan D. [Pharmaceutical physical chemistry laboratory, Department of Pharmacy, Faculty of Natural Sciences, ICESI University, Cali (Colombia); Rivera, Gustavo R. [SIT Biotech GmbH, BMZ 2 Otto-Hahn-Str. 15, 44227 Dortmund (Germany)

    2017-03-01

    Biocompatible polymeric materials with the potential to form functional structures, in association with different therapeutic molecules, in physiological media, represent a great potential for biological and pharmaceutical applications. Therefore, here the formation of a nano-complex between a synthetic cationic polymer and model drug (ampicillin trihydrate) was studied. The formed complex was characterized by size and zeta potential measurements, using dynamic light scattering and capillary electrophoresis. Moreover, the chemical and thermodynamically stability of these complexes were studied. The ionomeric material, here referred as EuCl, was obtained by equimolar reaction between Eudragit E and HCl. The structural characterization was carried out by potentiometric titration, FTIR spectroscopy, and DSC. The effect of pH, time, polymer concentration and ampicillin/polymer molar ratio over the hydrodynamic diameter and zeta potential were established. The results show that EuCl ionomer in aqueous media presents two different populations of nanoparticles; one of this tends to form flocculated aggregates in high pH and concentrations, by acquiring different conformations in solution by changing from a compact to an extended conformation. Moreover, the formation of an in situ interfacial polymer-drug complex was demonstrated, this could slightly reduce the hydrolytic degradation of the drug while affecting its solubility, mainly under acidic conditions. - Highlights: • The EuCl ionomer in aqueous media presents two different populations of nanoparticle, corresponding to proximally 15 nm and 150 nm. • The EuCl ionomer in aqueous media may form different structure depending on the pH and polymer concentration, which tends to form flocculated aggregates in high pH and concentrations. • The formation of an in situ interfacial polymer-drug complex was demonstrated, which could slightly reduce the hydrolytic degradation of the drug and affecting its solubility in

  15. CFORM- LINEAR CONTROL SYSTEM DESIGN AND ANALYSIS: CLOSED FORM SOLUTION AND TRANSIENT RESPONSE OF THE LINEAR DIFFERENTIAL EQUATION

    Science.gov (United States)

    Jamison, J. W.

    1994-01-01

    CFORM was developed by the Kennedy Space Center Robotics Lab to assist in linear control system design and analysis using closed form and transient response mechanisms. The program computes the closed form solution and transient response of a linear (constant coefficient) differential equation. CFORM allows a choice of three input functions: the Unit Step (a unit change in displacement); the Ramp function (step velocity); and the Parabolic function (step acceleration). It is only accurate in cases where the differential equation has distinct roots, and does not handle the case for roots at the origin (s=0). Initial conditions must be zero. Differential equations may be input to CFORM in two forms - polynomial and product of factors. In some linear control analyses, it may be more appropriate to use a related program, Linear Control System Design and Analysis (KSC-11376), which uses root locus and frequency response methods. CFORM was written in VAX FORTRAN for a VAX 11/780 under VAX VMS 4.7. It has a central memory requirement of 30K. CFORM was developed in 1987.

  16. Hydraulic Modular Dosaging Systems for Machine Drives

    Directory of Open Access Journals (Sweden)

    A. J. Kotlobai

    2005-01-01

    Full Text Available The justified principle of making modular dosaging systems for positive-displacement multimotor hydraulic drives used in running gear and technological equipment of mobile construction, road and agricultural machines makes it possible to synchronize motion of running parts. The examples of the realization of modular dosaging systems and an algorithm of their operation are given in the paper.

  17. Nanoscale phase transition behavior of shape memory alloys — closed form solution of 1D effective modelling

    Science.gov (United States)

    Li, M. P.; Sun, Q. P.

    2018-01-01

    We investigate the roles of grain size (lg) and grain boundary thickness (lb) on the stress-induced phase transition (PT) behaviors of nanocrystalline shape memory alloys (SMAs) by using a Core-shell type "crystallite-amorphous composite" model. A non-dimensionalized length scale lbarg(=lg /lb) is identified as the governing parameter which is indicative of the energy competition between the crystallite and the grain boundary. Closed form analytical solutions of a reduced effective 1D model with embedded microstructure length scales of lg and lb are presented in this paper. It is shown that, with lbarg reduction, the energy of the elastic non-transformable grain boundary will gradually become dominant in the phase transition process, and eventually bring fundamental changes of the deformation behaviors: breakdown of two-phase coexistence and vanishing of superelastic hysteresis. The predictions are supported by experimental data of nanocrystalline NiTi SMAs.

  18. Toward quality assessment of 3D printed oral dosage forms

    DEFF Research Database (Denmark)

    Markl, Daniel; Zeitler, Axel; Rades, Thomas

    2017-01-01

    The additive manufacturing industry achieved a corporate annual growth rate of 25.9% according to the Forbes analysis of the Wohlers Report 2016. This high growth rate is placed in perspective when looking at the past 27 years where the corporate annual growth rate has averaged 26.2% each year in...... methods to assess the quality of the 3D printed geometries. This will be especially important for pharmaceutical products where a sub-standard quality of the final product can have detrimental consequences for patient health and safety....

  19. Development and clinical application of oral dosage forms of taxanes

    NARCIS (Netherlands)

    Moes, J.J.

    2013-01-01

    Cancer is still one of the leading causes of death in the Western World. Despite the development and introduction of new anti-cancer agents, docetaxel and paclitaxel remain the cornerstone of adjuvant and metastatic chemotherapy against solid tumors. Taxanes belong to the class of anti-mitotic

  20. Spectrophotometric Determination of Cilostazol in Tablet Dosage Form

    African Journals Online (AJOL)

    Erah

    Purpose: To develop simple, rapid and selective spectrophotometric methods for ... Conclusion: These validated methods may be useful for routine analysis of cilostazol ... Keywords: Cilostazol tablets, UV spectrophotometry, Linear regression ...

  1. Near infrared spectroscopy in the development of solid dosage forms.

    Science.gov (United States)

    Räsänen, Eetu; Sandler, Niklas

    2007-02-01

    The use of near infrared (NIR) spectroscopy has rapidly grown partly due to demands of process analytical applications in the pharmaceutical industry. Furthermore, newest regulatory guidelines have advanced the increase of the use of NIR technologies. The non-destructive and non-invasive nature of measurements makes NIR a powerful tool in characterization of pharmaceutical solids. These benefits among others often make NIR advantageous over traditional analytical methods. However, in addition to NIR, a wide variety of other tools are naturally also available for analysis in pharmaceutical development and manufacturing, and those can often be more suitable for a given application. The versatility and rapidness of NIR will ensure its contribution to increased process understanding, better process control and improved quality of drug products. This review concentrates on the use of NIR spectroscopy from a process research perspective and highlights recent applications in the field.

  2. Kinetic spectrophotometric determination of ethamsylate in dosage forms.

    Science.gov (United States)

    El-Enany, Nahed; Belal, Fathalla; Rizk, Mohamed

    2007-01-01

    A simple and sensitive kinetic method has been developed for the determination of ethamsylate (ESL) in its pharmaceutical preparations. The method is based upon oxidation of ESL with 3-methyl-2-benzothiazolinone hydrazone hydrochloride in presence of cerium (IV) ammonium sulfate at room temperature for 20 min. The absorbance of the reaction product is measured at 514 nm. The absorbance-concentration plot was rectilinear over the range of 4-30 microg/mL (r = 0.9999). The lower detection limit was 0.267 microl/mL (9.110 x 10(-6) M) and the lower quantitation limit was 0.808 microg/mL. The different experimental parameters affecting the development and stability of the reaction product were studied and optimized. The proposed method was applied to the determination of ESL in formulations, and the results obtained were in good agreement with those obtained using a reference method. The proposed method was also used for the in vitro detection of ESL in spiked human plasma at its therapeutic concentration level.

  3. Spectrophotometeric determination of metoprolol in tablet dosage form

    African Journals Online (AJOL)

    Metoprolol, a beta-1 selective adrenegic receptor blocker antihypertensive agent is fairly new in Nigeria. In view of the endemic faking and adulterating of drugs in Nigeria, a simple, quick, and accurate method was developed for its assay. Metoprolol was coupled with 4-chloro-7-nitrobenzo-2-oxa-1, 3 diazole (NBD-Cl) in ...

  4. Emergence of 3D Printed Dosage Forms: Opportunities and Challenges

    OpenAIRE

    Albed Alhnan, Mohamed; Okwuosa, Tochukwu; Sadia, Muzna; Wan, Ka-Wai; Ahmed, Waqar; Arafat, Basel

    2016-01-01

    The recent introduction of the first FDA approved 3D-printed drug has fuelled interest in 3D printing technology, which is set to revolutionize healthcare. Since its initial use, this rapid prototyping (RP) technology has evolved to such as extent that it is currently being used in a wide range of applications including in tissue engineering, dentistry, construction, automotive and aerospace. However, in the pharmaceutical industry this technology is still in its infancy and its potential yet...

  5. The rationale of scored tablets as dosage form.

    NARCIS (Netherlands)

    Rodenhuis, N.; Smet, P.A.G.M. de; Barends, D.M.

    2004-01-01

    The aim of the study was to get insight into the rationale of scored tablets. This was pursued by studying patient's reasons for subdividing ("breaking") scored and unscored tablets. Patients who picked up their prescriptions in 5 community pharmacies in The Netherlands were questioned. Two-hundred

  6. quality evaluation of paracetamol in the bulk, dosage forms

    African Journals Online (AJOL)

    Prince Acheampong

    assay of paracetamol-codeine combination drug as well as estimation of the amount of ... post-market is very essential in the policy and technical guidelines of drug regulatory authorities such as the Food and Drugs Board. ... Pharmaceutical industries may also have simple analytical procedures for both in-process and.

  7. Microbial quality of some herbal solid dosage forms | Enayatifard ...

    African Journals Online (AJOL)

    Herbal remedies are widely used for the treatment and prevention of various diseases and often contain highly active pharmacological compounds. These products have the potential of contamination with different microorganisms. This is due to raw materials contamination and unhygienic production conditions.

  8. 77 FR 15961 - Oral Dosage Form New Animal Drugs; Phenylpropanolamine

    Science.gov (United States)

    2012-03-19

    ... Laboratories, Inc. The NADA provides for the veterinary prescription use of phenylpropanolamine hydrochloride... Veterinary Medicine (HFV-116), Food and Drug Administration, 7500 Standish Pl., Rockville, MD 20855, 240-276... Ely Rd., Pensacola, FL 32514, filed NADA 141-324 that provides for the veterinary prescription use of...

  9. Reflection on Solutions in the Form of Refutation Texts versus Problem Solving: The Case of 8th Graders Studying Simple Electric Circuits

    Science.gov (United States)

    Safadi, Rafi; Safadi, Ekhlass; Meidav, Meir

    2017-01-01

    This study compared students' learning in troubleshooting and problem solving activities. The troubleshooting activities provided students with solutions to conceptual problems in the form of refutation texts; namely, solutions that portray common misconceptions, refute them, and then present the accepted scientific ideas. They required students…

  10. Dosage of trace carbon in sodium (1963)

    International Nuclear Information System (INIS)

    Sannier, J.; Vasseur, A.

    1963-01-01

    A wet method for dosing carbon in sodium has been developed. The carbon is oxidised in a vacuum using Van SLYKE'S solution. The carbonic acid formed is measured volumetrically; its purity can be controlled by chromatographic analysis. The results obtained show that this method makes it possible to measure carbon in concentrations of about 10 ppm. (authors) [fr

  11. Characterization of phosphorus forms in lake macrophytes and algae by solution (31)P nuclear magnetic resonance spectroscopy.

    Science.gov (United States)

    Feng, Weiying; Zhu, Yuanrong; Wu, Fengchang; Meng, Wei; Giesy, John P; He, Zhongqi; Song, Lirong; Fan, Mingle

    2016-04-01

    Debris from aquatic macrophytes and algae are important recycling sources of phosphorus (P), which can result in continuing blooms of algae by recycling bioavailable P in the eutrophic lakes. However, knowledge of forms of P in aquatic macrophytes and algae and their contribution to internal loads of P in lakes is limited. Without such knowledge, it is difficult to develop appropriate strategies to remediate and or restore aquatic ecosystems that have become eutrophic. Therefore, in this work, P was extracted from six types of aquatic macrophytes and algae collected from Tai Lake of China and characterized by use of solution (31)P-nuclear magnetic resonance (NMR) spectroscopy. When extracted by 0.5 M NaOH-25 mM EDTA, extraction recovery of total P(TP) and organic P(Po) exceeded 90 %. Concentrations of Po in algae and aquatic macrophytes were 5552 mg kg(-1) and 1005 mg kg(-1) and accounted for 56.0 and 47.2 % of TP, respectively. When Po, including condensed P, was characterized by solution (31)P-NMR Po in algae included orthophosphate monoesters (79.8 %), pyrophosphate (18.2 %), and orthophosphate diester (2.0 %), and Po in aquatic macrophytes included orthophosphate monoesters (90.3 %), pyrophosphate (4.2 %), and orthophosphate diester (5.5 %). Additionally, orthophosphate monoesters in algal debris mainly included β-glycerophosphate (44.1 %), α-glycerophosphate (13.5 %), and glucose 6-phosphate (13.5 %). Orthophosphate monoesters in aquatic macrophytes mainly included β-glycerophosphate (27.9 %), α-glycerophosphate (24.6 %), and adenosine 5' monophosphate (8.2 %). Results derived from this study will be useful in better understanding nutrient cycling, relevant eutrophication processes, and pollution control for freshwater lakes.

  12. Structural analysis of salt cavities formed by solution mining: I. Method of analysis and preliminary results for spherical cavities

    International Nuclear Information System (INIS)

    Fossum, A.F.

    1976-01-01

    The primary objective of this effort is an analysis of the structural stability of cavities formed by solution mining in salt domes. In particular, the effects of depth (i.e. initial state of in situ stress), shape, volume (i.e. physical dimensions of the cavity), and sequence of salt excavation/fluid evacuation on the timewise structural stability of a cavity are of interest. It is anticipated that an assessment can be made of the interrelation between depth, cavern size, and cavern shape or of the practical limits therewith. In general, the cavity shape is assumed to be axisymmetric and the salt is assumed to exhibit nonlinear creep behavior. The primary emphasis is placed on the methodology of the finite element analysis, and the results of preliminary calculations for a spherically shaped cavity. It is common practice for engineers to apply elasticity theory to the behavior of rock in order to obtain near field stresses and displacements around an underground excavation in an effort to assess structural stability. Rock masses, particularly at depth, may be subjected to a rather complex state of initial stress, and may be nonhomogeneous and anisotropic. If one also includes complex geometrical excavation shape, the use of analytical techniques as an analysis tool is practically impossible. Thus, it is almost a necessity that approximate solution techniques be employed. In this regard, the finite element method is ideal as it can handle complex geometries and nonlinear material behavior with relative ease. An unusual feature of the present study is the incorporation into the finite element code of a procedure for handling the gradual creation or excavation of an underground cavity. During the excavation sequence, the salt is permitted to exhibit nonlinear stress-strain-time dependence. The bulk of this report will be devoted to a description of the analysis procedures, together with a preliminary calculation for a spherically shaped cavity

  13. Acemetacin cocrystals and salts: structure solution from powder X-ray data and form selection of the piperazine salt

    Directory of Open Access Journals (Sweden)

    Palash Sanphui

    2014-03-01

    Full Text Available Acemetacin (ACM is a non-steroidal anti-inflammatory drug (NSAID, which causes reduced gastric damage compared with indomethacin. However, acemetacin has a tendency to form a less soluble hydrate in the aqueous medium. We noted difficulties in the preparation of cocrystals and salts of acemetacin by mechanochemical methods, because this drug tends to form a hydrate during any kind of solution-based processing. With the objective to discover a solid form of acemetacin that is stable in the aqueous medium, binary adducts were prepared by the melt method to avoid hydration. The coformers/salt formers reported are pyridine carboxamides [nicotinamide (NAM, isonicotinamide (INA, and picolinamide (PAM], caprolactam (CPR, p-aminobenzoic acid (PABA, and piperazine (PPZ. The structures of an ACM–INA cocrystal and a binary adduct ACM–PABA were solved using single-crystal X-ray diffraction. Other ACM cocrystals, ACM–PAM and ACM–CPR, and the piperazine salt ACM–PPZ were solved from high-resolution powder X-ray diffraction data. The ACM–INA cocrystal is sustained by the acid...pyridine heterosynthon and N—H...O catemer hydrogen bonds involving the amide group. The acid...amide heterosynthon is present in the ACM–PAM cocrystal, while ACM–CPR contains carboxamide dimers of caprolactam along with acid–carbonyl (ACM hydrogen bonds. The cocrystals ACM–INA, ACM–PAM and ACM–CPR are three-dimensional isostructural. The carboxyl...carboxyl synthon in ACM–PABA posed difficulty in assigning the position of the H atom, which may indicate proton disorder. In terms of stability, the salts were found to be relatively stable in pH 7 buffer medium over 24 h, but the cocrystals dissociated to give ACM hydrate during the same time period. The ACM–PPZ salt and ACM–nicotinamide cocrystal dissolve five times faster than the stable hydrate form, whereas the ACM–PABA adduct has 2.5 times faster dissolution rate. The pharmaceutically acceptable

  14. Acemetacin cocrystals and salts: structure solution from powder X-ray data and form selection of the piperazine salt.

    Science.gov (United States)

    Sanphui, Palash; Bolla, Geetha; Nangia, Ashwini; Chernyshev, Vladimir

    2014-03-01

    Acemetacin (ACM) is a non-steroidal anti-inflammatory drug (NSAID), which causes reduced gastric damage compared with indomethacin. However, acemetacin has a tendency to form a less soluble hydrate in the aqueous medium. We noted difficulties in the preparation of cocrystals and salts of acemetacin by mechanochemical methods, because this drug tends to form a hydrate during any kind of solution-based processing. With the objective to discover a solid form of acemetacin that is stable in the aqueous medium, binary adducts were prepared by the melt method to avoid hydration. The coformers/salt formers reported are pyridine carboxamides [nicotinamide (NAM), isonicotinamide (INA), and picolinamide (PAM)], caprolactam (CPR), p-aminobenzoic acid (PABA), and piperazine (PPZ). The structures of an ACM-INA cocrystal and a binary adduct ACM-PABA were solved using single-crystal X-ray diffraction. Other ACM cocrystals, ACM-PAM and ACM-CPR, and the piperazine salt ACM-PPZ were solved from high-resolution powder X-ray diffraction data. The ACM-INA cocrystal is sustained by the acid⋯pyridine heterosynthon and N-H⋯O catemer hydrogen bonds involving the amide group. The acid⋯amide heterosynthon is present in the ACM-PAM cocrystal, while ACM-CPR contains carboxamide dimers of caprolactam along with acid-carbonyl (ACM) hydrogen bonds. The cocrystals ACM-INA, ACM-PAM and ACM-CPR are three-dimensional isostructural. The carboxyl⋯carboxyl synthon in ACM-PABA posed difficulty in assigning the position of the H atom, which may indicate proton disorder. In terms of stability, the salts were found to be relatively stable in pH 7 buffer medium over 24 h, but the cocrystals dissociated to give ACM hydrate during the same time period. The ACM-PPZ salt and ACM-nicotinamide cocrystal dissolve five times faster than the stable hydrate form, whereas the ACM-PABA adduct has 2.5 times faster dissolution rate. The pharmaceutically acceptable piperazine salt of acemetacin exhibits superior

  15. Adsorption of Cr (III from aqueous solution by two forms of a superabsorbant polymer : parametric study and effect of activation mode

    Directory of Open Access Journals (Sweden)

    Ouass A.

    2018-01-01

    Full Text Available The adsorption of chromium ions Cr3+ using two forms of a superabsorbant polymer PANa from aqueous solution was investigated. On one hand the equilibrium pH with the distilled water and the pH of point of zero charge have been studied in order to characterize the acid-base behavior of both of PANa forms. On the other hand, the effect of contact time between PANa and the metallic solution and stirring speed of aqueous solution on the adsorption rate were established to highlight the importance of PANa as an efficient adsorbent of chromium ions Cr3+.

  16. Effects of EDTA on the electronic properties of passive film formed on Fe-20Cr in pH 8.5 buffer solution

    International Nuclear Information System (INIS)

    Cho, Eun Ae; Kwon, Hyuk Sang; Beranrd, Frederic

    2003-01-01

    The electronic properties of the passive film formed on Fe-20Cr ferritic stainless steel in pH 8.5 buffer solution containing 0.05 M EDTA (ethylene diammine tetraacetic acid) were examined by the photocurrent measurements and Mott-Schottky analysis for the film. XPS depth profile for the film demonstrated that Cr content in the outermost layer of the passive film was higher in the solution with EDTA than that in the solution without EDTA, due to selective dissolution of Fe by EDTA. In the solution with EDTA, the passive film showed characteristics of an amorphous or highly disordered n-type semiconductor. The band gap energies of the passive film are estimated to be ∼ 3.0 eV, irrespective of film formation potential from 0 to 700 mV SCE and of presence of EDTA. However, the donor density of the passive film formed in the solution with EDTA is much higher than that formed in the solution without EDTA, due to an increase in oxygen vacancy resulted from the dissolution of Fe-oxide in the outermost layer of the passive film. These results support the proposed model that the passive film formed on Fe-20Cr in pH 8.5 buffer solution mainly consists of Cr-substituted γ-Fe 2 O 3

  17. A closed-form solution for moving source localization using LBI changing rate of phase difference only

    Directory of Open Access Journals (Sweden)

    Zhang Min

    2014-04-01

    Full Text Available Due to the deficiencies in the conventional multiple-receiver localization systems based on direction of arrival (DOA such as system complexity of interferometer or array and amplitude/phase unbalance between multiple receiving channels and constraint on antenna configuration, a new radiated source localization method using the changing rate of phase difference (CRPD measured by a long baseline interferometer (LBI only is studied. To solve the strictly nonlinear problem, a two-stage closed-form solution is proposed. In the first stage, the DOA and its changing rate are estimated from the CRPD of each observer by the pseudolinear least square (PLS method, and then in the second stage, the source position and velocity are found by another PLS minimization. The bias of the algorithm caused by the correlation between the measurement matrix and the noise in the second stage is analyzed. To reduce this bias, an instrumental variable (IV method is derived. A weighted IV estimator is given in order to reduce the estimation variance. The proposed method does not need any initial guess and the computation is small. The Cramer–Rao lower bound (CRLB and mean square error (MSE are also analyzed. Simulation results show that the proposed method can be close to the CRLB with moderate Gaussian measurement noise.

  18. Forms and Lability of Phosphorus in Algae and Aquatic Macrophytes Characterized by Solution 31P NMR Coupled with Enzymatic Hydrolysis

    Science.gov (United States)

    Feng, Weiying; Zhu, Yuanrong; Wu, Fengchang; He, Zhongqi; Zhang, Chen; Giesy, John P.

    2016-11-01

    Solution Phosphorus-31 nuclear magnetic resonance (31P NMR) spectroscopy coupled with enzymatic hydrolysis (EH) with commercially available phosphatases was used to characterize phosphorus (P) compounds in extracts of the dominant aquatic macrophytes and algae in a eutrophic lake. Total extractable organic P (Po) concentrations ranged from 504 to 1643 mg kg-1 and 2318 to 8395 mg kg-1 for aquatic macrophytes and algae, respectively. Using 31P NMR spectroscopy, 11 Po species were detected in the mono- and diester region. Additionally, orthophosphate, pyrophosphate and phosphonates were also detected. Using EH, phytate-like P was identified as the prevalent class of enzyme-labile Po, followed by labile monoester- and diester-P. Comparison of the NMR and EH data indicated that the distribution pattern of major P forms in the samples determined by the two methods was similar (r = 0.712, p < 0.05). Additional 31P NMR spectroscopic analysis of extracts following EH showed significant decreases in the monoester and pyrophosphate regions, with a corresponding increase in the orthophosphate signal, as compared to unhydrolyzed extracts. Based on these quantity and hydrolysis data, we proposed that recycling of Po in vegetative biomass residues is an important mechanism for long-term self-regulation of available P for algal blooming in eutrophic lakes.

  19. Structural properties of films and rheology of film-forming solutions of chitosan gallate for food packaging.

    Science.gov (United States)

    Wu, Chunhua; Tian, Jinhu; Li, Shan; Wu, Tiantian; Hu, Yaqin; Chen, Shiguo; Sugawara, Tatsuya; Ye, Xingqian

    2016-08-01

    The chitosan gallates (CG) were obtained by free-radical-initiated grafting of gallic acid (GA) onto chitosan (CS) in this work. The chemical structures of the CG were corroborated by UV-vis, GPC and (1)H NMR analysis. The grafting reaction was accompanied with a degradation of the CS molecule. The shear-thinning flow behavior of CG film-forming solutions (CG FFS) decreased with the grafting amount of GA into CS chain, while the CG FFS grafted at a lower GA value behaved like a networks containing entangled or cross-linked polymer chains with a more elastic behavior. The increasing of GA grafting onto the CS chain led to a reduction of tensile strength, elongation at break and water resistance in the corresponding films, but increases in the antioxidant and antimicrobial activities were observed. The microstructure of the film was investigated using scanning electron and atomic force microscope, and the results were closely related to the observed film properties. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Efficient removal of perfluorooctane sulfonate from aqueous film-forming foam solution by aeration-foam collection.

    Science.gov (United States)

    Meng, Pingping; Deng, Shubo; Maimaiti, Ayiguli; Wang, Bin; Huang, Jun; Wang, Yujue; Cousins, Ian T; Yu, Gang

    2018-07-01

    Aqueous film-forming foams (AFFFs) used in fire-fighting are one of the main contamination sources of perfluorooctane sulfonate (PFOS) to the subterranean environment, requiring high costs for remediation. In this study, a method that combined aeration and foam collection was presented to remove PFOS from a commercially available AFFF solution. The method utilized the strong surfactant properties of PFOS that cause it to be highly enriched at air-water interfaces. With an aeration flow rate of 75 mL/min, PFOS removal percent reached 96% after 2 h, and the PFOS concentration in the collected foam was up to 6.5 mmol/L, beneficial for PFOS recovery and reuse. Increasing the aeration flow rate, ionic strength and concentration of co-existing surfactant, as well as decreasing the initial PFOS concentration, increased the removal percents of PFOS by increasing the foam volume, but reduced the enrichment of PFOS in the foams. With the assistance of a co-existing hydrocarbon surfactant, PFOS removal percent was above 99.9% after aeration-foam collection for 2 h and the enrichment factor exceeded 8400. Aeration-foam collection was less effective for short-chain perfluoroalkyl substances due to their relatively lower surface activity. Aeration-foam collection was found to be effective for the removal of high concentrations of PFOS from AFFF-contaminated wastewater, and the concentrated PFOS in the collected foam can be reused. Copyright © 2018 Elsevier Ltd. All rights reserved.

  1. Positive solution of non-square fully Fuzzy linear system of equation in general form using least square method

    Directory of Open Access Journals (Sweden)

    Reza Ezzati

    2014-08-01

    Full Text Available In this paper, we propose the least square method for computing the positive solution of a non-square fully fuzzy linear system. To this end, we use Kaffman' arithmetic operations on fuzzy numbers \\cite{17}. Here, considered existence of exact solution using pseudoinverse, if they are not satisfy in positive solution condition, we will compute fuzzy vector core and then we will obtain right and left spreads of positive fuzzy vector by introducing constrained least squares problem. Using our proposed method, non-square fully fuzzy linear system of equations always has a solution. Finally, we illustrate the efficiency of proposed method by solving some numerical examples.

  2. Painleve Analysis and Determinant Solutions of a (3+1)-Dimensional Variable-Coefficient Kadomtsev-Petviashvili Equation in Wronskian and Grammian Form

    International Nuclear Information System (INIS)

    Meng Xianghua; Tian Bo; Yao Zhenzhi; Feng Qian; Gao Yitian

    2009-01-01

    In this paper, the investigation is focused on a (3+1)-dimensional variable-coefficient Kadomtsev-Petviashvili (vcKP) equation, which can describe the realistic nonlinear phenomena in the fluid dynamics and plasma in three spatial dimensions. In order to study the integrability property of such an equation, the Painleve analysis is performed on it. And then, based on the truncated Painleve expansion, the bilinear form of the (3+1)-dimensional vcKP equation is obtained under certain coefficients constraint, and its solution in the Wronskian determinant form is constructed and verified by virtue of the Wronskian technique. Besides the Wronskian determinant solution, it is shown that the (3+1)-dimensional vcKP equation also possesses a solution in the form of the Grammian determinant. (general)

  3. Semianalytical Solution for the Deformation of an Elastic Layer under an Axisymmetrically Distributed Power-Form Load: Application to Fluid-Jet-Induced Indentation of Biological Soft Tissues.

    Science.gov (United States)

    Lu, Minhua; Huang, Shuai; Yang, Xianglong; Yang, Lei; Mao, Rui

    2017-01-01

    Fluid-jet-based indentation is used as a noncontact excitation technique by systems measuring the mechanical properties of soft tissues. However, the application of these devices has been hindered by the lack of theoretical solutions. This study developed a mathematical model for testing the indentation induced by a fluid jet and determined a semianalytical solution. The soft tissue was modeled as an elastic layer bonded to a rigid base. The pressure of the fluid jet impinging on the soft tissue was assumed to have a power-form function. The semianalytical solution was verified in detail using finite-element modeling, with excellent agreement being achieved. The effects of several parameters on the solution behaviors are reported, and a method for applying the solution to determine the mechanical properties of soft tissues is suggested.

  4. Effect of Nitrogen Form and pH of Nutrient Solution on the Shoot Concentration of Phosphorus, Nitrate, and Nitrogen of Spinach in Hydroponic Culture

    OpenAIRE

    N. Najafi; M. Parsazadeh

    2010-01-01

    In order to study the effect of nitrogen form and pH of nutrient solution on the shoot concentration of P, nitrate, organic N + inorganic ammonium, and total N of spinach, a factorial experiment was conducted with two factors including pH of nutrient solution in three levels (4.5, 6.5 and 8.0) and nitrate to ammonium ratio of nutrient solution in five levels (100:0, 75:25, 50:50, 25:75 and 0:100). This factorial experiment was carried out in a completely randomized design with four replicatio...

  5. ENROBAGES POLYMERIQUES DE FORMES SOLIDES: CARACTERISATION ET OPTIMISATION

    OpenAIRE

    Muschert , Susanne

    2008-01-01

    Aqueous polymer dispersions are commonly used in the pharmaceutical industry to coat oral dosage forms and to allow for controlled drug delivery. They offer major advantages compared to organic polymer solutions, such as reduced environmental concerns and toxicity risks. However, care must be taken that the films are stable during long term storage and that decreasing drug release rates due to further polymer particle coalescence are avoided. The idea of this work was to add an appropriate se...

  6. beta. -Amyloid gene dosage in Alzheimer's disease

    Energy Technology Data Exchange (ETDEWEB)

    Murdoch, G H; Manuelidis, L; Kim, J H; Manuelidis, E E

    1988-01-11

    The 4-5 kd amyloid ..beta..-peptide is a major constituent of the characteristic amyloid plaque of Alzheimer's disease. It has been reported that some cases of sporatic Alzheimer's disease are associated with at least a partial duplication of chromosome 21 containing the gene corresponding to the 695 residue precursor of this peptide. To contribute to an understanding of the frequency to such a duplication event in the overall Alzheimer's population, the authors have determined the gene dosage of the ..beta..-amyloid gene in this collection of cases. All cases had a clinical diagnosis of Alzheimer's confirmed neuropathologically. Each Alzheimer's case had an apparent normal diploid ..beta..-amyloid gene dosage, while control Down's cases had the expected triploid dosage. Thus partial duplication of chromosome 21 may be a rare finding in Alzheimer's disease. Similar conclusions were just reported in several studies of the Harvard Alzheimer collection.

  7. Low-temperature metal-oxide thin-film transistors formed by directly photopatternable and combustible solution synthesis.

    Science.gov (United States)

    Rim, You Seung; Lim, Hyun Soo; Kim, Hyun Jae

    2013-05-01

    We investigated the formation of ultraviolet (UV)-assisted directly patternable solution-processed oxide semiconductor films and successfully fabricated thin-film transistors (TFTs) based on these films. An InGaZnO (IGZO) solution that was modified chemically with benzoylacetone (BzAc), whose chelate rings decomposed via a π-π* transition as result of UV irradiation, was used for the direct patterning. A TFT was fabricated using the directly patterned IGZO film, and it had better electrical characteristics than those of conventional photoresist (PR)-patterned TFTs. In addition, the nitric acid (HNO3) and acetylacetone (AcAc) modified In2O3 (NAc-In2O3) solution exhibited both strong UV absorption and high exothermic reaction. This method not only resulted in the formation of a low-energy path because of the combustion of the chemically modified metal-oxide solution but also allowed for photoreaction-induced direct patterning at low temperatures.

  8. Pharmacokinetics and Bioavailability of the GnRH Analogs in the Form of Solution and Zn2+-Suspension After Single Subcutaneous Injection in Female Rats.

    Science.gov (United States)

    Suszka-Świtek, Aleksandra; Ryszka, Florian; Dolińska, Barbara; Dec, Renata; Danch, Alojzy; Filipczyk, Łukasz; Wiaderkiewicz, Ryszard

    2017-04-01

    Although many synthetic gonadoliberin analogs have been developed, only a few of them, including buserelin, were introduced into clinical practice. Dalarelin, which differs from buserelin by just one aminoacid in the position 6 (D-Ala), is not widely used so far. Gonadotropin-releasing hormone (GnRH) analogs are used to treat many different illnesses and are available in different forms like solution for injection, nasal spray, microspheres, etc. Unfortunately, none of the above drug formulations can release the hormones for 24 h. We assumed that classical suspension could solve this problem. Two sets of experiments were performed. In the first one, buserelin and dalarelin were injected into mature female rats in two forms: suspension, in which the analogs are bounded by Zn 2+ ions and solution. The pharmacokinetic parameters and bioavailability of the analogs were calculated, based on their concentration in the plasma measured by high-performance liquid chromatography method (HPLC). In the second experiment, the hormones in two different forms were injected into superovulated immature female rats and then the concentration of Luteinizing hormone (LH), Follicle-stimulating hormone (FSH) and 17β-estradiol in the serum was measured by radioimmunological method. The Extent of Biological Availability (EBA), calculated on the base of AUC 0-∞ , showed that in the form of solution buserelin and dalarelin display, respectively, only 13 and 8 % of biological availability of their suspension counterparts. Comparing both analogs, the EBA of dalarelin was half (53 %) that of buserelin delivered in the form of solution and 83 % when they were delivered in the form of suspension. The injection of buserelin or dalarelin, in the form of solution or suspension, into superovulated female rats increased LH, FSH and estradiol concentration in the serum. However, after injection of the analogs in the form of suspension, the high concentration of LH and FSH in the serum persisted

  9. Intelligent system for improving dosage control

    Directory of Open Access Journals (Sweden)

    Fabio Cosme Rodrigues dos Santos

    2017-02-01

    Full Text Available Coagulation is one of the most important processes in a drinking-water treatment plant, and it is applied to destabilize impurities in water for the subsequent flocculation stage. Several techniques are currently used in the water industry to determine the best dosage of the coagulant, such as the jar-test method, zeta potential measurements, artificial intelligence methods, comprising neural networks, fuzzy and expert systems, and the combination of the above-mentioned techniques to help operators and engineers in the water treatment process. Current paper presents an artificial neural network approach to evaluate optimum coagulant dosage for various scenarios in raw water quality, using parameters such as raw water color, raw water turbidity, clarified and filtered water turbidity and a calculated Dose Rate to provide the best performance in the filtration process. Another feature in current approach is the use of a backpropagation neural network method to estimate the best coagulant dosage simultaneously at two points of the water treatment plant. Simulation results were compared to the current dosage rate and showed that the proposed system may reduce costs of raw material in water treatment plant.

  10. A brief history of dosage compensation

    Indian Academy of Sciences (India)

    depression of X-linked gene activity in the female, as well as by hyperexpression of the ... to the Harvey lecture, Muller had presented important ideas relative to dosage ... at Columbia. I do recall a talk by the popular physical anthro- pologist ...

  11. Global smooth solutions of 3-D null-form wave equations in exterior domains with Neumann boundary conditions

    Science.gov (United States)

    Jun, Li; Huicheng, Yin

    2018-05-01

    The paper is devoted to investigating long time behavior of smooth small data solutions to 3-D quasilinear wave equations outside of compact convex obstacles with Neumann boundary conditions. Concretely speaking, when the surface of a 3-D compact convex obstacle is smooth and the quasilinear wave equation fulfills the null condition, we prove that the smooth small data solution exists globally provided that the Neumann boundary condition on the exterior domain is given. One of the main ingredients in the current paper is the establishment of local energy decay estimates of the solution itself. As an application of the main result, the global stability to 3-D static compressible Chaplygin gases in exterior domain is shown under the initial irrotational perturbation with small amplitude.

  12. A Closed-Form Solution for Robust Portfolio Selection with Worst-Case CVaR Risk Measure

    Directory of Open Access Journals (Sweden)

    Le Tang

    2014-01-01

    Full Text Available With the uncertainty probability distribution, we establish the worst-case CVaR (WCCVaR risk measure and discuss a robust portfolio selection problem with WCCVaR constraint. The explicit solution, instead of numerical solution, is found and two-fund separation is proved. The comparison of efficient frontier with mean-variance model is discussed and finally we give numerical comparison with VaR model and equally weighted strategy. The numerical findings indicate that the proposed WCCVaR model has relatively smaller risk and greater return and relatively higher accumulative wealth than VaR model and equally weighted strategy.

  13. A closed-form solution for the two-dimensional transport equation by the LTS{sub N} nodal method in the energy range of Compton effect

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, B.D.A., E-mail: barbararodriguez@furg.b [Universidade Federal do Rio Grande, Instituto de Matematica, Estatistica e Fisica, Rio Grande, RS (Brazil); Vilhena, M.T., E-mail: vilhena@mat.ufrgs.b [Universidade Federal do Rio Grande do Sul, Departamento de Matematica Pura e Aplicada, Porto Alegre, RS (Brazil); Hoff, G., E-mail: hoff@pucrs.b [Pontificia Universidade Catolica do Rio Grande do Sul, Faculdade de Fisica, Porto Alegre, RS (Brazil); Bodmann, B.E.J., E-mail: bardo.bodmann@ufrgs.b [Universidade Federal do Rio Grande do Sul, Departamento de Matematica Pura e Aplicada, Porto Alegre, RS (Brazil)

    2011-01-15

    In the present work we report on a closed-form solution for the two-dimensional Compton transport equation by the LTS{sub N} nodal method in the energy range of Compton effect. The solution is determined using the LTS{sub N} nodal approach for homogeneous and heterogeneous rectangular domains, assuming the Klein-Nishina scattering kernel and a multi-group model. The solution is obtained by two one-dimensional S{sub N} equation systems resulting from integrating out one of the orthogonal variables of the S{sub N} equations in the rectangular domain. The leakage angular fluxes are approximated by exponential forms, which allows to determine a closed-form solution for the photons transport equation. The angular flux and the parameters of the medium are used for the calculation of the absorbed energy in rectangular domains with different dimensions and compositions. In this study, only the absorbed energy by Compton effect is considered. We present numerical simulations and comparisons with results obtained by using the simulation platform GEANT4 (version 9.1) with its low energy libraries.

  14. The potential of coconut fibers in raw and treated forms to remove 241Am from aqueous solutions

    International Nuclear Information System (INIS)

    Fonseca, Heverton C.O.; Jesus, Nella N.M. de; Nobre, Vanessa B.; Potiens Junior, Ademar; Sakata, Solange K.

    2013-01-01

    In the Radioactive Waste Management (GRR) at the Nuclear and Energy Research Institute (IPEN/CNEN-SP) vegetal biomass has been studied as adsorbent to remove radioisotopes from radioactive liquid wastes as part of the radioactive waste treatment program. In this work coconuts fiber was evaluate as biosorbent to remove 241 Am from aqueous solutions and many different parameters were studied such as particle size (35 and 80 mesh) and contact time (between 5 and 60 minutes). In order to evaluate if the treated biomass could remove more 241 Am the experiments were also performed using raw biomass and treated with H 2 O 2 in basic conditions. When the experiment was carried out using raw coconuts fiber with 80 mesh, neutral conditions after 5 minutes of contact time 99% of the radionuclide was removed from the aqueous solution. This result shows the potential of this biomass to remove 241 Am from radioactive liquid wastes. (author)

  15. The potential of coconut fibers in raw and treated forms to remove {sup 241}Am from aqueous solutions

    Energy Technology Data Exchange (ETDEWEB)

    Fonseca, Heverton C.O.; Jesus, Nella N.M. de; Nobre, Vanessa B.; Potiens Junior, Ademar; Sakata, Solange K., E-mail: sksakata@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    In the Radioactive Waste Management (GRR) at the Nuclear and Energy Research Institute (IPEN/CNEN-SP) vegetal biomass has been studied as adsorbent to remove radioisotopes from radioactive liquid wastes as part of the radioactive waste treatment program. In this work coconuts fiber was evaluate as biosorbent to remove {sup 241}Am from aqueous solutions and many different parameters were studied such as particle size (35 and 80 mesh) and contact time (between 5 and 60 minutes). In order to evaluate if the treated biomass could remove more {sup 241}Am the experiments were also performed using raw biomass and treated with H{sub 2}O{sub 2} in basic conditions. When the experiment was carried out using raw coconuts fiber with 80 mesh, neutral conditions after 5 minutes of contact time 99% of the radionuclide was removed from the aqueous solution. This result shows the potential of this biomass to remove {sup 241}Am from radioactive liquid wastes. (author)

  16. Closed form solution for the finite anti-plane shear field for a class of hyperelastic incompressible brittle solids

    Science.gov (United States)

    Stolz, Claude

    2010-12-01

    The equilibrium solution of a damaged zone in finite elasticity is given for a class of hyperelastic materials which does not suffer tension when a critical stretching value is reached. The study is made for a crack in anti-plane shear loading condition. The prescribed loading is that of linearized elastostatics conditions at infinity. The geometry of the damaged zone is found and the stationary propagation is discussed when the inertia terms can be neglected.

  17. Optimizing the dosage of stabilizing chemical

    OpenAIRE

    Harjula, Tomi

    2013-01-01

    A chemical company provides chemical treatment at customer mill in paper industry. This thesis work was done to determine the optimum dosage of stabilizing chemical. The theoretical framework explains the basics of paper brightness and bleaching and how these topics are connected to each other. The knowledge gained is very valuable and can possibly be used in the future in other similar applications as well. This thesis work contains confidential back ground information. Key ...

  18. Corrosion resistance and durability of superhydrophobic surface formed on magnesium alloy coated with nanostructured cerium oxide film and fluoroalkylsilane molecules in corrosive NaCl aqueous solution.

    Science.gov (United States)

    Ishizaki, Takahiro; Masuda, Yoshitake; Sakamoto, Michiru

    2011-04-19

    The corrosion resistant performance and durability of the superhydrophobic surface on magnesium alloy coated with nanostructured cerium oxide film and fluoroalkylsilane molecules in corrosive NaCl aqueous solution were investigated using electrochemical and contact angle measurements. The durability of the superhydrophobic surface in corrosive 5 wt% NaCl aqueous solution was elucidated. The corrosion resistant performance of the superhydrophobic surface formed on magnesium alloy was estimated by electrochemical impedance spectroscopy (EIS) measurements. The EIS measurements and appropriate equivalent circuit models revealed that the superhydrophobic surface considerably improved the corrosion resistant performance of magnesium alloy AZ31. American Society for Testing and Materials (ASTM) standard D 3359-02 cross cut tape test was performed to investigate the adhesion of the superhydrophobic film to the magnesium alloy surface. The corrosion formation mechanism of the superhydrophobic surface formed on the magnesium alloy was also proposed. © 2011 American Chemical Society

  19. Closed-Form Solutions of the Thomas-Fermi in Heavy Atoms and the Langmuir-Blodgett in Current Flow ODEs in Mathematical Physics

    Directory of Open Access Journals (Sweden)

    Efstathios E. Theotokoglou

    2015-01-01

    Full Text Available Two kinds of second-order nonlinear, ordinary differential equations (ODEs appearing in mathematical physics are analyzed in this paper. The first one concerns the Thomas-Fermi (TF equation, while the second concerns the Langmuir-Blodgett (LB equation in current flow. According to a mathematical methodology recently developed, the exact analytic solutions of both TF and LB ODEs are proposed. Both of these are nonlinear of the second order and by a series of admissible functional transformations are reduced to Abel’s equations of the second kind of the normal form. The closed form solutions of the TF and LB equations in the phase and physical plane are given. Finally a new interesting result has been obtained related to the derivative of the TF function at the limit.

  20. Characterization of phosphorus forms in lake macrophytes and algae by solution 31P nuclear magnetic resonance spectroscopy

    Science.gov (United States)

    Aquatic macrophytes and algae are important sources of phosphorus (P) in the lake environment that cause blooms of algae under certain biogeochemical conditions. However, the knowledge of forms of P in these plants and algae and their contribution to internal loads of lake P is very limited. Witho...