Formulation and evaluation of tenoxicam gels for tropical use

No Abstract. The East and Central African Journal of Pharmaceutical Sciences Vol. 8(1) 2005: 14-1

Formulation of Extended-Release Metformin Hydrochloride Matrix Tablets

Purpose: To develop and characterize an oral extended-release matrix tablet of metformin hydrochloride using a combination of a hydrophobic carrier and a hydrophilic polymer, and two types of formulation techniques.Methods: Various metformin hydrochloride formulations containing a hydrophobic carrier (stearic acid) and a hydrophilic polymer (polyethylene oxide) were prepared using a 32 factorial design. Two types of formulation techniques – melt granulation and direct compression – were evaluated. The influence of the carrier, polymer and preparation method on metformin release from the formulations in vitro as well as other physicochemical properties were studied. The release data were subjected to various release kinetic models and also compared with those of a commercial brand.Results: The physicochemical characteristics of all the granules and tablets were generally satisfactory. Optimization results indicate that the release rate of metformin HCl was directly proportional to the levels of stearic acid (SA) and polyethylene oxide (PEO) in the tablet formulations. Release rate was also dependent on the method of granulation used. Kinetic analysis showed that the formulation containing 30 %w/w of polymer exhibited release similar to that of the commercial brand with a similarity factor (f2) of 81.1. Melt granulation was more effective in extending drug release than direct compression. Release mechanism followed most closely the Korsemeyer-Peppas model with a correlation coefficient (r2) and 0.991.Conclusion: The use of a hydrophobic carrier along with a hydrophilic polymer effectively controls the initial rapid release of a highly water soluble drug such as metformin HCl. Hot melt granulation method was especially more effective in achieving this than the direct compression method.Keywords: Metformin hydrochloride, Matrix tablets, Polyethylene oxide, Stearic acid, Hot melt granulation, In vitro release

Isolation and morphological characterization of antibiotic producing actinomycetes

Purpose: To isolate and characterize antibiotic producing actinomycetes from soil samples in Belgaum, Karnataka, India. Methods: Crowded plate technique was used for the isolation of actinomycetes in media such assoybean – casein digest medium and actinomycetes isolation agar. The morphological and cultural characterization of one of the selected strains, designated A-4, was performed as per International Streptomycete Project (ISP). Results: Morphological and cultural studies showed that A-4 belonged to the Actinomycete genus. The morphological and cultural characteristics of the A-4 mutant showed cellular and aerial growth as well as soluble pigment formation in various ISP media. Conclusion: Findings from this investigation revealed that the selected strain, A-4, is an actinomycete.Keywords: Actinomycete, Antibiotic, MIC, Crowded plate technique, Morpholog

Development of mouth dissolving tablets of clozapine using two different techniques

Mouth dissolving tablets constitute an innovative dosage form that overcomes the problems of swallowing and provides a quick onset of action. In view of enhancing bioavailability an attempt has been made to study two different methods direct compression and sublimation in formulation of mouth dissolving tablets of clozapine. Total four formulations using various superdisintegrants and subliming agents were prepared. All prepared formulations were evaluated for physico-chemical parameters. The formulations exhibited good disintegration properties with total disintegration time in the range of 25 to 35 s. Comparative evaluation of two methods showed direct compression method is a better alternative to sublimation method as its formulations rapidly disintegrate in oral cavity. In vitro cumulative percentage drug release for formulations prepared by direct compression with explotab superdisintegrants shows 99.79 while sublimation method using camphor 93.58 release in 12 min. Kinetic studies indicated that all the formulations followed first order release with diffusion mechanism

Formulation of Extended-Release Metformin Hydrochloride Matrix Tablets

Purpose: To develop and characterize an oral extended-release matrix tablet of metformin hydrochloride using a combination of a hydrophobic carrier and a hydrophilic polymer, and two types of formulation techniques. Methods: Various metformin hydrochloride formulations containing a hydrophobic carrier (stearic acid) and a hydrophilic polymer (polyethylene oxide) were prepared using a 32 factorial design. Two types of formulation techniques – melt granulation and direct compression – were evaluated. The influence of the carrier, polymer and preparation method on metformin release from the formulations in vitro as well as other physicochemical properties were studied. The release data were subjected to various release kinetic models and also compared with those of a commercial brand. Results: The physicochemical characteristics of all the granules and tablets were generally satisfactory. Optimization results indicate that the release rate of metformin HCl was directly proportional to the levels of stearic acid (SA) and polyethylene oxide (PEO) in the tablet formulations. Release rate was also dependent on the method of granulation used. Kinetic analysis showed that the formulation containing 30 %w/w of polymer exhibited release similar to that of the commercial brand with a similarity factor (f2) of 81.1. Melt granulation was more effective in extending drug release than direct compression. Release mechanism followed most closely the Korsemeyer-Peppas model with a correlation coefficient (r2) and 0.991. Conclusion: The use of a hydrophobic carrier along with a hydrophilic polymer effectively controls the initial rapid release of a highly water soluble drug such as metformin HCl. Hot melt granulation method was especially more effective in achieving this than the direct compression method