FORMULATION AND EVALUATION OF GASTRO RETENTIVE DRUG DELIVERY SYSTEM OF STAVUDINE

Abstract

The present study was designed to formulate and evaluate hydro dynamically balanced Floating Drug Delivery Systems as controlled release modules, which prolongs the release rate of the drugs. Stavudine is an anti- retroviral, reverse transcriptase inhibitor (Nucleoside). Stavudine triphosphate inhibits the HIV reverse transcriptase by competing with natural substrate, thymidine triphosphate. It also causes termination of DNA synthesis by incorporating into it. Formulation of Stavudine as gastro retentive drug delivery systems (GRDDS) is especially advantageous over other prolonged type drug delivery systems and conventional tablets because the drug is having absorption window in the duodenum and jejunum level and having relatively short half life. Stavudine was taken as the model drug to optimized formulations was prepared. The floating ability of lipoidal fatty polymers Gelucire 13/01, Gelucire 43/ 01 is compared over various polymers like HPMC, HPMC K4M, Ethocel, Sodium carboxy methyl cellulose. The drug: polymer ratios used to prepare the different formulations were 1:0.5 and 1:1. Blend of all the formulations are prepared by melt granulation technique. All the tablets were subjected for dissolution study using USP dissolution apparatus (USP XXIII paddle method) and data were analyzed at 265nm. The drug release of Stavudine from all the formulations followed zero order kinetics. According to the dissolution profiles of formulations drug retardation was enhanced in 1:1 Drug: Polymer proportion than 1:0.5 proportions. Of all the formulations in which Gelucire 13/01 is used as a floating polymer, has retarded the drug successfully upto 12 hours.