Prasad K. Lende

Different formulation technologies intended for gastro retentive dosage form were investigated and patented over the years. The aim of this study was to formulate, optimize and evaluate the gastro retentive floating tablet of stavudine. The developed technology induces a low density dosage form containing high concentration of active pharmaceutical ingredient (API). In the present work, the in-vitro sustained release of stavudine from matrix of tablet containing HPMC K100M and Xanthan gum as release retardant polymers has been studied. Sodium bi-carbonate and citric acid are used as gas generating agents. The tablets were prepared by direct compression method. The tablets eroded upon contact with the release medium 0.1N HCl and  the relative importance of floating lag time,% swelling index and % drug release patterns varied significantly with the concentration of polymers. Optimization was done by using design expert 8.0.4.1 and optimized formulation F6 of stavudine floating tablet shows no significant change in hardness, drug content, floating lag time and % cumulative drug release pattern after the stability period of 3 months at 400c/75% relative humidity. Key-words- Stavudine, HPMC, Xanthan gum, floating tablet, in vitro buoyancy.