in vitro buoyancy.

The present investigation was aimed at estimating the effectiveness of the edible mucilage of Borassus flabellifer fruit as a polymer in the development of a gastric floating dosage form of ranitidine HCl. Borassus flabellifer fruit mucilage, was shown to aid in the formulation of floating tablets. In the present study, it was used as a pharmaceutical excipient and its efficiency was compared with HPMC in the formulation of ranitidine HCl floating tablets. Sodium bicarbonate was used as a gas-generating agent, ranitidine HCl  tablets were prepared by direct compression method. The prepared tablets were evaluated for physicochemical parameters and found to be within range viz. hardness, swelling index, floating capacity, thickness, and weight variation. Further, tablets were evaluated for in vitro release characteristics for 12 hrs. All in all, the formulation F3 manifested a prolonged release of the active ingredient. The optimized formulation F3 followed higuchi’s mechanism. Based on the diffusion exponent (n) value, the drug release was found to be diffusion controlled. From the study, it was evident that the mucilage manifested all the characteristics of a good pharmaceutical excipient that can be used for the formulation of floating tablets.

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.