Formulation and Optimization of Porous Osmotic Pump Tablets based Controlled Release System of Stavudine for the Treatment of HIV Infection

The current research was designed to develop controlled release osmotic pump tablets of stavudine a nucleoside reverse transcriptase inhibitor for the treatment of HIV infection. Wet granulation method was adopted for the development of tablets containing dose 80mg of stavudine. The coating membrane of core tablets were prepared by using cellulose acetate as wall forming agent, poly ethylene glycol as flux regulating agent, and sorbitol as pore forming agent. The formulated tablets were characterized by FTIR, DSC, pre compression parameters, post compression parameters, in vitro drug release study and scanning electron microscopy study. Among developed formulations SM5 Batch showed 96.06% of drug release in controlled manner at the end of 18hrs. The in vitro release kinetics data were fitted for different batches in various pharmacokinetic models such as zero order, first order, Higuchi, Korsmeyer Peppas and Hixon Crowell model. The optimized formulation was carried out for effect of pH in dissolution media, agitation intensity and osmotic pressure effect on dissolution media. Short term stability study (at 40±2ºC/75±5% RH for three months) on the best formulation confirmed that there was no significant changes in thickness, weight variation, %friability, drug content and in vitro drug release.