Formulation and Evaluation of Stavudine Sustain Release Matrix Tablets Using Purified Neem Gum as Release Retardant

Stavudine is used for the treatment HIV/AIDS. It is competitive inhibitor of reverse transcriptase enzyme. Stavudine has short half life of 1.5-3 hours and absorption of drug is 86%. To reduce frequency of dosing, adverse effects and to increase patient compliance sustain release matrix tablets of Stavudine was developed. Therefore the main objective of the present work is to prepare sustain release matrix tablets of Stavudine using Neem gum as binder alone and combinations of Neem gum and HPMC K4M (1:1). Sustain release binder property of Neem gum is not evaluated. Tablets were designed in such a way that it releases drug throughout GIT for 12 hours, by retarding the release and thus increase the half life of the drug. Stavudine showed maximum absorbance at a wavelength of 266nm. FTIR studies show no interaction between drug and excipients. Five F1-F5 formulations were developed by using various amount of Neem gum in range of 40-120 mg using non aqueous wet granulation method. Precompressional and post-compressional parameters were evaluated and were found to be within the limits. The dissolution studies were performed it showed that formulation F2 consisting of 80mg of polymer was found to release of the drug perfectly at 12 hour remaining F3, F4 and F5 shown prolong sustain release than required rate. F2 is optimized based on drug release and subjected to different kinetic models, it found to be concentration independent and by diffusion. Stability studies are conducted for optimized F2 formulation tablets, shows no much change.