DESIGN AND CHARACTERISATION SUSTAINED RELEASE MATRIX TABLETS OF REPAGLINIDE USING NATURALPOLYMERS

The objective of the present work is to develop and charectarisation of oral sustained release matrix tablets of Repaglinide. Repaglinide is anti-diabetic drug used extensively in the treatment of diabetis type II. Repaglinide is one of emerging short acting drug, so developed formulation provides the advantages of sustained release formulations. The natural polymers like pectin, guar gum, xanthan gum were utilized in the formulation of matrix tablets containing Repaglinide by wet granulation technique and evaluated for its drug release characteristics. Pectin, guar gum and xanthan gum are hydrophilic and rate controlling polymers. Granules were prepared and evaluated for loose bulk density, tapped bulk density, compressibility index and angle of repose, shows satisfactory results. Formulation was optimized on the basis of acceptable tablet properties hardness, friability, drug content, weight variations, swelling behavior and in vitro drug release. All the formulations showed compliance with pharmacopieal standards. The in vitro release study of matrix tablets were carried out in phosphate buffer pH 7.4 for 10 hr. Among all the formulations, F8 with shows 52.633% better sustained release at the end of 10 hrs. it has been found that the optimized formula F8 containing 80% of guar gum as drug retarding polymer shows better sustained effect for 10 hr when compared to other formulations. The results indicated that a decrease in release kinetics of the drug was observed by increasing the polymer concentration. The release data was fitted to various mathematical models such as, Higuchi, Korsmeyer-Peppas, First-order, and Zero order to evaluate the kinetics and mechanism of the drug release.The drug release of optimized formulation F8 follows zero order kinetics and the mechanism was found to be diffusion coupled with erosion (non- Fickian diffusion).