Formulation and Evaluation of Bilayer Matrix Tablets of Nebivolol Hydrochloride and Valsartan

摘要

The present study is an attempt to develop bilayer matrix tablets of Nebivolol Hydrochloride and Valsartan with immediate release for Nebivolol Hydrochloride and sustained release for Valsartan. Superdisintegrants such as sodium starch glycolate and Crosscarmellose sodium were evaluated for immediate release of Nebivolol Hydrochloride and polymers HPMC K100M and K4M for sustained release of Valsartan. Preformulation studies were performed prior to compression. The compressed bilayer tablets were evaluated for weight variation, thickness, hardness, friability, drug content and in vitro drug release using USP dissolution apparatus type 2 in 0.01N HCl and phosphate buffer pH 6.8. All the pre and post compression parameters were found to be within the acceptable limits. The results of dissolution show that the formulations B3 was the best of all immediate and sustained release layer batches. The release kinetics of Valsartan was subject to curve fitting analysis in order to identify the best fit kinetic model. The regression analysis proves that the best formulations follow zero order release and drug release by diffusion process based on Fick’s law of diffusion. The data for stability studies infer no considerable change in drug content and dissolution rates as per ICH guidelines. The best formulation B3 was subjected to in vivo pharmacokinetic studies in rabbit model. In vitro, In vivo correlation (IVIVC) showed considerable linearity. Hence a novel bilayer tablet formulation of Nebivolol Hydrochloride and Valsartan was successfully developed by combining both immediate (IR) and sustained (SR) release layers.