Preparation and in vitro characterization of gastroretentive atorvastatin calcium mucoadhesive tablets

Abstract

The present investigation concerns the development of mucoadhesive tablets of Atorvastatin calcium which were designed to prolong the gastric residence time after oral administration. Atorvastatin calcium has a maximum rate of absorption in the upper GI tract, but because of poor solubility in this region, it has a low bioavailability of 12%. In the present study mucoadhesion as a strategy to enhance the bioavailability of Atorvastatin calcium by increasing the gastric residence time was studied. Matrix tablets of Atorvastatin calcium were formulated using different viscosity grades of hydroxyl propyl methyl cellulose (HPMC K4M, HPMC K15M and HPMC K100 M) by direct compression method. The tablets were evaluated for physical properties, content uniformity, swelling index, bioadhesion and in vitro drug release. Swelling was increased as the concentration and viscosity of HPMC increases. It was evident from the study that the formulation F5 containing HPMC K15M exhibited desirable swelling and in vitro drug release of 101.23% at the end of 12 hrs with non fickian diffusion mechanism.