Formulation and Evaluation of Gastroretentive Floating Tablets of Lovastatin Using Natural Polymers

Abstract

Background: Lovastatin, a lipid-lowering agent, suffers from low bioavailability due to extensive first-pass metabolism and limited absorption in the gastrointestinal tract. A gastroretentive drug delivery system (GRDDS) offers a promising solution to enhance its therapeutic effectiveness. Objective: The present study aims to formulate and optimize gastroretentive floating tablets of Lovastatin using various grades of hydroxypropyl methylcellulose (HPMC) and natural polymers to achieve sustained drug release. Methods: Floating tablets were prepared by direct compression using HPMC K4M, HPMC K15M, and guar gum in varying ratios. The tablets were evaluated for pre-compression (bulk density, tapped density, Carr’s index, Hausner ratio) and post-compression (thickness, hardness, friability, drug content, buoyancy) parameters. In vitro dissolution studies were conducted for 12 hours, and the data were fitted into kinetic models to determine the release mechanism.Results: All formulations exhibited acceptable physicochemical characteristics. The optimized batch (F8) demonstrated more than 12 hours of buoyancy, high drug content (99.23%), and sustained release of 99.45% over 12 hours. Drug release followed first-order kinetics with Higuchi diffusion and non-Fickian transport mechanisms. Conclusion: Floating tablets of Lovastatin prepared with HPMC K4M, K15M, and guar gum can effectively sustain drug release over 12 hours and improve gastric retention. This system holds potential for enhanced therapeutic efficiency in hyperlipidaemia treatment. Keywords: Lovastatin, gastroretentive tablet, floating drug delivery, HPMC, sustained release, in vitro kinetic