Effect of Formulation Variables on the Release of Aceclofenac from Hpmc Matrix Tablets

The objective of this work was to study the effect of concentration and viscosity grade of HPMC, different diluents and inclusion of solid dispersions on the matrix tablets of aceclofenac. In present study, aceclofenac, a novel NSAID used for symptomatic treatment of pain and inflammation was formulated into matrix tablets with HPMC of two different viscosity grades (E50 LV and K15 M) by direct compression method. Before compression the formulations were evaluated for angle of repose, % compressibility and Hausner’s ratio. Tablets were evaluated for hardness, friability, weight variation, uniformity of thickness and diameter, and drug content. All precompressional and post-compressional parameters were found within the official limits. In vitro drug release studies were conducted for a period of 8 hrs using USP paddle method (II) at 37±0.5C and at 75rpm speed in pH 7.2 phosphate buffer. Type of polymer and its concentration has influenced the drug release from matrix tablets. With increasing concentrations and increasing polymer viscosity the release rate decreased. Release rate increased with the addition of PEG and PVP. There was significant increase in drug release by inclusion of solid dispersions in the matrix tablets. It can be concluded that by incorporating water soluble excipients such as PEG and PVP and solid dispersions of drug with PVP into the matrix, drug release can be increased. Dissolution data was analysed by Power law expression, Mt / M = kt . Release of drug from the tablets varied on the basis of formulation and was found to be non-Fickian and case II transport with different formulations. INTRODUCTION: Tablet forms the majority of oral dosage forms. Important reasons for their popularity are their convenience of application (patient compliance) and ease of preparation on an industrial scale . In the last two decades, controlled-release dosage forms have made significant progress in terms of clinical efficacy and patient compliance. Preparation of drug-embedded matrix tablet that involves the direct compression of a blend of drug, retardant material and additives is one of the least complicated approaches for delivering drug in a temporal pattern into the systemic circulation. The matrix system is commonly used for manufacturing controlled release dosage forms because it makes such manufacturing easy. A wide array of polymers has been employed as drug retarding agents each of which presents a different approach to the matrix concept .