EFFECT OF POLYMER RATIO AND EXCIPIENTS ON METOPROLOL TARTRATE RELEASE FROM CHITOSAN – SODIUM ALGINATE POLYMERIC IMPLANTS

Natural biodegradable chitosan-sodium alginate polymer combination is a promising candidate for preparing drug-loaded implants because of the availability and inexpensiveness of the polymers over the semi synthetic biodegradable ones. The main objective of this research was to prepare and evaluate a biodegradable implantable system of the drug metoprolol tartrate because it plays an important role in the treatment of high blood pressure, strokes, heart attacks and angina. 70:30 and 80:20 chitosan – sodium alginate combination implants of metoprolol tartrate with 15 and 30 minutes exposure time to glutaraldehyde for hardening were prepared. It was observed that loading efficiency and drug release could be influenced by varying polymer ratios, exposure times to glutaraldehyde and excipients. The implant formulated with 25 mg drug load in 70:30 chitosan – sodium alginate ratio with 15 minutes exposure produced the maximum sustained release for 15 days. Therefore, this formulation was chosen for preparing implants containing different excipients and the implants were evaluated for loading efficiency and in-vitro drug release. Morphological characteristics of the implants were analyzed using SEM. The release mechanism was explored and explained with zero order, first order, higuchi and korsmeyer-peppas models. Implants with excipients were found to follow first order model in most cases. also good co-relations were obtained with higuchi model. According to these models, the drug release from the implants was diffusion controlled, where the drug leaving the matrix through pores and channels formed by entry of dissolution medium.