Formulation and evaluation of bilayer floating tablets of simvastatin and lovastatin

This study was performed to design bilayer floating tablets of simvastatin and lovastatin to give sustained release of simvastatin and immediate release of lovastatin. Bilayer floating tablets comprised of two layers i.e, immediate and sustained release layers. Bilayer floating tablets of simvastatin and lovastatin was formulated by using HPMCK 100M and super disintegrants like sodium alginate, sodium starch glycolate, croscarmellose sodium, L-HPC and polyox WSR 303 which offers a suitable and practical approach in management of hypolipidemia. Sodium bicarbonate was used as gas generating agent. Accelerated stability studies were carried out as per ICH guidelines. Moreover 90% of lovastatin was released within 30 minutes. Simvastatin from controlled release layer for 12 hours. The release of simvastatin was found to follow a mixed pattern of Korsmeyer-Peppas, Hixson-Crowell and zero order release models. Therefore, biphasic drug release pattern was successfully achieved through bilayer floating tablets in this study.