FORMULATION AND IN-VITRO CHARACTERIZATION OF GASTRO RETENTIVE MUCOADHESIVE TABLETS OF LOVASTATIN
The purpose of this study was to design bilayer mucoadhesive tablets of Lovastatin. Bilayer mucoadhesive tablets comprised two layers, i.e., immediate release and controlled release layers. The immediate release layer comprised sodium starch glycolate, Crospovidone and Croscarmellose sodium as super disintegrant either alone or in combination and the sustained release layer comprised Chitosan, Sodium Alginate, Carbopol 934P, Sodium CMC HPMC K4M, HPMC K15M, HPMC K100M as the release retarding and mucoadhesive polymers. Direct compression method was used for formulation of the bilayer tablets. More than 90% of lovastatin was released within 30 min from the immediate release layer. HPMC K100M retarded the release of Lovastatin from the controlled release layer for 12 h. Diffusion exponents (n) were determined for all the formulations (0.135-0.594). The release of Lovastatin was found to follow first order kinetics and Korsmeyer-Peppas model. The optimized formulation was found to have good mucoadhesive strength in sheep gastric mucosa. Therefore, biphasic drug release pattern was successfully achieved through the formulation of mucoadhesive bilayer tablets in this study