Development and evaluation of nifedipine controlled release tablets prepared using mucoadhesive swellable polymer

Nifedipine is embedded in Gelcarin GP-379 to develop a prolonged release matrix. The effect of polymers levels (15, 20, 30 and 50% w/w), diluent type (lactose Fast Flo, DiTab, and Avicel PH-101), and drug levels (13, 20 and 30% w/w) on in vitro release rate of the drug were investigated. The formulation containing 13% nifedipine, 20% Gelcarin GP-379, and lactose Fast Flo controlled the dissolution rate of nifedipine and released approximately 51% drug at 8 h of testing dissolution. The use of different types of diluents, different drug levels, and different rotational speeds during dissolution testing did affect the drug release rate from the swellable matrices. The dissolution data were analyzed according to Higuchi model, zero order, first order, and Peppas kinetic model. Drug release was found to follow the anomalous diffusion model for swellable matrix.