Development and Characterization of Mucoadhesive Film of Nitrendipine for Buccal Administration

Mucoadhesive buccal patches containing nitrendipine were prepared using the solvent casting method. Chitosan was used as bio-adhesive polymer and different ratios of chitosan to PVP K-30 were used. The pre-formulation study using DSC revealed the compatibility of drug and polymer. Patches were evaluated for their physical characteristics like weight variation, drug content uniformity, folding endurance, surface pH, in vitro drug release, and in vitro buccal permeation study. Patches exhibited controlled release for a period of 8 h. The mechanism of drug release was found to be non-Fickian diffusion and followed the first-order kinetics. Incorporation of PVP K-30 generally enhanced the release rate. Swelling index was proportional to the concentration of PVP K-30. Optimized patches (F6) were characterized by moderate swelling; a convenient residence times as well as adequate drug release (93.4%). The surface pH of all patches was between 5.7 and 6.3 and hence patches should not cause irritation in the buccal cavity. Good correlation was observed between the in vitro drug release and in vitro drug permeation with a correlation coefficient of 0.99.