ABSTRACT:
The aim of this study was to develop effective bioadhesive buccal tablets of Isradipine. Isradipine is a dihydropyridine-class calcium channel antagonist. It binds to calcium channels with high affinity and specificity and inhibits calcium flux into cardiac and smooth muscle. It was selected as a model drug due to its extensive first-pass metabolism and low oral bioavailability (15-24%). Buccal tablets of Isradipine were prepared by direct compression method using bioadhesive polymers Carbopol 934P, Sodium alginate, Methocel K4M, and Hydroxy ethyl cellulose in various combinations and concentrations. The prepared tablets were evaluated by various parameters like weight variation, hardness, thickness uniformity, surface pH, swelling studies and Ex-vivo bioadhesive strength. The tablets were evaluated for in vitro release in pH 6.8 phosphate buffer for 8 hr in USP XXIV standard dissolution apparatus. In order to determine the mode of release, the data was subjected to Korsmeyer-Peppas diffusion model. The optimized formulations followed non-fickian release mechanism. The formulations F10, F14 and F18 exhibited good controlled release profile when compared with other formulations. FTIR spectral studies showed that there were no interactions between the drug and excipients. The present study concludes that buccal delivery of Isradipine tablets can be good way to bypass the first pass metabolism. Further the efficacy of the developed formulations has to be assessed by pharmacokinetic studies in humans.