Mucoadhesive buccal films of nifedipine were prepared by solvent casting technique using Hydroxyl propyl methyl cellulose, Eudragit RLPO, Eudrgit RSPO, Eudragit E100, and Ethyl cellulose. FT-IR interaction studies revealed that there was no interaction between nifedipine and polymers. Cumulative in vitro drug release in PBS pH 6.6 was in the range of 66.57% to 98.61% at the end of 12 h. Formulations F1, F2, F4, F5 followed first order kinetics and the formulation F3 followed zero order kinetics. The mechanism of drug release followed diffusion controlled rate process through a swollen matrix and water filled pores in the formulations. Optimized formulation, F3, containing nifedipine 10 mg in 41.09% w/v Hydroxy propyl methyl cellulose and 41.09% w/v Eudragit RLPO exhibited satisfactory swelling, adequate tensile strength and promising drug release for a period of 12 h. In vivo bioavailability in rabbits increased to 90% for formulation F3 as compared to 30 – 60% for pure drug nifedipine. A good correlation between in vitro release and in vivo absorption (R2= 0.8131) was observed. The films were evaluated for their physical characteristics like weight variation, drug content uniformity, thickness uniformity, folding endurance, content uniformity, swelling behaviour, tensile strength and surface pH. The films were found to be stable with respect to the amount of drug content and physical stability in both accelerated as well as at room temperature conditions for the period of study.
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