Original Articles: 2011 Vol: 3 Issue: 6
Buccal Mucoadhesive Films Containing Antihypertensive Drug: In vitro/in vivo Evaluation
Mucoadhesive drug delivery systems for diltiazem hydrochloride in the form of buccal films were developed and characterized for improving bioavailability. Several hydrophilic and hydrophobic film forming polymers either alone or in combination with bioadhesive polymers were used for film fabrication. The bioadhesive polymers studied were sodium carboxymethyl cellulose (SCMC), hydroxypropyl cellulose (HPC). Prepared films were evaluated for various physicochemical characteristics such as weight variation, thickness, drug content uniformity, folding endurance, surface pH, and in vitro drug release. The in vitro mucoadhesive strength and permeation studies were performed using chicken pouch mucosa. Further, in vivo testing of mucoadhesion time and acceptability were performed in human subjects. Results indicated that drug release, swelling index and mucoadhesion performance were found to depend upon polymer type and proportion. The majority of the developed formulations presented suitable adhesion and the mechanism of drug release was found to be non-Fickian diffusion. Good correlation was observed between in vitro drug release and in vitro drug permeation with correlation coefficient ranged between of 0.945 to 0.980. In addition, from healthy human volunteers, bioadhesive behavior were found to be satisfactory. Drug bioavailability of a selected diltiazem hydrochloride adhesive buccal film, F26 (1% HPC and 2%SCMC) was determent and compared with that of a commercial sustained release oral tablet (Altiazem® RS) as a reference formulation. The obtained Cmax and AUC0-∞ values were higher for buccal administration than oral administration and the difference was statistically significant (p <0.05). The percentage relative bioavailability of diltiazem hydrochloride from the selected buccal mucoadhesive film in rabbits was found to be 165.2%.