Optimization of Hydroxy Propyl Methyl Cellulose and Carbomer In Diltiazem Hydrochloride Mucoadhesive Buccal Film

Abstract

Diltiazem hydrochloride (HCl) is a category of calcium channel blocker used as an antihypertensive agent. Diltiazem HCl is a low bioavailable drug due to high first-pass metabolism and a short half-life (3-5 hours); hence mucoadhesive buccal film was made to overcome this weakness. Bioavailability of Diltiazem HCl increase if the buccal preparations can contact the mucosa for a sufficient time. Therefore, in this study, two polymers are combined to obtain good film characteristics, especially residence time and mucoadhesive strength. This study was aimed to optimize Hydroxy Propyl Methyl Cellulose (HPMC) and Carbomer's amount in Diltiazem HCl mucoadhesive buccal film. The formulas were prepared by the solvent casting method and optimized with design expert software. The release kinetics and mechanism were evaluated using DDSolver program. The optimum amount of polymer obtained from optimization was 40 mg of HPMC and 10 mg of Carbomer. The optimum formula's swelling index was 4.18. The mucoadhesive strength was 53.07 gF, and the mucoadhesive residence time was 529.33 min. The FTIR spectra showed there was no interaction between Diltiazem HCl and other excipients. Thus it did not disturb the therapeutic effect. Based on the DDSolver statistical parameters and curve-fitting, the dissolution model of Diltiazem HCl from buccal mucoadhesive film follows Korsmeyer-Peppas. The release exponent (n) is 0.55, which shows a non-fickian/anomalous diffusion release mechanism. These mechanisms represent drug release controlled by a combination of diffusion and erosion.