Formulation, characterization and in vitro release studies of terbinafine hydrochloride loaded buccal films

Buccal administration of different active ingredients as an alternative to oral or dermal routes has been widely studied. The films are one of the most investigated dosage forms regarding the buccal formulations developed using bioadhesive polymers. Having thin and flexible structures, the films remain in the mouth for their duration of action without causing any discomfort. There are many studies conducted to develop buccal films for local treatment of oral fungal infections. In this research, buccal films were prepared using terbinafine hydrochloride, which is frequently used orally and systemically in the treatment of fungal infections and has low water solubility. The films were prepared by solvent casting method using hydroxypropyl methyl cellulose (HPMC) and polyvinyl pyrrolidone K30 (PVP) as the bioadhesive polymers and glycerin (2-3%) as the plasticizer. Characterization properties including thickness, weight uniformity, flexibility, tensile strength, swelling capacity were examined and the bioadhesive characteristics were determined by Texture Analyzer device using bovine buccal tissue. According to the findings of bioadhesion studies, the highest bioadhesive properties were detected in F1 and F7 formulations, which contained 5% HPMC. In vitro release studies exhibited that F1 and F7 film formulations with 5% HPMC represented slower and more controlled release compared to F2 and F8 film formulations having 4% HPMC + 1% PVP. The results revealed that the developed buccal formulations loaded with terbinafine hydrochloride might be convenient for the local treatment of oral fungal infections.