Formulation and Invitro evaluation of diltiazem hydrochloride buccal films

Diltiazem hydrochloride is a calcium channel blocker and exhibits 40% oral bioavailability due to hepatic first pass effect. To overcome bioavailability problems, to reduce dose dependent side effects and frequency of administration, diltiazem hydrochloride buccal films were prepared using hydroxy propyl methyl cellulose (HPMC), hydroxy propyl cellulose (HPC), carbopol-934P and poly vinyl alcohol (PVA). The films were evaluated for physicochemical properties such as surface pH, bioadhesive strength, folding endurance and invitro dissolution test. From invitro dissolution studies, the drug release mechanism was found to be diffusion controlled and the rate of diffusion followed zero order kinetics. It was concluded that diltiazem hydrochloride buccal films prepared with HPC and carbopol with propylene glycol as plasticizer showed better release rate and good bioadhesive strength when compared to other formulations.