Formulation and Evaluation of Mucoadhesive Buccal Patch of An Antihypertensive Drug

Perindopril is an angiotensin converting enzyme inhibitor. The bioavailability of Perindopril following oral administration is 20 % due to high hepatic first pass metabolism. When administered orally, frequent dosing is needed due to its short biological half-life (0.8 to 1hr). sobuccal patches are one of the better option for perindopril administration. 9 Formulations were prepared using 32 full factorial designs by solvent-casting technique to explore the effects of sodium alginate and carbopol 934 (as independent variables) on drug release, mucoadhesive strength and retention time (as dependent variables). The prepared buccal patches were also evaluated for, weight uniformity, patch thickness, folding endurance, surface pH, swelling studies, % moisture content,% drug content, tensile strength, drug release studies, mucoadhesive strength, retention time. The ex-vivo permeation studies were carried out across excised sheep buccal mucosa using modified Franz diffusion cell. Patches exhibited drug release in the range of 70.37to 96.62% in 8 hrs. Drug release from patches followed zero order and higuchi release model and the mechanism of the drug release was due to swelling and erosion of hydrophilic polymers. The formulation was optimized with desirable drug release, mucoadhesive strength and retention time by applying computer software Design Expert 8.0.7.1. Ex-vivo drug release values for the cumulative amount of the drug permeated across the sheep buccal mucosa from optimized formulation was 76.76%. The experimented values were in good agreement with expected values for the optimized formulation which demonstrate the feasibility of the model in the development of buccal patches.