DESIGN, DEVELOPMENT AND EVALUATION OF TRANSDERMAL DRUG DELIVERY OF CAPTOPRIL, AN ANTIHYPERTENSIVE DRUG

Captopril was the first ACE inhibitor used for the treatment of hypertension. The present study was aimed to design and evaluate a matrix-type transdermal formulation containing captopril with different ratios of hydrophilic (Hydroxy propyl methyl cellulose E-15) and hydrophobic polymeric (Eudragit RS100) combinations plasticized with glycerin by the solvent evaporation technique. Effect of permeation enhancers such as oleic acid, dimethyl sulfoxide (DMSO) and dimethyl formamide (DMF) were studied. The interference of the polymers was ruled out by FT-IR studies. The prepared patches were tested for their physicochemical characteristics such as physical appearance, weight variation, thickness, folding endurance, percentage moisture absorption, percentage moisture loss, water vapour transmission, tensile strength and drug content. In vitro release studies of captopril loaded patches in phosphate buffer (pH, 7.4) exhibited drug release for 24 hours in the following order F3< F6< F5< F4. Data of in vitro release from patches were fit in to different equations and kinetic models to explain release kinetics. The models used were zero and first-order equations, Higuchi and Korsmeyer-Peppas models. Based on physicochemical properties and in vitro release studies, patch containing hydroxyl propyl methyl cellulose E-15 and Eudragit RS 100(1:1) with oleic acid as permeation enhancer, emerges as a best formulation. Skin irritation studies for the transdermal patches were assessed and were found to be free of irritation.