DEVELOPMENT, CHARACTERIZATION AND EVALUATION OF TRANSDERMAL PATCH OF PRAZOSIN HYDROCHLORIDE

In today's world about 74% of drugs are taken orally and are found not to be as effective as desired in the present scenario. So to overcome or to improve such character transdermal drug delivery system was emerged in form of transdermal patches. Transdermal drug delivery represents the most rapidly advancing areas of novel drug delivery. To overcome the difficulties of drug delivery through oral route easier way was introduced known as transdermal drug delivery system for example poor bio-availability, first pass metabolism and sometime responsible for rapid blood level. The present study was carried out to develop transdermal patches of prazosin hydrochloride with different ratio of HPMC (hydroxyl propyl methyl cellulose), EC (ethyl cellulose) by solvent casting method. Propylene glycol 3% is used as a plasticizer and Span 80 as permeation enhancer. The recognition of drug and the possible drug polymer relations were studied by FTIR spectroscopy. Formulated transdermal patches were evaluated with regard to physicochemical characteristics (thickness, folding endurance etc.) and In-vitro permeation studies were performed using Franz diffusion cell. The figures obtained from in-vitro permeation studies was treated by different conventional mathematical models (zero order, first order, Higuchi and Korsmeyer-peppa's) to determine the release mechanism from the transdermal patches formulations. Selection of a appropriate release model was based on the values of R2 (correlation coefficient), k (release constant) obtained from the curve fitting of release data. It was found that all the formulations follow the first order kinetics. The regression coefficients (R2) for the all formulations F1 to F4 of Higuchi plot was found to be almost linear.