FORMULATION AND EVALUATION OF TRANDERMAL PATCH OF RIVASTIGMINE TARTRATE

Transdermal drug delivery system are topically applied medication which is used to deliver the specific dose of drug direct entry into systemic circulation after passing through the skin barrier, and it avoid first pass effect. Transdermal patches deliver the drug for systemic effect at a predetermined and control rate through diffusion process. Transdermal drug technology specialists are continuing to search for new methods that can effectively and painlessly deliver large molecule in therapeutic quantities to overcome the difficulties associated with oral route, like poor bioavailability, first pass metabolism and sometime responsible for rapid blood level. The present study was carried out to develop transdermal patches of Rivastigmine with different ratio of HPMC (hydroxyl propyl methyl cellulose) and EC (ethyl cellulose) by solvent casting method. Propylene glycol 3% is used as a plasticizer and Span 80 as permeation enhancer. 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 data obtained from in- vitro permeation studies was treated by various 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 suitable 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. All prepared four Formulations, F1 showed maximum in vitro drug release. So, in general it was concluded that transdermal formulation prepared with HPMC (1:2) was the formula of choice as it showed better drug release. Keywords: Transdermal patch, Bioavailability, blood circulation.