The objectives of this compilation is to provide an overview of Transdermal drug delivery system. Here matrix patches of Glipizide by using different ratio of ethyl cellulose and polyvinylpyrrolidone K-30 preapared and characterized. The influence of oleic acid (OA) and its combined effect with propylene glycol (PG) on the percutaneous permeation of drug was also studied. All the in- vitro studies were conducted by using cellophane membrane and human cadaver skin. Data recorded over 24 hr was compared with that for control formulation (containing no enhancers) using Franz diffusion cells. Stability study and statistical analysis of data was also done. This book would be effective for those persons working at initial stage of Transdermal drug delivry.