A Review: Effect of Permeation Enhancers on the Penetration Mechanism of Transdermal Gel

Transdermal systems are non-invasive, convenient, and inexpensive and can be self-administered. They can provide sustained plasma concentration profile for long periods of time. The systems can greatly improve patient compliance through avoidance of first-past metabolism, improved bioavailability, reduction of systemic side effects and dosing schedule. In the past three decades, transdermal drug delivery has been developed to the stage where transdermal systems become a feasible way of delivering clinically effective drugs particularly those drugs with significant first-pass effect of the liver that can prematurely metabolize drugs. The advantages of this type of drug delivery include targeting specific areas of the body and decreasing the amount of drug necessary for effect as compared to drugs taken orally.