Permeation Enhancer for TDDS from Natural and Synthetic Sources: A Review

Abstract

The transdermal drug delivery is now a promising route of drug delivery system. This route has potential advantage of avoiding hepatic first pass metabolism, decrease side effects, gastrointestinal effects, improved patients compliance and increase bioavailability. The major limitation of this route is the difficulty of permeation of drug through skin. The outer most layer of the skin, the stratum corneum provides a protective barrier that prevents the loss of physiologically essential substances and provides greatest resistance to penetration and it is the rate limiting step of percutaneous absorption. Penetration enhancers are the agents which increase the permeability of skin, maintain the drug level in blood and improve the efficacy of drugs. These are nontoxic, inert substances having no therapeutic value but enhance the absorption of drug through skin by different approaches of penetration enhancement, Different studies have been carried out to find safe and suitable permeation enhancer to promote the percutaneous absorption of different drugs. The present review describe synthetic permeation enhancers and natural permeation enhancers with their properties and mechanism of action, it will help in the selection of suitable permeation enhancer for improving the transdermal permeation of poorly absorbed drugs.

KEYWORDS: Transdermal drug delivery system, Permeation enhancer, Natural, Synthetic.