Skin penetration enhancer's in transdermal drug delivery systems

Transdermal drug delivery is one of the most potential methods for drug application. Though the skin, in particular the stratum corneum, possesses a dreadful barrier to drug penetration thus limiting topical and transdermal bioavailability. So skin penetration enhancement techniques have been developed to improve bioavailability and to increase the range of drugs, the topical and transdermal delivery is a viable option. The technique is generally non-invasive, well accepted by patients and can be used to provide local delivery over several days. Various chemical enhancers are used to improve bioavailability of the drugs such as sulfoxides, fatty acids, azones and non ionic surfactants. This review article presents the comprehensive different aspects of drug delivery by transdermal route with various chemical penetration enhancers.