Transdermal drug delivery system has become the focus of formulation research in the last decade owing to its advantages like easy accessibility, non invasiveness, compliance, safety and effectiveness. In United States around 40% of the drug delivery candidate products under clinical evaluation were related to transdermal or dermal systems. Nevertheless, its clinical application has been limited due to barrier properties of skin, especially the stratum corneum. To enhance the permeation of drugs through the skin many attempts have been made by the investigators that led to development of...