Advanced techniques for penetration enhancement in transdermal drug delivery system.

Transdermal route has been recognized as a promising drug delivery system for systemic delivery of drugs and provides the advantage of avoidance of first-pass effect, ease of use, better patient compliance, maintaining constant blood level for longer period of time and decrease side effects. The major pitfalls of this route lie with difficulty in permeation of drugs through the skin. Several literatures have been published for enhancing the permeation of drugs by chemical approaches. However the present review highlighted about the advanced physical techniques used for enhancing delivery of drugs such as structure-based, electrically based, velocity based and several other miscellaneous physical techniques for enhancing the permeation of drugs. In addition to these, the present review also gives an exhaustive account on clinical data about these techniques and regulatory considerations for new drugs as well as generic product approval in transdermal drug delivery.