There is considerable interest in the skin as a site of drug application both for local and systemic effect. Skin penetration enhancement techniques have been developed to improve bioavailability and increase the range of drugs for which topical and transdermal delivery is a viable option. The noninvasive route of delivery systems has many advantages over the conventional delivery systems. Althoug its applications are limited by low skin permeability and physicochemical properties of drugs. The permeation of drugs through skin can be enhanced by various methods including physical methods such as iontophoresis, phonophoresis (use of ultrasound energy), eletroporation and by chemical penetration enhancers etc. The transdermal route has been recognized as one of the highly potential routes of systemic drug delivery. However, the major limitation of this route is the difficulty of permeation of drug through the skin. Studies have been carried out to find safe and suitable permeation enhancers to promote the percutaneous absorption of a number of drugs. The present review highlights various categories of penetration enhancers; the involved mechanism leading to a judicious selection of suitable penetration enhancers for improving the transdermal permeation of poorly absorbed drugs.
Loading....