NATURAL PERMEATION ENHANCER FOR TRANSDERMAL DRUG DELIVERY SYSTEM AND PERMEATION EVALUATION: A REVIEW
The transdermal drug delivery route is evolving as a potential route due to its advantages of bypassing the hepatic first pass metabolism, decreased side effects and gastrointestinal effects, improve patience compliance as it is a pain-free self-administration for patients, etc. The major setback appearing in this route is the difficulty of the drugs to penetrate through the skin as the stratum corneum (outermost layer of the skin) forms a protective barrier for the underlying tissues from the outer environment. A transdermally delivered drug can only show its action when it can cross the transdermal barrier to reach the systemic circulation and for helping on doing that the penetration enhancer are the agents which increase the permeability of the skin which on return maintains the drug level in the blood. Permeation enhancers can be of a chemical type, natural type, and physical type. The present review describes the natural permeation enhancers can be which be employed for transdermal permeation of drugs.