ABSTRACT
A “transdermal approach or technology” can be defined as any method that allows a drug or biological marker to transit skin in either direction. A transdermal drug delivery system allows the drug or molecule to transit from the outside of skin, through its various layers, and finally into the circulatory system to exert a pharmacological action. There may be some exceptions to this definition — for example, a system may concentrate the drug in the skin layers or near the surface of the skin to exert a localized effect, such as wound dressings for antisepsis or improved healing processes.
