TRANSDERMAL DRUG DELIVERY PATCHES: A REVIEW

For thousands of years, human civilizations have applied substances to the skin as cosmetic and medicinal agents. However, it was not until the twentieth century that the skin came to be used as a drug delivery route. In fact, Merriam Webster dates the word “transdermal” to 1944 highlighting that it is a relatively recent concept in medical and pharmaceutical practice. Transdermal drugs are self‐contained, discrete dosage form. Drug delivery through the skin to achieve a systemic effect without producing any fluctuations in plasma concentration of the drug. Topical administration of therapeutic agents offers many advantages over conventional oral and invasive methods of drug delivery. And also provide controlled release of the drug for extended period of the time. This review article covers brief outline advantages, skin pathways for transdermal drug delivery systems (TDDS), various components of transdermal patch, and approaches for preparation of transdermal patches, evaluation of transdermal system, general clinical considerations in the use of tdds and limitation of tdds. Key words: Transdermal, Permeation pathways, Drug delivery, Matrix, ReservoirÂ