Transdermal Drug Delivery System: A Review

Transdermal therapeutic systems, or transdermal patches, facilitate controlled release of active ingredients through the skin and into the systemic circulation. Drugs administered through such systems escape first pass metabolism and steady state is maintained similar to a continuous intravenous infusion for up to several days. The transdermal route of drug delivery has attracted researchers due to many biomedical advantages associated with it. However, excellent impervious nature of skin is the greatest challenge that has to be overcome for successfully delivering drug molecules to the systemic circulation by this route. This article gives a brief overview over principles behind transdermal drug delivery, as well as the advantages and disadvantages of transdermal therapeutic systems and the recent innovations in the field of transdermal drug delivery and also describes the methods of preparation of different types of transdermal patches, evaluation parameters and some available marketed products.