Transdermal Drug Delivery System: A Review

Transdermal drug delivery system (TDDS) is the administration of therapeutic agents through intact skin for systematic effect. It has emerged as a potential novel drug delivery system by improving the therapeutic efficacy and safety, maintain steady state plasma level of drugs and overcome significant drawbacks of the conventional oral dosage forms and parenteral preparations. TDDS is ideally suited for diseases that demand chronic treatment with frequent dosing. This review deals with a brief insight on the formulation aspects, the physical and chemical enhancers being explored to enhance the transdermal delivery of drugs across the stratum corneum, the evaluation parameters (physicochemical, in vitro, in vivo studies) and therapeutic applications of TDDS.