Abstract

Hemalatha P. C.* and Dr. V. Chandrakala

ABSTRACT

Transdermal drug delivery systems (TDDS) are dosage forms that involve drug transport to viable epidermal and or dermal tissues of the skin for local therapeutic effect while a very major fraction of drug is transported into the systemic blood circulation. It is one of the best pharmaceutical dosage forms for patients, who cannot take medicaments orally. On the application of transdermal patches, the delivery of the drug across the dermis gives the systemic effect. Advances in transdermal delivery systems (TDS) and the technology involved have been rapid because of the sophistication of polymer science which now allows the incorporation of polymeric additives in TDS in adequate quantity.[1] Careful polymer selection is essential to control the drug loading, release rate, and duration of release. Many polymers can be formulated into various drug delivery systems to address the controlled release, Targeted delivery and solubility enhancement strategies enable improved drug efficacy. The most critical factor in polymer selection is considering the interaction of the drug and polymer. Polymer selection will determine the mechanism of drug release (bulk erosion, system degradation) and the choice of polymer properties (molecular weight, surface charge) will influence release rate and impact pharmacokinetics. This article summarizes the factors contributing to polymers for the formulation aspects of the transdermal drug delivery system and emphasizes the selection criteria and various release patterns of polymers. In addition, Applications, Manufacturing considerations and recent developments of TDDS have also been reviewed.[2]