Transdermal Delivery Systems — Texture Application Note

Transdermal Drug Delivery Systems (TDDS) are a fundamental part of novel drug delivery systems. They are polymeric formulations applied to the skin to deliver the drug at pre-determined rates in order to achieve their systemic effect. There are several important advantages to TDDS such as the limitation of hepatic first pass metabolism. This is particularly useful to drugs that would normally undergo extensive first pass metabolism, drugs with a narrow therapeutic window, or even drugs with a short halflife causing non-compliance due to frequent dosing. Other advantages include maintenance of a steady plasma level, reduced side effects and enhanced therapeutic efficiency.

The use of adhesive patches for controlled release in applications, such as nicotine patches, appetite suppressants, contraceptive and hormone replacement therapy, has become popular worldwide. Adhesives on a patch generally help maintain contact between the transdermal system and skin surface. The adhesiveness of the patches is critical in the drug delivery mechanism, its safety, product quality, and efficacy. As such, a good adhesive should easily adhere to the skin with an applied finger pressure and be tacky enough to maintain a strong holding force. The adhesive should also be easily removed from the skin without leaving a residue.