An Overview of Transdermal Patches: Opportunities and Obstacles in Modern Drug Delivery

Abstract

Transdermal patches are a novel drug delivery system intended to deliver medication across the skin for systemic absorption. Transdermal patches have several benefits, including controlled and sustained release of the drug, improved patient compliance, and avoidance of first-pass metabolism, which is typical with oral administration. The patch is usually made up of a backing layer, a drug reservoir or matrix, and an adhesive layer that provides attachment to the skin. Release of the drug is achieved through the layers of the skin by diffusion, with formulation and skin properties dictating the rate of delivery. Transdermal patches have been applied in many therapeutic categories, such as pain (e.g., fentanyl patches), hormone replacement (e.g., estrogen patches), and smoking cessation. Designing efficient transdermal systems relies on the optimization of drug properties, enhancement of skin permeability, and the choice of suitable materials for the patch. While transdermal drug delivery has many advantages, problems like skin irritation, restricted drug choice, and patient variability remain. Nevertheless, continued developments in formulation technologies and materials are enhancing the efficacy, safety, and suitability of transdermal patches as a promising alternative for sustained drug delivery and enhanced therapeutic effects.