A Review on Transdermal Patches

Abstract

Transdermal drug delivery systems (TDDS) offer a promising approach for the controlled and sustained release of drugs through the skin, providing several advantages such as improved bioavailability, avoidance of first-pass metabolism, and enhanced patient compliance. This review focuses on the formulation and evaluation of transdermal patches containing Nateglinide, a short-acting insulin secretagogue used in the management of type 2 diabetes mellitus. Nateglinide exhibits low oral bioavailability and a short half-life, necessitating frequent dosing; thus, transdermal administration can help overcome these limitations. Various formulation methods—including solvent casting, film deposition, and matrix dispersion techniques—are discussed, with emphasis on the selection of suitable polymers (such as HPMC, Eudragit RL/RS, PVP, and ethyl cellulose) and plasticizers (like dibutyl phthalate and PEG 400) to achieve optimal patch flexibility and controlled drug release. Permeation enhancers such as oleic acid, propylene glycol, and DMSO play a vital role in enhancing drug flux through the stratum corneum. Evaluation parameters—thickness, tensile strength, folding endurance, moisture content, drug content uniformity, in vitro drug release, and ex vivo skin permeation studies—are critically reviewed. The transdermal delivery of Nateglinide offers a novel strategy for sustained glycemic control, reduced dosing frequency, and improved therapeutic efficacy in diabetes management.

Keywords: Transdermal drug delivery system (TDDS); Nateglinide; Type 2 diabetes mellitus; Controlled release; Solvent casting method; Polymer matrix.