A Review on Transdermal drug delivery systems (TDDS)

Abstract

Transdermal drug delivery systems (TDDS) have gained considerable importance as an alternative route for systemic drug administration, offering advantages such as sustained release, improved bioavailability, and avoidance of first-pass metabolism. This review focuses on the formulation and evaluation of transdermal patches containing Repaglinide and Metformin—two antidiabetic agents with complementary mechanisms of action for the effective management of type 2 diabetes mellitus. Repaglinide, a short-acting insulin secretagogue, and Metformin, an insulin sensitizer, together provide synergistic glycemic control when delivered through the transdermal route. Various formulation techniques such as solvent evaporation, film casting, and matrix dispersion methods are discussed, emphasizing the selection of suitable polymers (e.g., HPMC, PVP, Eudragit, and ethyl cellulose), plasticizers, and permeation enhancers (such as oleic acid, propylene glycol, or DMSO) to optimize drug release and skin permeation. Evaluation parameters including thickness, weight variation, folding endurance, drug content uniformity, moisture uptake, tensile strength, in vitro drug release, and ex vivo permeation studies are reviewed comprehensively. The transdermal patch formulation of Repaglinide and Metformin offers a promising approach for achieving controlled and sustained plasma drug levels, improving therapeutic efficacy, reducing dosing frequency, and enhancing patient compliance in long-term diabetic therapy.

Keywords: Transdermal drug delivery system (TDDS); Repaglinide; Metformin; Type 2 diabetes mellitus; Controlled release.