A COMPREHENSIVE REVIEW ON TRANSDERMAL DRUG DELIVERY SYSTEMS FOR PAIN MANAGEMENT: FORMULATION APPROACHES AND CLINICAL PERSPECTIVES

Transdermal drug delivery systems (TDDS) represent a modern and patient-friendly approach for pain management, offering several advantages over conventional oral and injectable routes. By delivering medication directly through the skin, these systems avoid first-pass hepatic metabolism, provide steady plasma drug levels, and improve overall therapeutic effectiveness and patient adherence. This review outlines the evolution of transdermal patches and their role in managing acute, chronic, neuropathic, and musculoskeletal pain. Clinically approved synthetic patches such as fentanyl, nicotine, nitroglycerin, clonidine, and lidocaine demonstrate the practical success of this technology. In addition, herbal-based patches containing bioactive compounds like capsaicin, curcumin, menthol, boswellic acid, aloe vera, and gingerol show promising potential for localized therapy with minimal systemic effects. Common formulation techniques, including solvent casting and membrane-based methods, are also discussed. Although limitations such as skin barrier resistance remain, ongoing advancements in polymers, permeation enhancers, and innovative delivery strategies continue to strengthen the future of transdermal pain therapy.