A Comprehensive Review on Transungual Drug Delivery: From Nail Anatomy to Treatment of Onychomycosis

Transungual drug delivery refers to the administration of therapeutic agents through the nail plate, providing a direct and effective route for treating localized nail and nail bed disorders. This review explores the anatomy of the nail, the factors influencing drug diffusion through the nail, and the challenges and strategies in overcoming these barriers. The nail’s unique structure, including its multiple layers and permeability properties, plays a crucial role in the effectiveness of transungual delivery systems. Additionally, the review highlights common nail diseases, particularly onychomycosis—a fungal infection that significantly impacts both health and quality of nail. This review article explores the various types of onychomycosis, its underlying pathophysiology, and current pharmacological treatments, with a particular focus on antifungal agents. Additionally, transungual delivery methods, including topical therapies and novel formulation approaches, are critically examined for their potential to enhance therapeutic outcomes. Finally, we explore advancements in topical therapies, including formulations and technologies designed to enhance drug penetration and efficacy, offering insights into promising future directions in transungual drug delivery for treating nail diseases, particularly onychomycosis.