Exhaustive Review on Nail Lacquer in the Treatment of Nail Diseases

Abstract

The delivery of drugs through the transungual route is necessary because many nail diseases such as onychomycosis, psoriasis, paronychia, and onycholysis require topical drug delivery through the nail plate to avoid the systemic side effects of drugs first-pass hepatic metabolism and to provide direct benefits at the site of disease. However, topical delivery is associated with the main drawback of poor permeability of drugs through the nail plate. The nail plate contains tight networks of cross-linked protein (keratin) that provide hardness to the nail. Successful permeation of drugs through this nail barrier can be achieved by mechanical or chemical approaches. The chemical methods (penetration enhancers) are mainly associated with the disruption of nail integrity. Nail lacquers are the most popular dosage form from the formulation viewpoint. As the solvent evaporates, lacquers create polymeric drug-loaded films on the nail tissue that have a high concentration of the drug and allow for prolonged contact with the tissue. The present article focuses on the emergence of nail lacquers as prospective transungual delivery systems for the treatment of various mild to moderate nail diseases.