Determination of the Efficacy of Terbinafine Hydrochloride Nail Solution in the Topical Treatment of Dermatophytosis in a Guinea Pig Model

The study evaluated the efficacy of terbinafine HCl nail solutions (TNS) in treating dermatophytosis using a guinea pig model. The formulations included a nail penetration enhancer, DDAIP HCl, and were compared to ciclopirox nail lacquer, the only FDA-approved topical treatment for onychomycosis at the time. The study involved 11 groups of guinea pigs, each with 5 animals, treated with various concentrations of TNS and DDAIP HCl. Results showed that TNS, both with and without DDAIP HCl, achieved 100% mycological efficacy, significantly outperforming ciclopirox. The addition of 0.5% DDAIP HCl to 5% and 10% TNS notably improved clinical efficacy. The findings suggested that TNS formulations, especially those enhanced with DDAIP HCl, were highly effective and warranted further clinical trials for treating dermatophytosis and onychomycosis.