Transungual delivery of efinaconazole: its deposition in the nail of onychomycosis patients and in vitro fungicidal activity in human nails.

Background: Effective transungual delivery of topical antifungal agents in onychomycosis has been hampered by poor nail permeation. To be effective they must have antifungal efficacy, and effectively permeate through the dense keratinized nail plate to the site of infection in the nail bed and nail matrix. The therapeutic efficacy of efinaconazole topical solution, 10% has been established in two phase 3 clinical trials in distal lateral subungual onychomycosis.

Safety and pharmacokinetics of efinaconazole 10% solution in healthy volunteers and patients with severe onychomycosis.

Objectives: To characterize the systemic exposure and pharmacokinetics of efinaconazole 10% solution and assess the potential for drug-drug interaction (DDI) in human volunteers and onychomycosis patients following topical administration.

Methods: Two single-center, open-label studies in healthy volunteers and severe onychomycosis patients. Efinaconazole 10% solution was applied topically to all 10 toenails (0.