The vehicle used in the topical antifungal efinaconazole 10% spread into the subungual space between the nail bed and nail plate, reaching the site of infection in patients with toenail onychomycosis, according to results from a small study.
Efinaconazole topical solution 10% has a broad spectrum of antifungal activity against the organisms most associated with toenail onychomycosis and has shown efficacy in two phase III trials, reported Dr. Boni E. Elweski of the University of Alabama, Birmingham, and her colleagues in the Journal of Drugs in Dermatology (J. Drugs Dermatol. 2014;13:1394-98). The vehicle for the topical solution was developed with low surface tension to create a greater probability of nail plate permeation and access through the subungual space, the study authors wrote.
To assess the effectiveness of the solution in reaching the site of infection, the researchers applied the vehicle to the toenails of 11 adult patients with moderate to severe onychomycosis. Two drops of test material (saturated fluorescein 0.6% in vehicle solution) were applied to the distal end of the toenail, and a brush was used to spread the solution below the surface of the nail and distal skin area in contact with the nail. Standard and UV pictures of the toenails were taken after 20-30 minutes, and the process was repeated 40-45 minutes later. Approximately 1-2 mm of the affected toenail was clipped, photographed, and clipped again.
The findings showed that the vehicle had spread into the subungual space, with deposition of fluorescein seen wherever the vehicle had reached, including the nail bed. Nail clippings also showed deposition to the underside of the nail plate. The data support the instructions for the use of efinaconazole topical solution 10%, which specifically state that the solution be brushed on the skin around the nail as well as the nail plate, the authors said. However, they noted that the study was performed without the active drug, and that results could differ if efinaconazole were included.
All of the study authors are either advisers for, or employees of, Valeant Pharmaceuticals, manufacturer of topical 10% efinaconazole.