Effect of Topical Antifungal Luliconazole on Hyphal Morphology of Trichophyton mentagrophytes Grown on in vitro Onychomycosis Model

Luliconazole, recently launched in Japan, is a novel topical imidazole antifungal agent for the treatment of onychomycosis. Using in vitro onychomycosis model, the effect of luliconazole on the morphology of the growing hyphae of Trichophyton mentagrophytes was investigated by scanning electron microscopy (SEM). The model was produced by placing human nail pieces on an agar medium seeded with conidia of T. mentagrophytes. After incubating the agar medium for 3 days, luliconazole was applied to the surface of the nail in which hyphal growth was recognized, then cultured for up to 24 h. The initial change after treatment with the drug was the formation of fine wrinkles on the surface of the hyphae, eventually, the hyphae were flattened, and after that, no hyphal growth was observed. On the other hand, when the nails were pretreated with luliconazole for 1 h, no hyphal growth was observed even after culturing for 24 h. This study suggests that luliconazole has a strong antifungal activity by inhibiting the ability of fungi to grow and the drug has both excellent nail permeation and retention properties.