Butenafine -d4 (KP363-d4) is the deuterium labeled Butenafine. Butenafine (KP363) is a potent and broad spectrum benzylamine antifungal agent. Butenafine inhibits fungal ergosterol biosynthesis at the point of squalene epoxidation, leading to a deficiency of the fungal cell membranes. Butenafine is effective against dermatophytes infections, such as ?tinea pedis, ?tinea cruris, tinea versicolor.