The hydrochloride salt form of naftifine, an allylamine derivate with synthetic broad-spectrum antifungal activity. Although the exact mechanism through which naftifine hydrochloride exerts its effect is unknown, it appears to selectively inhibit the enzyme squalene 2,3-epoxidase, thereby inhibiting the biosynthesis of sterol. This results in a decreased amount of sterols, especially ergosterol which is the primary fungal membrane sterol, and a corresponding accumulation of squalene in fungal cells. Naftifine hydrochloride can be fungicidal as well as fungistatic to yeasts depending on the concentration and the organisms involved.