Tolnaftate-d7 is intended for use as an internal standard for the quantification of tolnaftate by GC- or LC-MS. Tolnaftate is an antifungal compound used in certain formulations as a topical treatment of infections of the skin.1,2 It inhibits the in vitro growth of clinical isolates of dermatophyte species T. rubrum, T. mentagraphytes, T. verrucosum, E. floccosum, and M. canis with minimal inhibitory concentration 50 (MIC50) values of 0.05, 0.1, 0.006, 0.05, and 0.05 μg/ml, respectively.3 It also exhibits high potency against a wide range of pathogenic yeast and filamentous fungi grown in dextrose broth.4 The predicted target of tolnaftate is squalene epoxidase.5

|1. Adam, J.E., and Craig, G.E. Tolnaftate (tinactin), a new topical antifungal agent. Can. Med. Assoc. J. 93(19), 1004-1005 (1965).|2. Robinson, H.M., Jr., and Raskin, J. Tolnaftate therapy of mycotic infections. J. Invest. Dermatol. 42, 185-187 (1964).|3. Petranyi, G., Meingassner, J.G., and Mieth, H. Antifungal activity of the allylamine derivative terbinafine in vitro. Antimicrob. Agents Chemother. 31(9), 1365-1368 (1987).|4. Waitz, J.A., Moss, E.L., and Weinstein, M.J. Chemotherapeutic evaluation of clotrimazole [Bay b 5097, 1 (o-chloro-α-α-diphenylbenzyl) imidazole]. Appl. Microbiol. 22(5), 891-898 (1971).|5. Gregori-PuigjanÉ, E., Setola, V., Hert, J., et al. Identifying mechanism-of-action targets for drugs and probes. Proc. Natl. Acad. Sci. USA 109(28), 11178-11183 (2012).