Prophylactic Effect of NND-318, a New Antimycotic, on Experimental Dermatophytosis in Guinea Pigs

The prophylactic effect of NND-318 in polyethylene glycol 300 (PEG 300) solution and cream preparation was examined on experimental dermatophytosis in comparison with that of clotrimazole and bifonazole. Each agent was applied to the skin on the back of guinea pigs which were subsequently inoculated with Trichophyton mentagrophytes. When animals were treated once with 1 % NND-318 in PEG 300 solution 1,2,3 and 4 days before the inoculation, the number of infected loci with clinical symptoms was 0/12, 1/12, 0/12 and 2/12, respectively, and fungus-positive rates were 3, 7, 8 and 21%, respectively. Both parameters were significantly lower than those in the groups treated with 1% clotrimazole and 1% bifonazole in PEG 300 solution. When animals were treated once with 0.5% and 1% cream preparations of NND-318 1-4 days before the inoculation, the number of infected loci with clinical symptoms was 1/12-8/12 and 0/12, respectively, with increasing time intervals between drug-pretreatment and fungal challenge, and fungus-positive rates were 26-59% and 0-13%, respectively. Both parameters were significantly or tended to be lower than those in the groups treated with 1% clotrimazole and 1% bifonazole creams, which formulations are already available on the market. Since the prophylactic effect of NND-318 in both PEG 300 solution and cream preparation was better than that of reference agents, it is suggested that a sufficient amount of the antimycotic is retained in the skin tissue in an active form long enough to exert an antifungal effect.