To investigate the in vivo antimycotic activity of
bifonazole, a new
imidazole antifungal agent, the therapeutic effectiveness of several
bifonazole preparations in the topical treatment of experimental
Trichophyton mentagrophytes infection in guinea-pigs was tested. 1% cream, 1%
solution or 1%
polyethylene glycol solution of
bifonazole was applied to infected sites on the skin at a dose of 0.3 g/day for 14 or 21 consecutive days, starting on the 3rd or 5th day after the
infection. In all experiments,
clotrimazole was employed as a reference
drug in comparable formulations. The estimation of efficacy of treatment with active formulations was made on the basis of the score of skin lesion and the rate of positive skin cultures in comparison with those for infected, untreated or placebo-treated controls. The results are summarized as follows: (1) The treatment with each
bifonazole preparation resulted in a significant improvement in local symptoms and complete heal
as 6-10 days after initiation of application. After completion of the 14-day or 21-day treatment course, local skin cultures revealed either an elimination of or a significant decrease in the viable fungus count. (2) The therapeutic effectiveness of
bifonazole appeared to be dependent on the
duration of treatment; treatment in the 21-day course was more effective than that in the 14-day course, irrespective of the type of
drug preparation. All these results clearly demonstrate a favorable topical efficacy of each
bifonazole preparation in the guinea pig
dermatophytosis model.