Therapeutic effects of a novel DA5505 formulation on a guinea pig model of tinea pedis

Background/Objective: Tinea pedis, a superficial mycosal infection affecting the soles and toe webs of feet, is generally treated with terbinafine. However, the main problem with available marketed formulations is their inability to deliver terbinafine to the viable skin layers. Hence, the main aim of this study was to prepare a novel DA5505 formulation capable of penetrating and retaining terbinafine in deeper skin layers.Methods: Skin permeation and retention of terbinafine were analyzed following administration of different formulations (DA5505, Terbinew® gel, Lamisil Cream®, and Lamisil Once®) to mouse and porcine skin in vitro. In vivo efficacy of DA5505 in the guinea pig model was also evaluated.Results: Compared to marketed gel, cream, and solution formulations, DA5505 exhibited significantly higher skin permeation and retention of terbinafine in both mouse and porcine skin (p < 0.05). In vivo skin permeation studies further showed higher terbinafine content with improved pharmacokinetics for DA5505, following a single application similar to Lamisil Once®, compared with those for commercial solution and gel formulations. In addition, in vivo experiments revealed that DA5505 exhibited the highest antifungal effect among the formulations tested, by significantly reducing the number of culture-positive feet and intensity of infection (p < 0.001) in the guinea pig model.Conclusion: Hence, DA5505 exhibits potential for short-course (single application) effective treatment of tinea pedis