[Antifungal Activity of Luliconazole Nail Solution on in vitro and in vivo Onychomycosis Model]

Luliconazole Nail Lacquer for the Treatment of Onychomycosis: Formulation, Characterization and In Vitro and Ex Vivo Evaluation

Onychomycosis is the most common fungal infection of the nail affecting the skin under the fingertips and the toes. Currently, available therapy for onychomycosis includes oral and topical therapies, either alone or in combination. Oral antifungal medication has been associated with poor drug bioavailability and potential gastrointestinal and systemic side effects. The objective of this study was to prepare and evaluate the luliconazole nail lacquer (LCZ-NL) for the effective treatment of onychomycosis. In the current work, LCZ-NL was formulated in combination with penetration enhancers to overcome poor penetration. A 3² full factorial formulation design of experiment (DOE) was applied for optimization of batches with consideration of dependent (drying time, viscosity, and rate of drug diffusion) and independent (solvent ratio and film former ratio) variables. The optimized formulation was selected based on drying time, viscosity, and rate of drug diffusion. The optimized formulation was further evaluated for % non-volatile content assay, smoothness of flow, water resistance, drug content, scanning electron microscope (SEM), atomic force microscope (AFM), X-ray diffraction (XRD), differential scanning calorimetry (DSC), in vitro drug release, ex vivo transungual permeation, antifungal efficacy, and stability study. The optimized LCZ-NL contained 70:30 solvent ratio and 1:1 film former ratio and was found to have ~ 1.79-fold higher rate of drug diffusion in comparison with LULY™. DSC and XRD studies confirmed that luliconazole retains its crystalline property in the prepared formulation. Antifungal study against Trichophyton spp. showed that LCZ-NL has comparatively higher growth inhibition than LULY™. Hence, developed LCZ-NL can be a promising topical drug delivery system for treating onychomycosis.

A comparative study between two antifungal agents, Luliconazole and Efinaconazole, of their preventive effects in a Trichophyton-infected guinea pig onychomycosis model

An efficacious period of two topical antifungal drugs was compared in a Trichophyton mentagrophytes-infected onychomycosis model in guinea pigs treated with antifungal drugs prior to infection. Luliconazole 5% (LLCZ) and efinaconazole 10% (EFCZ) test solutions were applied to the animals’ nails once daily for 2 weeks followed by a nontreatment period of 2, 4, and 8 weeks. After each nontreatment period, the nails were artificially infected by the fungus. Drug efficacy was quantitatively evaluated by qPCR and histopathological examination of the nails collected following a 4-week post-infection period. The fungal infection was confirmed in the untreated group. Both LLCZ and EFCZ prevented fungal infection in the treated groups with the nontreatment period of 2 weeks. After the nontreatment period of 4 weeks, no infection was observed in the LLCZ-treated group; however, infection into the nail surface and fungal invasion into the nail bed were observed in the EFCZ-treated group. After the nontreatment period of 8 weeks, fungi were found in the nail surface and nail bed in some nails treated with EFCZ; however, no infection was observed in the nail bed of the LLCZ-treated group. The results suggest that LLCZ possesses longer-lasting antifungal effect in nails of the guinea pigs than EFCZ, and that this animal model could be useful for translational research between preclinical and clinical studies to evaluate the pharmacological efficacy of antifungal drugs to treat onychomycosis. This experimentally shown longer-lasting preventive effects of LLCZ could also decrease the likelihoods of onychomycosis recurrence clinically.