Luliconazole-loaded nanostructured lipid carrier: formulation, characterization, and in vitro antifungal evaluation against a panel of resistant fungal strains

Luliconazole (LCZ) is a topical imidazole antifungal agent with broad-spectrum activity. However, LCZ encounters challenges such as low aqueous solubility, skin retention, and penetration, which reduce its dermal bioavailability and hinder its efficacy in drug delivery. The aim of the present study was to formulate, characterize, and evaluate the in vitro antifungal efficacy of luliconazole-loaded nanostructured lipid carriers (LCZ-NLCs) against a panel of resistant fungal strains. The LCZ-NLCs were synthesized using a modified emulsification-solvent evaporation technique. Characterization involved assessing parameters such as poly-dispersity index (PDI), zeta potential, encapsulation efficiency (EE %), Field Emission Scanning Electron Microscopy (FESEM), Differential Scanning Calorimetry (DSC) analysis, and Attenuated Total Reflectance Fourier Transform Infrared (ATR-FTIR). Furthermore, in vitro drug release experiments, analysis of release kinetics, cytotoxicity assessments, and in vitro antifungal susceptibility tests were performed as part of the study. The findings indicated that LCZ-NLCs displayed nanoscale dimensions, uniform dispersion, and a favorable zeta potential. The encapsulation efficiency of LCZ in NLCs was approximately 90%. FESEM analysis revealed spherical nanoparticles with consistent shape. ATR-FTIR analysis indicated no chemical interaction between LCZ and excipients. In vitro drug release experiments demonstrated that LCZ-NLCs notably improved the drug's dissolution rate. The stability testing confirmed consistent colloidal nanometer ranges in the LCZ-NLCs samples. Additionally, cytotoxicity tests revealed no toxicity within the tested concentration. Moreover, in vitro antifungal susceptibility tests demonstrated potent antifungal activity of LCZ-NLCs against the tested resistant fungal isolates. The study findings suggest that the LCZ-NLCs formulation developed in this research could be a promising topical treatment for superficial fungal infections, especially in cases of resistant infections. However, the study needs further ex vivo and in vivo tests to ensure safety and efficacy.