Nanoemulsions (NEs) applied as drug delivery systems are particularly convenient to increase solubility and the release of the drug with poor water solubility in water. The aim of this study was to prepare NEs containing Ketoconazole (KTZ), a poorly water-soluble drug, characterize them and evaluate their antifungal activity against Candida albicans. The solubility of KTZ was studied in different essential oils. Clove and sweet fennel essential oils were chosen as the oily phase and Pluronic F127® and Cremophor RH40® as the non-ionic surfactants to take part in the water phase. Formulations were prepared by a high-energy emulsification method and they were evaluated in terms of physical appearance, mean droplet size and polydispersity index. The NEs were successfully obtained and the droplets mean size was less than 100 nm. To verify efficacy of the NEs, the viability and the growth of C. albicans were measured by the propidium iodide influx analysis and by counting colony-forming units (CFU/mL). The results showed that the loss of the fungal membrane integrity and growth decrease were obtained after the treatment with the KTZ NEs containing clove oil (NEs-CL-KTZ) and with the free KTZ. However, the number of non-viable cells were significantly (p < 0.01) higher on the cells treated with NEs-CL-KTZ compared to the free KTZ. The In Vitro drug release profile demonstrated that NEs-CL-KTZ formulation could increase more than nine times the release of KTZ when compared to KTZ cream. To conclude, NEs-CL-KTZ tested in the present study has demonstrated the most efficient formulation for the treatment of C. albicans infections.

Available treatments against human fungal pathogens present high levels of resistance, motivating the development of new antifungal therapies. In this context, the present work aimed to analyze direct electric current (DC) antifungal action, using an in vitro apparatus equipped with platinum electrodes. Candida albicans yeast cells were submitted to three distinct conditions of DC treatment (anodic flow-AF; electroionic flow-EIF; and cathodic flow-CF), as well as different charges, ranging from 0.03 to 2.40 C. Our results indicated C. albicans presented distinct sensibility depending on the DC intensity and polarity applied. Both the colony-forming unit assay and the cytometry flow with propidium iodide indicated a drastic reduction on cellular viability after AF treatment with 0.15 C, while CF- and EIF-treated cells stayed alive when DC doses were increased up to 2.40 C. Additionally, transmission electron microscopy revealed important ultrastructural alterations in AF-treated yeasts, including cell structure disorganization, ruptures in plasmatic membrane, and cytoplasmic rarefaction. This work emphasizes the importance of physical parameters (polarity and doses) in cellular damage, and brings new evidence for using electrotherapy to treat C. albicans pathology process. Bioelectromagnetics. 38:95-108, 2017. © 2016 Wiley Periodicals, Inc.