Nanometric Systems Containing Ozonated Oil with Potential Activity against Skin Pathogens

ABSTRACT

Some antimicrobial substances have unwanted side effects, besides difficulty in crossing the stratum corneum, prompting the need to search for alternative treatments. Ozonated vegetable oils present activity against some fungi and bacteria. This study has aimed to develop and characterize nanoemulsions and polymeric nanocapsules containing 5% ozonated sunflower seed oil for skin application with potential activity against skin pathogens. The formulations were obtained by interfacial deposition of preformed polymer (polymeric nanocapsules) and emulsification followed by Ultra-Turrax® agitation (nanoemulsion). The nanometric systems were evaluated in terms of their organoleptic and physicochemical properties, as well as ozonides presence. The stability of the systems was analyzed by centrifugation (pre-stability) and after 30 days in oven (40 °C) and refrigerator (4 °C) conditions. The antimicrobial activity was determined in vitro using dermatophytes, Candida and Staphylococcus species. Both formulations appeared white and homogeneous, with typical ozonated oil odor. The mean diameters and pH values were, respectively, 139 ± 7.6 nm and 3.2 ± 0.1 for the nanoemulsion and 149 ± 6.1 nm and 3.3 ± 0.2 for the polymeric nanocapsules. Zeta potential was −9 mV (nanoemulsion) and +11 mV (polymeric nanocapsules). The presence of ozonides was confirmed by FT-IR and the nanometric systems were considered stable. Susceptibility tests showed greater potential for the nanometric systems containing ozonated oil against fungi, especially dermatophytes. It was possible to increase the antimicrobial efficacy of the ozonated oil for eighteen of the twenty pathogen isolates tested. Thus, the developed nanometric systems containing ozonated oil may be considered potential treatments for skin infections.

KEYWORDS:

• Ozone
• Bacteria
• Fungi
• Nanocapsules
• Nanoemulsion
• Pathogens
• Skin

Data availability statement

The data that support the findings of this study are available from the corresponding author, RVC, upon reasonable request.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This research was financially supported by “Conselho Nacional de Desenvolvimento Científico e Tecnológico – CNPq” (project numbers 423066/2018-8, 141883/2018-9 and 314680/2021-7) and “Universidade Federal do Rio Grande do Sul (project number 37701)”. We acknowledge Evonik for their Eudragit® RS100 donation and professor Dr. Silvia Stanisçuaski Guterres for the access to the equipment for nanoparticle characterization.