Preservation of topical formulation using mycocins produced by Wickerhamomyces anomalus

Abstract

After reports of adverse reactions and endocrine disruption caused by some preservatives such as parabens, widely used in topical formulations and medicines, the cosmetic and pharmaceutical industry faces a considerable lack of additives with less toxicity, triggering interest in the search for the development of new preservative systems safe and effective. Natural substances with a broad spectrum of antimicrobial activity are interesting alternatives for the research of new preservatives. Mycocins are natural substances produced by killer yeasts. They have the potential to inhibit bacteria, filamentous fungi and yeast with a broad spectrum of action, low toxicity and low probability of inducing microbial resistance. This study aimed to verify the preservative activity of mycocins produced by Wickerhamomyces anomalus when incorporated into dermatological gels, stability of mycocins in the formulation and membrane irritation potential. β-glucanases determination assays, β-glucanase assay, microdilution, Challenge Test to evaluate the effectiveness of preservative action, stability tests and membran irritability assay in organotypic model. The WA92 supernatant showed β-glucanase activity of 3.80 U/mg. In the microdilution assay, all standard microorganisms tested were sensitive to WA92 mycocins at their maximum concentration of 3.80 U/mg. In the Challenge Test, the preservative efficacy criteria were met for bacteria, filamentous fungus and yeast. The results comprised a stable and non-irritating gel formulation using mycocins as a preservative at different concentrations, evaluation of stability through viscosity, density and pH and estimation of the preservative capacity of mycocins including comparisons with commonly used preservatives were showed in this study.