Selected Essential Oils in Cosmetic Emulsions: Process Oriented Stability Studies and Antimicrobial Activity

Abstract

Essential oils show self-preserving properties, which gives an opportunity for the cosmetic industry to reduce or even eliminate the application of synthetic preservatives like parabens, which are thought to be endocrine-disrupting compounds. The present study was focused on advancing of our understanding on antibacterial and antifungal properties of essential oils in cosmetic products. Especially, towards the development of practical and applicable aspects of abovementioned natural products. Presented procedures and results can be easily up-scaled and transferred to cosmetic industry. Results comprising procedure for preparation of a stable cosmetic emulsion using essential oils as natural preservatives, the evaluation of its stability by the turbidimetric method and estimation of preserving capabilities of essential oils including comparison with commonly used synthetic preservatives are presented in this present study. The stability evaluation of cosmetic emulsions revealed that the most stable emulsion is one comprising citrus oil (C= 2%) and vitamin E (C= 1.5%). The most unstable compositions are ones with rosemary oil (C= 2%), vitamin E (C= 1.5%) and citrus oil (C= 1%). Microbiological tests showed that the prepared emulsions consist of less than 10 CFU/g, which proves that the compositions are microbial clean and thus high quality.

These results confirm our hypotheses that essential oils can be effective natural preservatives in cosmetic formulations with concurrent stability and other features oriented on the possible commercial application.