The research, published in the International Journal of Cosmetic Science, looked at C-8 xylitol monoester and evaluated its antimicrobial effectiveness in cosmetics formulations.
Good antimicrobial properties
According to the team of scientists based in Brazil, the molecule shows good antimicrobial properties under test conditions, leading them to conclude that it could be an alternative to some of the preservatives available on the market today.
In order to investigate its effectiveness, the team determined the minimum inhibitory concentration for a number of microorganisms including Staphylococcus aureaus, Aspergilus niger and Candida albicans as well as performing a challenge test on the ingredient.
Tests were performed on 1 percent concentration in order to minimise potential toxicity, study author Lilian F. B. Amaral explained.
“…the results we present in the paper refer to 1%. Concentration is also related to toxic effects, thus, it is important perform safety tests before suggesting a higher concentration,” Amaral told CosmeticsDesign.com USA.
At this concentration and under the test conditions, Amaral and the team concluded that the ingredient could be considered as an alternative preservative for cosmetics.
However, results illustrated the ingredient was not as effective against Aspergilus niger as against the other microorganisms.
Commenting on this, Amaral explained that the C-8 xylitol monoester could be used in combination with other preservatives in order to increase its effectiveness.
“According to our knowledge, we can provide an unfavourable environment to A. niger growth and we can also add a fungicide (another preservative) to the formulation,” Amaral said.
More tests needed for regulatory purposes
Although these preliminary results are positive, the researcher did explain that in order for it to be recognised as a cosmetic preservative, a number of supplementary tests would need to be performed on C-8 xylitol monoester.
“The regulation requires a complete dossier, including physico-chemical analysis, safety tests, biodegradability, etc. If we intend to include it in a list of preservatives allowed, we have to continue several studies,” Amaral said.
Source: International Journal of Cosmetic Science
Evaluation of antimicrobial effectiveness of C-8 xylitol monester as an alternative preservative for cosmetic products
L.F.B. Amaral, N.S. Camilo, M.D.C.V. Pereda, C.E. Levy, P. Moriel and P.G. Mazzola