Interazioni tra conservanti e maschere di Biocellulosa - Interactions between preservatives and Biocellulose masks.

The focus of this work was to compare the behavior of two preservatives towards an innovative material, such as biocellulose, in order to find the one that best suited the formulation of a very popular cosmetic product from a commercial point of view, that are the disposable face masks. The formulation of face masks using a biodegradable material such as biocellulose allows to have a lower environmental impact than the classical polymers used in this field, in addition to all the beneficial properties of this material for the skin, such as for example a deeply moisturizing and soothing effect. The two preservatives chosen for this study, Levulinic Acid and Phenoxyethanol, are different both from a chemical point of view and as regards their mechanism of action. Furthermore, Levulinic Acid falls into the category of "non-preservative preservatives", while Phenoxyethanol is a classic chemical preservative. The choice of using a non-preservative preservative such as Levulinic Acid allows us to fulfill the claim "Preservative free", which is very popular in the cosmetic field in recent years and it is linked to the growing awareness of the possible aggressive impact of classic chemical preservatives on the skin microbiota. The study involved different steps, starting from adsorption studies and ending with an in vivo study on selected volunteers. The final goal was to evaluate which of the two preservatives showed the desired behaviour, that is being adsorbed by the mask, but then not released on the skin of the volunteers subjected to the tests, so as not to interfere with their cutaneous bacterial flora.