SÉBASTIEN MIKSA*, CÉLINE VINCENT
*Corresponding author
HelioScreen Cosmetic Science, Creil, France

Abstract

Beyond the static sun protection performance provided by sunscreen products against UV radiations, the photoprotection is challenged by consumers in real conditions of use (such as the Water Resistance) but none standardized nor harmonized in vivo or in vitro method are available today concerning the Sand Resistance assessment. For this purpose, a new relevant in vitro method has been developed to allow the evaluation of the Sand Resistance percentage of a sunscreen product by comparing the in vitro SPF before and after a specific agitation in a standardized sand.

INTRODUCTION
Beyond the static sun protection performance provided by sunscreen products against UVB and UVA radiations, the photoprotection is challenged by consumers under real conditions of use such as the Water Resistance, the Rub Resistance, the Sweat Resistance, etc. In this way, one of the factors concerns the Sand Resistance as an important component linked to real condition of use on the beach, but none standardized nor harmonized in vivo or in vitro method are available today. In other terms, the sand resistance of a sunscreen product represents its capacity to retain the photoprotection performance after a contact with sand.

Few proposals have been recently published with in general, a totally different sand application with for example a too vigorous in vitro rub stress (1) (by means of an electric toothbrush) or without an in vivo rub stress (2) (sand was only poured). Moreover, in the vivo study (2), only 1 sunscreen product was tested by only 1 laboratory and according to only 1 method challenging the relevance of the method in terms of value and in terms of reproducibility between operators. Additionally, the sand gr ...