Clay facial masks--formulations that contain a high percentage of solids dispersed in a liquid vehicle--have
become of special interest due to specific properties presented by clays, such as particle size, cooling index,
high adsorption capacity, and plasticity. Although most of the physicochemical properties of clay dispersions
have been studied, specific aspects concerning the physicochemical stability of clay mask products remain
unclear. This work aimed at investigating the accelerated physicochemical stability of clay mask formulations
stored at different temperatures. Formulations were subjected to centrifuge testing and to thermal
treatment for 15 days, during which temperature was varied from -5.0 ø to 45.0øC. The apparent viscosity
and visual aspect (homogeneity) of all formulations were affected by temperature variation, whereas color,
odor, and pH value remained unaltered. These results, besides the estimation of physicochemical stability
under aging, can be useful in determining the best storage conditions for clay-based formulations.