title: Clay facial masks: physicochemical stability at different storage temperatures.
abstract: 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 degrees to 45.0 degrees C. 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.
authors.affiliation: Department of Pharmacy, School of Pharmaceutical Sciences, University of São Paulo, 580 Prof. Lineu Prestes Av., Bl-13, 05508-900, Cidade Universitária, São Paulo, SP, Brazil.
authors.forename: Vivian
authors.initials: V
authors.lastname: Zague
authors.forename: Diego
authors.initials: D
authors.lastname: de Almeida Silva
authors.forename: André Rolim
authors.initials: AR
authors.lastname: Baby
authors.forename: Telma Mary
authors.initials: TM
authors.lastname: Kaneko
authors.forename: Maria Valéria Robles
authors.initials: MV
authors.lastname: Velasco
mesh_terms: D000538:Aluminum Silicates / Q000737:chemistry*; D000077215:Clay; D003116:Color; D003358:Cosmetics / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D017592:Skin Care / Q000379:methods; D013696:Temperature; D014783:Viscosity
chemical_list: D000538:Aluminum Silicates; D003358:Cosmetics; D000077215:Clay