Physicochemical Characterization and In Vitro Evaluation of the Sun Protection Factor of Cosmetic Products Made from Natural Clay Material

Clay has been widely used as photo protectants in rural places of South Africa. Recently, there are wide range of products which are marketed in SouthAfrica as clay cosmetics which are used for photo protection. In this work, in vitro determination of the sun protection factor (SPF) of newly formulated cosmetics produced from natural clay material from the Bizana region in the Eastern Cape Province of South Africa was performed by spectrophotometric means. The SPF values found for clay material, face cream, foundation, face mask and scrub were 1.18, 18.33, 13.71, 6.74 and 9.53, respectively. The same materials were characterized using thermogravimetric analysis (TGA), Fourier-transforminfrared spectroscopy (FTIR), X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscope (SEM) equipped with energy dispersive spectrometry (EDS) and inductively coupled plasma (ICP). Based on FTIR, XRD, XRF and SEM-EDS results, kaolinite, goethite and quartz were the major minerals found in the clay. Toxic elements such as mercury and cadmium were not detected during ICP analysis; however, traces of lead (0.72-2.14 mg kg(-1)) and arsenic (0.49-0.69 mg kg(-1)) were found in cosmetic products. The results obtained in this study indicate that the cosmetic products manufactured from clay have sun protection ability.