Characterization of Functional Nanomaterials in Cosmetics and its Cytotoxic Effects

Abstract

The ultraviolet (UV) rays from sun are generally divided in three types such as UVA (315~400 nm), UVB (280~315 nm) and UVC (100~280 nm). Among these, the UVC rays with the highest energy get absorbed completely as they pass through the atmospheric layer. The UVA and UVB rays which penetrate through the atmospheric layer pose a threat for the humankind due to its carcinogenic nature to human skin. Hence it is necessary to develop the cosmetics which absorb the UV rays to prevent the damage of the skin. Generally, the Tinosorb M (2,2'Methyl-enbis[6-(2H benzotriazol-2- yl)-4-(1,1,3, 3-tetra-methylbutyl) phenol]) is mixed in the cosmetics which absorb UVB rays. But almost 97% of the UV rays consist of UVA rays which are mainly responsible for the damage of skin. Recently, the sun-screening cosmetics containing the nanoparticles such as ZnO and TiO2 nanoparticles or nanorods have attracted great attention for protecting skin from UVA by reducing the amount of UVB penetrating into the skin due to the reflection and scattering. Therefore, it is necessary to investigate the risk factors involved in the usage of these nanoparticles in cosmetics. The present studies involve the characterization of cosmetics containing TiO2 and ZnO nanoparticles and its comparison with the commercial samples. The absorbance measurements in the range of UVA were performed in order to determine the absorption efficiency of nanoparticles extracted from the cosmetics samples. The transmission electron microscopic analysis revealed the morphology of the nanoparticles. The in vitro cell viability tests were performed as a function of particles size in order to determine the cytotoxicity of the nanoparticles. © International Federation of Medical and Biological Engineering 2009.