Zinc Oxide Nanoparticles in Cosmetic Products

This study is focused on the evaluation of zinc oxide properties and behavior at commercially available cosmetic ingredients by in vitro methods of dermal absorption of zinc oxide and its subsequent chemical determinations. Two methods for determination of ZnO were used and the results were compared. The spectrophotometric method (SPM) was selected for its sensitivity and atomic absorption spectroscopy (AAS) was selected as a reference method. The study was also aimed at monitoring the samples during storage and evaluation of changes in ZnO properties by photon correlation spectroscopy (PCS). Both methods for determination of zinc oxide content in model samples were in good agreement. In the samples obtained by the dermal absorption higher values were always acquired by SPM method. This difference will be the subject of further investigation. It was also found that the zinc oxide undergo agglomeration in cosmetic product. Key-Words: Zinc oxide, dermal absorption, spectrophotometric determination, atomic absorption spectroscopy