Particle Size Determination of Mineral-Based Sunscreens: A Complex Analytical Application
Mineral-based sunscreens have gained popularity due to their excellent ability to scatter ultraviolet (UV) rays without causing photo-induced skin irritation from chemical-based sunscreens. Of the 18 U.S. Food and Drug Administration approved active ingredients for sunscreen drug products, only two are mineral based. Zinc oxide remains stable at high temperature and in neutral pH, covers a broad spectrum of UV radiation, and is even mildly antibacterial. Three over-the-counter zine oxide sunscreens were purchased and analyzed using Partica LA-960V2 Laser Diffraction Particle Size Analyzer. A standard 15 mL fraction cell accessory fitted with a magnetic stir bar was chosen for this experiment.