Glycerol-Filled Silicone Adhesive Patches With Excellent Sun Protection

Numerous medical conditions such as cancer, eczema, moles, and burns may leave patients with increased sensitivity to UV light. A UV-protective patch that provides a healing environment for sensitive or broken skin is therefore developed from two-phase glycerol-silicone adhesives. The adhesives are prepared using a simple processing method in which high shear forces mix glycerol and silicone prepolymers that are subsequently cured to form a stable, free-standing adhesive containing inherent discrete glycerol droplets. These materials are excellent candidates for wound care adhesives, since glycerol increases the silicone adhesives' water absorption while providing low peel forces and gentle adherence to the skin. Adhesives show increased sun protection properties with increasing glycerol content. When TiO2, a well-known ingredient in sunscreen products, is added to the glycerol-filled silicone adhesives, the sun protection factor reached SPF 100 without compromising the mechanical or peel strength properties. Further, the sun protective properties of the TiO2-filled glycerol-silicone adhesives prove to be stable when exposed to 80% relative humidity for 20 h to simulate performance during typical usage.