The development of an improved carrier system for sunscreen formulations based on crystalline lipid nanoparticles.

The aim of this study was the in vitro evaluation of the efficacy of two different carrier systems for the molecular sunscreen benzophenone-3. One carrier system was a conventional o/w emulsion, the other consisted of highly crystalline lipid nanoparticles (CLN). It was observed that CLN act as physical sunscreens themselves and show improved photoprotection compared with a placebo emulsion with the same lipid content. Incorporation of a molecular sunscreen further improves the protection level in a synergistic way. This in vitro study based on the Transpore test by Diffey showed that the amount of molecular sunscreen can be decreased by up to 50% while maintaining the UV protection efficacy. Therefore, the use of CLN as an active carrier for sunscreens is a promising innovation.