Influence of liposphere preparation on butyl-methoxydibenzoylmethane photostability

The incorporation of butyl-methoxydibenzoylmethane (BMDBM), one of the most efficient and frequently used UV-A blockers, into lipospheres was examined in order to decrease the light-induced sunscreen degradation. Lipospheres, obtained by the melt technique and using tristearin as the lipid material and hydrogenated phosphatidylcholine as the emulsifier, showed proper features in terms of size (10–40 μm), BMDBM loading level (21.63% ± 0.90%, w/w) and physical state. Photolysis studies, involving irradiation of lipospheres with simulated sunlight before and after their introduction in emulsion formulations, demonstrated a relevant enhancement of the encapsulated sunscreen photostability in comparison with unencapsulated BMDBM.