Solid lipid nanoparticle compositions containing (a) 1 to 40% by weight of an oil-soluble UV absorber, (b) 20 to 98.9% by weight of a solid lipid, (c) 0.1 to 20% by weight of an emulsifier and (d) 0 to 40% by weight of a liquid lipid or a liquid oil-miscible UV absorberThe compositions according to the invention enhance the solubility behaviour of oil-soluble UV filters in cosmetic formulations and thereby also improve their effectiveness.