Solid lipid nanoparticles (SLN) are regarded as interesting carriers to improve sunscreens’ safety and effectiveness. In this work, surfactant effects on the physico-chemical properties of SLN loading two of the most widely used UV-filters, octylmethoxycinnamate (OMC) and butylmethoxydibenzoylmethane (BMBM), were evaluated and the interactions between SLN components and loaded UV-filters were investigated by differential scanning calorimetry (DSC).