A pharmaceutical composition comprises, as a therapeutically active ingredient, a corticosteroid and/or vitamin D derivative incorporated as a solid solution or dispersion in lipid nanopartides, said lipid nanopartides being solid at ambient temperature and comprising a first lipid with a melting point above body temperature, the first lipid being a wax selected from the group consisting of esters of C12-24 alcohols and C12-24 fatty acids, glyceryl mono-, di- or triesters of C12-24 fatty acids, C12-24 fatty alcohols, and cholesterol, optionally a second lipid which is an oil at ambient temperature and miscible with the first lipid, and a pharmaceutically acceptable surfactant.