The invention relates to superfine microparticles and nanoparticles and a process for their gentle preparation with exclusion of water or minimization of water and/or exclusion of plasticizers and/or reduced temperature load, in which a matrix material is subjected to a high-pressure homogenization process in an anhydrous or water-poor medium and/or at low temperatures, preferably room temperature (20° C.) and in particular below the freezing point of water, which leads to a gentle particle reduction with minimization of the impairment of the chemical stability of the homogenized material.