A method for producing crystalline microparticles of active substance isprovided, comprisingthe steps in which a suspension is prepared from primary particles of theactive substance, asolution of the active substance, non-solvent for the active substance andinert formed pieces,the suspension is mixed, whereupon the active substance crystallizes out ofthe suspension, theactive substance is separated in the form of product particles and the productparticles are thendried, wherein the primary particles and the product particles arecrystalline, are in the moststable crystal modification of the active substance, have a crystal surfacearea of 3-10 m2/g andthe size distribution of the primary and product particles is each d50 = 1-2µm, d99 <； 6 µm andd100 <； 12 µm. Furthermore, microparticles of active substance and a solidform of particles ofactive substance obtainable according to the method are provided.
