A new scalable process to control the particle size and the particle size distribution in active pharmaceutical ingredients (API)​, comprises 5 steps: (i) a suspension prepn. in a mixt. of solvents in which the API and​/or excipient is partially sol. in one of the solvents; (ii) particle size redn. of the suspension; (iii) aging; (iv)​stopping the aging by solvent removal; and (v) optionally, a step of isolating the processed ingredients in the form of powder.