PROCESS FOR SMALL PARTICLE FORMATION

摘要

The present invention is concerned with a process for the preparation of small particles through precipitation. More particularly, the present invention relates to such a process which employs a fluid solution comprising a solvent and solute to be precipitated and a non-gaseous antisolvent, said solvent being soluble in or miscible with the antisolvent and said solute being substantially insoluble in the antisolvent, wherein the process comprises the successive steps of: a. feeding a stream of the fluid solution and a stream of the antisolvent into a mixing zone (5) where both streams are thoroughly mixed to achieve a condition of super saturation whilst ensuring that hardly any nucleation occurs during the mixing; b. feeding the resulting mixture of the fluid solution and the antisolvent into a nucleation zone (6) allowing nucleation to commence; c. allowing the nuclei formed in the nucleation zone the grow to particles with a volume weighted average diameter of no more than 50 ~m, preferably of no more than 7 ~m. d. collecting the particles and separating them from the antisolvent.