Process for small particle formation

摘要

Disclosed is a process for the preparation of small particles through precipitation. 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: feeding a stream of a fluid solution and a stream of the antisolvent into a mixing zone where both streams are thoroughly mixed to achieve a condition of super saturation while ensuring that hardly any nucleation occurs during the mixing; feeding the resulting mixture of the fluid solution and the antisolvent into a nucleation zone allowing nucleation to commence; allowing the nuclei formed in the nucleation zone to grow to particles with a volume weighted average diameter of no more than 50 mum, preferably of no more than 7 mum.; and collecting the particles and separating them from the antisolvent.