METHOD OF PARTICLE FORMATION

摘要

The invention provides a method for forming particles of a substance 2, comprising: (a) preparing a solution or suspension of the substance in a vehicle 6; (b) introducing the solution or suspension into a particle formation vessel 1 via a fluid inlet means 5; and (c) introducing with the solution or suspension a primary supercritical fluid 8 capable of acting as an anti-solvent for the substance, under conditions which allow the supercritical fluid to extract the vehicle from the solution or suspension and hence cause the formation of particles of the substance; wherein a (preferably supercritical) secondary fluid 12 is introduced into the particle formation vessel with the solution or suspension and/or the primary supercritical fluid, upstream of or at the point at which particle formation occurs, the secondary fluid having a lower capacity for extracting the vehicle than that of the primary supercritical fluid. The invention also provides the use of such a secondary fluid for the purpose of eliminating, at least substantially, blocking of the fluid inlet means and/or of the fluid supply line(s) to the inlet means, in such a particle formation method, and/or for the purpose of reducing pressure fluctuations in the fluid inlet means and/or fluid supply line(s).