Methods for particle micronization and nanonization by recrystallization from organic solutions sprayed into a compressed antisolvent

Abstract

A method and an apparatus useful for the production of microparticles and nanoparticles are disclosed in which a compressed fluid and a solution including a solvent and a solute are introduced into a nozzle to produce a mixture. The mixture is then passed out of the nozzle to produce a spray of atomized droplets. The atomized droplets are contacted with a supercritical antisolvent to cause depletion of the solvent in the droplets so that particles are produced from the solute. Preferably, these particles have an average diameter of 0.6 μm or less. The invention can be used in the pharmaceutical, food, chemical, electronics, catalyst, polymer, pesticide, explosives, and coating industries, all of which have a need for small-diameter particles.