Patent ID: 7455797

Claim:
A method of producing a particulate suspension comprising: providing: a supercritical fluid; a first solvent that is soluble in the supercritical fluid; a second solvent that is substantially insoluble in the supercritical fluid and is at least partially soluble in or miscible with the first solvent; and a solute that is soluble in the first solvent and is substantially insoluble in the second solvent and the supercritical fluid; contacting the first solvent, the second solvent and the solute together to form a solution; contacting the solution with the supercritical fluid in an extraction chamber maintained at a temperature and pressure above the critical point of the supercritical fluid, the supercritical fluid extracting the first solvent from the solution and thereby causing the solute to precipitate in the form of particles that become suspended in the second solvent and thus form the particulate suspension; and separating the particulate suspension from the first solvent by flowing the first solvent out of the extraction chamber with the supercritical fluid via a backpressure regulator, separately flowing the particulate suspension out of the extraction chamber and into a collection vessel, isolating the collection vessel from the extraction chamber, and draining the particulate suspension from the collection vessel.