Patent ID: 7279181

Claim:
A method of producing particles comprising: providing a supercritical fluid or compressed gas having a surfactant dissolved therein; providing a solution comprising one or more solutes dissolved in one or more solvents; contacting the solution and the supercritical fluid or compressed gas having the surfactant dissolved therein together in a dispersion assembly to form a stabilized solution-in-supercritical fluid or compressed gas emulsion having a continuous phase comprising the supercritical fluid or compressed gas and a discontinuous phase comprising the solution; spraying the stabilized solution-in-supercritical fluid or compressed gas emulsion through an orifice across a pressure drop in the form of spray droplets into an expansion vessel that is maintained at a pressure and a temperature sufficient to cause at least a portion of the supercritical fluid or compressed gas to decompress into a gas phase and to cause the discontinuous phase of the solution-in-supercritical fluid or compressed gas emulsion in the spray droplets to freeze and thus form frozen particles; and freeze-drying the frozen particles to obtain particles comprising the one or more solutes that are substantially devoid of the one or more solvents and the supercritical fluid or compressed gas.