The present invention provides a method for the production of porous particles that involves extracting an organic solvent from a water-in-oil-in-water emulsion. In accordance with the method of the invention, a first aqueous solution including a porosity-promoting agent is emulsified into an organic solution including a therapeutic constituent and, optionally, a matrix material to form a water-in-oil emulsion. The water-in-oil emulsion is then emulsified into a second aqueous solution including a surfactant to form the water-in-oil-in-water emulsion. Extraction of the organic solvent from the water-in-oil-in-water emulsion, such as by supercritical fluid extraction, causes the therapeutic constituent and optional matrix material to precipitate and thus form an aqueous suspension of porous particles. The aqueous suspension can be centrifuged, filtered and lyophilized to obtain dry porous particles suitable for use in the deep lung delivery of drugs and other therapeutic agents.