the present invention provides a method of producing porous structures , particles or matrixes , which may be comprised of one or a plurality of components , an apparatus for carrying out the method and particles formed in accordance with the method . the method is particularly suitable for producing porous composite or pure particles for pharmaceutical applications . in accordance with the method , a composite comprising a material such as a pharmaceutical , a biodegradable polymers and / or a biological agent is formed . the composite must further comprise a material that is soluble in supercritical fluid . extraction of the supercritical fluid soluble material produces porous structures , which may be in the form of particles or matrixes .