Microparticle production technique is presently a major development of dense gas antisolvent precipitation applications

mainly in the pharmaceutical

food

cosmetic and specialty chemical industries. In this paper the process flow schemes and characteristics of GAS(SAS)，ASES，SEDS and PGSS are introduced respectively

both mono-constituent and composite microparticles

which make the controlled release of active components practicable

could be produced by using the four processes previously described. Comparatively speaking

the feasibility of producing dry uniformly sized micronised material by using dense gas antisolvent technology has been well established on laboratory or bench scale except for that specific experimental phenomena could not be explained satisfactorily.The relationship between particle size

morphology and operating conditions has not been exactly correlated yet.Translating these advantages to commereial scale remains a challenge for engineers. To date few models have been successfully applied to the above processes as relatively little is known about the nature of dense gas antisolvent precipitation.Models are correlative rather than predictive. The inherent relationship among unit dimension

construction of equipment

process parameters

particle size and morphology has not been established because the dominant controlling factors are not thoroughly understood. Based upon an analysis of these processes

the scale-up pathway

current issues relating to antisolvent micronisation techniques and the focus in further fudy are addressed.