Supercritical fluids can be used in the production of powders or microparticles with possible use in the pharmaceutical industry. With conventional techniques, there is little control over powder properties, such as particle size. By rapidly depressurizing materials dissolved in CO2, micro-particles are produced with drugs or other components of interest embedded in a substrate. This is accomplished by pumping the mixture through a capillary where the CO2 is vaporized at the outlet, leaving powders behind. This powder has uses such as time released drugs.