Abstract
Supercritical carbon dioxide has been thought to be new-type attractive solvents and has been applied in pharmaceutical material processing because their solvent power is moderate, and their transport properties are favorable in mass transfer rates. Particle production technologies using supercritical carbon dioxide are relatively new and efficient approach to prepare high purity （solvent-free） and fine particles. First, this article has described the solvent characteristics such as solubility and the structure of supercritical carbon dioxide. Second, this article has reviewed several recently proposed particle production technologies using supercritical carbon dioxide. In particular, rapid expansion of supercritical solutions （RESS） technique using supercritical carbon dioxide has been paid much attention and has been expected as an effective and environmentally friendly nanoparticle design method. The study on the production of drug nanoparticles via the RESS technique using supercritical carbon dioxide has been presented in this article. We successfully produced nanoparticles （about 200 nm） of RS-（±）-ibuprofen. We have also proposed the particulate design by the RESS based on the supersaturation between a section of preparing a supercritical solution saturated with a solute and that of production of solid particles.
