Rapid expansion of supercritical solutions (ress ): fundamentals and applications

The rapid expansion of supercritical solutions is a promising new technology for particle formation. The absence of liquid organic solvents, the mild processing temperatures, and the purity of the final product make this process particularly attractive for biomedical applications. In our laboratory, the technique has been used to produce bioerodible polymeric microspheres loaded with a therapeutic drug, a composite suitable for controlled delivery applications. The mathematical modelling of nucleation and growth during the expansion process is useful both in the interpretation of experimental observations, and as a guide for the identification of process conditions leading to unimodal particle size distributions.