ABSTRACT
A supercritical fluid (SCF) process for particles production was first reported in Hannay and Hogarth (1879). In spite of this fact, it was only within the last four decades that supercritical fluid techniques were systematically investigated for micronization of pharmaceuticals, natural substances, pigments, (bio)polymers, superconductor precursors, among others (Tong et al. 2001, Shariati and Peters 2003, Reverchon 1999). Different SCF techniques have been proposed taking advantage of the peculiar properties of the supercritical solvent, particularly supercritical carbon dioxide (scCO2) (Brunner 2004). The SCF is defined as a fluid that is above its critical temperature (T C) and pressure (p C), being CO2 the most common one due to its relatively low critical temperature (31.18°C) and mild critical pressure (7.4 MPa). Feature properties of a SCF are the liquid-like densities, the gas-like transport properties, and the continuous adjustable solvent power by fine tuning the temperature and pressure. Taking advantage of these 328properties, several SCF-based techniques have been developed for particle generation overcoming technical and environmental problems associated to the conventional ones (Türk 2014).
