The Supercritical Fluid Extraction of Emulsions (SFEE) uses supercritical carbon dioxide to remove the organic solvent from an emulsion, causing the precipitation of active compounds dissolved in this organic phase. Compared with alternative conventional techniques such as the evaporation of emulsions, in SFEE the time scale of the precipitation is reduced to fractions of second, making it possible to produce very small and highly homogeneous particles.
During the extraction, each solvent drop behaves as a miniature supercritical antisolvent precipitator, thus allowing to achieve a very controlled reduction of particle size down to the sub-micrometric or nanometric scale.
Besides reducing particle size, by dispersing the micro and nanoparticles of the active compound inside micelles of the surfactant used to form emulsions, a stable aqueous dispersion of poorly water-soluble active compounds can be obtained.
This technique is best suited for the processing of sensitive natural and pharmaceutical compounds. Some applications developed in our group include carotenoids (beta-carotene, lycopene, astaxanthin) and quercetin.
Recent updates of our progress with this technique can be found in posts of Gyorgy Lévai.