Role of Phase Behavior and Atomization in the Supercritical Antisolvent Precipitation
An experimental study on supercritical antisolvent (SAS) precipitation has been performed to gain insight into the role of phase behavior and atomization in controlling morphology and dimension of precipitates. The mixture yttrium acetate/dimethyl sulfoxide has been used as the main model system and supercritical CO 2 has been used as the antisolvent. Two SAS apparatuses (laboratory and pilot scale) with two injector arrangements and operating with various injector diameters in the range 60-500 μm have been used. The results showed that operating above the mixture critical point (MCP) of the ternary mixture yttrium acetate/dimethyl sulfoxide/ carbon dioxide, sub-micrometric particles are ge…
Nimesulide adsorbed on silica aerogel using supercritical carbon dioxide
Silica aerogel (SA) was loaded with nimesulide, a drug model compound, to demonstrate the potentiality of adsorption processes based on the usage of supercritical carbon dioxide to treat poorly water-soluble drugs, forming new kinds of drug delivery systems. Adsorption isotherms and kinetics were measured and described by models. The effect of pressure, temperature and solution concentration on loaded SA were also studied. Modelling of kinetic data showed that the sorption process was best described by a pseudo-second-order model. The adsorption isotherm data were best fitted by the Freundlich isotherm. The drug/SA composites were characterized using scanning electron microscopy, X-ray micr…