Supercritical antisolvent precipitation

Reverchon, E. (1999) Supercritical antisolvent precipitation of micro- and nano-particles. Journal of Supercritical Fluids, 15 (1), 1-21. 

Chapter Eight is concerned with a major question connected with the development of high pressure technologies in the process and chemical industry, i.e., the economic evaluation of production carried out at high pressures. In this case, also, the matter is discussed in relation to three important examples dense gas extraction, polymerization and supercritical antisolvent precipitation processes. 

Novel methods of preparation of vanadium phosphate catalysts have been explored by several groups these methods include hydrothermal synthesis, gas-phase s)mthesis, supercritical antisolvent precipitation, and the use of templates and structure-directing agents to modify the bulk... 

Hutchings and coworkers (78-83) pioneered the use of supercritical antisolvent precipitation to prepare a number of catalyst and support materials including vanadium phosphates. Vanadium phosphate precursor solutions were prepared from VOCI3 and H3PO4 refluxed in isopropanol. In the supercritical antisolvent precipitation method, a solution of the material to be precipitated and supercritical CO2 are pumped through a coaxial nozzle at temperatures and pressures above the critical point of... 

Hutchings and coworkers (78,149,150) prepared vanadium phosphate catalysts by using supercritical antisolvent precipitation. These materials were found to be amorphous by XRD and by electron diffraction, but they showed activity about twice as high as that of the standard vanadium phosphate catalysts. 

FIGURE 28 TEM and electron diffraction pattern (insert) of the vanadium phosphate catalyst prepared via supercritical antisolvent precipitation. 

At present, the most promising process seems to be the supercritical antisolvent precipitation, which is the most widely applied " and has been recently proposed on a semi-industrial scale. However, despite the fact that many works have been published on SAS precipitation, only a limited number of them have focused on the mechanisms controlling particle formation and on the role of the process parameters on the morphology and on the dimensions of the precipitated powders. This lack of information can be one of the main factors hampering the industrial application of this process. 

Case e is the result of precipitation under conditions above the ternary MCP and is the true supercritical antisolvent precipitation. The formation of very small particles indicates that characteristic times for surface tension disappearance are very short, droplets are not formed at the exit of the injector and the very small particles are released from the fluid phase. These aspects have been studied in the previously cited works of Werling and Debenedetti," which underline the interplay among the different consecutive or simultaneous process that characterize SAS, mainly mass transfer under sub-critical and supercritical conditions. The characteristic times... 

Reverchon, E. De Marco, L Caputo, G. Della Porta, G. Pilot scale micronization of amoxicillin by supercritical antisolvent precipitation. J. Supercrit. Fluids 2003, 26 (1), 1-7. 

Reverchon E. Supercritical antisolvent precipitation its applications to microparticle generation and products fractionation. Proceedings of the 5th Meeting on Supercritical Fluids, Materials, and Natural Products Processing. Vol. 1. Nice France, 1998 221-236. 

Baldyga J, Henczka M, Czarnocki R, Shekunov BY. Scale-up of the supercritical antisolvent precipitation process. Inz Ap Chem 2002 41 20-21. 

Reverchon E. Review supercritical antisolvent precipitation of micro- and nanoparticles. J Supercri Fluids 1999 15(1) 1-21. 

Krober H, Teipel U. Materials processing with supercritical antisolvent precipitation process parameters and morphology of tartaric acid. J Supercrit Fluids 2002 22 229-235. 

Reverchon E, Della Porta G. Production of antibiotic micro- and nanoparticles by supercritical antisolvent precipitation. Powder Technol 1999 106 23-29. 

Reverchon E, De Marco I, Della Porta G. Rifampicin microparticles production by supercritical antisolvent precipitation. Int J Pharm 2002 243 83-91. 

Reverchon E, Della Porta G, Pallado P. Supercritical antisolvent precipitation of salbutamol microparticles. Powder Technol 2001 114 17-22. 

Reverchon E. Supercritical antisolvent precipitation of micro-and nanoparticles. J Supercrit Fluids 1999 15 1-21. 

Reverchon E, De Rosa I, Dela Porta G. Elfect of process parameters on the supercritical antisolvent precipitation of microspheres of natural pol5mers. High Pressure Chem Eng 1999 6271 251-254. 

Kompella UB, Koushik K. Preparation of drug delivery systems using supercritical fluid technology. Crit Rev Ther Drug 2001 18 173-199. Reverchon E. Supercritical antisolvent precipitation of micro- and nanoparticles. J Supercrit Fluid 1999 15 1-21. 

RantakylaM, Jantti M, Aaltonen O, Hurme M. The effect of initial drop size on particle size in the supercritical antisolvent precipitation (SAS) technique. J Supercrit Fluids 2002 24 251-263. 

The line for recycling the SCF is also indicated in Figure 2.3-7. Knowledge of the volumetric expansion of the liquid phase with pressure and of the precipitation pressure at the selected temperature are essential for performing any supercritical antisolvent precipitation experiment. The concentration of HC in the starting organic solution also affects the shape and dimensions of the product obtained. 

Bakhbakhi, Y, Asif, M., Chafidz, A., and Ajbar, A. Formation of biodegradable polymeric fine particles by supercritical antisolvent precipitation process. Polymer Engineering and Science 53 (2013) 564-570. 

In the second method the solution is sprayed through a nozzle into compressed carbon dioxide the process is termed as precipitation with compressed antisolvent (PCA) [33] and liquid or supercritical antisolvents can be employed. In the case of continuous flow of the solution and of the antisolvent the process is termed also as aerosol solvent extraction system (ASES) [34], in the case of countercurrent flow and supercritical antisolvent precipitation (SAS) in the case of co-current flow [35]. 

Reverchon, E. (1998) Supercritical Antisolvent Precipitation Its Application to Microparticle Generation and Products Fractionation, Proceedings of the 5 Meeting on Supercritical F/niir,Nice, 221-236. 

RepkaMA, Langley NA, DiNunzio J (2013) Melt extrusion materials, technology and drug product design. AAPS advances in the pharmaceutical sciences series, vol 9. Springer, New York Reverchon E, De Marco I, Delia Porta G (2002) Rifampicin microparticles production by supercritical antisolvent precipitation. Int J Pharm 243(l-2) 83-91... 

Tang, Z., Edwards, J., Bartley, J., Taylor, S., Carley, A., Herzing, A., Kiely, C., and Hutchings, G. (2007) Nanocrystalline cerium oxide produced by supercritical antisolvent precipitation as a support for high-activity gold catalysts. J. Catal,... 

Reverchon, E., De Marco, L, Torino, E. (2007). Nanoparticles production by supercritical antisolvent precipitation A general interpretation. The Journal of Supercritical Fluids, 43, 126-138. 

Reverchon, E., Adami, R., Caputo, G., De Marco, I. (2008). Spherical microparticles production by supercritical antisolvent precipitation Interpretation of results. The Journal of... 

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