Supercritical fluid technologies processes

Generating surface-modified, submicrometersized particles of water-insoluble drugs with supercritical fluid technology processes IDD technology. Acquired Phasex s proprietary SCF- based processes. 

The two fluids most often studied in supercritical fluid technology, carbon dioxide and water, are the two least expensive of all solvents. Carbon dioxide is nontoxic, nonflammable, and has a near-ambient critical temperature of 31.1°C. CO9 is an environmentally friendly substitute for organic solvents including chlorocarbons and chloroflu-orocarbons. Supercritical water (T = 374°C) is of interest as a substitute for organic solvents to minimize waste in extraction and reaction processes. Additionally, it is used for hydrothermal oxidation of hazardous organic wastes (also called supercritical water oxidation) and hydrothermal synthesis. 

Over the past decade, much progress in supercritical fluid technology has occurred. For example, supercritical fluids have found widespread use in extractions (2-5), chromatography (6-9), chemical reaction processes (10,11), and oil recovery (12). Most recently, they have even been used as a solvent for carrying out enzyme-based reactions (14). Unfortunately, although supercritical fluids are used effectively in a myriad of areas, there is still a lack of a detailed understanding of fundamental processes that govern these peculiar solvents. 

Supercritical fluid technology has been widely used in extraction and purification processes in the food and pharmaceuticals industryPl 1 1 and for techniques such as supercritical fluid chromatography. Recently, there has been a significant increase in interest of the use of sub- as well as supercritical (SC) carbon dioxide as a substitute for chlorofluorocarbons (CFCs) for a variety of specific and specialized applications t in which the choices of enviromnentally acceptable alternatives are quite limited. 

The technique may be viewed as an alternative to the addition of cosolvents or modifiers (sometimes termed entraimrs) that are commonly used in supercritical fluid technology to enhance the polarity of the fluid. For cleaning processes, however, these cosolvents may be toxic or detrimental in various ways to the substrate. In addition, these modifiers are usually more difficult to separate downstream from the process due to their high volatility. In contrast, surfactants typically have very low volatility and thus interact to a much lesser degree with the substrate. Furthermore, they often dramatically improve the solubility of polar species, well beyond that of simple modifiers. 

Clavier, J. Perrut, M. Scale-up issues for supercritical fluid processing. In Supercritical Fluid Technology for Drug Pro- 61. duct Development York, P., Kompella, U.B., Shekunov, B.,... 

Poliakoff, M. Howdle, S.M. George, M.W. Clean chemistry in supercritical fluids. In Process Technology Proceeding, Rudolf von Rohr, C.T.Ph., Ed. Elsevier Science B.V. Amsterdam, Netherlands, 1996, 67-72. 

A fluid is supercritical when it is compressed beyond its critical pressure (Pc) and heated beyond its critical temperature (r, ). Supercritical fluid technology has emerged as an important technique for supercritical fluid extraction (SFE). In many of the industrial applications, it has replaced conventional solvent-based or steam extraction processes, mainly due to the quality and the purity of the final product and environmental benefits. 

More polymerization reactions carried out at supercritical conditions, select biomass conversion supercritical fluid technologies for hydrogen production, wider use of supercritical water oxidation processes, portfolio of self-assembly applications, a spate of opportunities in process intensification, many supercritical fluid aided materials synthesis applications, and numerous reactions for synthesis of specialty chemicals are expected for years to come. 

N. Bonnaudin, "A Solution for the Treatment of Wastewater from Food and Pharmaceutical Industries Hydrothermal Oxidation, Presented at The Role of Supercritical Fluid Technology in Pharmaceutical/Nutraceutical/Food Processing, Supermat Network Seminar, July 6-8, 2005 (www.univ-pau.fr/supermat/OP6.pdf). 

Scheme 7 (A) Schematic of the process of producing nanoparticles using supercritical fluid technology. See, for example. Ref. 73.

Weber M, Thies MC. Understanding the RESS process. In Ya-Ping Sun, ed. Supercritical fluid technology in materials science and engineering. New York Marcel Dekker, 2002 387-437. 

Bustami RT, Chan HK, Foster NR. Aerosol delivery of protein powders processed by supercritical fluid technology. Proceedings of the Conference on Respiratory Drug Delivery VII, Palm Harbor, FL, 2000 611-613. 

Developing particles for inhalation with its recently acquired Bradford Particle Technology, UK, a pioneer in the use of supercritical fluids for processing drug powders. 

Developing coating processes that use supercritical fluid technology. 

Palakodaty S, Sloan R, Kordikowski A, York P. Pharmaceutical and biological materials processing with supercritical fluids. In Sun Y-P, ed. Supercritical Fluid Technology in Materials Science and Engineering. New York Marcel Dekker, 2002 439-A90. 

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