Supercritical fluid technology preparation

Kompella, U.B. and Koushik, K. (2001). Preparation of drug dehvery systems using supercritical fluid technology. Crit. Rev. Then Drug Carrier Syst., 18, 173-199. 

Sunol, S.G., Sunol, A.K., Keskin, O., Guney,0., Supercritical fluid aided preparation of aerogels and their characterization , in Innovations in Supercritical Fluids Science and Technology Chapter 17, pp 258-268, edited by K. W. Hutchenson and N. R. Foster, ACS Symposium Series 608 (1995). 

Tservistas, M. Levy, M.S. Lo-Yim, N.Y.A. O Kennedy, R.D. York, R Humphreys, G.O. Hoare, M. The formation of plasmid DNA-loaded pharmaceutical powders using supercritical fluid technology. Biotech. Bioeng. 2001, 71, 12-18. Bodmeier, R. Chen, H. Indomethacin polymeric nanosuspensions prepared by microfluidization. J. Controlled Release 1990, 12, 223-233. 

Preparing particle formulations using the acquired Separex technology. Separex S.A. is a French company known for its supercritical fluid technology for particle engineering. 

Kompella UB, Koushik K. Preparation of drug delivery systems using supercritical fluid technology. Crit Rev Ther Drug Carrier Syst 2001 18 173-199. Petersen RC, Matson DW, Smith RD. Precipitation of polymeric materials from supercritical fluid solution the formation of thin films, powders, and fibers. Polym Prepr (Am Chem Soc, Div Pol Chem) 1986 27 261-262. 

Koushik K, Bandi N, Kompella UB. Respiratory delivery of a peptide drug degradation pathways, transport mechanisms, and sustained release large porous microparticles prepared using supercritical fluid technology. AAPS Pharm Sci 2002 4, (Abstract R6117). 

Varshosaz J, Hassanzedh F, Mahmoudzadeh M, Sadeghi A (2009) Preparation of cefuroxime axetil nanoparticles by rapid expansion of supercritical fluid technology. Powder Technol 189(1) ... 

Preparation and Processing of Nanoscale Materials by Supercritical Fluid Technology... 

Besides the supercritical fluid extraction (SFE) for preparation of medicines and materials processing, supercritical fluid technology involves processes such as supercritical anti-solvent (SAS), rapid expansion supercritical solutions (RESS), rapid expansion of a supercritical solution into a liquid solvent (RESOLV), supercritical assisted atomization (SAA), impregnation and solution enhanced dispersion by supercritical CO2 (SEDS) that involves the supercritical fluid in drug processing to drug delivery systems. 

The basic idea of enantiomer resolution using supercritical fluid technology is that after the partial diastereo-mer formation of the racemate, only the free enantiomeric mixture is soluble in supercritical fluid,e.g., supercritical carbon dioxide (5CCO2). As illustrated in the flow sheet of the resolution process (Figure 1.43), it consists of three parts preparation of the sample, extraction, and processing the raffinate. 

Nanocapsules act like a reservoir, which are called vesicular systems. They carry the active substance entrapped in the solid polymeric membrane or on their surfaces. The cavily inside contains either oil or water. A schematic diagram of Polymer Nanocapsules is shown in Fig. 9.2 [5], There are different methods that are used nowadays to prepare polymeric nanoparticles, such as nanoprecipitation (also termed as the solvent diffusion and solvent displacement method), solvent evaporation, dialysis, microemulsion, surfactant-free emulsion, salling-out, supercritical fluid technology, and interfacial polymerization [2]. Among these methods, nanoprecipitation is a fast and simple process, which does not require a pre-prepared polymer emulsion before the nanoparticle preparation. It produces a dispersion of nanoparticles by precipitation of preformed hydrophobic polymer solution. Under... 

More elaborate sample preparation is often needed for complex sample matrices, e.g., lotions and creams. Many newer SP technologies such as solid-phase extraction (SPE), supercritical fluid extraction (SFE), pressurized fluid extraction, accelerated solvent extraction (ASE), and robotics are frequently utilized (see Ref. [2]). Dosage forms such as suppositories, lotions, or creams containing a preponderance of hydrophobic matrices might require more elaborate SP and sample cleanup, such as SPE or liquid-liquid extraction. 

The objective of this panel was to develop protocols that could be used today with a minimum of methods development. The panel members recognized that promising research is currently underway to develop new techniques for sample preparation. However, procedures such as supercritical fluid extractions or preparative ion chromatographic separation of polar fractions are still considered to be in a research phase and not yet ready for general laboratory application. The procedures presented will be periodically reviewed and updated as the state of available technology improves. 

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