Supercritical Fluid Technology: A Review - Supercritical Fluid Technology: A Review - Open Access Pub

The challenges ever faced by pharmaceutical industry is mainly due to discovery of new drugs and development of new technologies. Supercritical fluid (SCF) technology is one such technique, which has become an important tool in the production of different particulate systems along with extraction and drying of protein and peptides during last couple of decade because of its specific properties such as flexibility in use, reduced environmental concern and its simplicity. In this review, we briefly describe the operating principles and parameters influencing each one of SCF processes along with their merits and perspectives. The application of SCF technology in pharmaceutical industry, including particle and crystal engineering, composite particles’ preparation, coating of solid dosage form, liposome preparation, extraction and protein and peptide drying are discussed. DOI10.14302/issn.2328-0182.japst-12-145 Although SCF technology is in use from late 19th century as a tool to understand the natural mineralization, the commercial exploitation of SCF technology has began in the 1970s. This was particularly motivated by environmental concern, capability of some SCFs for replacing toxic industrial solvent and finally, the SCF processes might be economical to liquid extraction and distillation methods 1, 2. A fluid is said to be supercritical, when its pressure and temperature exceed their respective critical value (Tc- critical temperature and Pc- critical pressure). In the phase diagram Figure 1 the critical point located at the right upper end and the phase area beyond of this point is the SCF region 3. Above the Tc, it is not possible to liquefy a gas by increasing the pressure. In other words, a SCF can behave as either a liquid or a gas, but is actually neither. The physicochemical properties of a SCF compared with those of liquid and gas were presented elsewhere in the literature 4. Figure 1. Typical diagram of supercritical region. However, the SCF has a unique thermo-physical property. As the pressure is raised, the density of the gas increases without significant increase in viscosity while the ability of the fluid to dissolve compounds also increases. A gas may have little to no ability to dissolve a compound under ambient condition can completely dissolve the compound in supercritical range. Therefore, SCF provide a greater avenue as its solvation power is altered by careful control of changes in temperature and/or pressure 5. All gases can form SCF above specific sets of Pc and Tc values, but in most of the cases, the transition to the