Forming processes of pharmaceutical active principles in supercritical phase

Supercritical fluids are now used in a large number of processes and in a wide variety of industrial sectors, including chemicals, agrifood, cosmetics, nutraceuticals, pharmaceuticals, health, textiles, plastics, building materials, automobiles and mechanical engineering, and more latterly in the energy sector and waste industry. In most applications, supercritical fluids are used as solvents, but they can also be used as reagents, particularly super-critical water. Besides “reactive” processes, supercritical fluids are mainly used for extraction, fractionation, purification, cleaning, materials processing, particle generation, encapsulation and impregnation. A recent emerging application of supercritical fluids makes use of the biocidal properties of supercritical carbon dioxide, which allows efficient microbial inactivation or bioburden lowering. Finally, one application of supercritical fluids in the field of separation is in analytical and preparative supercritical fluid chromatography.

This article focuses on the use of supercritical fluids for drug product development, and outlines the different processes for processing drugs, either pure or together with excipients, to produce sustained-release drug delivery systems. Drug purification processes are not addressed here. Our purpose is to provide all the information needed to select the most appropriate process according to the characteristics of the raw drug and of the final product targeted.