Impregnation processes
Forming processes of pharmaceutical active principles in supercritical phase

Supercritical fluids are vectors/impregnating agents of choice because of their specific properties described above: a liquid-like density (200 to 900 kg · m^–3), a gas-like viscosity (10^–5 to 9 × 10^–5 Pa · s), a diffusivity higher than in liquid phase (2 × 10^–8 to 7 × 10^–8 m² · s^–1) and a very low interfacial tension. The transport of a solute, solubilized in a supercritical phase, inside a solid matrix is therefore facilitated. The supercritical impregnation of a solid matrix yields a matrix impregnated more evenly and with shorter processing time than in a liquid phase. When the impregnation is carried out with CO₂ SC and without adding a co-solvent,...