Preparation of drug delivery systems using supercritical fluid technology

Small changes in temperature and pressure near the critical region induce d ramatic changes in the density and solubility of supercritical fluids, ther eby facilitating the use of environmentally benign agents such as CO2 for t heir solvent and antisolvent properties in processing a wide variety of mat erials. While supercritical fluid technologies have been in commercial use in the food and chromatography industries for several years, only recently has this technology made inroads in the formulation of drug delivery system s. This review summarizes some of the recent applications of supercritical fluid technology in the preparation of drug delivery systems. Drugs contain ing polymeric particles, plain drug particles, solute-containing liposomes, and inclusion complexes of drug and carrier have been formulated using thi s technology. Also, polymer separation using this technology is enabling th e selection of a pure fraction of a polymer, thereby allowing a more precis e control of drug release from polymeric delivery systems.