Micronization of alpha- and beta-cyclodextiins solubilized in dimethylsulfoxide (DMSO) has been successfully performed using the Supercritical AntiSolvent (SAS) precipitation. We obtained sub-microparticles, microparticles and expanded microparticles of both cyclodextrins, ranging from about 0.1 to 11 pm, varying the concentration of the liquid solution from 5 to 200 mg/mL, process temperature (40-60 degrees C) and pressure (90-180 bar). Particularly, we observed for both materials that, increasing the concentration of the liquid solution, decreasing the pressure or increasing the temperature, the mean particle size increased and the particle size distribution enlarged. We also tried to relate the morphologies obtained to the position of the process operating point with respect to the mixture critical point (MCP) of the ternary system cyclodextrin-DMSO-CO2. (c) 2007 Elsevier B.V. All rights reserved.