Supercritical carbon dioxide (SCO2) was used as anti-solvent to precipitate Piroxicam, a nonsteroidal anti-inflammatory drug, from different organic solvents (acetone, ethyl acetate and dichloromethane). Physicochemical properties of the samples were analyzed before and after the treatment to highlight possible changes in the form of the crystals. The solid state analysis of both products untreated and treated with CO2, showed that the applied method choose a particle size reduction and transition to the pure a form resulting in needle-shaped crystals, regardless of the chosen solvent. In order to identify which process was responsible for the above results. Piroxicam was further precipitated from the same three solvents by traditional evaporation method (RV-samples). The dissolution profiles of Piroxicam processed in SCO2 show a better dissolution performance of Piroxicam over their corresponding system obtained by traditional evaporation method. These results manifest that SAS technology is a controllable way to improve bioavailability of water-insoluble drugs. (C) 2010 Elsevier B.V. All rights reserved.