A synthetic method was used for measuring the solubility of griseofulvin in acetone-CO2 and ethanol-CO2 mixtures. In this method, CO2 is added gradually to a liquid solution previously introduced in a sapphire cell of variable volume. Resulting mixtures may have compositions richer in organic solvents than in CO2, close to compositions found in the batch anti-solvent process. Measurements with the griseofulvin-CO2-acetone system were made at 312.15 K at 60 and 100 bar, and at 326.15 K and 100 bar. Concerning the griseofulvin-CO2-ethanol system, investigations were carried out at 100 bar at temperatures of 312.15 and 326.15 K. The solubility of griseofulvin in acetone decreases at all investigated conditions when the CO2 is added. In this case, CO2 is acting as an anti-solvent. In contrast to this, griscofulvin solubility in ethanol-CO2 mixtures is higher than the solubility in either pure solvents within a certain range of CO2 molar fractions. In this case, CO2 is acting as a co-solvent and promotes the solubility of griseofulvin. (C) 2003 Elsevier B.V. All rights reserved.