The solubilities of paclitaxel in supercritical carbon dioxide and nitrous oxide were measured to identify the optimum conditions for extraction and to verify the thermal stability of the drug under supercritical conditions. The solubility in carbon dioxide was measured at 311.1, 322.2 and 328.9 K and over a pressure range of 14.12-34.62 MPa, whereas that in nitrous oxide was measured at 326.2 K and over a pressure range of 14.03-27.72 MPa. Paclitaxel was found to be more soluble in nitrous oxide than in carbon dioxide, although the solubilities in both cases were very low and ranged from 1.1 x 10(-6)-7.4 x 10(-6) mole fraction.