Recrystallization and Micronization of Taxol Using the Supercritical Antisolvent (SAS) Process

Recrystallization and micronization of taxol solubilized in EtOH has been performed using the supercritical antisolvent precipitation (SAS). An orthogonal array design (OAD), OAD(16) (4(5)), was employed to optimize parameters of the SAS process. We obtained microparticles and nanoparticles of taxol, the minimum mean particle size (MPS) of which was about 150.5 nm under the selected conditions, 2.5 mg/mL of the concentration of the drug solution, 57 degrees C of process temperature, 20 MPa of process pressure, 150 mu m of nozzle internal diameter (ID), and 6.6 mL/min of drug solution flow rate. The micronized product has also been characterized using scanning electron microscopy (SEM), high performance liquid chromatography-mass spectrometry (LC-MS), X-ray diffraction (XRD), differential scanning calorimetry (DSC), and Fourier-transform infrared spectroscopy (FTIR), to verify the influence of the micronization process on the final product properties. Results showed that SAS process had not induced degradation of taxol and that micronized taxol particles had lower crystallinity. These results suggest that micronized powder of taxol has a great potential to be a drug delivery system in cancer therapy.