Vapor-Induced Phase Transformations in Docetaxel

Vapor-induced transformations of docetaxel anhydrous (form D-A) under ambient conditions have been studied using methanol, ethanol, and water as the solvent media. The online vapor-induced transformations were monitored by powder X-ray diffractometry. New solid forms (solvates/hydrates/anhydrous) of docetaxel anhydrous were obtained in stoichiometric ratios which were characterized completely using powder X-ray diffraction, differential scanning calorimeter, thermogravimetric analysis, and spectroscopic (C-13 solid-state nuclear magnetic spectroscopy, solution H-1 NMR, and Fourier transform infrared) techniques. The new forms namely methanol solvate (D-M), ethanol solvate (D-E), monohydrate (D-MH), trihydrate (D-TH), and anhydrous (DAN-I and DAN-II) were identified through structural analysis.