Synthesis, Characterization, and Control Strategies for Cabazitaxel-Related Substances at Scale

Cabazitaxel 1 is an antineoplastic agent belonging to the taxane class and approved for the treatment of hormone-refractory prostate cancer. During the optimization process of cabazitaxel, six related substances were detected using the gradient high-performance liquid chromatography technique. A thorough study was undertaken to identify, prepare, and control these six related substances. The molecular weights were determined by liquid chromatography–mass spectrometry analysis. Using spectroscopic analysis (high-resolution mass spectrometry (HRMS), infrared (IR), and NMR), the structures were determined as an amino alcohol derivative (CRS-1), 7,10-dimethoxy-10-deacetylbaccatin III (CRS-2), an N-formyl-related substance (CRS-3), 7,10,13-trimethoxy-10-deacetylbaccatin III (CRS-4), a DiBOC-related substance (CRS-5), and a process-related intermediate (CRS-6). The mechanistic aspects of the formation, synthesis, and control strategy of the associated substances were examined in detail.