Preclinical assessment of Orteronel(®), a CYP17A1 enzyme inhibitor in rats.

Orteronel (TAK-700) is a novel and selective inhibitor of CYP17A1, which is expressed in testicular, adrenal and prostate tumor tissues. Orteronel is currently in Phase-III clinical development for metastatic castration-resistant prostate patients. The objective of the study is to assess the permeability, metabolic stability (in various preclinical and human liver microsomes), identify the major CYPs involved in the metabolism of Orteronel.

Development and validation of an RP-HPLC method for the quantitation of Orteronel (TAK-700), a CYP17A1 enzyme inhibitor, in rat plasma and its application to a pharmacokinetic study.

A novel, simple, specific, sensitive and reproducible high-performance liquid chromatography assay method has been developed and validated for the estimation of Orteronel in rat plasma. The bioanalytical procedure involves extraction of Orteronel and phenacetin (internal standard) from rat plasma with a simple liquid-liquid extraction process. The chromatographic analysis was performed on a Waters Alliance system using a gradient mobile phase conditions at a flow rate of 1 mL/min and a C18 column maintained at ambient room temperature.

Development and validation of a highly sensitive LC-ESI-MS/MS method for the determination of Orteronel® (TAK-700) in rat plasma: application to a pharmacokinetic study.

Background: A highly sensitive, specific and high-throughput LC-ESI-MS/MS method in the positive mode has been developed and validated for the quantitation of Orteronel® (TAK-700) in rat plasma using YM-55208 as an internal standard.

Results: The assay procedure involves extraction of Orteronel and internal standard from rat plasma with liquid-liquid extraction method. Chromatographic separation was achieved using an isocratic mobile phase at a flow rate of 0.

Validated RP-HPLC/UV method for the quantitation of abiraterone in rat plasma and its application to a pharmacokinetic study in rats.

A novel, simple, specific, sensitive and reproducible high-performance liquid chromatography (HPLC) assay method has been developed and validated for the estimation of abiraterone (ART) in rat plasma. The analytical procedure involves extraction of ART and diclofenac (internal standard, IS) from rat plasma with a simple liquid-liquid extraction process. The chromatographic analysis was performed on a Waters Alliance system with a Betasil C(18) column maintained at ambient room temperature and an isocratic mobile phase [acetonitrile-water-10 mm potassium dihydrogen phosphate (pH 3.

Development and validation of an enantioselective LC-MS/MS method to quantify enantiomers of (±)-TAK-700 in rat plasma: lack of in vivo inversion of (+)-TAK-700 (Orteronel) to its antipode.

A highly sensitive, specific and enantioselective assay has been developed and validated for the estimation of TAK-700 enantiomers [(+)-TAK-700 and (-)-TAK-700] in rat plasma on LC-MS/MS-ESI in the positive-ion mode. Liquid-liquid extraction was used to extract (±)-TAK-700 enantiomers and IS (phenacetin) from rat plasma. TAK-700 enantiomers were separated using methanol and 5 mm ammonium acetate (80:20, v/v) at a flow rate of 0.