Determination of Abiraterone and Its Metabolites in Human Serum by LC-ESI-TOF/MS Using Solid-phase Extraction

We developed and validated a liquid chromatography-electrospray ionization-time of flight/mass spectrometry method for the determination of abiraterone (Abi) and its metabolites (Delta 4-Abi, 3-keto-5 alpha-Abi, 3 alpha-OH-5 alpha-Abi and 3/3-OH-5 alpha-Abi) in human serum using Abi-d4 as the internal standard. As a pretreatment procedure of serum samples, solid-phase extraction based on a silica-gel cartridge was used. The relative recovery of Abi and its metabolites was over the ranges of 84.5 - 109.2% at a concentration of 6.0 ng mL-1 for Abi and 0.6 ng mL-1 for its metabolites. The method was free from matrix effects. The calibration curve of Abi was linear over the range of 2.0 - 400 ng mL-1 and those of its metabolites over the ranges 0.2 - 40 ng mL-1. The results of the intra- and inter-day accuracy and precision data were within the FDA acceptance criteria. The optimized method was applied for the determination of Abi and its metabolites in human serum after oral administration of Abi acetate.

Automated summary

A liquid chromatography method was developed and validated for the determination of abiraterone and its metabolites in human serum, with solid-phase extraction used as the pretreatment procedure. The method demonstrated high recovery rates, linearity in calibration curves, and accuracy and precision within FDA criteria, and was successfully applied for determining abiraterone and its metabolites in human serum after oral administration of abiraterone acetate.