Analysis of abiraterone stress degradation behavior using liquid chromatography coupled to ultraviolet detection and electrospray ionization mass spectrometry.

A validated stability-indicating LC-UV-ESI-MS analytical method was established to analyze abiraterone (ABR) and its potential degradation products (DPs) and was performed according to ICH guidelines. Trace amounts of DPs that might be released under different environmental conditions were determined. Stress conditions, including the effect of heat, acid-base hydrolysis, oxidation and UV-light were investigated. ABR was found to be sensitive to UV light and oxidation. Five potential mono-oxygenated ABR products were generated upon exposure to UV-irradiation. Di-, tri-, and tetra-oxygenated ABR were detected and progressively increased in quantity upon longer exposure to UV light. The ESI-MS response factors (RF) of potential DPs and ABR were not comparable. The ESI-MS response factor of each single potential degradation product was derived from the LC-UV analysis of concentrated solutions of pure and degraded ABR. The ESI-MS limit of detection (LOD) and limit of quantification (LOQ) of ABR were 30 and 80 pg/μL, respectively. The intra-day RSD was 0.20%, and the inter-day RSD was 0.30%.