Δ(4)-Abiraterone (D4A) is a recently discovered active metabolite of the oral anti-androgen drug abiraterone acetate. For quantification of this metabolite in human plasma, a liquid chromatography-tandem mass spectrometry (LC–MS/MS) method was developed and validated. Human plasma samples of patients treated with abiraterone acetate were prepared by protein precipitation with acetonitrile. The method was validated over a linear range of 0.2–20 ng/mL. Intra-assay and inter-assay variabilities were within ±15% of the nominal concentrations for quality control (QC) samples at medium and high concentrations and within ±20% at the lower limit of quantification (LLOQ), respectively. The described method for quantification of D4A was validated successfully and implemented to support therapeutic drug monitoring in patients treated with abiraterone acetate.

Δ（4）-阿比特龙（D4A）是最近发现的口服抗雄激素药物醋酸阿比特龙的活性代谢产物。为了定量分析人血浆中的这种代谢物，开发并验证了液相色谱-串联质谱（LC-MS / MS）方法。醋酸阿比特龙治疗的患者血浆样品是通过乙腈进行蛋白沉淀制备的。该方法在0.2–20 ng / mL的线性范围内得到验证。对于质量控制（QC）样品，中浓度和高浓度，测定内和测定间差异分别在标称浓度的±15％范围内，在定量下限（LLOQ）的范围内，批内测定值之间的差异在±20％之内。所描述的D4A定量方法已成功验证并得以实施，以支持用醋酸阿比特龙治疗的患者的治疗药物监测。