Deng Pan, Ji Cheng, Dai Xiaojian, Zhong Dafang, Ding Li, Chen Xiaoyan
Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 501 Haike Road, Shanghai 201203, PR China.
Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 501 Haike Road, Shanghai 201203, PR China; Department of Pharmaceutical Analysis, China Pharmaceutical University, 24 Tongjiaxiang, Nanjing 210009, PR China.
J Chromatogr B Analyt Technol Biomed Life Sci. 2015 May 1;989:71-9. doi: 10.1016/j.jchromb.2015.03.002. Epub 2015 Mar 9.
Capecitabine (Cape) is a prodrug that is metabolized into 5'-deoxy-5-fluorocytidine (DFCR), 5'-deoxy-5-fluorouridine (DFUR), and 5-fluorouracil (5-FU) after oral administration. A liquid chromatography-tandem mass spectrometry method for the simultaneous determination of capecitabine and its three metabolites in human plasma was developed and validated. The ex vivo conversion of DFCR to DFUR in human blood was investigated and an appropriate blood sample handling condition was recommended. Capecitabine and its metabolites were extracted from 100 μL of plasma by protein precipitation. Adequate chromatographic retention and efficient separation were achieved on an Atlantis dC18 column under gradient elution. Interferences from endogenous matrix and the naturally occurring heavy isotopic species were avoided. Detection was performed in electrospray ionization mode using a polarity-switching strategy. The method was linear in the range of 10.0-5000 ng/mL for Cape, DFCR, and DFUR, and 2.00-200 ng/mL for 5-FU. The LLOQ was established at 10.0 ng/mL for Cape, DFCR, and DFUR, and 2.00 ng/mL for 5-FU. The inter- and intra-day precisions were less than 13.5%, 11.1%, 9.7%, and 11.4%, and the accuracy was in the range of -13.2% to 1.6%, -2.4% to 2.5%, -7.1% to 8.2%, and -2.0% to 3.8% for Cape, DFCR, DFUR, and 5-FU, respectively. The matrix effect was negligible under the current conditions. The mean extraction recoveries were within 105-115%, 92.6-101%, 94.0-100%, and 85.1-99.9% for Cape, DFCR, DFUR, and 5-FU, respectively. Stability testing showed that the four analytes remained stable under all relevant analytical conditions. This method has been applied to a clinical bioequivalence study.
卡培他滨（Cape）是一种前体药物，口服给药后可代谢为5'-脱氧-5-氟胞苷（DFCR）、5'-脱氧-5-氟尿苷（DFUR）和5-氟尿嘧啶（5-FU）。建立并验证了一种液相色谱-串联质谱法，用于同时测定人血浆中的卡培他滨及其三种代谢物。研究了人血液中DFCR向DFUR的体外转化，并推荐了合适的血样处理条件。通过蛋白沉淀从100μL血浆中提取卡培他滨及其代谢物。在Atlantis dC18柱上进行梯度洗脱，实现了充分的色谱保留和有效分离。避免了内源性基质和天然存在的重同位素物种的干扰。采用极性切换策略在电喷雾电离模式下进行检测。该方法对Cape、DFCR和DFUR的线性范围为10.0-5000 ng/mL，对5-FU为2.00-200 ng/mL。Cape、DFCR和DFUR的LLOQ设定为10.0 ng/mL，5-FU为2.00 ng/mL。日间和日内精密度分别小于13.5%、11.1%、9.7%和11.4%，准确度分别为-13.2%至1.6%、-2.4%至2.5%、-7.1%至8.2%和-2.0%至3.8%，分别针对Cape、DFCR、DFUR和5-FU。在当前条件下，基质效应可忽略不计。Cape、DFCR、DFUR和5-FU的平均提取回收率分别在105-115%、92.6-101%、94.0-100%和85.1-99.9%范围内。稳定性测试表明，四种分析物在所有相关分析条件下均保持稳定。该方法已应用于一项临床生物等效性研究。
