Department of Basic Pharmaceutical Sciences, School of Pharmacy, West Virginia University, Morgantown, WV, USA.
J Chromatogr B Analyt Technol Biomed Life Sci. 2012 Jun 1;898:32-7. doi: 10.1016/j.jchromb.2012.04.010. Epub 2012 Apr 20.
Tegafur is a 5-fluorouracil (5-FU) prodrug widely used outside the United States to treat colorectal cancer as well as cancers of the head and neck. The resulting plasma concentrations of tegafur are much higher than those of 5-FU; thus, analytical methods are needed that are sensitive enough to detect low plasma concentrations of 5-FU and robust enough to simultaneously analyze tegafur. Previous LC-MS/MS methods have either failed to demonstrate the ability to simultaneously measure low 5-FU and high tegafur plasma levels, or failed to be applicable in clinical studies. Our goal was to develop a method capable of measuring low concentrations of 5-FU (8-200 ng/ml) and high concentrations of tegafur (800-20,000 ng/ml) in human plasma and to subsequently evaluate the utility of the method in patient samples collected during a phase I clinical study where oral doses of either 200mg or 300 mg UF®/LV (uracil and tegafur in a 4:1 molar ratio plus leucovorin) were administered. A combined LC-MS/MS and LC-UV method was developed utilizing negative ion atmospheric pressure ionization (API). The method provides an accuracy and precision of <10% and <6%, respectively, for both analytes. Material recoveries from the liquid-liquid extraction technique were 97-110% and 86-91% for tegafur and 5-FU, respectively. Utilization of this method to determine tegafur and 5-FU plasma concentrations followed by noncompartmental pharmacokinetic analyses successfully estimated pharmacokinetic parameters (C(MAX), t(MAX) and AUC(0-10h)) in the clinical study patients. Overall, this method is ideal for the simultaneous bioanalysis of low levels of 5-FU and relatively higher levels of its prodrug, tegafur, in human plasma for clinical pharmacokinetic analysis.
替加氟是一种 5-氟尿嘧啶（5-FU）前体药物，在美国以外广泛用于治疗结直肠癌以及头颈部癌症。替加氟在血浆中的浓度比 5-FU 高得多；因此，需要足够灵敏以检测低浓度 5-FU 且足够稳健以同时分析替加氟的分析方法。以前的 LC-MS/MS 方法要么未能证明同时测量低 5-FU 和高替加氟血浆水平的能力，要么未能适用于临床研究。我们的目标是开发一种能够测量人血浆中低浓度 5-FU（8-200ng/ml）和高浓度替加氟（800-20,000ng/ml）的方法，并随后评估该方法在一项 I 期临床研究中采集的患者样本中的实用性，在该研究中，口服剂量为 200mg 或 300mg UF®/LV（尿嘧啶和替加氟的摩尔比为 4:1，加用亚叶酸）。采用负离子大气压电离（API）开发了一种 LC-MS/MS 和 LC-UV 联合方法。该方法对两种分析物的准确度和精密度分别小于 10%和 6%。液-液萃取技术的物质回收率分别为替加氟和 5-FU 的 97-110%和 86-91%。该方法用于测定替加氟和 5-FU 血浆浓度，然后进行非房室药代动力学分析，成功地估算了临床研究患者的药代动力学参数（C(MAX)、t(MAX)和 AUC(0-10h)）。总体而言，该方法非常适合同时分析人血浆中低水平的 5-FU 和其前体药物替加氟的相对较高水平，用于临床药代动力学分析。
