Loos W J, Kehrer D, Brouwer E, Verweij J, de Bruijn P, Hamilton M, Gill S, Nooter K, Stoter G, Sparreboom A
Department of Medical Oncology, Rotterdam Cancer Institute (Daniel den Hoed Kliniek), The Netherlands.
J Chromatogr B Biomed Sci Appl. 2000 Jan 28;738(1):155-63. doi: 10.1016/s0378-4347(99)00513-7.
Lurtotecan (GI147211; LRT) is a semisynthetic and water-soluble analogue of the topoisomerase I inhibitor camptothecin. To determine whether the therapeutic efficacy of LRT in patients could be improved, the drug was encapsulated in liposomes (NX211; Gilead Sciences). In order to allow accurate description of the pharmacokinetic behavior of NX211 in cancer patients, we have developed sensitive RP-HPLC assays with fluorescence detection (lambdaex=378 nm; lambdaem=420 nm) for the determination of total LRT levels in human plasma and urine. Sample pretreatment involved deproteinization with 10% (w/v) aqueous perchloric acid-acetonitrile (2:1, v/v), and chromatographic separations were achieved on an Inertsil-ODS 80A analytical column. The lower limit of quantitation (LLQ) was established at 1.00 ng/ml in plasma (200-microl sample) and at 100 ng/ml in urine (200 microl of 40-fold diluted sample). The within-run and between-run precisions were <7.5%. LRT concentrations in urine of <100 ng/ml were determined by a modified procedure comprising a single solvent extraction with n-butanol-diethyl ether (3:4, v/v). In this assay, the fluorescence signal of LRT was increased 14-fold prior to detection by post-column exposure to UV light (254 nm) in a photochemical reaction unit. The LLQ of this assay was 0.500 ng/ml (150-microl sample) and the within-run and between-run precisions were <10%.
鲁替康（GI147211；LRT）是拓扑异构酶I抑制剂喜树碱的半合成水溶性类似物。为了确定鲁替康对患者的治疗效果是否可以提高，该药物被包裹在脂质体中（NX211；吉利德科学公司）。为了准确描述NX211在癌症患者中的药代动力学行为，我们开发了灵敏的反相高效液相色谱荧光检测法（激发波长λex=378 nm；发射波长λem=420 nm），用于测定人血浆和尿液中的总鲁替康水平。样品预处理包括用10%（w/v）的高氯酸水溶液-乙腈（2:1，v/v）进行脱蛋白处理，色谱分离在Inertsil-ODS 80A分析柱上进行。血浆（200微升样品）中的定量下限（LLQ）设定为1.00纳克/毫升，尿液（200微升40倍稀释样品）中的定量下限设定为100纳克/毫升。批内和批间精密度均<7.5%。尿液中鲁替康浓度<100纳克/毫升时，采用改良方法测定，该方法包括用正丁醇-乙醚（3:4，v/v）进行单次溶剂萃取。在该测定中，鲁替康的荧光信号在光化学反应单元中柱后暴露于紫外光（254纳米）后检测前增加了14倍。该测定方法定量下限为0.500纳克/毫升（150微升样品），批内和批间精密度均<10%。
