Hubbard K Elaine, Schaiquevich Paula, Bai Feng, Fraga Charles H, Miller Laura, Panetta John C, Stewart Clinton F
Department of Pharmaceutical Sciences, St. Jude Children's Research Hospital (SJCRH), Memphis, Tennessee 38105, USA.
Biomed Chromatogr. 2009 Jul;23(7):707-13. doi: 10.1002/bmc.1173.
Individualization of topotecan dosing reduces inter-patient variability in topotecan exposure, presumably reducing toxicity and increasing efficacy. However, logistical limitations (e.g. requirement for plasma, intensive bedside plasma processing) have prevented widespread application of this approach to dosing topotecan. Thus, the objectives of the present study were to develop and validate an HPLC with fluorescence detection method to measure topotecan lactone in whole blood samples and to evaluate its application to individualizing topotecan dosing. Plasma samples (200 microL) were prepared using methanolic precipitation, a filtration step and then injection of 100 microL of the methanolic extract onto a Novapak C(18), 4 microm, 3.9 x 150 mm column with an isocratic mobile phase. Analytes were detected with a Shimadzu Fluorescence RF-10AXL detector with an excitation and emission wavelength of 370 and 520 nm, respectively. This method had a lower limit of quantification of 1 ng/mL (S/N >or= 5; RSD 4.9%) and was validated over a linear range of 1-100 ng/mL. Results from a 5-day validation study demonstrated good within-day and between-day precision and accuracy. Data are presented to demonstrate that the present method can be used with whole blood samples to individualize topotecan dosing in children with cancer.
拓扑替康给药个体化可降低患者间拓扑替康暴露的变异性，推测可降低毒性并提高疗效。然而，后勤方面的限制（例如对血浆的需求、床边密集的血浆处理）阻碍了这种拓扑替康给药方法的广泛应用。因此，本研究的目的是开发并验证一种采用荧光检测的高效液相色谱法，用于测量全血样本中的拓扑替康内酯，并评估其在拓扑替康给药个体化中的应用。血浆样本（200微升）通过甲醇沉淀、过滤步骤制备，然后将100微升甲醇提取物注入到一个粒径为4微米、尺寸为3.9×150毫米的诺瓦帕克C18柱上，流动相为等度洗脱。使用岛津荧光RF-10AXL检测器检测分析物，激发波长和发射波长分别为370纳米和520纳米。该方法的定量下限为1纳克/毫升（信噪比≥5；相对标准偏差4.9%），并在1-100纳克/毫升的线性范围内进行了验证。一项为期5天的验证研究结果表明，日内和日间精密度及准确度良好。本文提供的数据表明，本方法可用于全血样本，以实现癌症患儿拓扑替康给药的个体化。
