Stinson S F, Hill K, Siford T J, Phillips L R, Daw T W
Laboratory of Drug Discovery Research and Development, Developmental Therapeutics Program, Division of Cancer Treatment Diagnosis and Centers, National Cancer Institute-FCRDC, Frederick, Maryland 21702, USA.
Cancer Chemother Pharmacol. 1998;42(4):261-5. doi: 10.1007/s002800050815.
Flavopiridol is a flavone which inhibits several cyclin-dependent kinases, and exhibits potent growth-inhibitory activity against a number of human tumor cell lines both in vitro, and when grown as xenografts in mice. It is currently being evaluated in a phase I clinical trial at the National Cancer Institute. The objective of this project was to develop and validate an analytical method for the assay of flavopiridol in human plasma, with sufficient sensitivity to permit the plasma pharmacokinetics of flavopiridol to be studied during clinical trials.
Flavopiridol was isolated from human plasma samples by extraction with t-butylmethyl ether following alkalinization with borate buffer (pH 8.0). The extract was evaporated, the residue was dissolved in mobile phase, and analyzed by reversed-phase high-pressure liquid chromatography. Chromatography was accomplished with a polymer-based C18 column eluted with a mobile phase consisting of methanol-phosphate buffer, pH 11.0 (53:47 v/v). Electrochemical detection (ECD) was employed.
Flavopiridol was recovered from human plasma with an efficiency of 85-87%. Calibration curves were linear over the concentration range 10-500 nM (4.4-219 ng/ml). Plasma standard concentrations were measured with an accuracy and precision ranging from 3.2% to 10%. Regression analysis of flavopiridol concentrations of 15 clinical trial plasma samples ranging in concentration from approximately 50 to 4000 microM quantitated by both ECD and mass spectrometry showed close agreement. The equation of the regression line was y = 1.02x + 8 with a correlation coefficient of 0.969. Continuous infusion of flavopiridol in four patients for 72 h at a rate of 50 mg/m2 per day, resulted in mean steady-state plasma concentrations of from 200 to 300 nM. Levels declined in a biexponential manner following termination of the infusion, falling to approximately 10 nM after 48 h.
An analytical method for the assay of flavopiridol in human plasma was developed with sensitivity to at least 10 nM. The assay is accurate, precise and specific, and is suitable for determination of plasma flavopiridol concentrations for pharmacokinetic studies during clinical trials.
黄酮哌啶醇是一种黄酮类化合物，可抑制多种细胞周期蛋白依赖性激酶，在体外以及在小鼠体内作为异种移植物生长时，对多种人类肿瘤细胞系均表现出强大的生长抑制活性。目前美国国立癌症研究所正在对其进行I期临床试验评估。本项目的目的是开发并验证一种用于测定人血浆中黄酮哌啶醇的分析方法，该方法具有足够的灵敏度，以便在临床试验期间研究黄酮哌啶醇的血浆药代动力学。
用硼酸盐缓冲液（pH 8.0）碱化后，用人血浆样品通过叔丁基甲醚萃取分离黄酮哌啶醇。提取物蒸发后，残留物溶解于流动相中，并用反相高压液相色谱法进行分析。色谱分离使用基于聚合物的C18柱，用由甲醇 - 磷酸盐缓冲液（pH 11.0，53:47 v/v）组成的流动相洗脱。采用电化学检测（ECD）。
从人血浆中回收黄酮哌啶醇的效率为85 - 87%。校准曲线在10 - 500 nM（4.4 - 219 ng/ml）浓度范围内呈线性。血浆标准浓度的测量准确度和精密度范围为3.2%至10%。通过ECD和质谱法定量的15个临床试验血浆样品中黄酮哌啶醇浓度范围约为50至4000 microM，回归分析显示两者结果高度一致。回归线方程为y = 1.02x + 8，相关系数为0.969。四名患者以每天50 mg/m²的速率连续输注黄酮哌啶醇72小时，导致平均稳态血浆浓度为200至300 nM。输注终止后，浓度以双指数方式下降，48小时后降至约10 nM。
开发了一种用于测定人血浆中黄酮哌啶醇的分析方法，其灵敏度至少为10 nM。该测定方法准确、精密且特异，适用于在临床试验期间药代动力学研究中测定血浆黄酮哌啶醇浓度。
