A Reversed-Phase HPLC Method For Determining Camptothecin In Plasma With Specificity For the Intact Lactone Form of the Drug
A Reversed-Phase HPLC Method For Determining Camptothecin In Plasma With Specificity For the Intact Lactone Form of the Drug
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DOI：
10.1080/01483919108049653
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发表时间：
1991-06
影响因子：
1.3
通讯作者：
J. Supko;L. Malspeis
中科院分区：
文献类型：
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作者：
J. Supko;L. Malspeis
摘要 喜树碱是一种末端带有α-羟基-δ-内酯环的五环吲哚生物碱，在生理pH值的水介质中与解离的开内酯羧酸盐平衡存在。两种组分之间的平衡速率足够慢，足以通过反相 HPLC 进行分离。通过使用冷却至-70°C的内标甲醇溶液脱蛋白后立即直接分析血浆样品，可以选择性测定药物的完整内酯形式。在蛋白质沉淀之前用高氯酸将样品酸化至pH 2，实现了羧酸盐的完全内酯化，因此提供了总药物水平的测量。羧酸盐的血浆浓度可以根据总药物和完整内酯测定之间的差异来计算。色谱分析在 5 μm Ultrasphere ODS 柱 (4.6 mm × 25 cm) 上进行，随后是带有洗脱液的 1.5 cm RP-18 Brownlee Guard 柱。
Abstract Camptothecin is a pentacyclic indole alkaloid with a terminal α-hydroxy-δ-lactone ring, which in aqueous media at physiological pH, exists in equilibrium with the dissociated open-lactone carboxylate. the rate of equilibration between the two components is slow enough to permit their separation by reversed-phase HPLC. Selective determination of the intact lactone form of the drug was achieved by direct analysis of plasma samples immediately upon deproteinization with a solution of the internal standard in methanol chilled to −70°C. Acidification of the sample to pH 2 with perchloric acid prior to protein precipitation effected complete lactonization of the carboxylate and, therefore, provided a measure of total drug levels. Plasma concentrations of the carboxylate may be calculated from the difference between total drug and intact lactone determinations. Chromatography was performed on a 5 μm Ultrasphere ODS column (4.6 mm × 25 cm) preceded by a 1.5 cm RP-18 Brownlee Guard column with an eluent c...