Department of Pharmacy and Pharmaceutical Sciences, St. Jude Children's Research Hospital, Memphis, TN, USA.
Department of Oncology, St. Jude Children's Research Hospital, Memphis, TN, USA.
J Chromatogr B Analyt Technol Biomed Life Sci. 2024 Sep 15;1245:124273. doi: 10.1016/j.jchromb.2024.124273. Epub 2024 Aug 14.
Preclinical studies have demonstrated that liposomal irinotecan (CPT-11), a topoisomerase I inhibitor, has broad activity against adult cancers, including pancreatic, gastric, colon, lung, glioma, ovarian, and breast cancer. Encapsulation of irinotecan into liposomes can modify its pharmacokinetic properties dramatically. Also, the pharmacokinetic profiles of liposomal drug formulations are not fully understood; thus, bioanalytical methods are needed to separate and quantify nonencapsulated vs. encapsulated concentrations. In this study, two robust, specific, and sensitive LC-MS/MS methods were developed and validated to separate and quantify the nonencapsulated CPT-11 (NE-CPT-11) from the sum-total CPT-11 (T-CPT-11) and its major metabolite, SN-38, in human plasma after intravenous administration of liposomal irinotecan. NE-CPT-11 and SN-38 were separated from plasma samples by using solid-phase extraction, and T-CPT-11 was measured by protein precipitation. The liposomal CPT-11 formulation was unstable during sample storage and handling, resulting in elevated NE-CPT-11 concentration. To improve the stability of liposomal CPT-11, a cryoprotectant solution was added to human plasma samples prior to storage and processing. CPT-11, SN-38, and their respective internal standards, CPT-11-d10 and SN-38-d3, were chromatographically separated on a reversed-phase C analytical column. The drugs were detected on a triple quadrupole mass spectrometer in the positive MRM ion mode by monitoring the transitions 587.3 > 124.1 (CPT-11) and 393.0 > 349.1 (SN-38). The calibration curves demonstrated a good fit across the concentration ranges of 10-5000 ng/mL for T-CPT-11, 2.5-250 ng/mL for NE-CPT-11, and 1-500 ng/mL for SN-38. The accuracy and precision were within the acceptable limits, matrix effects were nonsignificant, recoveries were consistent and reproducible, and the analytes were stable under all tested storage conditions. Finally, the LC-MS/MS methods were successfully applied in a phase I clinical pharmacokinetic study of nanoliposomal irinotecan (Onivyde®) in pediatric patients with recurrent solid malignancies or Ewing sarcoma.
临床前研究表明，伊立替康脂质体（CPT-11）是一种拓扑异构酶 I 抑制剂，对包括胰腺癌、胃癌、结肠癌、肺癌、神经胶质瘤、卵巢癌和乳腺癌在内的成人癌症具有广泛的活性。将伊立替康包封在脂质体中可以显著改变其药代动力学特性。此外，脂质体药物制剂的药代动力学特征尚未完全了解；因此，需要生物分析方法来分离和定量未包裹的与包裹的浓度。在这项研究中，开发并验证了两种强大、特异、灵敏的 LC-MS/MS 方法，用于分离和定量人血浆中静脉注射伊立替康脂质体后的总 CPT-11（T-CPT-11）及其主要代谢物 SN-38 中的未包裹 CPT-11（NE-CPT-11）。通过固相萃取从血浆样品中分离 NE-CPT-11 和 SN-38，并用蛋白沉淀法测定 T-CPT-11。脂质体 CPT-11 制剂在样品储存和处理过程中不稳定，导致 NE-CPT-11 浓度升高。为了提高脂质体 CPT-11 的稳定性，在储存和处理前向人血浆样品中加入了冷冻保护剂溶液。CPT-11、SN-38 及其各自的内标 CPT-11-d10 和 SN-38-d3 在反相 C 分析柱上进行色谱分离。药物在正 MRM 离子模式下通过监测 587.3 > 124.1（CPT-11）和 393.0 > 349.1（SN-38）的跃迁在三重四极杆质谱仪上进行检测。校准曲线在 T-CPT-11 的浓度范围为 10-5000ng/mL、NE-CPT-11 的浓度范围为 2.5-250ng/mL、SN-38 的浓度范围为 1-500ng/mL 时表现出良好的拟合度。准确度和精密度均在可接受范围内，基质效应无显著性，回收率一致且重现性好，在所有测试的储存条件下分析物均稳定。最后，该 LC-MS/MS 方法成功应用于儿科复发性实体瘤或尤文肉瘤患者中纳米脂质体伊立替康（Onivyde®）的 I 期临床药代动力学研究。
