Zagazig University, Faculty of Pharmacy, Department of Analytical Chemistry, Egypt.
J Chromatogr B Analyt Technol Biomed Life Sci. 2011 Jul 15;879(22):2081-8. doi: 10.1016/j.jchromb.2011.05.039. Epub 2011 Jun 1.
A selective UHPLC-MS/MS method for determination of the therapeutic peptide octreotide in human plasma was developed and validated. This assay used a UHPLC C(18) column with 1.7 μm particle size for efficient separation and an ion-exchange SPE for selective extraction. Octreotide and its labeled internal standard, [(13)C(6)Phe(3)] octreotide, were extracted from human plasma using a simple Oasis® WCX μElution SPE method and analyzed with a total chromatographic run time of 7.5 min. Matrix effects were studied during method development by direct monitoring of representative phospholipids. On-line removal of phospholipids using column switching and pre-column back-flushing was carried out to trap and remove any residual phospholipid matrix interferences. The UHPLC column provided baseline separation between the analyte and matrix peaks. The chromatographic conditions yielded optimal retention and excellent peak shape for both the analyte and internal standard. The assay was linear in the concentration range of 0.025-25.0 ng/ml, inter- and intra-assay precision and accuracy were within 6.1% and ±1.93%, respectively. Recovery was ∼73%. Post-extraction addition experiments showed that matrix effects were less than 4%. This method for octreotide in human plasma has been validated and utilized to support of clinical pharmacokinetic studies.
建立并验证了一种用于测定人血浆中治疗肽奥曲肽的选择性 UHPLC-MS/MS 方法。该测定法采用 1.7μm 粒径的 UHPLC C(18)柱进行高效分离，并采用离子交换 SPE 进行选择性提取。奥曲肽及其标记的内标 [(13)C(6)Phe(3)]奥曲肽，采用简单的 Oasis®WCX μElution SPE 方法从人血浆中提取，总色谱运行时间为 7.5 分钟。在方法开发过程中，通过直接监测代表性磷脂来研究基质效应。通过柱切换和预柱反冲洗在线去除磷脂，以捕获和去除任何残留的磷脂基质干扰。UHPLC 柱在分析物和基质峰之间提供了基线分离。色谱条件为分析物和内标提供了最佳的保留和出色的峰形。该测定法在 0.025-25.0ng/ml 的浓度范围内呈线性，批内和批间精密度和准确度分别在 6.1%和±1.93%范围内。回收率约为 73%。提取后添加实验表明，基质效应小于 4%。该方法已用于人血浆中的奥曲肽，并已用于支持临床药代动力学研究。
