Lanckmans Katrien, Clinckers Ralph, Van Eeckhaut Ann, Sarre Sophie, Smolders Ilse, Michotte Yvette
Department of Pharmaceutical Chemistry, Drug Analysis and Drug Information, Research Group Experimental Pharmacology, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090 Brussels, Belgium.
J Chromatogr B Analyt Technol Biomed Life Sci. 2006 Feb 2;831(1-2):205-12. doi: 10.1016/j.jchromb.2005.12.003. Epub 2005 Dec 28.
A microbore LC-MS/MS method is developed and validated for the quantification of the anti-epileptic drug oxcarbazepine (OXC) and its active metabolite 10,11-dihydro-10-hydroxycarbamazepine (MHD) in rat brain microdialysates, together with the internal standard for microdialysis probe calibration, 2-methyl-5H-dibenz(b,f)azepine-5-carboxamide (m-CBZ). The benefits of gradient versus isocratic separation are shown, next to the improved sensitivity resulting from the addition of 0.1% formic acid to the mobile phase. The coupling of microdialysis with ESI-MS requires sample desalting for which column switching was applied. Using weighed regression to calculate the calibration curves (1-1000 ng/mL), the assay was validated in terms of linearity, accuracy and precision, yielding a sensitive (limit of quantification is 1 ng/mL) and selective method for quantification of OXC, MHD and m-CBZ. By applying this method, we were able to determine the extracellular concentrations of OXC and MHD during at least 4h after intraperitoneal (i.p.) administration of 10 mg/kg OXC.
开发并验证了一种微径液相色谱-串联质谱法，用于定量大鼠脑微透析液中的抗癫痫药物奥卡西平（OXC）及其活性代谢物10,11-二氢-10-羟基卡马西平（MHD），同时还用于微透析探针校准的内标2-甲基-5H-二苯并(b,f)氮杂卓-5-甲酰胺（m-CBZ）。展示了梯度分离与等度分离的优势，以及向流动相中添加0.1%甲酸所带来的灵敏度提高。微透析与电喷雾电离质谱联用需要进行样品脱盐，为此采用了柱切换技术。使用加权回归计算校准曲线（1 - 1000 ng/mL），该方法在线性、准确度和精密度方面得到了验证，从而得到了一种灵敏（定量限为1 ng/mL）且选择性好的方法来定量OXC、MHD和m-CBZ。通过应用该方法，我们能够在腹腔注射10 mg/kg OXC后至少4小时内测定OXC和MHD的细胞外浓度。
