中文摘要：

目的：建立灵敏、快速、准确的LC-MSn 方法测定咪达唑仑/1′-羟基咪达唑仑及其在大鼠脑内的药代动力学过程。方法 SD大鼠股静脉注射CYP3A探针药物咪达唑仑（剂量5 mg＆#183;kg-1）。采用微透析技术,在2μl＆#183;min-1流速下收集脑微透析液样品2.4 h,收集时间间隔为8 min。以LC-MSn法在线检测微透析样品。选用Agilent Eclipse Plus-C18色谱柱（2．1 mm ＆#215;50 mm,3．5μm）,流动相为2 mmol＆#183;L-1乙酸铵水溶液和乙腈,梯度方式洗脱。采用电喷雾电离源（ ESI）,扫描方式为多反应离子监测模式（ MRM ）,咪达唑仑 m/z：326.1/291.1；1′-羟基咪达唑仑m/z：342.1/324.1；内标地西泮m/z：285.1/154．0。结果咪达唑仑和1′-羟基咪达唑仑的线性范围分别为0．78~100和0．195~12.5μg＆#183;L-1,最低定量下限0．2μg＆#183;L-1,批内、批间RSD均＆lt;7%, RE值在-1．34~-8%范围内。结论此检测方法快速、灵敏,可用于脑微透析液中咪达唑仑/1′-羟基咪达唑仑的含量测定,结合微透析技术有助于深入进行脑代谢的相关研究。

英文摘要：

Aim To develop a sensitive, rapid and ac-curate LC-MSn method for determination of midazolam/1′-hydroxymidazolam and their pharmacokinetic char-acteristics in rat brain. Methods SD rats received in-travenous injection of midazolam （ 5 mg ＆#183; kg-1 ） via femoral vein, a probe drug of cytochrome P450 3A. The microdialysis （ MD ） samples in situ brain were collected every 8 mins at 2. 0μl＆#183;min-1 in 2. 4 hours. Analytes in brain dialysate were quantified by the pro-posed LC-MSn method. Gradient elution was performed on an Agilent Eclipse Plus-C18 column （ 2 . 1 ＆#215; 50 mm, 3. 5 μm）. The mobile phase consisted of 2 mmol ＆#183;L-1 ammonium acetate and acetonitrile. The analyte was detected using electrospray ionization （ ESI ） in multiple reaction monitoring （ MRM） modes. The reac-tion selected ions were 326 . 1/291 . 1 m/z for midazo-lam, 342. 1/324. 1 m/z for 1′-hydroxymidazolam and 285. 1/154. 0 m/z for diazepam as internal standard. Result The linear ranges of midazolam and 1′-hydroxymidazolam were 0 . 78~100 and 0 . 195 ~12 . 5μg＆#183;L-1 respectively. The lower limit of quantification was 0 . 2 μg ＆#183; L-1 . The RSD of intra- and inter-batch precisions was less than 7 %. The RSD of accuracy was from -1 . 34 to -8 %. Conclusion This sensi-tive and rapid LC-MSn method is suitable for determi-nation of midazolam/1′-hydroxymidazolam in rat brain dialysate. MD combined with LC-MSn method may give assistance to deep and further studies of drug metabo-lism and CYP3A enzyme in brain.