高效液相色谱-质谱法测定比格犬血浆中的艾普拉唑及其药代动力学

运用高效液相色谱-电喷雾质谱(HPLC-ESI-MS)技术,建立了快速、简单、灵敏的比格犬静脉滴注艾普拉唑钠盐后血药浓度的检测方法。血浆样品采用蛋白沉淀法,以丁螺环酮作为内标,色谱柱为Teknokroma Kromasil C18(100 mm×2.1 mm, 5 μm),流动相为水-甲醇-乙腈(69:8:23, v/v/v)(含0.1%的甲酸),流速0.2 mL/min,采用电喷雾(ESI)离子源以正离子方式检测。绘制血药浓度-时间曲线,并采用DAS 2.0计算药代动力学参数。方法学实验结果表明内源性杂质不干扰艾普拉唑和内标的测定,线性范围为5～10000 μg/L (r=0.994),最低定量限为5 μg/L,精密度和准确度均符合生物样品测定的要求。低、中、高3个浓度的绝对回收率在106%左右,基质效应小于142.0%,表明该方法适合比格犬血浆中艾普拉唑浓度的测定及药代动力学研究。比格犬静脉滴注艾普拉唑钠盐3个剂量(0.2 mg/kg、0.8 mg/kg和3.2 mg/kg)后的药-时曲线下面积(AUC(0~∞))分别为(2.4×104±3×103)、(8.8×104±1.6×104)和(5.4×105±8×104) μg/L•min,呈线性药物代谢动力学过程。     

Identification of ilaprazole metabolites in human urine by HPLC‐ESI‐MS/MS and HPLC‐NMR experiments

Ilaprazole is a new proton pump inhibitor designed for the treatment of gastric ulcers, and limited data is available on the metabolism of the drug. In this article, the structural elucidation of urinary metabolites of ilaprazole in human was described by HPLC‐ESI‐MS/MS and stopped‐flow HPLC‐NMR experiments. Urinary samples were precipitated by sodium carbonate solution, and then extracted by liquid–liquid extraction after adding ammonium acetate buffer solution. The enriched sample was separated using a C₁₈ reversed‐phase column with the mobile phase composed of acetonitrile and 0.05 mol/L ammonium acetate buffer solution in a gradient solution, and then directly coupled to ESI‐MS/MS detection in an on‐line mode or ¹H‐NMR (500 MHz) spectroscopic detection in a stopped‐flow mode. As a result, four sulfide metabolites, ilaprazole sulfide (M1), 12‐hydroxy‐ilaprazole sulfide (M2), 11,12‐dihydroxy‐ilaprazole sulfide (M3) and ilaprazole sulfide A (M4), were identified by comparing their MS/MS and NMR data with those of the parent drug and available standard compounds. The main biotransformation reactions of ilaprazole were reduction and the aromatic hydroxylation of the parent drug and its relative metabolites. The result testified that HPLC‐ESI‐MS/MS and HPLC‐NMR could be widely applied in detection and identification of novel metabolites. Copyright © 2010 John Wiley & Sons, Ltd.