Gastric ulcer (GU) is one of the major gastrointestinal disorder diseases, with increasing incidence and prevalence globally. Modified Xiaochaihu granules (MXCHG) have been used effectively for treating chronic gastritis and GU clinically. To investigate the pharmacokinetics and tissue distribution of MXCHG, an ultraperformance liquid chromatography-electrospray ionization-tandem mass spectrometry (UPLC-ESI-MS/MS) method was established for the simultaneous determination of 8 bioactive ingredients (baicalin, wogonoside, baicalein, liquiritin, glycyrrhizic acid, berberine hydrochloride, saikosaponin a, and saikosaponin d) in rat plasma and various tissues using puerarin as an internal standard (IS). The biological samples were pretreated by protein precipitation with acetonitrile. The chromatographic separation was carried out on a C₁₈ column with a gradient mobile phase consisting of acetonitrile and 0.1% formic acid in water. All analytes and IS were quantitated through ESI in the positive/negative ion multiple reaction monitoring mode. The mass transitions were as follows: m/z 445.0 → 268.5 for baicalin, m/z 458.7 → 282.8 for wogonoside, m/z 269.2 → 222.6 for baicalein, m/z 417.0 → 254.8 for liquiritin, m/z 822.1 → 350.8 for glycyrrhizic acid, m/z 336.0 → 319.9 for berberine hydrochloride, m/z 780.3 → 618.5 for saikosaponin, and m/z 415.0 → 294.6 for the IS. The validated method was successfully applied to the pharmacokinetics and tissue distribution study of 8 compounds in rat plasma and tissues after the intragastric administration of MXCHG. The results demonstrated that 8 components were distributed widely and rapidly in various rat tissues after intravenous administration. Tissue deposition of the compounds in the rats was mainly in the small intestine and stomach. The present study can provide more useful information to guide the clinical use of MXCHG and the developed analytical method can also be applied for further clinical pharmacokinetic studies.

胃溃疡（GU）是主要的胃肠道疾病之一，在全球范围内发病率和患病率均在上升。改性小柴胡颗粒（MXCHG）已被有效地用于临床治疗慢性胃炎和GU。为了研究MXCHG的药代动力学和组织分布，建立了一种超高效液相色谱-电喷雾串联电离质谱（UPLC-ESI-MS / MS）方法，用于同时测定8种生物活性成分（黄in苷，w子苷，黄ical苷，liquiritin，使用葛根素作为内标（IS）在大鼠血浆和各种组织中的甘草酸，盐酸小ber碱，皂苷A和皂苷d）。通过用乙腈进行蛋白质沉淀对生物样品进行预处理。色谱分离在C柱上进行₁₈柱，梯度流动相由乙腈和0.1％甲酸的水溶液组成。通过正离子/负离子多反应监测模式下的ESI对所有分析物和IS进行定量。质量转变如下：黄ical苷m / z 445.0→268.5，皂甙类化合物m / z 458.7→282.8，黄ical苷m / z 269.2→222.6，liquiritin m / z 417.0→254.8，m / z 822.1→350.8甘草酸，m / z盐酸小ber碱336.0→319.9 ，皂苷总皂苷m / z 780.3→618.5，m / z415.0→294.6（用于IS）。经验证的方法已成功应用于MXCHG胃内给药后大鼠血浆和组织中8种化合物的药代动力学和组织分布研究。结果表明，静脉内给药后，有8种成分在各种大鼠组织中广泛而迅速地分布。化合物在大鼠中的组织沉积主要在小肠和胃中。本研究可以提供更多有用的信息来指导MXCHG的临床应用，并且开发的分析方法也可以用于进一步的临床药代动力学研究。