UPLC-MS/MS法测定Beagle犬血浆中S-奥拉西坦浓度

目的 建立灵敏、准确的Beagle犬血浆中S-奥拉西坦浓度的UPLC-MS/MS检测方法,并用于该药在Beagle犬体内的药动学研究。方法 血浆样品经甲醇沉淀蛋白后,以甲醇-水溶液(85∶15, V/V,内加 10 mmoL 乙酸铵和 0.1%甲酸)为流动相,用 HP Amide LC-MS/MS Column(100 mm×3 mm ID,5 μm)分离,采用电喷雾离子源,以多反应监测(MRM)方式进行正离子检测,定量分析的离子反应分别为 m/z 159.0/114.1(S-奥拉西坦) 和 m/z 143.0/126.1(内标,吡拉西坦)。结果 S-奥拉西坦线性范围为 0.05~50 μg/mL,定量下限为 0.05 μg/mL,日内、日间精密度(RSD)均小于15%。S-奥拉西坦大鼠血浆样品在储存、预处理、分析期间均显示良好的稳定性。应用此法研究了6只Beagle犬单剂量口服S-奥拉西坦 50 mg/kg 后的药动学特点。结论 该方法快速、专属、灵敏、适用性强,可应用于S-奥拉西坦的临床前药动学研究。

A sensitive and specific UPLC-MS/MS analysis and preliminary pharmacokinetic characterization of S-oxiracetam in Beagle dogs

AIM: To develop a sensitive and specific ultra performance liquid chromatography-electrospray ionization-tandem mass spectrometry (UPLC-ESI-MS/MS) method for the identification and quantification of S-oxiracetamin in Beagle dog plasma.METHODS: The method involved the addition of piracetam as internal standards, protein-precipitation, UPLC separation, and quantification by MS/MS system using positive electrospray ionization in the multiple reaction monitoring mode (MRM). An HP Amide C₁₈ column (100 mm×3.00 mm, 5 μm) was used as the analytical column, while a mixture of methanol-water was used as the mobile phase. The precursor/product ion transitions selected were m/z 159.0/114.1 for S-oxiracetam and m/z 143.0/126.1 for I.S.RESULTS: The lower limit of quantification of S-oxiracetam was 0.05 μg/mL.The method was linear in the concentration range of 0.05-50 μg/mL.The intra-day and inter-day precisions (RSD) were within 15.0% for the analytes. S-oxiracetam was proved to be stable during all sample storage, preparation and analytical periods.The method was successfully applied to a pharmacokinetic study in dogs after intragastric administration of S-oxiracetam with a dose of 50 mg/kg.CONCLUSION: The proposed method enables unambiguous identification and quantification for the preliminary pharmacokinetic studies of S-oxiracetam.