HPLC-MS/MS测定比格犬血浆中维他昔布浓度及其药代动力学研究

目的: 建立快速灵敏的HPLC-MS/MS法测定Beagle犬血浆中维他昔布的浓度，并研究维他昔布在健康Beagle犬体内的药代动力学特征。方法: 血浆样品的处理采用叔丁基甲醚液液萃取方法，内标为塞来昔布。色谱柱：Thermo Syncronic-C₁₈(2.1 mm×100 mm，5 μm)；流动相：甲醇(含0.1%的甲酸)-水(含0.1%的甲酸)，梯度洗脱；流速：200 μL·min^-1；进样量：5 μL；柱温：20℃。质谱采用ESI⁺源，多重反应监测(MRM)模式，毛细管温度350℃，喷雾电压4.5 kV，鞘气压力199.96 kPa，辅气压力165.48 kPa，源内碰撞诱导解离电压：-10 V，碰撞气(氩气)压力0.1995 Pa，选择检测离子反应对为m/z 347.9→269.0(维他昔布)，m/z 382.0→362.0(塞来昔布)。单剂量给药30 mg后，测定Beagle犬血浆中维他昔布的浓度，并计算药代动力学参数。结果: 维他昔布在0.5~1000 ng·mL^-1浓度范围内线性良好(r=0.9980)，定量下限为0.5 ng·mL^-1。提取回收率均高于89%，日间、日内RSD均小于13%，专属性良好，在本实验涉及的条件下样品稳定。Beagle犬血浆中维他昔布的C_max为(94.27±57.18)ng·mL^-1，T_max为(2.08±2.01)h，t_1/2为(5.87±3.37)h，AUC_{0~36 h}为(625.88±375.70)h·ng·mL^-1。结论: 该方法简便、准确，专属性强，适用于维他昔布在Beagle犬体内的药代动力学研究。

Objective: To develop a rapid,specific and sensitive HPLC-MS/MS method for the determination of vitacoxib in Beagle dog plasma and study its pharmacokinetic characteristics in healthy Beagle dogs. Methods: The assay method involved liquid-liquid extraction of the analyte from plasma samples with methyl tert-butyl ether.Celecoxib was used as the internal standard(IS).The Thermo Syncronic-C₁₈ column(2.1 mm×100 mm,5 μm)was used with the mobile phase of methanol(containing 0.1% formic acid)and water(containing 0.1% formic acid)at the flow rate of 0.2 mL·min^-1.The injection volume was 5 μL,the column temperature was 20℃.The detection was performed by electrospray ionization mass spectrometry in the multiple reaction monitoring(MRM)mode.The positive ion scan mode was used to detect vitacoxib and celecoxib(IS).The MRM transitions of m/z 347.9→269.0,and 382.0→362.0 were used to quantify vitacoxib and celecoxib(IS).The settings of the mass spectrometer were as follows:spray voltage 4.5 kV and capillary temperature 350℃.The sheath gas and auxiliary gas pressures were 199.96 kPa and 165.48 kPa,respectively.The source CID voltage was -10 V.The collision gas(argon)pressure was 0.1995 Pa.After a single oral dose of 30 mg vitacoxib,the concentration and the pharmacokinetic parameters of vitacoxib were calculated. Results: The assay was linear in the range of 0.5-1000 ng·mL^-1 with a correlation coefficient(r)of 0.9980.The lowest limit of quantification was 0.5 ng·mL^-1.The intra-day and inter-day precision(RSDs)were lower than 13% and the extraction recovery was higher than 89%.The stability of this HPLC-MS/MS method was satisfactory too.The main pharmacokinetic parameters of C_max,T_max,t_1/2 and AUC_{0-36 h} were(94.27±57.18)ng·mL^-1,(2.08±2.01)h,(5.87±3.37)h and(625.88±375.70)h·ng·mL^-1,respectively. Conclusion: The HPLC-MS/MS determination method is simple,accurate,and selective for pharmacokinetic studies of vitacoxib in Beagles.