LC-MS/MS法测定犬体内托拉塞米浓度及相对生物利用度研究

LC-MS/MS determination of torasemide in Beagle dog plasma and bioavailability evaluation

目的:建立LC-MS/MS法测定Beagle犬体内托拉塞米的浓度,并研究托拉塞米缓释片的相对生物利用度。方法:色谱柱为Waters Sym-metry-C18(100mm×4.6mm,5μm);流动相为甲醇∶20mmol/L甲酸铵(65∶35,V∶V);流速0.4mL/min;柱温30℃。采用两制剂双周期随机交叉试验设计,分别给予6只Beagle犬受试制剂或参比制剂5mg,采用LC-MS/MS法测定给药后不同时间的血药浓度。结果:托拉塞米线性范围为0.02～5μg/mL,最低定量限为0.02μg/mL,分析方法灵敏、稳定、特异性高。受试制剂和参比制剂的主要药动学参数:峰浓度(Cmax)、达峰时间(tmax)和药-时曲线下面积(AUC0-48h)分别为(2.6±0.5)g/mL和(3.0±0.6)g/mL、(3.3±1.4)h和(1.2±0.8)h、(36.1±11.0)g.h.mL-1和(32.1±13.1)g.h.mL-1。以AUC0-48h计算,受试制剂的相对生物利用度F为(118.0±28.3)%。结论:该方法操作简单、准确、重复性好,并成功地运用于犬体内托拉塞米相对生物利用度的研究。

AIM. To establish an LC-MS/MS method for the determination of torasemide in Beagle dog plasma, and study the relative bio- availability of the torasemide sustained release tablets. METHODS： A reversed phase HPLC column of Waters Symmetry-C18 （100 mm × 4. 6 mm, 5 μm） was used in the experiment. Aceto- nitrile-20 mmol/L ammonium formate （65 ： 35, V/V） was used as mobile phase at the flow rate of 0.4 mL/min, the column temperature was set at 30 ℃. A single oral dose of 5 mg torasemide release tablets or reference tablets were given to Beagle dogs in an open randomized two way rossover design. The concentrations of plasma ;amples collected at the different time were deermined by LC-MS/MS method. RESULTS： Vith the linear range of 0.02--5 μg/mL and the ）wet limit quantification of 0.02 μg/mL, the ,C-MS/MS method had high sensitivity, stability and specificity. The main pharmacokinenc pa rameters of test sustained release tablets and ref- erence tablets were as follows-the Cmax were （2.6±0.5） μg/mL and （3.0±0.6） g/mL,the t were （3.3 ± 1.4） h and （ 1.2 ±0.8） h, the AUC0 48hwere （36.1±11.0） μg· h· mL^-1 ancl （32.1±13.1） μg· h· mL^-1. Compared to reg- ular tablets, the bioavailability of sustained release tablets was （118.0±28.3）Y00. CONCLUSION： The method is simple, accurate and robust for the determination o{ torasemide in Beagle dog plasma, and successfully applied it to the bioavailahility evaluation of torasemide sustained release tablets given to Beagle dogs.