LC-MS/MS法测定坦索罗辛在比格犬血浆中的浓度及其缓释制剂的药动学研究

Determination of tamsulosin in dog plasma by LC-MS/MS and study on its pharmacokinetics

目的:建立坦索罗辛血药浓度LC-MS/MS测定方法,并研究坦索罗辛缓释制剂在比格犬体内的药代动力学。方法:6只比格犬空腹单次口服给予含有0.4 mg的盐酸坦索罗辛缓释胶囊,给药前(0 h)、给药后不同时间点各采血0.3 mL,分离血浆后,加入内标愈创木酚甘油醚,经乙酸乙酯萃取,以甲醇:水:甲酸(80∶20∶0.2,V/V/V)为流动相,在反相C18色谱柱进行分离。采用电喷雾离子源(ESI源)的正离子方式检测,扫描方式为选择反应监测(SRM),用于定量分析的离子反应为m/z409.0→m/z228.0(坦索罗辛)和m/z199.0→m/z125.0(内标,愈创木酚甘油醚)。结果:坦索罗辛在线性范围内0.05～10.0 ng/mL线性良好,定量下限为0.05 ng/mL,批内、批间精密度(RSD)均小于13.4%。盐酸坦索罗辛缓释制剂0.4 mg口服给药后AUC0-24 h为(7.82±1.92)ng.h.mL-1、AUC0-∞为(8.04±2.02)ng.h.mL-1t、1/2为(2.96±2.13)h。结论:LC-MS/MS法灵敏度高、分析快速,适用于比格犬血浆中坦索罗辛的药动学研究,坦索罗辛缓释胶囊口服给药后半衰期短,消除快。

AIM： To establish an LC-MS/MS method for the determination of tamsulosin in dog plasma and to study pharmacokinetics of tamsulosin hydrochloride controlled release capsules in Beagle dogs. METHODS： The 0.3 mL of blood samples were collected at before and different times after six Beagle dogs were received an oral dose of 0.4 mg tamsulosin.Tamsulosin and the internal standard（guaifenesin） were extracted by ethyl acetate from dog plasma,and separated on a Thermo C18 column using methanol-water-formic acid（80∶20∶0.2,V/V/V） as mobile phase.Elecrospray ionization（ESI） source was applied and operated in the positive ion mode.Quantification was performed using selected reaction monitoring（SRM） mode.The transitions for tamsulosin and guaifenesin were m/z 409.0→m/z 228.0 and m/z 199.0→m/z 125.0,respectively.RESULTS：The linear concentration ranges of the calibration curves for tamsulosin were 0.05-10.0 ng/mL.The lower limit of quantification was 0.05 ng/mL.The intra-and inter-run relative standard deviations（RSD） were lower than 13.4%.The pharmacokinetic parameters of tamsulosin was as follows： AUC0-24 h（7.82±1.92） ng·h·mL-1,AUC0-∞（8.04±2.02） ng·h·mL-1,t1/2（2.96±2.13） h.CONCLUSION： The method is simple,high sensitivity and is proved to be suitable for pharmacokinetic study for tamsulosin in Beagle dogs.The half-life is short,and its clearance from dog body is very quick.