四氢小檗红碱及其前药的比格犬药代动力学研究

目的建立同时定量检测比格犬全血中抗焦虑新药四氢小檗红碱(THB)及其前药9-乙酰四氢小檗红碱硫酸盐(ATHBS)的LC-MS/MS方法,并研究四氢小檗红碱在比格犬体内的药代动力学及生物利用度。方法建立检测全血中THB和ATHBS的LC-MS/MS方法,进行专属性、线性、回收率、稳定性、精密度和准确度等方法学验证。比格犬单次口服和静脉注射3 mg.kg-1ATHBS后考察了前药与活性代谢产物THB的血药浓度-时间变化,应用WinNonlin软件得到药代动力学参数和口服生物利用度。结果 ATHBS和THB在2～2 000μg·L-1的浓度范围内呈良好的线性(r>0.9985),定量下限均为2μg·L-1。THB和ATHBS的回收率分别大于78.74%和75.52%,日内和日间精密度(RSD)均在10.79%之内,准确度(RE)在-10.3%～3.92%的范围内。比格犬单次静注和口服ATHBS后,前药均能快速转化成为活性产物,血中浓度在60 min降至检测限之下。静注组THB在2 min达峰,Cmax为(605.99±102.88)μg·L-1,消除半衰期T12为(7.03±1.77)h,AUC(0-t)为(718.64±143.01)h·μg·L-1。口服组THB在15min达到(77.71±26.60)μg.L-1的峰值,药-时曲线在6 h出现第2个小峰,T 12为(5.89±3.95)h,AUC(0-t)为(179.62±91.64)h·μg·L-1,口服生物利用度为26.2%。结论建立的LC-MS/MS定量方法快速、简便、灵敏,可用于同时研究前药和THB的药代动力学。比格犬口服或静注ATHBS后,前药在体内可快速转化成为活性产物,THB达峰迅速,血药浓度消除较快,口服生物利用度较好。

Pharmacokinetic study of tetrahydroberberrabine and its prodrug in Beagle dogs

Aim To develop a LC-MS/MS method for simultaneous quantification of tetrahydroberberrabine(THB) and its prodrug,9-acetyl tetrahydroberberrabine sulfate(ATHBS),and to investigate their pharmacokinetic profiles in Beagle dogs.Method Blood concentrations of ATHBS and THB were measured with a validated LC-MS/MS method.Blood-time profiles of THB were determined in Beagle dogs after a single intravenous or oral dose of ATHBS(3 mg·kg-1).The pharmacokinetic parameters were obtained with the WinNonlin software.Result A good linearity was observed over the concentration range of 2～2 000 μg·L-1(r>0.9985)with the lower limit of quantification at 2 μg·L-1 for both ATHBS and THB.The recoveries were more than 78.74% and 75.52% for THB and ATHBS,respectively.The intra and inter-day precisions(RSD) were all within 10.79% and the assay accuracies(RE) ranged from-10.30%～3.92%.The results of the pharmacokinetic study indicated that ATHBS could be converted into its active metabolite THB very rapidly in Beagle dogs after oral and intravenous administrations.Intravenous THB reached the blood peak of(605.99±102.88) μg·L-1 at 2 min,followed by a biphasic decline.T12 was(7.03±1.77)h and AUC(0-t) was(718.64±143.01)h·μg·L-1.For oral administration,the Cmax of THB(77.71±26.60)μg·L-1 was observed at 15 min and a second smaller peak was detected at 6h post-dose.T12 was(5.89±3.95)h and AUC(0-t) was(179.62±91.64)h·μg·L-1.The oral bioavailability calculated as THB was 26.2%.Conclusion The LC-MS/MS method is proved to be simple,sensitive and rapid.It has been successfully used for the pharmacokinetic study in dog.ATHBS can be metabolized rapidly in dog to release its active component THB,which quickly appears in blood.The oral bioavailability of THB was moderate.