【作者】 程娟；

【导师】 李俊；

【作者基本信息】 安徽医科大学 ， 药剂学， 2010， 硕士

【摘要】 A771726是免疫调节药来氟米特(leflunomide,LEF)在机体内的活性代谢物,后者在临床上主要用于治疗类风湿关节炎、系统性红斑狼疮、抗移植排斥反应和银屑病。A771726是原形药物,在体内直接吸收起作用,省略了前体药物转化的环节,目前正在申报一类新药。本实验旨在观察其在静脉注射和口服两种给药途径下在大鼠体内肝肠循环的情况,来验证其在体内是否存在肝肠循环,以及发生这种循环的药物占给药量的百分比,了解其在生物体内的代谢转化过程,提供新药临床前研究资料,以支持人体药代动力学研究并为临床用药提供参考依据。1.生物样品中A771726分析方法的建立本文采用液液萃取法提取生物样品中A771726,色谱分析采用C18柱,流动相组成为:0.01mol/L甲酸铵缓冲液:甲醇=54.7:45.3;检测波长288nm。采用本文建立的生物样品预处理方法和高效液相色谱法分离测定生物样品中A771726,生物样品预处理回收率高,色谱分离选择性好。本法的准确度、精密度、灵敏度、专属性和定量线性范围均达到了体内药物分析的要求。该方法成功运用于该药在大鼠体内肝肠循环的研究。2.静脉注射A771726在大鼠体内的药代动力学研究本部分通过静脉注射给予大鼠A771726,在给药后按时间点采集大鼠血样,利用HPLC分析技术测定各时间点大鼠血浆中A771726的含量,通过运用DAS软件应用统计矩原理求算药动学参数,直读法记录AUC(0-t)、AUC(0-∞)、MRT(0-∞)、Tmax和Cmax,客观地依据原始数据来估算药动学参数。药动学参数如下AUC(0-t):632.53±51.17 mg/L·h ;AUC(0-∞):(2397.774±178.92) mg/L·h;MRT:(38.11±10.77)h;t1/2:(22.23±9.94)h,而配对鼠中的供胆汁组药动学参数为:AUC(0-t):(502.41±29.47)mg/L·h;AUC(0-∞):(1352.85±184.51)mg/L·h;MRT:(24.77±6.17)h;t1/2:(11.94±3.04)h,两组大鼠的药动学参数相比较,发现配对鼠模型中供胆汁大鼠的AUC、MRT、t1/2都比正常组大鼠小,证明了A771726确实存在肝肠循环这一过程。3.静脉注射A771726在大鼠体内的肝肠循环的研究运用配对大鼠肝肠循环模型研究A771726在大鼠体内从胆汁重吸收的药动学过程,采用HPLC法测定血浆中A771726浓度,药动学参数用DAS软件统计矩法计算。配对大鼠肝肠循环模型表明,胆汁供体大鼠AUC(0-t):(502.41±29.47)mg/L·h ,AUC(0-∞):(1352.85±184.51)mg/L·h,胆汁受体大鼠的AUC(0-t):(127.28±23.69)AUC(0-∞)(314.94±21.15)mg/L·h。A771726静脉注射后存在肝肠循环现象,约有静脉注射给药量的23.8%进入肝肠循环。4.口服给药途径A771726肝肠循环研究实验采用大鼠肝肠循环模型研究口服A771726在大鼠体内肝肠循环情况,用HPLC法测定两组大鼠给药后12 h胆汁及尿液中药物浓度,计算其累积排泄量,药动学参数用DAS软件统计矩法计算。大鼠肝肠循环模型表明, A771726口服后存在肝肠循环现象,约有供体鼠胆汁排泄量的16.88%进入肝肠循环。更多还原

【Abstract】 A771726 is the active metabolic product of leflunomide the later is a type of immunoregulatory agents.leflunomide educes the pharacological action by metabolized in A771726,and it has been extensively exerted on rheumatoid arthritis,systemic lupus erythematosus,anti-rejection orgn transplantation and psoriasis.A771726 is a active compound,which is directly absorbed in vivo,abbreviate the transformation of prodrug. The works of this paper were designed to investigate the existence of enterohepatic circulation of A771726 and the amount of A771726 involved in this process after intravenous(iv) or intragastric(ig) administration in the rats and investigate the metabolic profile of it,so as to support the pharmacokinetics study in human and offer the reference for clinical dosage and dosage form changing.Part one:The establishment of analytical method of A771726 in biological matrix A high-performance liquid chromatographic method has been developed for the separation and analysis of A771726 in rats,using a liquid extraction as sample pretreatment for biological matrix.Separation was obtained on a Kromasil C18 column,using an excitation wavelength of 288nm.The chromatographic method used provided good separation and analysis condition.The recovery rate,accuracy rating,precision,saitivity,specificity and the linear range of quantitation of this method all reach the requisition of pharmaceutical analysis.The method has been successfully used to support the study of enterohepatic cycling of A771726 in rats.Part two: Pharmacokinetics of A771726 in Rats after Intravenous Ad -ministration In this part, A771726 in plasma was determined by HPLC in order to assess the degree of absorption after intravenous(iv) administration in the rats.The pharmacokinetic parameters were estimated with the computer program DAS using non-compartmental analysis.Read the parameters such as AUC(0-t)、AUC(0-∞)、MRT(0-∞)、Tmax and Cmax directly,thus the pharmacokinetic parameters can be objectively estimated based on the original data. The pharmacokinetic parameters were estimated to be AUC(0-t):(632.53±51.17) mg/L·h ;AUC(0-∞):(2397.774±178.92) mg/L·h;MRT:(38.11±10.77)h;t1/2:(22.23±9.94)h, and in the enterhepatic cucling model,the bile-donor group’s pharmacokinetic parameters were estimated to be AUC(0-t):(502.41±29.47)mg/L·h;AUC(0-∞):(1352.85±184.51)mg/L·h;MRT:(24.77±6.17)h;t1/2:(11.94±3.04)h.Compared the two groups of rats’pharmacokinetic parameters,the bile-donor’s parameters were smaller than the normal group’s. This result suggested that enterohepatic cycling of A771726 exist in rats .Part three: Enterohepatic Cycling of A771726 in Rats after Intravenous Ad -ministrationRat enterohepatic cycling model was applied to study the process of biliary reabsorption of A771726. Plasma A771726 levels were determined by a HPLC method. The pharmacokinetic parameters were estimated with the soft ware DAS using non-compartmental analysis.In the enterohepatic cycling model, the bile-donor group’s pharmacokinetic parameters were estimated to be AUC(0-t):(502.41±29.47)mg/L·h ,AUC(0-∞):(1352.85±184.51)mg/L·h and the bile-recipient group’s pharmacokinetic parameters were estimated to be AUC(0-t) :( 127.28±23.69),AUC(0-∞):(314.94±21.15)mg/L·h. The findings suggested that enterohepatic cycling of A771726 exist in rats after iv administration. Approximately 23.8% of the intravenous administration dosage enters the enterohepatic circulation.Part four: Enterohepatic Cycling of A771726 in Rats after Intragastric AdministrationRat enterohepatic cycling model was applied to study the process of biliary reabsorption of of A771726. Bile and urine A771726 levels were determined by a HPLC method. Bile and urine samples were collected within 12 h after ig administration of A771726,and the cumulative percentage of biliary excretion of A771726 in rats was calculated. The findings suggested that enterohepatic cycling of A771726 exist in rats after ig administration. Approximately 16.88% of the bile-donor rats’biliary excretion of A771726 enters the enterohepatic circulation.更多还原