【作者】 宋乃宁；

【导师】 刘昌孝； 李全胜；

【作者基本信息】 天津医科大学 ， 药理学， 2005， 硕士

【摘要】 目的:研究盐酸二甲双胍（MET）在大鼠体内小肠的吸收特征、吸收部位以及吸收机理,并根据大鼠实验结果预测该药物在人体内的吸收特征,以期对MET的长效缓释制剂的设计制备提供重要的依据。在此前期实验的基础上,进行MET缓释制剂的人体相对生物利用度和生物等效性研究,以证实其制剂的缓释特征。 方法:1.采用SPIP实验技术测定MET在大鼠小肠吸收的小肠有效渗透系数(P_eff,rat)。分别在大鼠十二指肠肠段、空肠肠段以及回肠肠段进行相同浓度的MET溶液(药物浓度为50μg·mL^-1)的灌流实验,以考察该药物在大鼠小肠的吸收是否呈现吸收部位依赖性。另外在十二指肠肠段进行高、中、低三个浓度的MET溶液(药物浓度分别为10,50和2001.μg.mL^-1)的灌流实验,以考察该药物在大鼠小肠的吸收是否受药物浓度的影响。此外,在十二指肠肠段考察P-糖蛋白（P-gp）抑制剂盐酸维拉帕米（VER）的存在对MET吸收的影响,即在MET浓度为50μg·mL^-1的灌流药液中加入VER使其浓度为400μg·mL^-1,并将此混合药液进行灌流,观察P_eff,rat是否增加。根据以上大鼠实验求得的P_eff,rat,按照已有关系可以预测MET在人体小肠吸收的P_eff,man以及吸收药物的百分比（fa,man）,从而得到该药物在人体小肠的吸收特征。2.18名健康男性受试者分别随机三交叉、三周期自身对照单剂量口服MET缓释试验制剂（T₁和T₂）与市售MET缓释参比制剂（R）,以及随机双交叉、双周期自身对照多剂量口服试验制剂（T₂）和参比制剂（R）,分别于给药后0～24h（单剂量）以及72～168h（多剂量）内的一系列时间点采集静脉血样,采用HPLC-UV法对血浆药物浓度进行检测,从而进行MET缓释制剂单剂量和多剂量给药的人体相对生物利用度与生物等效性研究。 结果:1.小肠吸收实验中,不同吸收部位和药物浓度对吸收的影响结果:①相同浓度的MET（50μg·mL（-1））在大鼠小肠各肠段灌流结果显示,该药物更多还原

【Abstract】 Objectives: To characterize the intestinal transport and mechanism of MET in rats, thus to estimate its absorption property in human and further to provide theoretical basis for the design and preparation of the drug in sustained release system. Another objective is to study the relative bioavailability of MET sustained-release tablets in healthy male volunteers, and to evaluate the bioequivalence of the drug made in two formulations （test drugs, T₁, T₂） to MET sustained-release tablets already for sale （reference product, R）.Methods: 1. The effective intestinal permeability of MET was investigated using single-pass intestinal perfusion （SPIP） technique in male, Wistar rats. （1）SP1P was performed in three isolated intestinal segments （duodenum, jejunum and ileum） at same concentration of MET (50μgmL^-1) to test if the intestinal transport of MET exhibited site-dependent changes. （2）And the experiment was performed in the same isolated intestinal segment （duodenal segment） at three different concentrations of MET (10, 50, 200μgmL^-1) to test if the intestinal transport of MET exhibited concentration-dependent changes. （3）Besides, P-gp inhibitor VER (400μg-mL^-1) was co-perfused with MET (50μgmL^-1) in the duodenum segment to find out if the intestinal absorption of MET was affected by P-gp exiting along the gastrointestinal track. Stability studies were conducted to ensure that the loss of MET could be only attributed to intestinal absorption. （4）Based on the P_eff values obtained in the present study and using established relationships, the effective intestinal permeability of MET in human P_eff,man ) and fraction dose absorbed(fa,_man) in vivo for MET was estimated. 2. An open-label, single-dose, randomized, three-way crossover clinical trial and an open-label, multiple-doses, randomized, two-way crossover clinical trial both recruited thesame 18 healthy volunteers were carried out to study single-dose administration of MET test drugs （Tj and T2） and reference drug （R）, and multiple-doses administration of test drug （Ti） and reference drug（R）, respectively. Venous blood samples were collected among 0²4h （single-dose） and 72-168h （multiple-doses） after drug administration. The plasma drug concentrations were determined using HPLC method. Calculate the relative bioavailability of test drugs to reference drug, and evaluate bioequivalence between test drugs and reference drug.Results: 1. Intestinal absorption experiment: （l）Intestinal absorption site dependent changes in permeability were found in the jejunum and ileum where the /\,# values at 50ugmL"’ （3.3795 ± 0.5447 xlO"5cm-s"’ and 3.2100 ± 0.1752 xlO"5 cms"1） were significantly lower than the value in the duodenum at the same concentration （5.8837±0.9287xl0"5cnvs"’, P<0.0l）. （2） Furthermore, concentration dependent changes in permeability values were also found in the duodenum where the Peffvalue at 200(j,gmL"’ （2.7086 ± 0.2595xl0"5cnvs"’） was significantly lower than the values at two lower concentrations （5.1324 ± 0.5137xl0’5cms"’ at lOugmL"’ and 5.8837 ± 0.9287xl0"5cm-s"1 at 50ugmL"\ P<Q.0l）. （3）VER did not affect the measured duodenum P^for MET at SOug-mL"1, no significant increase in permeability was found after co-perfusion with VER （400ugmL"’） in duodenum （5.8837 ± 0.9287x10"5cms"’ for MET at 50ug-mL"’ and 5.3102 ± O.5848xlO"5cms"’ for co-perfusion with 400ugmL’ verapamil, P>0.05）. （4）The Peff, ,,wn and fa,man were estimated to be in the range of 1.005lxlO"4².1481 xlO’4 cms"1 and 74.25%⁹4.50%, repectively. 2. Various pharmacokinetic parameters were determined from plasma MET concentrations. （l）After single-dose administration （T|, T2, R）, there was no statistical significant difference in AUC, Cmax and tmax either among the three treatments or formulations by ANOVA after log-transformation of the data and two one-sided t-test, and the relative bioavailabilities for test drugs to the reference drug, were 98.8% ± 13.0% and6更多还原