莲心碱的药物动力学及生物药剂学研究

【作者】 许磊；

【导师】 陈济民； 程刚；

【作者基本信息】 沈阳药科大学 ， 药物制剂， 2001， 硕士

【摘要】 莲心碱（liensinine，以下简称为Lien）是从中药莲子心中提出的一种双苄基异喹啉单醚键型生物碱，具有降压、抗心律失常等作用。到目前为止，对其报道多集中在药理及提取、分析方面，有关其制剂、药物动力学和生物药剂学的报道很少，国内外药典对Lien均无收载，默克索引亦无收载。本文从莲心碱的提取入手，建立了Lien的高效液相色谱分析法，对Lien的理化性质、药物动力学与生物药剂学进行了初步的研究。 本文首先考察了各种提取条件对药物提取率的影响，确定Lien的提取方法为用甲醇对药材进行提取后挥干甲醇，残渣用酸提碱沉法分离出有效成分，再用硅胶柱分离得莲心碱。 本文分别考察、建立了正相和反相两种高效液相色谱法来测定莲心碱的含量。首先用硅胶柱建立了以氢溴酸右美沙芬为内标的正相液相色谱法，药物浓度在0.5～6μg/mL内呈线性，最低检测限为0.016μg/mL，相关系数为0.9998，日内、日间精密度均小于6.1％，但硅胶柱易污染，寿命较短，目前应用较少，所以本文又用ODS柱建立了以己酮可可碱为内标的反相高效液相色谱法，可用于测定体外样品及生物样品中Lien的含量。血药浓度在0.25～100μg/ml范围内呈线性关系，相关系数为0.9999，日内、日间精密度均小于5.3％。血浆样品中最低检测浓度为0.042μg/mL。各种生物样品的提取回收率均在80％以上，日内、日间精密度均满足要求。本法简便、可靠、线性范围广，可满足对药物各种理化性质及临床药物动力学研究的需要。本论文以反相高效液相色谱法作为Lien体内外样品的分析方法。 沈阳药科大学硕士学位论文 摘要 本文研究了Lien的有关理化性质，实验结果表明Lien的熔点为96～ 98 C；易溶于甲醇、丙酮、氯仿等有机溶剂，易溶于酸水和碱水，溶于乙 醚，不溶于水；在水中和醇中的紫外吸收系数不同，分别为124．l和175．7； 油水分配系数的测定表明随着加值的增加，药物的油水分配系数基本上 呈增加趋势，Lien的油水分配系数为18．l；药物的PKa为8．22，表明Lien 是一种弱碱性化合物；Lien的平均血浆蛋白结合率为36．1％，在血中较不 稳定，与血细胞的结合较弱；Li6rl原料药的稳定性较差，对光、热很敏感， 对湿较为敏感，应密封低温避光保存；Lien的水溶液极为不稳定，对温度 和光照都极为敏感，且随着PH值的增加稳定性降低，应避光冷冻保存。 本文采用大鼠在体小肠回流实验装置，研究了Lien的小肠吸收动力 学。实验结果表明：在体小肠不结扎与结扎的药物最终吸收程度分别为 16．9％和历．3％，经方差分析，两者无显著性差异（P＞0．05），表明Lien 的大鼠小肠吸收率不受胆汁分泌的影响；Lien在体小肠实验中三种不同浓 度下的吸收速度常数之间没有显著性差异叩＞0．05），表明Lien的吸收 机制在该浓度范围内属于被动吸收。 本文研究了Lien在大鼠体内的药物动力学特征和生物利用度情况。 大鼠静脉注射两种剂量（8．54和 16．gmg／kg）药物后，其药时过程符合H 室开放模型特征并呈现线性动力学；大鼠灌胃及肝门静脉给药后，其药时 过程符合单隔室一级吸收模型；大鼠经灌胃、肝门静脉、颈静脉交叉给药 后，灌胃的绝对生物利用度为4．39％，肝门静脉注射的绝对生物利用度为 24．5％。经理论计算，口服给药后，约有17．9％的药物被胃肠道吸收进入肝 门静脉，在肝脏中，又有75．5％的药物被肝清除。 本文考察了小鼠尾静脉注射Lien后心、肝、脾、肺、肾、脑、胃、 小肠和血浆中药物浓度的经时变化，统计矩分析结果表明，药物在小鼠体 内AUC的大小顺序为肾、肺、心、脾、血、肝、胃、小肠、脑；药物在小 二 沈阳药科大学硕士学位论文 摘要 一 鼠体内MRT的大小顺序为脾、肺、心、脑、肾、血、肝、小肠、胃。药物 体内脏器分布用统计矩方法计算出的 AUC和 MRT，再结合C＿进行描述，较 为合理。更多还原

【Abstract】 Liensinine(Lien) is a double benzyl isoquinoline single ether bond alkaline extracted from louts plumule. It has been found to possess antihypertensive and anriarrhythmic effects. Until now, the report of Lien has been focused on pharmacology, analysis and extraction, but there are few studies about its formulation, phaimacokinetics and biophannaceutics. It was not included either in the pharmacopoeia of China and other countries, or in the Merck Index. In this study, we investigated the extractive method, the analytic method, physicochemical properties, pharmacokinetics and biopharmaceutics of Lien. All kinds of conditions of extraction were exploited in this report and the best extractive method of Lien used in this study at last was that the medicinal material was extracted by methanol, volatilizing the methanol, and then dissolving the resultants by the acid and depositing the active components by the alkali. At last, Lien was purified by the silica column. Two method was developed for the determination of Lien by HPLC. One was the NP-HPLC, the other was the RP-HPLC. In the former method, dextromethmorphan was used as the internal standard. The calibration curve was linear in the range from 0.5 ii gImL, with r=Th9998, and the detection limit was 0.0 16 t gImL. The precision for within-day and between-day were both below 6.1%. In the latter method, dentoxifylline was used as the internal standard. The calibration cure in plasma was 0.25 100 i g/mL, with r0.9999, and the detection limit was 0.042 ii gImL, the precision for within-day and between-day were both below 5.3%. The extraction recoveries of all biosamples were over 80%. The relative standard deviations for with-day and between-day both met the requirements for analysis. The results showed that these method can be used feo the study of Lien. We choosed the RP-HPLC to determine the concentration of Lien in all biosamples. Some physicochemical properties of Lien was studied. The melt point of Lien was 96?8. The solution degree were better in methanol, acetone, chloroform, acid water and alkaline water than in ethyl ether,but it cannot be solved in water. The E$ was 124.1 in water and 175.7 in ethanol. The was increased with the increase of pH. The P~ of the drug was 18.1. The pKa of the drug was 8.22. The mean plasma protein binding ratio of Lien was 36.1%. The stability of the drug was poor and it was sensitive to light and heat. In this research improved intestinal absorption experiments of rat were used to study the absorption of Lien in intestinal tract. It was found that there was not significant difference in absorptive extent (PA%) in rats between without and with bile duct-ligated ( PA% was 16.9 for the former and 15.3 for the latter respectively). It showed that the intestinal absorptive extent of Lien was not influenced by the excretion of bile. The experiment results at three different concentrations indicated that the transport mechanism of Lien was passive diffusion. The pharmacokinetics and bio availability of Lien was investigated using rats. After i.v. administration of 8.54 and 16.9 mg/kg Lien, the concentration-time curves of Lien were better fitted to two compartment open model, and the elimination of Lien was linear kinetics. After oral administration and hepatic port更多还原