【作者】 李丁；

【导师】 侯惠民；

【作者基本信息】 上海医药工业研究院 ， 药剂学， 2009， 博士

【摘要】 本文选择肝素钠(Unfractionated Heparin,UFH)和低分子肝素钠(Low Molecular Weight Heparin,LMWH)为模型药物,探讨通过黏膜给药途径在离子电渗和促渗剂的作用下增加大分子药物生物利用度的可能。两种模型药物多用于预防或治疗深部静脉血栓和肺栓塞等疾病,通常经注射给药,以钠盐形式存在,在水性介质中呈离子化状态。其中,UFH是一类糖胺聚糖,分子量为14000左右(范围3000～30000),由糖醛酸和葡萄糖胺以1, 4键连接的重复二糖单位组成的多糖链混合物,LMWH由UFH经降解或解聚获得,分子量为5000左右(范围3000～8000)。本研究以活化部分凝血活酶时间(Activated Partial Thromboplastin Time,APTT)法测定黏膜透过液和动物血浆中的LMWH和UFH,方法学研究表明,标准曲线的相关系数分别为0.9951和0.9967。回收率考察发现,在试验条件下,水溶液、黏膜匀浆液和电场作用均不干扰APTT测定。LMWH和UFH对不同黏膜的渗透系数为鸡嗉囊膜>犬舌下黏膜>大鼠肠黏膜。研究结果表明,聚乙二醇辛酸/癸酸甘油酯(Labrasol)有明显促吸收作用,其促渗效果随用量的增加而增加。考察不同电流对LMWH和UFH透过大鼠直肠黏膜的影响发现,药物在正极和负极下,电场对其均有促渗作用。电流密度相同时,负极下的促渗效果优于正极下,脉冲方波电流优于恒直流电流。药物的黏膜渗透系数随直流和脉冲电流电流强度的增加而增大。其中占空比1?1、60次/分钟的脉冲电流促渗效果最好,对2000 IU/ml LMWH溶液和4000 IU/ml UFH溶液透大鼠直肠黏膜的增渗比分别可达37.45和38.66。采用生物黏附材料卡波普(Carbopol)和海藻酸钠(Alginate Sodium)制备了LMWH和UFH的口腔给药膜剂;采用高分子材料聚氧乙烯(PEO)制备了二者的直肠给药胶液。研究发现,在0.33mA/cm2、4.5V直流电流作用下,LMWH的PEO胶液家兔直肠给药的生物利用度为皮下注射的25%,与不加电场直肠给药相比可提高8倍。大鼠口服LMWH溶液生物利用度为皮下注射的7%左右,而UFH不到1%;加入吸收促进剂Labrasol后,LMWH口服生物利用度提高到约14%,而UFH依然在1%以下;在离子电渗(0.45mA/cm2)方波电流作用下,大鼠口腔给予LMWH和UFH膜剂,生物利用度分别提高到20%和6%左右,大鼠直肠给予PEO的胶液的生物利用度则分别提高到约35%(LMWH)和16%(UFH),电场对药物透过黏膜吸收进入体循环有明显促进作用。用低压直流电(4.5V)也有显著促进作用,该结果提示将来可制备简单的、低成本的离子电渗药器组合产品。更多还原

【Abstract】 In order to improve the bioavailability of macromolecule drugs such as peptide and protein through mucosa, the iontophoresis and penetration enhancer were used with LMWH and UFH as model drugs. Sodium heparin(UFH as well as LMWH) can ionize in water, and has to be administered by injection. The molecular weight of UFH is about 14000 daltons (range 3000～30000 daltons),and the LMWH?s is about 5000 daltons (range 3000～8000 daltons).The Activated Partial Thromboplastin Time(APTT) method was used to determinate LMWH and UFH in various solution through various mucosa and in the animal plasma after administration. The coefficients correlation of the standard curve were 0.9951 and 0.9967 for LMWH and UFH, and the pH of the solution, mucosa homogenate and electrical field had no interference for the method.The order of permeability coefficient of LMWH and UFH for different mucosa was chicken crop>dogs? oral cavity>rats? intestine. The enhancer(5% Labrasol) increased the penetration of LMWH and UFH through mucosa both in vitro and in vivo.We proved that the iontophoresis can significantly improve the permeability of LMWH and UFH using not only the DC but also the PC in the same electrical intensity. The pulsed current with [on/off] ratio 1:1 and cycle of 60 times per minute is better than other electricity pattern in iontophoretic mucosal permeation. The ER of 2000 IU/ml LMWH solution and 4000 IU/ml UFH solution permeated rats? rectal mucosa were 37.45 and 38.66 respectively.The LMWH and UFH films prepared with Carbopol and Alginate Sodium were for oral cavity delivery, the polyoxyethylene (PEO) gum-solution was prepared for rectal administration. It was found that the bioavailability of LMWH PEO gum-solution administered in rabbits? rectum using iontophoresis(0.33mA/cm2 DC) was 25% of the sc administration, which was 8 times higher than without iontophoresis.The oral bioavailability of LMWH and UFH solution administered in rats were 7% and below 1% respectively. If the solution contained 5% Labrasol, the bioavailability of LMWH was increased to 14%, but that of UFH was still below 1%.With 0.45mA/cm2 PC iontophoresis, the bioavailabilities of LMWH and UFH films iontophoresis administered in rats? oral cavity were approximately 20% and 6% respectively compared with sc.Under the same electricity, the bioavaibilities of LMWH and UFH PEO gum-solution administered from rat rectum was 35% and 16% respectively.It suggested that the rectal iontophoretic delivery system is a useful vehicle to improve the absorption of macromolecuar drugs, and we believe it would be developed as combination products in the near future.更多还原