中药难溶性成分的药物纳米晶自稳定pickering乳液的构建及口服吸收机制研究

There are many ingredients in chinese herbal drugs, especially the oleaginous or insoluble ingredients with poor oral absorption, which is a great challenge for chinese medicine pharmaceutics. The nanocrystal self-stabilized pickering emulsions(NSSPE), one kind of emulsions using nanocrystals of insoluble ingredient instead of surfactants or solid particles as stabilizers, has been created by our group firstly, which could improve the oral bioavailability of insoluble ingredients, increase the safety and stability of preparations. However, the preparation theory and absorption mechanism are still not clear..In this study, the NSSPE is fabricated and charactered by using puerarin and tanshinone ⅡA as nanocrystals which are the main insoluble active ingredients of TongMai prescription which is composed of Radix Puerariae Lobatae, Radix Puerariae Lobatae and Rhizoma Chanxiong. and Rhizoma Chanxiong oil as main oil phase. The key influencing factors and laws about the formation of NSSPE are investigated. The stability and solidification method of NSSPE are researched. The oral bioavailability of NSSPE in rats is studied. The absorption mechanism of NSSPE is revealed by in vitro dissolution study, state change study of NSSPE in simulated gastrointestinal digestion and caco-2 cell transport and uptake in vitro..The research could set theoretical and technic foundation for the use of NSSPE in chinese medicine pharmaceutics, and provide a novel preparation for chinese medicine prescriptions containing insoluble ingredients eventually.

中药成分复杂，特别是富含油脂性和水难溶性成分，口服吸收困难。课题组原创了药物纳米晶自稳定皮克林乳液（NSSPE），用难溶性药物自身纳米晶代替表面活性剂或异种固体微粒制备乳剂，可提高药物的口服吸收，增强制剂的安全性、稳定性。但尚无其构建理论和口服吸收机制的研究。项目以通脉方（葛根、丹参、川芎组成）的难溶性有效成分葛根素、丹参酮ⅡA的纳米晶为固体微粒稳定剂，以川芎油为主要油相，制备NSSPE。通过构建NSSPE，表征其结构、性质，探寻影响NSSPE成型的关键因素；考察NSSPE的稳定性，研究其固体化方法；通过大鼠灌胃的生物利用度实验，考察NSSPE提高难溶性成分口服吸收的效果；通过NSSPE的体外溶出实验、在胃肠道中的状态变化实验和体外caco-2细胞实验，揭示其口服促吸收机制。研究可为NSSPE在中药制剂中的应用奠定理论基础，搭建技术平台，为富含难溶性有效成分的中药口服制剂的研究提供新剂型。

中药成分复杂，特别是富含油脂性和水难溶性成分，口服吸收困难，影响了其临床应用。项目以通脉方（葛根、丹参、川芎组成）的难溶性有效成分葛根素、丹参酮ⅡA和阿魏酸的纳米晶为固体微粒稳定剂，以中药挥发油为主要油相，研究药物纳米晶自稳定Pickering乳液（NSSPE），以提高中药难溶性成分的口服吸收。通过考察药物-油相性质（油相的表面张力、黏度、药物的表面能、油水分配系数、纳米晶粒径、Zeta电位及药物-水-油的三相接触角）、水相pH、固体微粒浓度、水油体积比等因素对NSSPE成型与稳定的影响，揭示了影响NSSPE构建的重要因素。荧光显微镜、扫描电镜、激光共聚焦显微镜等微观结构表征证实，上述葛根素、丹参酮ⅡA和阿魏酸均可吸附于川芎油- Labrafil M 1944 CS（9:1，v/v）的油滴界面，稳定Pickering乳滴，界面吸附率分别为29.40 ± 1.00%、84.44 ± 2.12%和22.09 ± 2.24%。采用效应面优化法进一步优化了葛根素NSSPE的制备工艺，最终制得了乳滴粒径、药物含量和Zeta电位分别为12.39 0.91 m、4.49 0.21 mgmL-1和-47.73 2.21 mV的葛根素NSSPE，室温下可稳定6个月。分别以海藻糖-PVPK30（8:1）、羟丙基-β-环糊精为保护剂，冷冻干燥和喷雾干燥均可将液态的葛根素NSSPE固体化，制得的NSSPE干乳再分散后能迅速恢复成均匀的乳液，乳滴粒径、电位、药物含量、界面吸附等性质无显著变化，40℃、75%的相对湿度下可稳定3个月以上。大鼠药动学研究证实，NSSPE显著提高了葛根素的口服吸收：其相对于对于原料药、纳米晶和吐温80稳定的普通乳的生物利用度分别为262.43%、155.92%和223.65%。大鼠单向肠灌流实验显示，NSSPE显著增强了葛根素在十二指肠的吸收。其促进吸收机制与药物溶出无关。Caco-2细胞实验显示跨膜转运同时存在被动转运和主动转运，以及小窝蛋白介导的内吞作用。该研究结果为NSSPE在中药制剂，尤其是复方制剂中的应用奠定了理论基础，搭建了技术平台。