Studies on the encapsulation of oxymatrine into liposomes by ethanol injection and pH gradient method
Studies on the encapsulation of oxymatrine into liposomes by ethanol injection and pH gradient method
复制标题
DOI：
10.1080/03639040600760556
复制
发表时间：
2006-08-01
影响因子：
3.4
通讯作者：
Deng, Y.
中科院分区：
文献类型：
--
作者：
Du, S.;Deng, Y.
氧化苦参碱是从中药苦参和苦豆中提取的主要活性生物碱成分。近年来，氧化草碱被发现具有显著的抗肝活性，在国内已被用于治疗乙型肝炎。在本研究中，我们试图将氧化苦参碱包埋在脂质体中，以促进氧化苦参碱向肝脏的传递，提高对肝炎的治疗效果。通过处方前考察，获得药物的溶解度、pKa、logP等理化性质，为合理设计脂质体制剂提供依据。以大豆卵磷脂为原料，采用乙醇注射和pH梯度加载法制备脂质体。同时对影响捕集效率的因素进行了研究和比较。乙醇注射法制得的脂质体包封率小于20%。脂质组成和水介质对捕集效率有一定影响。而采用pH梯度法制备的脂质体包封率可达50%以上。在主动加载过程中，内部pH缓冲容量、脂质组成和药脂比对包封效率有较大影响，而孵育温度对包封效率几乎没有影响。
Oxymatrine is the major active alkaloid constituent extracted from traditional Chinese herb medicine Sophora flavescens Ait (Kushen) and Sophora alopecuroides (Kudouzi). In recent years, oxymatnine had been found to posses remarkable anti-hepatic activity and has been used for treating hepatitis B in clinical therapy in China. In this study, we attempted to entrap oxymatrine into liposomes to facilitate the delivery of oxymatrine to the liver and enhance the therapeutic efficiency for hepatitis. Preformulation investigation was performed to obtain the drug physicochemical properties such as solubility, pKa, and logP for rational liposomes preparation design. Liposomes were prepared with soybean lecithin by ethanol injection and pH gradient loading methods. At the same time the factors affecting the entrapment efficiencies were investigated and compared. Ethanol injection method yielded liposomes with entrapment efficiency less than 20%. The lipid composition and aqueous medium had some effects on entrapment efficiency. However, liposomes could be produced with entrapment efficiency above 50% by pH gradient method. The internal pH buffer capacity, the lipid composition, and drug-to-lipid ratio greatly influenced the entrapment efficiency, while the incubation temperature had almost no effect on entrapment efficiency in the active loading procedure.