碘海醇脂质体的研制

Preparation of iohexol liposomes

目的制备碘海醇脂质体并考察其体内外性质。方法采用逆相蒸发法制备碘海醇脂质体,用透射电镜观察脂质体的外观形态,激光散射测定Zeta电位和粒度分布,UV法测定脂质体的包封率,家兔体内实验验证造影效果。结果脂质体为封闭的多层囊状或多层圆球体,大小均匀。空白脂质体平均粒径166.2nm,多分散性指数0.461,Zeta电位-2.10mV;碘海醇脂质体平均粒径189.1nm,多分散性指数0.262,Zeta电位+3.40mV,碘海醇脂质体包封率81.92%;体内试验结果表明,脂质体包裹的造影剂比普通造影剂CT峰值推后,信号增强,作用时间延长。结论采用逆相蒸发法制备的碘海醇脂质体,包封率较高,体内应用可减少给药剂量、延长作用时间,并可能减小对血管和中枢神经的毒性。

OBJECTIVE: To study the preparation of iohexol liposomes and its properties in vivo and in vitro. METHODS: The liposomes were prepared by reverse-phase evaporation technique. The morphology of the liposomes was detected by transmission electron microscope. The Zeta potential and particle size distribution were evaluated by laser scatter. The entrapment efficiency was determined by UV. The opacification effect was authenticated by CT in rabbits. RESULTS: The lioosomes were in spherical or ellipsoidal shape, with multilayer and uniform size. The mean diameters of blank liposomes and iohexol liposomes were 166.2 nm and 189.1 nm, respectively. The polydispersity indexes were 0.461 and 0.262, respectively. The Zeta potentials were -2.10 mV and +3.40 mV, respectively. The entrapment efficiency of iohexol liposomes was 81.92%. In vivo study showed that, compared with iohexol injection, the CT peak value of liposomal iohexol was delayed. Iohexol liposomes had stronger signals and longer effective time than iohexol injection. CONCLUSION: The drug in the liposomes prepared by reverse-phase evaporation technique was highly entrapped into the liposomes. When used in vivo, iohexol liposomes may reduce the dosage, prolong the effective time and reduce the side effection on the blood vessels and the cerebral nerves.