氟比洛芬脂质体的制备及其载药性能研究

Preparation and Drug Carrying Characteristics of Flurbiprofen Liposomes

利用薄膜蒸发-超声分散法制备氟比洛芬脂质体,通过鱼精蛋白凝聚法测定脂质体对氟比洛芬的包封率和载药率,研究了氟比洛芬脂质体载药性能的影响因素.结果表明,制得的氟比洛芬脂质体的粒径为100～250 nm,具有良好的分散性;氟比洛芬定位于脂质体的疏水基团区域,它在卵磷脂相和水相中的分配系数KD为815.6.当卵磷脂浓度为5.4×10-4mol.L-1时,所得脂质体对氟比洛芬的包封率和载药率比较理想;随着氟比洛芬与卵磷脂的质量比的增加,脂质体对氟比洛芬的载药率增大,包封率降低;胆固醇可以调节脂质体膜的稳定性,胆固醇与卵磷脂的质量比应该控制在0.3以下,过高浓度的胆固醇会大量插入膜内使得膜的刚性增强,导致脂质体对氟比洛芬的载药率和包封率降低.

Flurbiprofen liposomes were prepared by thin film evaporation and ultrasonic technique. The encapsulation efficiency and drug loading of flurbiprofen liposomes were determined with the protamine aggregation method. The impact factors on drug carrying characteristics of flurbiprofen liposomes were discussed. The results indicate that flurbiprofen liposomes have good dispersion and their average diameter are about 100 - 250 nm. Flurbiprofen molecules were located in the hydrophobic group region of liposomes and the partition coefficient KD of flurbiprofen between the liposomes and the aqueous phase was 815.6. The obtained liposomes have better entrapment efficiency and drug loading when the concentration of lecithin is 5.4 ×10^-4mol·L^-1. With the increase of flurbiprofen/lecithin mass ratio, the drug leading of flurbiprofen liposomes increases, while its encapsulation efficiency decreases. Cholesterol can adjust the stability of liposomal membrane and the mass ratio of cholesterol to lecithin should be lower than 0. 3. However, higher cholesterol concentration makes a great amount of cholesterol insert into membrane and leads to larger membrane rigidity, which decreases the entrapment efficiency and drug loading of liposomes.