Wang Zhi-xuan, Deng Ying-jie, Zhang Xiao-peng
School of Pharmacy, Shenyang Pharmaceutical University, China.
Yao Xue Xue Bao. 2006 Apr;41(4):318-22.
The liposome/water partition coefficients of salmeterol and budesonide between aqueous phase and liposomes were determined and the factors that influence their partition coefficients were studied, the mechanism of interaction between the two drugs and phospholipid bilayer was elucidated.
The liposome/water partition coefficients of the two drugs were determined by equilibrium dialysis technique. The change of the partition coefficients of the two drugs along with liposome composition and medium was also studied.
The partition coefficients of the two drugs decreased with the increase of cholesterol content and saturation of phospholipid used. The liposome/water partition coefficient of salmeterol increased with the increase of liposome surface negative charge, medium pH and ionic strength, while the liposome surface charge, medium pH and ionic strength had no distinct effect on the liposome/water partition coefficient of budesonide.
The liposome/water partition coefficient of drug was affected by the type, saturation of phospholipid used in liposome preparation, the cholesterol content and surface charge of liposome, as well as the pH and ionic strength of medium also have effect on the liposome/water partition coefficient of drug. Accordingly, in order to reflect the actual partition of drug in biological membrane, the determination condition including liposome composition and medium should be similar to the biological membrane.
测定沙美特罗和布地奈德在水相和脂质体之间的脂质体/水分配系数，研究影响其分配系数的因素，阐明两种药物与磷脂双分子层之间的相互作用机制。
采用平衡透析技术测定两种药物的脂质体/水分配系数。还研究了两种药物的分配系数随脂质体组成和介质的变化情况。
两种药物的分配系数随胆固醇含量的增加和所用磷脂饱和度的增加而降低。沙美特罗的脂质体/水分配系数随脂质体表面负电荷、介质pH值和离子强度的增加而增加，而脂质体表面电荷、介质pH值和离子强度对布地奈德的脂质体/水分配系数无明显影响。
药物的脂质体/水分配系数受脂质体制备中所用磷脂的类型、饱和度、脂质体的胆固醇含量和表面电荷影响，介质的pH值和离子强度也对药物的脂质体/水分配系数有影响。因此，为反映药物在生物膜中的实际分配情况，包括脂质体组成和介质在内的测定条件应与生物膜相似。
