Department of Pharmaceutics, Faculty of Pharmacy and Isfahan, Pharmaceutical Sciences Research Center, Isfahan University of Medical Sciences, Iran.
Acta Pharm. 2012 Mar;62(1):31-44. doi: 10.2478/v10007-012-0006-1.
The objective of this work was to study the effect of fatty acid chain length grafted to methoxy poly(ethylene glycol) (mPEG) on self assembling properties of micelles for etoposide delivery. Three amphiphilic copolymers were synthesized using mPEG, myristic acid, stearic acid and behenic acid through an esteric linkage. The particle size and zeta potential of the micelles were determined by the dynamic light scattering method. Etoposide was loaded into micelles by film casting using various drug/polymer ratios. Drug release was studied by the dialysis method. The structure of copolymers was confirmed by (1)H NMR and FTIR. Central micellar concentration (CMC) measurements showed that the longer hydrophobic chains formed more thermodynamically stable micelles. Among the prepared copolymers, etoposide showed the highest solubility in the mPEG-behenic copolymer. Drug loading efficiency depended on the hydrophobic chain length and drug/polymer ratio. The highest drug loading efficiency was found in mPEG-myristic micelles with 1:20 drug/polymer ratio. Micelles released 80 % of loaded drug within about 5 h.
本工作旨在研究接枝到甲氧基聚乙二醇（mPEG）上的脂肪酸链长度对依托泊苷传递自组装胶束的影响。通过酯键，使用 mPEG、肉豆蔻酸、硬脂酸和山嵛酸合成了三种两亲性共聚物。通过动态光散射法测定胶束的粒径和 zeta 电位。通过不同的药物/聚合物比例，采用薄膜蒸发法将依托泊苷载入胶束中。通过透析法研究药物释放。通过（1）H NMR 和 FTIR 确认共聚物的结构。中心胶束浓度（CMC）测量表明，较长的疏水链形成了热力学更稳定的胶束。在所制备的共聚物中，依托泊苷在 mPEG-山嵛酸共聚物中表现出最高的溶解度。载药效率取决于疏水链长度和药物/聚合物的比例。在药物/聚合物比例为 1:20 的 mPEG-肉豆蔻酸胶束中发现了最高的载药效率。胶束在大约 5 小时内释放了 80%的载药。
