Ohnishi Naozumi, Tanaka Shota, Tahara Kohei, Takeuchi Hirofumi
Pharmaceutical Science & Technology Unit, Eisai Co., Ltd., 1 Kawashimatakehaya-machi, Kakamigahara, Gifu 501-6195, Japan; Laboratory of Pharmaceutical Engineering, Gifu Pharmaceutical University, 1-25-4 Daigaku-nishi, Gifu 501-1196, Japan.
Laboratory of Pharmaceutical Engineering, Gifu Pharmaceutical University, 1-25-4 Daigaku-nishi, Gifu 501-1196, Japan.
Int J Pharm. 2015 Feb 20;479(2):302-5. doi: 10.1016/j.ijpharm.2014.12.056. Epub 2015 Jan 7.
We evaluated the drug-encapsulation state of insulin (INS)-loaded liposome using a novel column-switching HPLC system that can automatically separate unloaded drug from encapsulated drug by hydrophobic interaction. When the INS-loaded liposome was dispersed in water (pH 7.4), the encapsulation efficiency (EE) obtained by the column-switching HPLC system was consistent with that obtained by a conventional ultracentrifugation method. However, the INS-loaded liposome dispersed in 0.1% acetic acid (pH 3.3) showed disagreement between the EEs obtained by both methods. Considering the results of particle size, zeta potential, and transmission electron microscope (TEM) observations, we hypothesized that the column-switching HPLC method was able to distinguish INS adsorbed onto the liposome surface from the encapsulated INS, although an ultracentrifugation method precipitated the adsorbed INS onto the liposome surface along with the encapsulated INS. Therefore, the novel column-switching HPLC system may be a more accurate and useful technique for characterization and optimization of the INS-loaded liposome formulation.
我们使用一种新型柱切换高效液相色谱系统评估了载胰岛素（INS）脂质体的药物包封状态，该系统可通过疏水相互作用自动将未负载的药物与包封的药物分离。当载INS脂质体分散在水中（pH 7.4）时，通过柱切换高效液相色谱系统获得的包封效率（EE）与通过传统超速离心法获得的结果一致。然而，分散在0.1%乙酸（pH 3.3）中的载INS脂质体在两种方法获得的EE之间存在差异。考虑到粒径、zeta电位和透射电子显微镜（TEM）观察结果，我们推测柱切换高效液相色谱法能够区分吸附在脂质体表面的INS和包封的INS，而超速离心法会使吸附在脂质体表面的INS与包封的INS一起沉淀。因此，新型柱切换高效液相色谱系统可能是一种更准确、有用的技术，用于载INS脂质体制剂的表征和优化。
