Terryn Hélène, Maquille Aubert, Houée-Levin Chantal, Tilquin Bernard
Laboratory of Chemical and Physicochemical Analysis of Drugs (CHAM), Université Catholique de Louvain, Brussels, Belgium.
Int J Pharm. 2007 Oct 1;343(1-2):4-11. doi: 10.1016/j.ijpharm.2007.04.012. Epub 2007 Apr 24.
The degradation of irradiated human insulin in aqueous solutions was investigated in order to protect the protein against ionizing radiation. The influence of the drug concentration, excipients and irradiation temperature were studied. Aqueous solutions at pH 2 were irradiated by gamma rays or by accelerated electrons. Two different high-performance liquid chromatography (HPLC) methods were used: reverse-phase high-performance liquid chromatography (RP-HPLC)/UV and size exclusion liquid chromatography (SEC/UV) to investigate both the fragmentation and the formation of higher molecular weight proteins. In solution without excipients irradiated at ambient temperature at 10 kGy, the loss of human insulin is almost complete. Addition of radio-protecting excipients (free radicals scavengers) and cryo-irradiation allowed to decrease insulin degradation. The best radio-protector used was ascorbic acid in aqueous solution and oxidized glutathione in the frozen solutions. Only the combination of these two approaches (addition of scavenger and freezing) enables the irradiated human insulin in aqueous solution to meet the European Pharmacopoeia requirements for chemical potency (>or=90%).
为保护蛋白质免受电离辐射，对辐照后的人胰岛素在水溶液中的降解情况进行了研究。考察了药物浓度、辅料及辐照温度的影响。用γ射线或加速电子对pH 2的水溶液进行辐照。采用两种不同的高效液相色谱（HPLC）方法：反相高效液相色谱（RP-HPLC）/紫外检测法和尺寸排阻液相色谱（SEC/紫外检测法），以研究高分子量蛋白质的片段化及形成情况。在室温下以10 kGy剂量辐照且无辅料的溶液中，人胰岛素几乎完全损失。添加放射防护辅料（自由基清除剂）及冷冻辐照可减少胰岛素降解。最佳的放射防护剂是水溶液中的抗坏血酸和冷冻溶液中的氧化型谷胱甘肽。只有这两种方法（添加清除剂和冷冻）相结合，才能使水溶液中辐照后的人胰岛素满足欧洲药典对化学效价（≥90%）的要求。
