Physico-chemical stability of co-formulation of PEGylated human amylin with insulin

Since the discovery of amylin no combined formulation with insulin has been made available. Amylin or its triple proline analog pramlintide are not compatible in solution with insulin. The drug candidate hAmy-PEG5k is a novel monoPEGylated amylin derivative with improved physicochemical properties and retained similar pharmacological activity compared to free amylin and pramlintide. We have investigated the short- and long-term physicochemical compatibility of hAmy-PEG5k co-formulated with slow-acting human insulin analogs glargine or detemir. While human amylin promptly aggregates over a large range of pH, and both free and in the presence of regular, glargine or detemir insulin, the hAmy-PEG5k analog is stable at these conditions as shown by Thioflavin T (ThT) binding assay. When hAmy-PEG5k (100 or 500 µg/mL) was added to the commercial formulations of either insulin glargine or detemir (95 IU/mL), the combinations remained stable after 6 months stored at 4 °C, as probed by ThT, dynamic light scattering (DLS) measurements and high performance liquid chromatography (HPLC) analyses, confirming the absence of amyloid fibers, minor aggregation products or loss of material. These results suggest hAmy-PEG5k and the insulin analogs glargine and detemir are physicochemically compatible and are candidate ready-to-use fixed-dose combinations.

自胰淀素（amylin）被发现以来，尚未有与其联用的胰岛素复方制剂获批上市。胰淀素或其三脯氨酸类似物普兰林肽（pramlintide）在溶液中与胰岛素不相容。候选药物hAmy-PEG5k是一种新型单聚乙二醇化胰淀素衍生物，其理化性质得到改善，且与游离胰淀素、普兰林肽相比保留了相似的药理学活性。本研究考察了hAmy-PEG5k与长效人胰岛素类似物甘精胰岛素（glargine）或地特胰岛素（detemir）联用后的短期与长期理化相容性。人胰淀素在宽泛pH范围内会快速聚集，无论单独存在还是与常规胰岛素、甘精胰岛素或地特胰岛素共存时均是如此；而通过硫黄素T（ThT）结合实验证实，hAmy-PEG5k类似物在上述条件下保持稳定。当将浓度为100 μg/mL或500 μg/mL的hAmy-PEG5k添加至浓度为95 IU/mL的商用甘精胰岛素或地特胰岛素制剂中时，于4℃储存6个月后，该复方制剂仍保持稳定。通过硫黄素T、动态光散射（DLS）检测与高效液相色谱（HPLC）分析验证，未检测到淀粉样纤维、少量聚集产物或药物成分损失。上述结果表明，hAmy-PEG5k与甘精胰岛素、地特胰岛素这两种胰岛素类似物具备理化相容性，有望成为可直接使用的固定剂量复方制剂候选品种。