Kreilgaard L, Frokjaer S, Flink J M, Randolph T W, Carpenter J F
Department of Pharmaceutics, The Royal Danish School of Pharmacy, Copenhagen, Denmark.
Arch Biochem Biophys. 1998 Dec 1;360(1):121-34. doi: 10.1006/abbi.1998.0948.
Freeze-drying is often used to improve storage stability of therapeutic proteins. In order to obtain a product with optimal storage stability it is important to understand the mechanisms by which solutes protect the protein against freeze-drying-induced stresses and also against damage induced during subsequent storage. The objective of the current study was to examine the importance of various mechanisms proposed to account for acute and long-term storage stability using recombinant human Factor XIII (rFXIII)4 as a model protein. Initially, for acute stability during freeze-drying, it was found that solutes which formed an amorphous phase stabilized rFXIII to a greater degree than solutes which crystallized during freeze-drying. However, only amorphous solutes which were able to hydrogen bond to the protein, and thus preserve the native protein structure in the dried solid, provided optimal acute stability. Thus, in addition to forming an amorphous phase, it was also important to possess the ability to hydrogen bond to the protein. Long-term storage stability was found to be optimal in the presence of solutes which formed and maintained amorphous phases with Tg values above the storage temperature and which also preserved the native protein structure during freeze-drying. Solute crystallization during storage compromised storage stability.
冷冻干燥常用于提高治疗性蛋白质的储存稳定性。为了获得具有最佳储存稳定性的产品，了解溶质保护蛋白质免受冷冻干燥诱导的应力以及后续储存期间诱导的损伤的机制非常重要。本研究的目的是使用重组人因子 XIII（rFXIII）4 作为模型蛋白，研究为解释急性和长期储存稳定性而提出的各种机制的重要性。最初，对于冷冻干燥期间的急性稳定性，发现形成无定形相的溶质比冷冻干燥期间结晶的溶质能更大程度地稳定 rFXIII。然而，只有能够与蛋白质形成氢键并因此在干燥固体中保留天然蛋白质结构的无定形溶质才能提供最佳的急性稳定性。因此，除了形成无定形相之外，还必须具备与蛋白质形成氢键的能力。发现长期储存稳定性在存在形成并保持无定形相且玻璃化转变温度（Tg）值高于储存温度并且在冷冻干燥期间也保留天然蛋白质结构的溶质时最佳。储存期间溶质结晶会损害储存稳定性。
