Department of Pharmaceutical Sciences, University of Connecticut, Storrs, Connecticut 06226; Sterile & Specialty Drug Products, Sterile Formulation Sciences, Merck & Co. Inc., Kenilworth, New Jersey 07033.
Department of Pharmaceutical Sciences, University of Connecticut, Storrs, Connecticut 06226.
J Pharm Sci. 2020 Jun;109(6):1896-1904. doi: 10.1016/j.xphs.2020.02.014. Epub 2020 Feb 27.
Controlling ice nucleation, at a fixed higher temperature, results in larger ice crystals, which can reduce the ice/freeze-concentrate interface area where proteins can adsorb and partially unfold. Moreover, limited work has been done to address any effects on short-term stability due to a slow ramp or long isothermal hold after the ice nucleation step. The objective was to evaluate the effect of the ice nucleation temperature and residence time in the freeze-concentrate on in-process or storage stability of representative proteins, human IgG, and recombinant human serum albumin. The results suggest a higher ice nucleation temperature can minimize aggregation of protein pharmaceuticals, which are labile at ice/aqueous interface. Apart from the ice nucleation step, the present study identified the residence time in the freeze-concentrate as the critical factor that influences protein stability post ice nucleation. At a temperature where enough mobility exists (i.e., above T' of the formulation), the long residence time in the freeze-concentrate can result in significant protein aggregation during the process. In addition to stability, the findings revealed that not only the ice nucleation temperature but also the thermal history of the formulation post ice nucleation defines the surface area of ice and the porous structure of the freeze-dried cake.
控制固定较高温度下的成冰过程，会导致冰晶增大，从而减少蛋白质可以吸附和部分展开的冰/冷冻浓缩物界面面积。此外，由于成冰步骤后的升温速率较慢或等温保持时间较长，针对其对短期稳定性的任何影响，目前的研究工作还很有限。本研究的目的是评估冷冻浓缩物中的成冰温度和停留时间对代表性蛋白质（人 IgG 和重组人血清白蛋白）在制品或储存期间稳定性的影响。结果表明，较高的成冰温度可以最小化在冰/水界面不稳定的蛋白药物的聚集。除了成冰步骤之外，本研究还确定了在冷冻浓缩物中的停留时间是影响成冰后蛋白质稳定性的关键因素。在存在足够流动性的温度下（即制剂的 T'以上），在冷冻浓缩物中的长时间停留会导致在过程中发生显著的蛋白质聚集。除了稳定性之外，研究结果还表明，不仅成冰温度，而且制剂在成冰后的热历史也决定了冰的表面积和冷冻干燥蛋糕的多孔结构。
