Protein Pharmaceutical Development, Biogen Idec, Cambridge, Massachusetts 02142, USA.
J Pharm Sci. 2013 Feb;102(2):347-51. doi: 10.1002/jps.23414. Epub 2012 Dec 11.
We present evidence that homogeneous submicron particles can influence the growth rate of larger particles upon long-term storage in a temperature-dependent manner. Interferon-beta-1a was thermally stressed at 50°C for 6 h and characterized using nanoparticle tracking analysis (NTA), microflow digital imaging (MFI), and circular dichroism (CD) spectroscopy. This study showed selective formation of submicron particles exhibiting a perturbed protein conformation. These thermally induced submicron particles were spiked into an unstressed solution at three levels, and then monitored for micron-sized particle formation upon storage at 5°C and 25°C for 12 months. The resulting particle growth effects were temperature dependent. NTA and MFI results at 5°C showed little evidence that initial submicron particle levels impacted particle growth across the range ~0.03-25 μm. In contrast, MFI results at 25°C indicated that particle growth in the 1-10 μm size range correlated strongly with initial submicron particle levels, and particle counts in the 10-25 μm size range were highest after 12 months for the samples with highest initial submicron particle content.
我们提供的证据表明，在温度依赖的方式下，均匀的亚微米颗粒可以影响大颗粒的生长速率。干扰素-β-1a 在 50°C 下热应激 6 小时，并使用纳米颗粒跟踪分析（NTA）、微流动数字成像（MFI）和圆二色性（CD）光谱进行表征。这项研究表明，亚微米颗粒的选择性形成表现出蛋白质构象的扰动。这些热诱导的亚微米颗粒被注入到未受应力的溶液中三个水平，然后在 5°C 和 25°C 下储存 12 个月，监测微米级颗粒的形成。由此产生的颗粒生长效应是温度依赖性的。在 5°C 时，NTA 和 MFI 的结果几乎没有证据表明初始亚微米颗粒水平会影响~0.03-25μm 范围内的颗粒生长。相比之下，在 25°C 时，MFI 的结果表明，1-10μm 大小范围内的颗粒生长与初始亚微米颗粒水平密切相关，并且在 12 个月后，初始亚微米颗粒含量最高的样品中 10-25μm 大小范围内的颗粒计数最高。
