Polysorbates (PS) are commonly used as stabilizers of biopharmaceuticals such as monoclonal antibodies (mAbs). However, they are prone to chemical and enzymatic degradation. The latter can be caused by residual host cell proteins (HCPs) in the drug substance. Degradation affects the functionality of the PS surfactant which can lead to formation of particles. An increasing number of publications describe enzymatic PS degradation. Significant efforts have been made to characterize HCP removal during Downstream Processing (DSP) of mAbs and to develop mitigation strategies. Here we describe the use of glycine buffer for acidic elution in Protein A affinity chromatography compared to acetate buffer, which is more commonly used in the biopharmaceutical industry. Increased turbidity was observed during pH re-adjustment after low pH virus inactivation when using glycine buffer. Analytical data suggests that this turbidity is caused by the formation of precipitates which include HCP and DNA impurities. Additionally, as a zwitterion, glycine does not contribute to conductivity; this further enhances HCP removal during anion-exchange flow-through chromatography. Although glycine is well known as a possible elution buffer for Protein A affinity chromatography, its positive impact on HCP removal and PS stability have not yet been described in literature.

中文翻译：

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缓冲系统改善了单克隆抗体纯化中宿主细胞蛋白杂质的去除


聚山梨酯 （PS） 通常用作生物制药的稳定剂，例如单克隆抗体 （mAb）。然而，它们容易发生化学和酶降解。后者可能是由原料药中残留的宿主细胞蛋白 （HCP） 引起的。降解会影响 PS 表面活性剂的功能，从而导致颗粒的形成。越来越多的出版物描述了酶促 PS 降解。在单克隆抗体下游加工 （DSP） 过程中表征 HCP 去除并制定缓解策略方面，已经做出了重大努力。在这里，我们描述了在蛋白 A 亲和层析中使用甘氨酸缓冲液进行酸性洗脱，与生物制药行业中更常用的乙酸盐缓冲液进行比较。当使用甘氨酸缓冲液时，在低 pH 病毒灭活后 pH 重新调整过程中观察到浊度增加。分析数据表明，这种浑浊是由沉淀物的形成引起的，其中包括 HCP 和 DNA 杂质。此外，作为两性离子，甘氨酸对电导率没有贡献;这进一步增强了阴离子交换流通色谱过程中 HCP 的去除。尽管甘氨酸是众所周知的蛋白 A 亲和层析的可能洗脱缓冲液，但其对 HCP 去除和 PS 稳定性的积极影响尚未在文献中描述。