Reich Johannes, Tamura Hiroshi, Nagaoka Isao, Motschmann Hubert
Endotoxin Test Service, Microcoat Biotechnologie GmbH, Bernried, Germany.
LPS (Laboratory Program Support) Consulting Office, Tokyo, Japan; Department of Host Defense and Biochemical Research, Juntendo University Graduate School of Medicine, Tokyo, Japan.
Biologicals. 2018 May;53:1-9. doi: 10.1016/j.biologicals.2018.04.001. Epub 2018 Apr 21.
The inability to detect endotoxin added to undiluted drug samples has been called: Low Endotoxin Recovery (LER). The phenomenon has caused concerns amongst drug manufacturing quality control scientists in that manufactured solutions contaminated with endotoxin could show false-negative results via routine Limulus-based tests. The time-dependent appearance of LER has been analyzed in detail to provide a better understanding of the mechanism. The assumption has been that the root-cause of LER involves the interplay of endotoxin with surfactants and results in aggregate structures that are complexed with surfactants. The endotoxin molecules when complexed with surfactants are not accessible for Limulus-based detection. The results demonstrate a predominant role of complex-forming agents. It was shown that although the presence of surfactants is a strong prerequisite for masking, it does not determine the kinetics of endotoxin masking. Interestingly, the endotoxin concentration itself had no substantial impact on LER kinetics. By adjusting the ratios of complex-forming constituents, including surfactant, chelator and endotoxin, and by testing the order in which the constituents are added, a new model for simulating masking kinetics has been determined. Our work provides for the first time a model to simulate masking kinetics of endotoxin which lends a better understanding of LER.
低内毒素回收率（LER）。这种现象引起了药品生产质量控制科学家的关注，因为被内毒素污染的制成溶液通过常规鲎试剂检测可能会出现假阴性结果。已详细分析了LER随时间的出现情况，以便更好地理解其机制。一直以来的假设是，LER的根本原因涉及内毒素与表面活性剂的相互作用，并导致与表面活性剂复合的聚集体结构。与表面活性剂复合的内毒素分子无法通过鲎试剂检测到。结果表明络合剂起主要作用。结果表明，虽然表面活性剂的存在是掩盖现象的一个重要前提，但它并不能决定内毒素掩盖的动力学。有趣的是，内毒素浓度本身对LER动力学没有实质性影响。通过调整包括表面活性剂、螯合剂和内毒素在内的络合成分的比例，并测试成分添加的顺序，确定了一种模拟掩盖动力学的新模型。我们的工作首次提供了一个模拟内毒素掩盖动力学的模型，有助于更好地理解LER。
