This "masking" is typically a time- and temperature-dependent process driven by specific formulation components, most notably the combination of and chelating agents (like citrate or phosphate buffers). These components cause the endotoxin lipopolysaccharides (LPS) to form macromolecular complexes that the LAL reagents cannot recognize, leading to potentially false-negative results. Core Components of TR 82
LER occurs when spiked endotoxin standards cannot be recovered from a drug product matrix using traditional Factor C-based assays, such as the Limulus Amebocyte Lysate (LAL) test or recombinant Factor C (rFC).
Published in March 2019, , titled Low Endotoxin Recovery , is a definitive industry resource for addressing one of the most challenging phenomena in modern biopharmaceutical quality control.
The report is the culmination of three years of work by a task force including experts from the U.S. FDA , academia, and the pharmaceutical industry. Key sections include: Technical Report No. 82: Low Endotoxin Recovery | PDA
This report provides a science-based framework for understanding, detecting, and mitigating Low Endotoxin Recovery (LER)—a masking effect that can prevent the reliable detection of endotoxins in biologics.
