Endotoxin Masking is a phenomenon which renders endotoxin inaccessible for detection with conventional methods such as LAL. Endotoxin Masking is currently a highly important issue in the field of Bacterial Endotoxin Testing (BET) addressed by the FDA. Whereas the European authorities have not yet given official recommendations, the FDA requires dedicated spike recovery studies and extended quality control data by manufacturers of biopharmaceuticals. In recent presentations and publications, the problem of inadequate or Low Endotoxin Recovery (LER) has been addressed by several pharma manufacturing companies and scientists. To solubilize antibodies, certain formulations are applied, which consist of surfactants and buffer components. The complex relationship between the formulation components, active pharmaceutical ingredient (API) and the potential endotoxin contamination has been shown to change the activity of endotoxin in Limulus based detection systems.
Finding the Missing Endotoxin - Development of the Endo-RS® Endotoxin Recovery Kit: Based on thorough experimental work, Hyglos has previously elaborated a detailed model on the driving forces responsible for endotoxin masking. Only through understanding the underlying mechanisms of LER, the Hyglos scientists have been able to develop a dedicated sample preparation kit for demasking endotoxin in protein formulations containing surface active agents: Endo-RS®.
The new method consists in the following steps:
- Disturbing Hydrogen Bonding,
- Adsorption of Surfactants,
- Displacement of the Endotoxin and
- Change of the Endotoxin Aggregate form into micelles required for detection.
Hyglos offers the needed reagents as a complete sample preparation kit - Endo-RS® Endotoxin Recovery Kit. Endo-RS® must be applied in combination with the EndoLISA® Endotoxin Detection Assay, because the solid phase of EndoLISA® ensures the complete removal of sample matrix. This advantage of EndoLISA® is important since the reagents needed for demasking the endotoxin would otherwise interfere with homogeneous methods such as LAL.