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Overcoming low endotoxin recovery (LER) effects with MAT

Low endotoxin recovery (LER) effects have become a mainstay of challenges facing pharma manufacturing and supply sites. While LAL and RPT have proven ineffective in helping overcome low endotoxin recovery effects, finally MAT promises hope. 


What is the low endotoxin recovery (LER) effect?

Low endotoxin recovery – often described as a masking effect – points to where a reduced quantity of endotoxin is recovered after an undiluted product is spiked with a known quantity of endotoxin. Whilst the low endotoxin recovery effect is an occurrence that was initially observed in products containing the excipients polysorbate and citrate, subsequent studies in this area have found instances of low endotoxin recovery effects in a variety of other products too – for instance, those with phosphate-containing formulations.

Although the principle which underlies the low endotoxin recovery effect is still to be fully comprehended, a growing body of literature provides glimpses of understanding. Specifically, where low endotoxin recovery effects have occurred, changes in the structure of the LPS molecule were observed which led to decreased endotoxin binding to factor C – the crucial component in stimulating the enzymatic cascade required for endotoxin detection in the LAL or rFC test.

"MAT BioTech provided both the technology and the insights we needed to overcome the low endotoxin recovery effects we didn't know what to do with."


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Why is the low endotoxin recovery effect a problem?

Low endotoxin recovery effects pose significant problems for manufacturing and supply sites during the process of routine testing a drug as a part of it’s batch release. In this process, the labs test both a spiked sample of a drug batch as their control and an unspiked sample in a bid to detect possible endotoxin contaminations within the batch. While testing the spiked solution, the internal validity of the test results is determined — ensuring that where for instance the amount of LPS detected is low, that is in fact due to the low amount of LPS in the sample, not due to the assay’s inability to detect LPS within that particular drug. 

Where the LPS recovery percentage found after testing a spiked drug solution is below 50%, low endotoxin recovery effects are at play. When a low endotoxin recovery effect is observed in the testing of a spiked solution, the implication is that upon testing it’s paired unspiked solution, if there was contamination of endotoxins, such contaminations would not be detected by the assay and thus the batch from which these samples derived would pose significant risk to patient safety if released. Unless these low endotoxin recovery effects are overcome, and it is established that the drug is not contaminated with endotoxins, the drug will not be released into the market.

By this same token, low endotoxin recovery effects pose an interesting headache for manufacturers. Specifically, products that are not in fact contaminated by endotoxins and are completely safe from this perspective, could be stalled from being released due to the low endotoxin recovery effects observed while testing them.

Learn more about MAT over a call with the scientists that commercialised it.

Wouldn't it be nice to set-up your PC with Bill Gates on the line rather than the computer store that sold it to you? Unlike other MAT providers, our team comprises the very scientists that designed the CTL-MAT kit and those provided by almost every other MAT provider out there. Any questions you may have – big or small – you can be rest assured in knowing that they'll be able to answer.

What are the options for overcoming low endotoxin recovery effects?

When compared to the LAL or rFC test, the monocyte activation test (MAT) has been found to be significantly less susceptible to low endotoxin recovery effects. This lower susceptibility to low endotoxin recovery effects is understood to likely root in the biological rather than enzymatic reaction by which the MAT assay works.

One early piece of research pointing to this was carried out by Dinarello et al. (1984) who evidenced the failure of LAL in detecting the endotoxins (i.e. a low endotoxin recovery effect, though the term had not yet been coined) that were present in a biosynthetic human growth hormone, which in turn induced inflammatory responses among healthy recipients upon their injection. When MAT was implemented however, the pyrogens were successfully detected and safety of the injected drug was ensured.

Since then, a growing body of research has been adding weight to this. One such recent example that underlines the usefulness of MAT in the face of low endotoxin recovery effects is Mozier’s (2019) paper titled ‘MAT as a developmental pyrogen test tool’. This paper predominantly describes the industrial application of EP 2.6.30 for MAT as an alternative to the RPT as a risk assessment when using the endotoxin test for pyrogen testing. It also, however, discusses how MAT may assist in troubleshooting when products display low endotoxin recovery effects. Specifically, the study proposes MAT as the preferred release test if MAT/RPT results are negative but the product exhibits low endotoxin recovery effects when using in BET.

MAT BioTech can help you overcome low endotoxin recovery effects by —

MAT BioTech partners with some of the very largest pharmaceutical companies in the world in their employment of our CTL-MAT kit. As many of our partners have at some point, in some way, faced a low endotoxin recovery effects obstacle, we’ve gained a great deal of experience in how to help overcome low endotoxin recovery effects using our MAT technology.

For example, when conducting tests on biologics like intravenous immunoglobulin (IVIG), we observed low endotoxin recovery effects at higher concentrations of these products. However, the low endotoxin recovery effects observed were ultimately overcome as we were able to dilute these products thanks to the market leading sensitivity (Lower Limit of Detection = 0.004 EU/ml) of our MAT kit. Product specific validation of each of these products then successfully resulted in finding 3 different product dilutions with an LPS recovery percentage between the allowable range of 50-200% — thus not exceeding the MVD of the product.

While the sensitivity of our MAT kit enables significant flexibility in overcoming low endotoxin recovery effects, there are many other means by which our market leading technology has been found to assist partners in their tackling of low endotoxin recovery effects. Why not reach out to us via our contact page so we can schedule an online consultation and discuss how we might be able to help overcome the low endotoxin recovery effects you’re experiencing.

Want to overcome low endotoxin recovery effects?

Simply reach out to us and we’ll schedule an online consultation with our chief scientist. Together we’ll devise a plan to successfully overcome your low endotoxin recovery effects.

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