Endotoxin testing: the future of recombinant methods (panel)

 

The most commonly used method for detecting endotoxin in biological drugs for many decades has been Limulus amebocyte Lysate (LAL) based kinetic assays.

The reagent is dependent upon harvesting horseshoe crabs, which places a dependence upon animals and this brings with it ethical, ecological and logistical issues.

New methods are now available which is based on the same reaction principle as LAL but is produced without the need for animal-derived raw material.

These are under the broad terms of ‘recombinant’ endotoxin detection reagents.This was the subject of a recent European Pharmaceutical Review Expert Panel discussion.

Due to advantages of performance and for the other issues it is becoming more important for pharmaceutical companies to evaluate the use of these recombinant technologies.

Peer-reviewed literature was evaluated comparing results obtained with recombinant reagents to those with LAL.

Yet, for laboratory users, there are choices to be made in terms of whether to change, when to change, how to change, and what to change to.

To help to answer these questions, it was my pleasure to chair an expert panel composed of:

 

• Ingo Spreitzer, Deputy Head Microbiology Safety Section, Paul-Ehrlich-Institut
• Radha Tirumalai, Senior Principal Scientist, Merck Research Laboratories
• Phil Duncanson, an industry expert speaking in a personal capacity
• Allen Burgenson, SME Testing Services, Lonza

 

The panel discussed the following questions:

 

1. What has been the driver for recombinant lysate?
2. What is the view of regulators about recombinant lysate?
3. Where should users begin their journey with recombinant lysate?
4. How do recombinant reagent test methods differ - recombinant Factor C (rFC) and recombinant Cascade Reagents (rCR)?
5. How should users approach the selection between these different technologies?
6. How reliable overall are recombinant lysate solutions?
7. Are there any products or materials against which recombinant lysate is more challenging?
8. Do recombinant lysates improve endotoxin test performance?
9. How should a laboratory approach qualifying a recombinant lysate?
10. What advice do you have for approaching a regulator for a method change?
11. What is the likelihood of a unified pharmacopeial approach for recombinant lysate methods?

 

You can watch the discussion here: https://app.swapcard.com/event/the-future-of-bio-pharmaceutical-analysis-online-summit-2024/planning/UGxhbm5pbmdfMTkyNzc4MA==

 

Dr. Tim Sandle, Pharmaceutical Microbiology Resources (http://www.pharmamicroresources.com/)

Novel Aptasensors for Endotoxin Detection Are Advancing Drug Discovery

 

Assessing levels of endotoxin during the development of pharmaceutical products and for the assessment of patients under medical care forms an important part of the pharmaceutical and healthcare system. Depending on the product type, there are complexities involved. Bacterial endotoxin can form a stable interaction with other biomolecules thus making its removal difficult especially during the production of biopharmaceutical drugs. The detection of endotoxin (generally synonymous with lipopolysaccharide where the molecule’s lipid A moiety possesses most of the biological activity) is important for patient safety due to its pyrogenic properties and ability to trigger a form of septic shock.

 

In addition, endotoxin can be difficult to detect when bound with protein in the human body. This makes endotoxin testing for certain applications significantly challenging, especially for drug development and medical research, such as screening patients with severe sepsis and septic shock.

 

 

To meet this challenge, innovations in endotoxin testing are being developed in the form of biosensor technology. The most promising of these is a form of electrochemical aptasensor2 which detects endotoxin through voltammetric determination of lipopolysaccharide. Aptamers show great affinity toward their target analytes, such as with endotoxin. The aptamer recognizes the molecular target against which it was previously in vitro selected. There are several such sensors in research use and the development phases are promising. Furthermore, these technologies have the potential to meet the requirements of ‘rapid microbiological methods’ in that they meet the criteria of good performance, accuracy, repeatability and had a shorter time-to-results. This article reviews progress in this area of endotoxin detection.

 

Sandle, T. (2021) Novel Aptasensors for Endotoxin Detection Are Advancing Drug Discovery, American Pharmaceutical Review, July / August 2021, pp1-3

 

Posted by Dr. Tim Sandle, Pharmaceutical Microbiology Resources (http://www.pharmamicroresources.com/)

Bacterial Endotoxin Test using LAL methodology: overcoming interfering factors

        Image by cogdogblog - https://www.flickr.com/photos/cogdog/6224395337/, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=56998030

The Bacterial Endotoxin Test, using LAL methodology, is a key in-process and final product release test for sterile pharmaceuticals and medical devices. One of the challenges with LAL methodology is overcoming interfering substances as demonstrated by inhibition or enhancement of an endotoxin challenge. Here, Bio Products Laboratory’s Dr Tim Sandle discusses the interfering substances issue and provides some guidance to overcome it.

 

 

Sandle, T. (2021) Bacterial endotoxin test using LAL methodology: overcoming interfering factors, European Pharmaceutical Review, Issue 4,Special Supplement: QA/QC Environmental Monitoring, at: https://edition.pagesuite.com/html5/reader/production/default.aspx?pubname=&edid=8011f861-3b23-409f-beb7-5bae16d120c4

 

Posted by Dr. Tim Sandle, Pharmaceutical Microbiology Resources (http://www.pharmamicroresources.com/)