Endotoxins research supports recombinant reagent use for pharma QC
Posted: 9 January 2026 | Catherine Eckford (European Pharmaceutical Review) | No comments yet
Replacing LAL reagents with animal-free alternatives addresses industry commitments to improve QC practices’ ethics and sustainability.
Recombinant assays could be a promising and viable alternative to the use of horseshoe crab-derived reagents during endotoxin testing, according to new research from AstraZeneca.
In their study, Cliffe et al. evaluated the performance of five animal-free, recombinant assays against the traditional Limulus amoebocyte lysate (LAL) assay for endotoxin detection during pharmaceutical water testing.
Specifically, they compared the following attributes of both assay types:
- Sensitivity (limit of detection)
- Specificity for lipopolysaccharide (LPS) via endotoxin spike recovery at different concentrations
- Suitability for water testing
- Positive Product Control (PPC) recovery
- Precision (sample, PPC and standard curve)
- Ruggedness across multiple testers.
Recombinant Factor C (rFC) and Recombinant Cascade Reagent (rCR) demonstrated comparable sensitivity and performance to the reference LAL assay, according to the authors.
The rCR method “displayed comparable kinetics and chromogenic signal output [while] the rFC-based assay also performed reliably in the concentrations tested. Furthermore, qualitative and quantitative agreement with the LAL method was observed for most samples analysed”.
Recombinant Factor C (rFC) and Recombinant Cascade Reagent (rCR) demonstrated comparable sensitivity and performance to the reference LAL assay”
This equivalence “indicates a degree of robustness and standardisation within recombinant reagent manufacturing”, however Cliffe et al. emphasised the importance of ongoing validation to ensure continued suitability.
The LAL assay has long served as a mainstay reference method for endotoxin detection. Notably, Europe reached a new milestone this week after European Pharmacopoeia removed general chapter 2.6.8. Pyrogens from its texts. rFC is included in Issue 13.1, making it one of the seven alternative methods chosen for bacterial endotoxins testing (BET) (general chapter 2.6.14).
On the other hand, rCR is not yet a part of the Ph. Eur., although the European Pharmacopoeia Commission (EPC) is working towards future consideration of its use in its texts.
Overall, the findings by Cliffe et al. support the pharma industry’s ongoing transition toward sustainable, animal-free quality control practices.
The research was published in EJPPS.
Related topics
Big Pharma, Endotoxin, Endotoxin Detection, QA/QC, Research & Development (R&D), Sustainability, Therapeutics
