Published in European Pharmacopoeia (Ph. Eur.) Supplement 10.3, the new general chapter 2.6.32. Test for bacterial endotoxins using recombinant factor C describes a test for bacterial endotoxins (BET) that can be used as an alternative to the classic limulus amoebocyte lysate (LAL)-based methods for the quantification of endotoxins from gram-negative bacteria. The method described involves the use of a recombinant factor C (rFC) based on the gene sequence of the horseshoe crab and fluorimetric detection, in keeping with the kits currently available on the European market.

Also published in Supplement 10.3 is the revised chapter 5.1.10. Guidelines for using the test for bacterial endotoxins, which has been updated to reflect the new status of rFC-based methods and give prerequisites for their deployment by users of the pharmacopoeia.

With the introduction of general chapter 2.6.32, Ph. Eur. users will have the possibility of using a standardised method, which will become official in the 39 signatory countries to the Ph. Eur. convention. A test for bacterial endotoxins using rFC can be used in the same way as LAL-based methods, after demonstration of its fitness for use for the specific substance or product. The use of rFC for BET testing does not need to be validated, thus facilitating the implementation of rFC-based methods by users. It should be noted however, that the replacement of an LAL-based method prescribed in a monograph by an rFC-based method is considered as the use of an alternative method as described in the Ph. Eur. General Notices.

For BET testing, the world currently relies on a single source of lysate, the horseshoe crab family, and more specifically, two species of the crab, Limulus polyphemus and Tachypleus tridentatus (both of which are known to be endangered). The publication of the new general chapter 2.6.32 therefore marks a significant step towards alleviating the need for these animal resources.

The EDQM’s Director, Susanne Keitel, pointed out that “When used under appropriate conditions, rFC-based methods provide the same guarantee of a product’s compliance with the test for bacterial endotoxins – and therefore, of its safety for use in patients – as LAL-based methods”.

The new general chapter 2.6.32 and the revised general chapter 5.1.10 will become effective on 1 January 2021.

See also:

• European Pharmacopoeia 10th Edition
• European Pharmacopoeia Commission
• European Pharmacopoeia work programme