Testing considerations following the discontinuation of PYROGENT^® Gel Clot LAL Assays with 0.25 EU/ml sensitivity

To support customers impacted by the discontinuation of PYROGENT^® Gel Clot LAL Assays with 0.25 EU/ml sensitivity, the information below outlines testing options to support your ongoing testing needs. Whether you want to continue testing with the gel clot method or are considering a transition to a quantitative or recombinant technology, Lonza offers several options to support your laboratory requirements. 

Continue testing with the gel clot method

For customers wanting to continue to test with the gel clot method, we do offer a variety of other kit configurations which utilize more sensitive lysates, including:

16 tests/vial options:

If you are considering switching to one of our 16 tests/vial PYROGENT^® Gel Clot offerings (0.06 EU/ml or 0.125 EU/ml sensitivities), we do not expect product revalidation would be needed given that these products generally use the same formulation as the 0.25 EU/ml lysate. However, customers should determine whether any validation or verification activities are required based on their intended use, applicable internal procedures and regulatory requirements, and for documentation, you should recalculate your MVD using the sample endotoxin release limit divided by the labeled kit sensitivity.

50 tests/vial options:

If you are considering switching to one of our other 50 tests/vial PYROGENT^® Gel Clot offerings (0.03 EU/ml, 0.06 EU/ml or 0.125 EU/ml sensitivities), please note that they differ in formulation from the 0.25 EU/ml lysate. Therefore, if you have not previously validated the product/formulation combination, we recommend that the following testing be performed. As with any new lot of LAL that comes to your lab, an Initial Qualification (IQ) assay is required before the product is used for end-product release testing. In addition, because this is a formulation change, you must ensure that your product does not interfere with the clotting of the lysate. At a minimum, we recommend evaluating one representative lot of each product at the dilution routinely used for testing, including a Positive Product Control (PPC). Customers should also follow any applicable internal validation or method verification procedures to confirm the suitability of the reagent for their intended use. A positive result with the PPC indicates that your product is not interfering with the alternate formulation. If you do not get a positive result with the PPC, you should run a full Inhibition and Enhancement protocol to determine the appropriate dilution or pre-treatment. You will need to recalculate your Maximum Valid Dilution (MVD) using the sample endotoxin release limit divided by the labeled kit sensitivity.

 

Considering a transition to quantitative endotoxin testing?

If your lab is exploring a switch from the qualitative gel clot assay to a quantitative assay, we have several options to support you in this transition. Our Kinetic-QCL^® Kinetic Chromogenic LAL and PYROGENT^® 5000 Kinetic Turbidimetric LAL Assays not only detect the presence of endotoxin but also directly determine the amount of endotoxin in the sample. This means that results can be analyzed over time to identify trends before issues arise. Kinetic LAL methods enhance endotoxin testing by transforming it from a qualitative release tool into a quantitative process-control tool. This advancement offers improved sensitivity, objectivity, readiness for automation, and provides actionable data for modern pharmaceutical manufacturing. By replacing subjective visual interpretations of clot formation with objective, electronically captured analytical data, kinetic LAL methods improve data integrity. They also offer enhanced traceability, auditability, and electronic records management, supporting compliance with ALCOA+, Annex 11, and 21 CFR Part 11 standards.

Exploring recombinant technology?

There is a growing need for recombinant technologies that help alleviate, and eventually replace, the use of animal resources for endotoxin testing. Our PyroGene^® rFC Assay helps detect bacterial endotoxins with high specificity, consistency, and regulatory acceptance while reducing reliance on horseshoe crab–derived lysate.

We’re here to help

If you are evaluating alternative products or considering a change in testing methodology, Lonza's Scientific Support team is available to assist with product selection and testing considerations. As an additional resource, educational videos and Quick Guides on how to perform each of these assays are available through the QC Insider^® Toolbox.