USP Provides Guidelines for rFC Reagent

The U.S. Pharmacopeia (USP) published a Compendial Notice and Prospectus regarding the introduction of recombinant Factor C (rFC) – a synthetic alternative to naturally sourced reagents derived from horseshoe crabs – into the official text of the USP-NF. This latest step is part of an effort to introduce more methods for detection of bacterial endotoxins, an important early step in the process for vaccine development and other injectable therapeutics.

USP is also making draft guidelines on rFC testing available for developers of COVID-19 vaccine and therapies as part of the Trust Accelerated program. The program provides USP standards and access to USP scientists who are volunteering their technical expertise to support the development of novel vaccines, monoclonal therapies, antiviral and cell therapies, and convalescent plasma treatments being developed for the Covid-19 pandemic. This includes advising on the application of rFC-based test methods for these products.

As a synthetic reagent, rFC provides an alternative to Limulus amebocyte lysate (LAL) and Tachypleus amebocyte lysate (TAL) – reagents sourced from the blood of horseshoe crabs and used for endotoxin tests. A primary benefit of the rFC reagent is improved consistency and sustainability. Variation is a common feature among all animal-sourced products. The consistency of a synthetic can make manufacturing and testing processes easier to control and because rFC can be made in unlimited quantities, it is more sustainable.

The addition of rFC to the pharmacopeia provides alternatives to animal-based products. Other examples: Insulin test, cell-based assay to measure bioactivity, as an alternative to animal-based assays; Somatropin growth hormone, cell-based and chromatographic assays to measure activity, as an alternative to animal-based assays