Articles in this Issue
Tim Sandle, PhD
Parenteral pharmaceutical products, ingredient water, and some constituent materials undergo bacterial endotoxin testing since endotoxins are pyrogenic in humans and above a threshold this can induce severe physiological reactions. The conventional method to assess for endotoxin is with the Limulus amebocyte lysate (LAL) assay.
USP <85>,“Bacterial Endotoxins Test”(BET) is a harmonized compendial analytical procedure that describes the use of lysates (extracts) prepared from the blood cells (amebocytes) of horseshoe crabs to detect and quantify endotoxins activity in parenteral products (USP 2019a).
Part one of this three-part series examined the scientific basis for recombinant methods and the history and extensive studies utilized previously for the acceptance of alternate tests in the field of pyrogen and bacterial endotoxins testing.
Quality control analyses of all types ensure patient safety by providing evidence that the article under test meets its approved acceptance criteria. These analyses must be validated to demonstrate a capability of detecting, and where possible or required, quantifying the parameter they are purported to measure. Our two prior articles (Akers et al., 2020a; Akers et al., 2020b) have reported what precisely this means for alternative tests in the field of pyrogen and bacterial endotoxins testing. In endotoxins testing any capable alternate method must detect and, depending on the assay, quantify contaminant(s) that are likely to be in the product comparably to the standard compendial method.
Horseshoe crab blood carries factors that react to antigens found on and in gramnegative
bacteria walls by forming a clot around it.