Endotoxin limits in formulations for preclinical research.

This brief commentary discusses a review of the current status on endotoxin limits, a critical parameter, for formulations to be administered to animals. The endotoxin units set by United States Pharmacopoeia (USP), and the techniques specified by USP for endotoxin testing are described. Endotoxin limits for preclinical research animal models were derived based on the threshold pyrogenic human dose of 5 E.U. per kg. The limits calculated would act as a guideline for endotoxin limits in preclinical species. A quick reference chart for endotoxin limits is included to provide a guideline for endotoxin limits for animal models used in preclinical research. Derivation of endotoxin limits from K/M for doses and animal models not included in the chart could be calculated as described.