Application of LAL for detection of endotoxin in antibiotic preparations

The Limulus amebocyte lysate (LAL) test has been investigated as an alternative method to the USP pyrogen test for the detection of endotoxin contamination in these antibiotic preparations: clindamycin phosphate, lincomycin hydrochloride, neomycin sulfate, and spectinomycin hydrochloride. The antibiotic preparations were tested at the maximum concentrations that would not inhibit gelation of LAL. The USP pyrogen test was also performed for comparison. The LAL and the USP pyrogen tests correlated extremely well when an acceptance criterion based on the minimum pyrogenic dose (MPD) of endotoxin per human dose of drug was used for the LAL test. Use of this MPD provides a practical and feasible acceptance creiterion for the LAL test and assures that the LAL sensitivity approximates or surpasses that of the USP pyrogen test.