Formulae for maximum valid dilution

The preparation of test specimens using the MVD calculation represents a reasonable approach to equating the sensitivity of the in vitro and in vivo tests for endotoxin. Labeling of LAL reagents and control standard endotoxins are a point of confusion for the parenterals industry. Government and reagent suppliers must work together expeditiously to provide test materials that are explicitly labeled as to reactivity in EU/ml and ng/ml. The relatively greater reactivity of LAL reagent to environmental endotoxin than the rabbit bioassay provides a greater margin of safety for the in vitro approach than previously anticipated, and suggests that rabbit retest of LAL failures may be appropriate for specific products.