Endotoxin limit

The maximum amount of endotoxin allowed in a product, calculated by dividing the threshold pyrogenic dose per kilogram of body weight for the route of administration (the K value) by the maximum dose per kilogram. It is the basis of the endotoxin specification and, together with the sensitivity of the method, of the maximum valid dilution. Routes such as intrathecal administration have much lower thresholds, which can make the limit hard to meet. Japanese documents often show the calculation with the K value written out.