[Determination of tetanus antitoxin levels in human immunoglobulins for intravenous use and in tetanus immunoglobulins by enzyme linked immunosorbent assay]
The present European Pharmacopoeia monograph for human tetanus immunoglobulin specifies that the estimate of potency has to be performed in guinea pigs or mice. In the course of the state control of such products we have so far used the potency test in mice. Aimed at a reduction of the numbers of animals used for testing tetanus potency of immunoglobulins in the course of official batch release we have used the enzyme linked immunosorbent assay (ELISA). 51 batches of 19 different immunoglobulin preparations of 10 manufacturers were included. Almost all tetanus immunoglobulins contained more than 250 I.U. of tetanus antitoxin per millilitre as agreed with manufacturers during marketing authorization negotiations in Germany. Normal human immunoglobulins for intravenous use had - depending on individual products - lower and fluctuating tetanus antitoxin titers. However, some of them fulfil the Ph. Eur. Monograph requirement of not less that 50 I.U./ml. The question is raised whether such products could be useful in treatment of persons with view to their immediate bioavailability, whenever the antitoxin titer is stated in particular on the package inserts. Our titration results were reliably reproducible. We have drawn the conclusion that we can largely renounce at animal tests when determining tetanus antitoxin potency in immunoglobulins.
Mainka
Christian
C
Paul-Ehrlich-Institut, Bundesamt für Sera und Impfstoffe, D-Langen.
Haase
Manfred
M