The standarization of pyrogens / by W.D.M. Paton.

  • Paton, William D. M.
Date:
1950
Catalogue details

Licence: In copyright

Credit: The standarization of pyrogens / by W.D.M. Paton. Source: Wellcome Collection.

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    UNITED NATIONS WORLD HEALTH ORGANIZATION Of XPERT COMMITTEE ON BIOLOGICAL STANDARDIZATION ^NATIONS UNIES ORGANISATION MONDIALE DE LA SANTE ' 'I VJH0/BS/90 30 October 1950 ORIGINAL; ENGLISH THE STANDARDIZATION OF ’PYROGENS by J W. D* Mo Paton, M*A, National Institute for Medical Research, London N*W0 7 (1) . Bacteria capable of-producing pyrogens are widely distributed in natural y/aters and In other sources, ^ ; and pyrogen can be formed by ' (4) them within a few hours* As a result, contamination of drugs, particularly of antibiotics prepared by bacterial action, and of solutions for parenteral’administration (such as blood substitutes) can occur very easily* Once such contamination has occurred, the pyrogens are not easily removed, for (7 8 10 j many of them resist the autoclave and pass'ordinary filters* } ' It has thus become necessary for^ certain pharmacopoeial preparations to pass a test for freedom from pyrogenicity0 Since the’ actual amounts of pyrogen present are usually minute, of the order of microgram or less, this -test Is necessarily a biological one* / £? \ (2) The tests in current use are based on the- definition by Co Tuiw,‘ of the nMinimal Pyrogenic Dose’b this Is the dose per kilogram of body weight which-, when- injected intravenously into a rabbit, does not cause a rise in body temperature of more than CL5 - Q.6°C« within four hours, . The United States Pharmacopoeia and British pharmacopoeia tests stipulate that a given amount of test material should not cause a rise of more than 0o6°Ch above the initial body temperature, with readings taken during the three hours after,the Injection In all these tests a 5?biological unit*1 is adopted, that is a standard based on the assumption that the sensitivity of the .rabbit to pyrogens is constant from one laboratory to another*