Thromb Haemost 1984; 52(02): 148-153
DOI: 10.1055/s-0038-1661160
Original Article
Schattauer GmbH Stuttgart

A Collaborative Study Designed to Establish the 4th International Standard for Heparin

D P Thomas
The National Institute for Biological Standards and Control, Hampstead, London, U. K.
,
A D Curtis
The National Institute for Biological Standards and Control, Hampstead, London, U. K.
,
T W Barrowcliffe
The National Institute for Biological Standards and Control, Hampstead, London, U. K.
› Author Affiliations
Further Information

Publication History

Received 03 May 1984

Accepted 02 July 1984

Publication Date:
19 July 2018 (online)

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Summary

An international collaborative study, in which 22 laboratories participated, was carried out to establish a replacement for the International Standard for Heparin. A total of 248 assays were analyzed, including APTT, thrombin inhibition and anti-Xa assays, as well as pharmacopoeial assays. Overall, there was less than 5% difference in the mean potency estimates of the candidate preparations, by all assay methods. The freeze-dried preparation 82/502 demonstrated the closest parallelism by bioassay to the existing standard and was established by WHO as the 4th International Standard for Heparin, with an assigned unitage of 1780 i.u. per ampoule.