Summary
A European collaborative study, in which 16 laboratories participated, was carried
out to assess the performance of the European Pharmacopoeia (EP) monograph methods
for anticoagulant activities (anti-Xa and anti-IIa assays) of low molecular mass (EMM)
heparin and to assess the suitability of six candidate materials as the EP working
standard for LMM heparin. There was good interlaboratory agreement for both types
of assays as indicated by most gcv’s being less than 10%, indicating acceptable performance
of the EP assay methods. All the candidate preparations gave dose-response curves
parallel to the 1st International Standard for Low Molecular Weight heparin and to
each other. All preparations, possibly with the exception of E and F, gave similar
performance as measured by interlaboratory agreement and would be suitable as working
standards. Based on these data, preparations A, B, C and D have been established by
the EP as official EP Biological Reference Preparations and they will be issued as
successive batches.
