A COLLABORATIVE STUDY OF PROPOSED EUROPEAN PHARMACOPEIA REFERENCE PREPARATIONS OF LOW-MOLECULAR-MASS HEPARIN

A European collaborative study, in which 16 laboratories participated, was carried out to assess the performance of the European Pharmacopoe ia (EP) monograph methods for anticoagulant activities (anti-Xa and an ti-IIa assays) of low molecular mass (LMM) heparin and to assess the s uitability of six candidate materials as the EP working standard for L MM heparin. There was good interlaboratory agreement for both types of assays as indicated by most gcv's being less than 10%, indicating acc eptable performance of the EP assay methods. All the candidate prepara tions gave dose-response curves parallel to the 1st International Stan dard for Low Molecular Weight heparin and to each other. All preparati ons, possibly with the exception of E and F, gave similar performance as measured by interlaboratory agreement and would be suitable as work ing standards. Based on these data, preparations A, B, C and D have be en established by the EP as official EP Biological Reference Preparati ons and they will be issued as successive batches.