title: An evaluation of the British Pharmacopoeial assay of heparin: a comparison with other methods.
abstract: The potencies of six commercially manufactured heparins have been measured by the British Pharmacopoeial (BP) assay and activated partial thromboplastin time (APTT), protamine sulphate, and anti-Xa assays. The APTT/BP potency ratios were found to vary with the preparation but this was not dependent on the tissue source of heparin. For mucosal heparins, the anti-Xa/BP potency ratios were close to unity, but for heparin of lung origin the anti-Xa potency was approximately one-quarter of the BP potency. Four heparin fractions prepared by column gel chromatography of a commercial heparin were similarly examined by all four assays, and there was a wide divergence between the BP potency estimates and those obtained with the other methods. The degree of divergence was found to depend on the molecular size of the fraction.
mesh_terms: D001702:Biopharmaceutics; D005069:Evaluation Studies as Topic; D006493:Heparin / Q000592:standards*; D008970:Molecular Weight; D012015:Reference Standards; D006113:United Kingdom
chemical_list: D006493:Heparin