A new low molecular weight heparin derivative. In vitro and in vivo studies

We present here the in vitro and in vivo evaluation of a new heparin low molecular weight (LMW) derivative that can be prepared on an industrial scale. The in vitro anti activated factor Xa (anti Xa) activity was 67 per cent that of standard heparin while anti-thrombin and anticoagulant activities were respectively limited to 16 and 10 per cent. The same discrepancy between anti Xa and anticoagulant activity was found after intravenous (IV) or subcutaneous (SC) injection to ten healthy volunteers. From the kinetic of the anti Xa activity disappearance it can be assumed that the mechanism of elimination of LMW heparin is not strongly different from that of traditional heparin.