HEAT-STABILITY OF 2 CANDIDATE INTERNATIONAL REFERENCE PREPARATIONS FOR RECOMBINANT HUMAN TISSUE FACTOR

Adequate heat stability of international reference preparations (IRP) for thromboplastin (tissue factor) is an essential requirement. Accele rated degradation testing was performed by three laboratories on two c andidate IRP for recombinant human tissue factor. Heat treatment of th ese candidates resulted in slight shortening of the PT, contrasting wi th heat-induced prolongation of the PT observed with a conventional hu man brain derived IRP. Heat stability of these candidates was improved when compared with the stability of previous recombinant human tissue factor preparations. The PT-ratio did not change significantly when t he candidates were stored for 28 days at 44 degrees C. It can therefor e be concluded that both candidates are acceptable with regard to stab ility.