Accelerated degradation test of lyophilized recombinant tissue factor-liposome preparations

Accelerated degradation experiments were performed to assess the heat stability of lyophilized recombinant tissue factor-liposome preparations from two different manufacturers. When stored at 4 degrees C, these preparations did not show a significant change of the prothrombin time (PT). Two preparations (coded rTF-2 and rTF-a) showed a progressive prolongation of the PT on storage at 30 degrees C, 37 degrees C, and 44 degrees C. The third preparation showed an initial decrease of the PT at 37 degrees C and 44 degrees C followed by a progressive prolongation. Although none of the three preparations was absolutely stable at 30 degrees C, 37 degrees C and 44 degrees C, rTF-2 had the advantage that its PT-ratio (and hence its International Sensitivity Index) did not change under the conditions used in this study. The PT-ratio with a reference material for rabbit brain tissue factor (CRM149S) stored under similar conditions, did not change either.