[Stability of streptokinase incubated in various solvents at different temperatures (author's transl)].

Streptokinase was dissolved in various solvents and the decay recorded. The method employed was a recently described clot lysis assay for quantitative streptokinase determination. The decrease in activity of 5 u streptokinase, 1500 u streptokinase, and 50,000 u steptokinase dissolved in one milliltre of different solvents (NaCl solution, glucose solution, laevulose solution, dextran solution (Rheomacrodex), gelatin solution (Haemaccel, starch solution (Plasmasteril,albumin solution, Michaelis buffer, heparin-glucose solution) and incubated over various periods of time (15 min, 30 min, 45 min, 60 min, 4h, 8h, 12h, 48h) was investigated. Solution media tested for streptokinase-potecting quality were broken down into three groups.-Group I: Solvents displaying excellent stabilizing properties (gelatin, albumin).-Group II: Solvents displaying medium stabilizing properties (dextran, levulose)--Group III: Solvents displaying properties (starch, NaCl, glucose, Michaelis buffer).--In testing streptokinase concentrations as used for therapeutic purpose (1500 u/ml, 50,000 u/ml), no decay was found to take place over observation periods as long as 48 h. This finding was independent of the different solvents (Group I, II or III) employed. Heparin stored with streptokinase at rooom temperature did not alter the streptokinase stability. From the clinical point of view, the choice of solvents for streptokinase infusion turned out to be of minor importance.