| 摘要 |
Fibrinolysin suitable for intravenous injection is obtained by treating sterile human profibrinolysin in an aqueous solution at a temperature of 25 DEG C. and a pH between 6 and 7.5 with sufficient streptokinase to convert all of said profibrinolysin to fibrinolysin, cooling, acidifying to pH 1.8 to 3.5 to precipitate impurities, adding to the clarified solution a miscible water soluble organic solvent at a temperature between -3C DEG . and -7 DEG C. and allowing to stand until the fibrinolysin is precipitated. The profibrinolysin is first sterilised by heating an aqueous solution containing less than 10% profibrinolysin and having a pH of 3.0 to 6.5 and ionic strength below 0.3 at 60 DEG C. per 10 hours to destroy hepatitis virus. Excess streptokinase in pyrogenfree water (200,000 to 600,000 sk units) is added to the solution of profibrinolysin containing 10 to 50 m.g. per ml. profibrinolysin and allowed to stand 5-60 minutes at 25 DEG C. After acidification and removal of the precipitated impurities, other impurities may be removed by adding methanol to a concentration of 6% by volume at -3 DEG C. to -7 DEG C. Methanol is then added to a concentration of 60% by volume at -3 DEG C. to -7 DEG C. and is maintained at this temperature until the precipitation of fibrinolysin is complete. After washing, the precipitate is suspended in pyrogen-free water and lyophilised. The methanol may be replaced by ethanol or acetone. The fibrinolysin has an activity of 100,000 fibrinolytic units per milligram of nitrogen; is soluble in water and saline; free from streptokinase, prothrombin, thrombin, thromoplastin, fibrinogen and fibrin; is incapable of clotting fibrinogen or of converting prothrombin to thrombin rapidly; is not inhibited by prothrombin; is capable of destroying fibrinogen, fibrin and prothrombin (slowly); and remaining in solution without clot formation when an aqueous solution is treated with thrombin, fibrinogen or a combination of fibrinogen and thromboplastin. Specification 869,122 is referred to.
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