Process for producing a high purity antihemophilic factor concentrate

In a process for producing high purity antihemophilic factor concentrate having enhanced specific activity and reduced fibrinogen impurity by the steps of:

• (a) isolating an antihemophilic factor containing starting material selected from blood plasma and a blood plasma fraction;
• (b) forming a solution of the so-isolated antihemophilic factor containing starting material from step (a);
• (c) performing a first plasma protein precipitation by adding to the solution of the antihemophilic factor containing starting material from step (b) about 1-4% (w/v), based on volume of solution from step (b), of polyethylene glycol, and adjusting the pH of the resulting mixture to about 6.6-6.8 and the temperature of the resulting mixture to about 5-10.degree. C., and agitating the resulting mixture for about 15 minutes;
• (d) separating the precipitate and recovering the supernatant aqueous polyethylene glycol solution resulting from step (c);
• (e) performing a second plasma protein precipitation by adjusting the polyethylene glycol concentration of the aqueous-polyethylene glycol solution from step (d) to about 9-15% (w/v), based on volume of solution from step (d), and adjusting the pH of the resulting mixture to about 5.7-6.8 and the temperature of the resulting mixture to about 5.degree.-10.degree. C. and agitating the resulting mixture for about 15 minutes;
• and
• (f) separating the supernatant aqueous-polyethylene glycol solution and recovering the precipitate from step (e);
• the improvement comprising
• (i) combining with the polyethylene glycol in the first precipitation in step (c) a suspension containing about 1-3% by weight, based on total weight of suspension, of aluminum hydroxide in water, the aluminum hydroxide suspension being used in the ratio of about 0.1-0.25 g of aluminum hydroxide suspension per 1 g of protein in the starting antihemophilic factor containing starting material, and
• (ii) combining with the polyethylene glycol in the second precipitation in step (e) about 10-20% by weight, based on total volume of solution in step (e), of glycine and about 10-20% by weight, based on total volume of solution in step (e), of sodium chloride.