Simplified methods for preparation of very high purity Factor VIII concentrate

Claim 2

In a process for preparing Factor VIII concentrate, the improvement comprising the step of holding a buffer solution containing Factor VIII and about 6% polyol at a temperature of from about 0° to about 5° C until precipitation occurs.

Claim 3

In the process for preparing Factor VIII concentrate, the improvement comprising the step of precipitating fibrinogen selectively from a solution of plasma or plasma cryoprecipitate in buffer by the addition of about 4% by volume of polyol to said solution, concentrating the Factor VIII in the solution by increasing the polyol concentration to about 6% and holding the 6% polyol containing solution at from about 0° to about 5° until precipitation occurs and then redissolving the precipitated Factor VIII in buffer solution to yield a solution containing very high purity Factor VIII which is substantially free of contaminating foreign protein.

Claim 4

In the process for preparing Factor VIII concentrate, the improvement comprising the step of precipitating fibrinogen selectively from a solution of plasma or plasma cryoprecipitate in buffer by the addition of about 4% by volume of polyol to said solution, concentrating the Factor VIII in the solution by increasing the polyol concentration to about 6% and holding the 6% polyol containing solution at from about 0° to about 5° until precipitation occurs and then redissolving the precipitated Factor VIII in buffer solution to yield a solution containing very high purity Factor VIII which is substantially free of contaminating foreign protein.

Claim 5

The process of claim 2 wherein the source of Factor VIII is cryoprecipitate dissolved in from about 2 to about 4 times the volume thereof in citrate buffer.

Claim 6

The process of claim 3 wherein the volume ratio of the cryoprecipitate to buffer is about 1 to 3.

Claim 7

In a process for removing pyrogens from a buffer solution of Factor VIII the improvement comprising the addition of about 6% polyol to said solution and holding the resulting polyol containing solution at a temperature of from about 0° to about 5° C to thereby precipitate Factor VIII, leaving in solution the pyrogenic material.

Claim 8

In a process for removing pyrogens from a buffer solution of Factor VIII the improvement comprising the addition of about 6% polyol to said solution and holding the resulting polyol containing solution at a temperature of from about 0° to about 5° C to thereby precipitate Factor VIII, leaving in solution the pyrogenic material.

Claim 9

In the process of claim 5 the addition of polyol to buffer solutions of Factor VIII in two steps, first adding about 4% polyol followed by separation of precipitate from the solution and the addition of 2% polyol and maintaining the solution at from about 0° to 5° until precipitation of Factor VIII occurs.

Claim 10

The process of claim 5 wherein the solution contains about 1 to 3 gram percent protein.

Claim 11

In the concentration of Factor VIII the improvement comprising holding a solution of about 1 part of Factor VIII containing blook fraction obtained from plasma cryoprecipitation in about 3 parts of citrate buffer containing about 6% polyol at a temperature of from about 0° to 5° to thereby cause precipitation of Factor VIII from said solution and redissolving said Factor VIII in buffer to give a very high purity Factor VIII containing solution.

Claim 12

In the concentration of Factor VIII the improvement comprising holding a solution of about 1 part of Factor VIII containing blook fraction obtained from plasma cryoprecipitation in about 3 parts of citrate buffer containing about 6% polyol at a temperature of from about 0° to 5° to thereby cause precipitation of Factor VIII from said solution and redissolving said Factor VIII in buffer to give a very high purity Factor VIII containing solution.