Granted Patent B2

US 8,772,461 · App. 12/937,454 · Granted Jul 8, 2014

Abstract

Claims (22)

1. A method for concentrating a plasma protein of a solution comprising the protein, the method comprising:

a) ultrafiltering the solution using a first membrane to form a first retentate solution comprising the protein at a first concentration, wherein the first membrane has a molecular weight cutoff sufficient to retain at least a portion of the protein present in the solution;

b) diafiltering the first retentate solution with an aqueous solution using the first membrane to form a second retentate solution comprising the protein at about the first concentration;

c) formulating the second retentate solution comprising the diafiltered protein with glycine and adjusting the pH to form a formulated second retentate solution; and

d) ultrafiltering the formulated second retentate solution of step c using a second membrane to form a final retentate solution comprising the protein at a second concentration, wherein the second membrane has a molecular weight cutoff of about twice the molecular weight cutoff of the first membrane, wherein the second concentration is greater than the first concentration.

2. The method of claim 1 , wherein the protein is IgG.

3. The method of claim 1 , wherein the first membrane is a polyethersulfone C-screen membrane having a molecular weight cutoff of 50 kDa.

4. The method of claim 1 , wherein the first concentration is about 5% protein (w/v).

5. The method of claim 1 , wherein the aqueous solution is a water.

6. The method of claim 1 , wherein the second membrane is a hollow fiber membrane.

7. The method of claim 1 , wherein the second membrane has a molecular weight cutoff of 100 kDa.

8. The method of claim 1 , wherein the second concentration is at least about 19% protein (w/v).

9. The method of claim 1 , wherein the first membrane has a molecular weight cutoff sufficient to retain at least 90% of the protein present in the solution.

10. The method of claim 4 , wherein the first concentration is about 5%, wherein, in step c), the about 5% diafiltered protein is formulated to about 0.16 to about 0.30 M glycine and the pH is adjusted to about 4.3.

11. A method for concentrating a protein of a solution comprising the protein, the method comprising:

a) ultrafiltering the solution using a first membrane to form a first retentate solution comprising the protein at a first concentration of about 5%, wherein the first membrane has a molecular weight cutoff sufficient to retain at least about 90% of the protein;

b) diafiltering the first retentate solution using the first membrane with water to form a second retentate solution comprising the protein at about the first concentration;

c) formulating the about 5% diafiltered protein of step b) to about 0.16 to about 0.30 M glycine, wherein the formulating further comprises adjusting pH to about 4.3; and

d) ultrafiltering the second retentate solution using a second membrane to form a final retentate solution comprising the protein at a second concentration of about 19 to about 21%, wherein the second membrane has a molecular weight cutoff of about twice the molecular weight cutoff of the first membrane, wherein the second concentration is greater than the first concentration.

12. The method of claim 11 , wherein the protein is IgG.

13. The method of claim 12 , wherein the first membrane has a molecular weight cutoff of about 25 kDa to about 75 kDa.

14. The method of claim 13 , wherein the first membrane has a molecular weight cutoff of about 50 kDa, wherein the second membrane has a molecular weight cutoff of about 100 kDa.

Assignments (31)