Method of filtering viruses from a factor VIII solution
View Patent ↗Method for preparing a factor VIII solution that is essentially free of viruses and essentially devoid of vWF (von Willebrand factor) and factor VIII-vWF complexes by (a) obtaining a starting factor VIII solution devoid of factor VIII-vWF complexes; and (b) filtering the solution through a hydrophilic virus filter.
1. A method for preparing a factor VIII solution comprising:
(a) obtaining a starting factor VIII solution comprising factor VIII-von Willebrand factor (factor VIII-vWF) complexes; and
(b) filtering said solution through a hydrophilic virus filter, wherein the virus filter has a mean pore size of 13 to 17 nm and
wherein the filtering occurs in the presence of CaCl 2 ions, at a pressure of less than 0.3 bar and a temperature of about 35±5° C.; and
wherein the filtered solution is free of viruses and devoid of high molecular forms of vWF and factor VIII-vWF complexes.
2. The method according to claim 1 , wherein the CaCl 2 is present in the solution from 0.2 M to saturation.
3. The method according to claim 1 , wherein the starting factor VIII solution is treated with an effective amount of an anti-viral solvent, a detergent, or both.
4. The method according to claim 1 , wherein the starting factor VIII solution is immunopurified.
5. The method according to claim 1 , wherein the starting factor VIII solution comprises recombinantly produced factor VIII.
6. The method according to claim 1 , wherein the starting factor VIII solution of (a) is derived from a cryoprecipitated fraction of plasma.
7. The method according to claim 6 , wherein the starting factor VIII solution is obtained by a further heparin precipitation.
8. The method according to claim 1 , wherein the CaCl 2 is present in the solution from 0.35 M to saturation.
9. The method according to claim 8 , wherein the filter has a pore size of 15 nanometers.
10. The method according to claim 8 , wherein the filter is used at a pressure lower than 0.2 bar.
11. The method according to claim 1 , further comprising dissociating factor VIII-vWF complexes of the starting solution prior to (b) filtering.
12. The method according to claim 11 , wherein the factor VIII-vWF complexes of the starting factor VIII solution are dissociated by ion exchange chromatography.
13. The method according to claim 12 , wherein the starting factor VIII solution of (a) is derived from a cryoprecipitated fraction of plasma.