Preparation of intermediate-purity factor VIII concentrate by direct gel filtration of cryoprecipitate.

We report a new method to produce a solvent/detergent-treated and severe dry heat-treated factor VIII (FVIII) concentrate (3-6 IU FVIII:C/mg protein). This method, which uses a single purification step after cryoprecipitation, is suitable for scale-up to production levels. FVIII was obtained from solvent/detergent-treated cryoprecipitate by a single gel filtration step using Sephacryl S-400HR. The freeze-dried product was stable to heating at 80 degrees C for 72 h. The yield of the solvent/detergent and severe dry heat-treated product was 230 IU FVIII:C/kg plasma. The reconstituted product gave a 10% loss in FVIII:C activity after heating at 37 degrees C for 6 h. The feasibility of this method suggests that gel filtration using S-400HR can be used solely or as part of a purification process for the preparation of high-purity FVIII concentrates.