FACTOR-VIII CONCENTRATE OF INTERMEDIATE PURITY AND HIGHER POTENCY

A fractionation method has been modified to produce a factor VIII concentrate of intermediate purity and a potency of about 12 iu/ml, suitable for injection by syringe. The solubility, ease of filtration and purity of the concentrate have been improved by including a stage in which contaminants are precipitated at controlled temperature, pH and ionic strength. A summary of the first 50 production‐scale batches is presented. Plasma can be harvested from whole blood and frozen within eight hours of donation, or after overnight storage of whole blood, with no significant difference in overall yield. 1979 AABB