Preparation and heat-treatment of factor-IX-concentrates

The stability to dry heat of different prothrombin complex concentrates depends on their composition, i.e. on the way of preparation and on additives such as reducing or non-reducing sugars. Alcohol precipitation, for instance, and addition of fructose or sorbitol as stabilizers is unsuitable for products which are intended to be heat-treated in the lyophylized state. Among the tests applied, only clotting-factor activities and--to a minor degree--turbidity, measured at 650 nm, responded significantly to small changes in heat-treatment. Finally, we were able in good yield to produce a factor IX high potency concentrate by adsorption on DEAE-Sephadex and ammonium sulphate precipitations. The freeze dried material can be heated for up to 96 hours and 70 degrees C without any sign of denaturation.