The present invention relates to pharmaceutical preparations comprising two-chain Factor VIII that are essentially free of Factor VIII-Light Chains (FVIII-LCs) which are not associated with Factor VIII-Heavy Chains (FVIII-HCs) having higher purity and which are less immunogenic. The invention also relates to methods to test the suitability of a pharmaceutical Factor VIII preparation and to methods to reduce in pharmaceutical Factor VIII preparations the amount of FVIII-HCs which are not associated with FVIII-LCs and/or of FVIII-LCs which are not associated with FVIII-HCs.
