Abstract: Intravenous plasma derivatives having an acceptably lowered content of externally caused deleterious activity or exogenous activity, and their method of production are provided. The method includes the steps of mixing bentonite and an aqueous solution of plasma derivative containing exogenous activity, the bentonite and the mixing time being sufficient to adsorb exogenous activity, and isolating the aqueous phase from the bentonite. Optionally, for the removal of residual exogenous activity, the step of treatment of the aqueous phase with bentonite is repeated and/or the bentonite-treated aqueous phase is further purified by ion-exchange chromatography.