Nanofiltration, a New Specific Virus Elimination Method Applied to High‐Purity Factor IX and Factor XI Concentrates

Abstract
We have validated the use of two new regenerated multilayered structured cellulose membranes (BMM), Planova 15 N and Planova 35 N, with respective mean pore sizes of 15 and 35 nm, as a new filtration system to eliminate viruses in highly purified factor IX and factor XI concentrates. Virus spiking experiments indicated that single dead-end filtration on the membranes could remove more than 5.7–7.8 log10 of human immunodeficiency virus, bovine viral diarrhoea virus, porcine pseudorabies virus, reovirus type 3, and simian virus 40, as well as the small non-enveloped viruses, poliovirus Sabin type 1 and bovine parvovirus. In vitro control tests and animal studies (Wessler stasis model, rat hypotension model) of the two concentrates did not reveal any significant differences with the non-nanofiltered material. Viral filtration of plasma derivatives on porous polymeric membranes might be an essential step in the improvement of their viral safety.