Studies on the Stability of VIII:C during the Manufacture of a Factor VIII Concentrate for Clinical Use

Abstract

The stability of VIII:C was investigated by monitoring samples taken at different points from a routine process for the manufacture of factor VIII concentrate and by examining the stabilising influence of a number of product formulations. Loss of VIII:C over process-finishing procedures (formulation, 0.22 µm filtration, dispensing) was associated with a citrate-induced inactivation which could be prevented by controlling the ionised calcium concentration of the solution. These results were obtained using a one-stage clotting assay but were not observed using a two-stage assay. No evidence for activation was found in vitro (e.g. by FPA generation and VIII:C stability) and the yield increase suggested by the one-stage assay was supported by results from a controlled clinical evaluation.

The manufacture of blood plasma products in Scotland: a brief history

“…Heat treatment of Factor VIII concentrate began in November 1984, within days of a report that HIV might be inactivated by this procedure and with stocks obtained from donations obtained from late-1983 being heat treated. Calcium was added to stabilise factor VIII during processing, 11 a technique now widely used in the preparation of both recombinant and plasma-derived Factor VIII concentrates. Further research led to the introduction of a new Factor VIII concentrate in 1987 which could be heated at an even higher temperature, 12 and eventually confirmed as effective against hepatitis C virus (HCV).…”