Physical Stability of Albinterferon-α2b in Aqueous Solution: Effects of Conformational Stability and Colloidal Stability on Aggregation

Controlling aggregation in protein therapeutics is a significant challenge. In this study, the aggregation behavior of albinterferon-α2b, a genetic fusion protein combining human serum albumin and α-interferon, was examined as a function of solution conditions. The stability was monitored during agitation and during storage at elevated temperature, where the extent of aggregation was determined using size-exclusion chromatography. The osmotic second virial coefficient and the free energy of unfolding were measured for each sample. This study demonstrates that both increasing conformational stability and maximizing colloidal stability help to maintain the physical stability of albinterferon-α2b. © 2012 Wiley Periodicals, Inc. and the American Pharmacists Association