Study on the Effect of Solution Conditions on Heat Induced-Aggregation of Human Alpha Interferon

A major problem in the formulation of therapeutic proteins is the irreversible protein aggregation. Recombinant human interferon alpha2b (rhIFN2b) has poor stability and undergoes physical degradation. The aim of this study was to investigate the effect of solution conditions on the heat-induced aggregation of rhIFNα2b. The protein was incubated for 1 h at 40°C–70°C and for up to 240 h at 50C and its aggregation tendency was then studied using optical density (at 350 nm), SE-HPLC, dynamic light scattering and SDS-PAGE methods. The effect of various pH (5, 6 and 7) and buffer concentrations of (10, 55 and 100 mM) on the aggregation of protein following incubation at 50C for 72 h was also evaluated. The results obtained for samples incubated at 50C for up to 240 h showed that OD350 and the amount of higher molecular weight aggregates (HMW) increased and the monomer content decreased significantly (p