Freeze-drying of HESylated IFNα-2b: Effect of HESylation on storage stability in comparison to PEGylation

A comparison of lyophilized PEGylated and HESylated IFN alpha was carried out to investigate the influence of protein conjugation, lyoprotectants as well as storage temperature on protein stability. Results show that PEG tends to crystallize during freeze-drying, reducing protein stability upon storage. In contrast, HESylation (R) drastically improved the stability over PEGylation by remaining totally amorphous during lyophilization, with and without lyoprotectants while providing a high glass transition temperature of the freeze-dried cakes. (C) 2015 Elsevier B.V. All rights reserved.