Effect of Lyophilization on Stability of PEG-Protein Conjugate

A Case Study with Peginterferon alfa-2b


  • Chintan Patel Department of Pharmaceutics & Pharmaceutical Technology, Ramanbhai Patel College of Pharmacy, Charotar University of Science and Technology (CHARUSAT), CHARUSAT campus, Changa 388421, India
  • Gayatri Patel Department of Pharmaceutics & Pharmaceutical Technology, Ramanbhai Patel College of Pharmacy, Charotar University of Science and Technology (CHARUSAT), CHARUSAT campus, Changa 388421, India https://orcid.org/0000-0002-2523-1281




Depegylation, Lyophilization, Stability, Residual moisture content, Peginterferon alfa-2b


The purpose of the present study was to develop stable lyophilized formulation of peginterferon alfa-2b which is acquiescent to the short lyophilization process. The present study evaluates the effect of buffering components and cryoprotectant(s) on depegylation of the peginterferon alfa-2b in combination with lyophilization process. Finally, a short lyophilization process was identified which can produce a stable pharmaceutical form of peginterferon alfa-2b without any depegylation during long-term storage. Formulations were analyzed mainly for depegylation by HP-size exclusion chromatography and in-vitro antiviral activity. Residual moisture content in the lyophilized product was also used as a key indicating parameter to check its role with respect to depegylation upon storage under various temperature conditions. It was observed that the peginterferon alfa-2b when formulated in presence of cryoprotectant like sucrose requires longer lyophilization process of about 5 days, irrespective of the buffering components used, to reduce the level of residual moisture content and thereby to produce the stable formulation without depegylation. A stable formulation in presence of high concentration of lactose as a cryoprotectant was developed which can withstand stresses exerted to protein-polymer conjugate during lyophilization phases without any significant depegylation. A short lyophilization process of about 48 hours can be utilized for peginterferon alfa-2b when formulated in presence of lactose as a cryoprotectant through which a stable lyophilized formulation can be produced as against longer process required when sucrose is used a cryoprotectant, which is essential from commercial point of view as lyophilization is a costly process.


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How to Cite

Patel, C., & Patel, G. (2023). Effect of Lyophilization on Stability of PEG-Protein Conjugate: A Case Study with Peginterferon alfa-2b. Brazilian Journal of Pharmaceutical Sciences, 59, e201120. https://doi.org/10.1590/s2175-97902023e201120



Original Article