Impact of additives on the formation of protein aggregates and viscosity in concentrated protein solutions.
In concentrated protein solutions attractive protein interactions may not only cause the formation of undesired aggregates but also of gel-like networks with elevated viscosity. To guarantee stable biopharmaceutical processes and safe formulations, both phenomenons have to be avoided as these may hinder regular processing steps. This work screens the impact of additives on both phase behavior and viscosity of concentrated protein solutions. For this purpose, additives known for stabilizing proteins in solution or modulating the dynamic viscosity were selected. These additives were PEG 300, PEG 1000, glycerol, glycine, NaCl and ArgHCl. Concentrated lysozyme and glucose oxidase solutions at pH 3 and 9 served as model systems. Fourier-transformed-infrared spectroscopy was chosen to determine the conformational stability of selected protein samples. Influencing protein interactions, the impact of additives was strongly dependent on pH. Of all additives investigated, glycine was the only one that maintained protein conformational and colloidal stability while decreasing the dynamic viscosity. Low concentrations of NaCl showed the same effect, but increasing concentrations resulted in visible protein aggregation.
Institute of Engineering in Life Sciences, Section IV: Biomolecular Separation Engineering, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany.
Katharina Christin
KC
Bauer
Institute of Engineering in Life Sciences, Section IV: Biomolecular Separation Engineering, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany.
Susanna
S
Suhm
Institute of Engineering in Life Sciences, Section IV: Biomolecular Separation Engineering, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany.
Anna Katharina
AK
Wöll
Institute of Engineering in Life Sciences, Section IV: Biomolecular Separation Engineering, Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany. Electronic address: juergen.hubbuch@kit.edu.
Jürgen
J
Hubbuch
D002626:Chemistry, Pharmaceutical / Q000379:methods; D003102:Colloids; D005079:Excipients / Q000737:chemistry*; D005949:Glucose Oxidase / Q000008:administration & dosage* / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D009113:Muramidase / Q000008:administration & dosage* / Q000737:chemistry; D019999:Pharmaceutical Solutions; D066329:Protein Aggregates; D011487:Protein Conformation; D055550:Protein Stability; D017550:Spectroscopy, Fourier Transform Infrared; D014783:Viscosity
D003102:Colloids; D005079:Excipients; D019999:Pharmaceutical Solutions; D066329:Protein Aggregates; D005949:Glucose Oxidase; D009113:Muramidase
ArgHCl; Glycine; Microrheology; NaCl; Phase behavior; Protein conformation; Protein interactions