TY - JOUR
T1 - Investigating thermally induced aggregation of Somatropin- new insights using orthogonal techniques
AU - Västberg, Amanda
AU - Bolinsson, Hans
AU - Leeman, Mats
AU - Nilsson, Lars
AU - Nylander, Tommy
AU - Sejwal, Kushal
AU - Sintorn, Ida Maria
AU - Lidayová, Kristina
AU - Sjögren, Helen
AU - Wahlgren, Marie
AU - Elofsson, Ulla
PY - 2023
Y1 - 2023
N2 - Three orthogonal techniques were used to provide new insights into thermally induced aggregation of the therapeutic protein Somatropin at pH 5.8 and 7.0. The techniques were Dynamic Light Scattering (DLS), Asymmetric Flow-Field Flow-Fractionation (AF4), and the TEM-based analysis system MiniTEM™. In addition, Differential Scanning Calorimetry (DSC) was used to study the thermal unfolding and stability. DSC and DLS were used to explain the initial aggregation process and aggregation rate at the two pH values. The results suggest that less electrostatic stabilization seems to be the main reason for the faster initial aggregation at pH 5.8, i.e., closer to the isoelectric point of Somatropin. AF4 and MiniTEM were used to investigate the aggregation pathway further. Combining the results allowed us to demonstrate Somatropin's thermal aggregation pathway at pH 7.0. The growth of the aggregates appears to follow two steps. Smaller elongated aggregates are formed in the first step, possibly initiated by partly unfolded species. In the second step, occurring during longer heating, the smaller aggregates assemble into larger aggregates with more complex structures.
AB - Three orthogonal techniques were used to provide new insights into thermally induced aggregation of the therapeutic protein Somatropin at pH 5.8 and 7.0. The techniques were Dynamic Light Scattering (DLS), Asymmetric Flow-Field Flow-Fractionation (AF4), and the TEM-based analysis system MiniTEM™. In addition, Differential Scanning Calorimetry (DSC) was used to study the thermal unfolding and stability. DSC and DLS were used to explain the initial aggregation process and aggregation rate at the two pH values. The results suggest that less electrostatic stabilization seems to be the main reason for the faster initial aggregation at pH 5.8, i.e., closer to the isoelectric point of Somatropin. AF4 and MiniTEM were used to investigate the aggregation pathway further. Combining the results allowed us to demonstrate Somatropin's thermal aggregation pathway at pH 7.0. The growth of the aggregates appears to follow two steps. Smaller elongated aggregates are formed in the first step, possibly initiated by partly unfolded species. In the second step, occurring during longer heating, the smaller aggregates assemble into larger aggregates with more complex structures.
U2 - 10.1016/j.ijpharm.2023.122829
DO - 10.1016/j.ijpharm.2023.122829
M3 - Article
C2 - 36948472
AN - SCOPUS:85151369842
SN - 0378-5173
VL - 637
JO - International Journal of Pharmaceutics
JF - International Journal of Pharmaceutics
M1 - 122829
ER -