(497c) X-Ray Reflectivity and Pendant Drop Tensiometry Measurements of the Competitive Adsorption of Mabs and Excipients at the Air-Water Interface
The first part of the talk focuses on understanding the nature of single component systems about the reversible/irreversible adsorption for Polysorbate 80 (PS-80) and mAbs in histidine. Pendant bubble tensiometer is used to characterize the equilibrium and dynamic surface tension. Additionally, a double-capillary setup of the pendant drop tensiometer is used to exchange mAb solutions with histidine buffer. X-ray reflectivity is used to measure adsorbed amounts and understand the molecular configurations of the adsorbed molecules. A box-refinement method based on the model independent approach7 is used to predict the structural information on an Angstrom scale. The surface activity of the mAbâs is correlated to the hydrophobic patches present on the protein surface using a parameter termed Spatial Aggregation Propensity (SAP).8 The second part focuses on the competitive adsorption of the mAb and excipient systems using these same tools.
1. Nidhi, K., Indrajeet, S., Khushboo, M., Gauri, K. & Sen, D. J. Hydrotropy: A promising tool for solubility enhancement: A review. Int. J. Drug Dev. Res. 3, 26â33 (2011).
2. Maa, Y. F. & Hsu, C. C. Protein denaturation by combined effect of shear and air-liquid interface. Biotechnol. Bioeng. 54, 503â12 (1997).
3. Henson, A. F., Mitchell, J. R. & Mussellwhite, P. R. The surface coagulation of proteins during shaking. J. Colloid Interface Sci. 32, 162â165 (1970).
4. Mahler, H.-C., Senner, F., Maeder, K. & Mueller, R. Surface Activity of a Monoclonal Antibody. J. Pharm. Sci. 98, 4525â4533 (2009).
5. Weiss, W. F., Young, T. M. & Roberts, C. J. Principles, approaches, and challenges for predicting protein aggregation rates and shelf life. J. Pharm. Sci. 98, 1246â1277 (2009).
6. Kerwin, B. A. Polysorbates 20 and 80 Used in the Formulation of Protein Biotherapeutics: Structure and Degradation Pathways. J. Pharm. Sci. 97, 2924â2935 (2008).6.
7. Blasie, J., Zheng, S. & Strzalka, J. Solution to the phase problem for specular x-ray or neutron reflectivity from thin films on liquid surfaces. Phys. Rev. B 67, 224201 (2003).
8. Chennamsetty, N., Voynov, V., Kayser, V., Helk, B. & Trout, B. L. Design of therapeutic proteins with enhanced stability. Proc. Natl. Acad. Sci. 106, 11937â11942 (2009).