(11j) Quantifying the Adsorption Dynamics between Mabs and Surfactants at the Air/Water Interface

The adsorption of biomolecules at the air-water interfaces is of crucial concern in the development of new processes for monoclonal antibody (mAb)-based pharmaceuticals. Air/water interfaces are ever-present during the manufacture (filtration, chromatography) and production (freezing, thawing, filtration and filling) of the drug product, and continues during the storage, transportation and administration of the therapeutics to the patients. The pharmaceutical industry uses a multicomponent formulation that includes use of surface active excipients. As excipients readily adsorb, providing a shield at the air/water interface to prevent the adsorption of mAbs. However, the molecular mechanism of this multicomponent adsorption system is still unknow. We have used pendant bubble tensiometry to characterize the equilibrium and dynamic surface tension to explore the co-adsorption of the two-component systems. X-ray reflectivity (XR) is used to quantify the surface adsorbed amounts and mechanistically understand the competitive adsorption process as they race to the interface. Finally, a kinetic model is presented for the competitive adsorption process with six different mAbs, to predict the critical concentration of excipient necessary to prevent the adsorption of the mAbs