Electrostatic Interactions of Monoclonal Antibodies With Subcutaneous Tissue

Abstract

It was found that positively charged monoclonal antibodies bind to subcutaneous tissue in a manner that is dependent on ionic strength and pH, suggesting the electrostatic nature of the interaction. As expected, saturation of both nonspecific and electrostatic subcutaneous binding sites was observed after incubation with highly concentrated monoclonal antibody solutions. Additionally, it was demonstrated using model proteins that electrostatic effects of buffer components depend on ionic strength of ions bearing opposite charge rather than total ionic strength of the solution. These results suggest that electrostatic interactions may play a role in absorption processes of positively charged therapeutic proteins after subcutaneous administration.