Opalescence Arising from Network Assembly in Antibody Solution

Abstract

Opalescence of therapeutic antibody solutions is one of the concerns in drug formulation. However, the mechanistic insights into the opalescence of antibody solutions remain unclear. Here, we investigated the assembly states of antibody molecules as a function of antibody concentration. The solutions of bovine gamma globulin and human immunoglobulin G at around 100 mg/mL showed the formation of submicron-scale network assemblies. The network assembly resulted in the appearance of opalescence with a transparent blue color without the precipitates of antibodies. Furthermore, the addition of trehalose and arginine, previously known to act as protein stabilizers and protein aggregation suppressors, was able to suppress the opalescence arising from the network assembly. These results will provide an important information for evaluating and improving protein formulations.

Portable Microfluidic Viscometer for Formulation Development and in Situ Quality Control of Protein and Antibody Solutions

“…Numerous therapeutic proteins such as monoclonal antibodies (mAbs) are formulated as liquid solutions for subcutaneous self-administration. Given the low-volume requirements for subcutaneous injections, an appropriate dosing requires these proteins to be formulated at high concentration (≥150 mg/mL). , At these concentrations, molecular surface properties such as charge distribution and hydrophobicity mediate weak multivalent protein–protein interactions that can induce reversible self-association of the drug products. − The result is the formation of transient and highly dynamic protein clusters and networks that can resist fluid deformation and macroscopically manifest as either opalescence or high viscosity. − A high tendency for nonspecific interactions can have deleterious effects on the entire chain of the drug products and high viscosity can induce pain during injection. As such, special precautions are implemented during the formulation of these drug products to ensure protein stability while simultaneously optimizing the viscosity of the formulation.…”