Challenges and solutions to manufacturing of low viscosity, ultra-high concentration IgG1 drug products: From late downstream process to final fill finish processing.

Challenges in manufacturing of high concentration antibody formulations have seldom been discussed. These are observed mainly form late downstream operations where antibody gets concentrated to its final strength, to final fill finish processing and containerization of the product. Present paper summarizes challenges typically observed in manufacturing and processing of high concentration antibody products and provides turnkey solutions to these typical challenges in order to have their consistent and robust manufacturing process. IgG1 has been used as model protein for studying the challenges and providing solutions to them. The late downstream challenges like increased viscosity limiting further concentration can be resolved by used of viscosity modifying agents in the formulation. Replacement of conventionally used 'A' screen membranes with 'D' screen or using single pass TFF can further provide advantage in targeting higher concentrations for same protein with lesser shear and aggregation. Using 0.5μm/0.2μm asymmetric or bilayered membrane instead of conventional 0.2μm membrane resulted in better flux while filtration of high concentration IgG1 formulation. In process holding time during filling operation was optimized to be <60min based on the nozzle drying time for high concentration IgG1 formulation. Appropriate control strategy of replacing filling nozzles and performing periodic fill weight check was proposed for fill finish process of high concentration IgG1 formulation.