%0 Journal Article %T Case Study in the Design of a Surrogate Solution for Use in Biopharmaceutical Drug Product Process Development. %A Boksa K %A Walsh P %A Shah A %J AAPS PharmSciTech %V 22 %N 1 %D Jan 2021 6 %M 33404995 %F 4.026 %R 10.1208/s12249-020-01881-z %X The use of an aqueous-based surrogate solution in at-scale process development for biopharmaceutical drug products enables significant reduction in the usage of costly drug substance and improves confidence in initial drug product production runs performed using active biotherapeutic. Strategies for the formulation design of a surrogate solution that is representative of the unit operations in a typical drug product manufacturing process for a biopharmaceutical are presented herein, and a case study for the development of a surrogate solution for an example protein drug product is discussed. The surrogate was shown to have similar physical attributes to the drug product, including viscosity, surface tension, and density. The surrogate was used in at-scale process development of compounding, filling, and lyophilization operations in a single technical run, and the performance was shown to be similar to that of the drug product solution, providing a cost-effective and readily available option for process development while minimizing operator exposure to potentially hazardous drug solution and limiting drug wastage.