Investigation into Clearance of Organic Compounds from Biomanufacturing Process Streams during Ultrafiltration/Diafiltration

Ultrafiltration and diafiltration (UF/DF) operations have been demonstrated to clear leachables from the drug substance, however there is limited data available. Hence, it is beneficial to characterize leachables removal during UF/DF. In this work, the reduction capacity for 28 selected organic compounds spiked into 3 different proteins during UF/DF processes was investigated using liquid chromatography high resolution mass spectrometry. Most compounds (24) showed clearance over 98% across the process for the 3 protein materials. The specific protein characteristics and process parameters for each protein had a minimal impact on clearance, with sieving coefficients essentially the same for each of the 3 protein processes. Physicochemical properties of the studied compounds had a decisive impact on clearance with the octanol-water coefficient (Log P) being most important. Compounds with Log P <4 had sieving coefficients close to ideal clearance, and compounds with Log P >7 showed lower but still significant clearance (> 93%). Other influential parameters on clearance were identified to be polarizability, solvent accessible surface area and molecular weight. Orthogonal Partial Least Square (OPLS) regression models were developed and validated using the sieving coefficient to characterize and predict clearance behaviour of organic compounds during UF/DF. Results from this study lay a solid foundation for the understanding and prediction of UF/DF capacity to remove potential organic leachables. Leachables clearance modelling represents an impactful tool which may be utilized to support product safety assessments. Data presented herein demonstrate that UF/DF provides a significant leachables risk reduction with respect to unit operations upstream of UF/DF.