Assessing detergent-mediated virus inactivation, protein stability and
impurity clearance in biologics downstream processes
Abstract
Detergent-mediated virus inactivation (VI) provides a valuable
orthogonal strategy for viral clearance particularly for next generation
continuous manufacturing. Furthermore, there exists an industry-wide
need to replace the conventionally employed detergent, Triton X-100,
with eco-friendly alternatives. This study provides a systematic
approach to screen detergents as VI agents through the study of VI of
three different enveloped viruses for monoclonal antibodies and fusion
proteins. We investigated three major aspects of VI namely, the impact
of VI agent on the therapeutic quality attributes, clearance of the VI
agent and other impurities through subsequent chromatographic steps and
lastly the efficacy of VI for the said detergent. Several quality
attributes such as charge variance, oxidation, deamidation,
glycosylation and aggregation were investigated. Aggregation was a key
indicator of stability. Experimental and modeling data was used to
decipher the mechanism and kinetics of aggregation for pH sensitive
molecules by exploring worst case VI conditions. We found product
aggregation and its kinetics to be driven by extrinsic factors such as
detergent and protein concentration. Aggregation was also impacted by
initial aggregation level as well as intrinsic factors such as the
protein sequence and detergent hydrophobicity and critical micelle
concentration (CMC). VI efficiency was dependent on the virus tested,
duration of incubation as well as detergent CMC and concentration.
Dodecyl maltopyranoside (DDM) was found to be a promising candidate for
potential application in VI. Knowledge gained here on factors driving
product stability and VI provides valuable insight to design,
standardize and optimize conditions (concentration, duration of
inactivation) for screening of detergent-mediated VI.