Effects of Temperature and Osmolytes on Competing Degradation Routes for an IgG1 Antibody. Issue 10 (19th July 2013)

• Record Type: Journal Article
• Authors: Roberts, Christopher J.; Nesta, Douglas P.; Kim, Nayoung
• Is Part Of: Journal of pharmaceutical sciences. Volume 102:Issue 10(2013:Oct.)
• Page Start: 3556
• Page End: 3566
• Publication Date: 2013-07-19
• Subjects: Pharmacy -- Periodicals; 615.1
• DOI: 10.1002/jps.23668
• Languages: English
• ISSNs: 0022-3549

Abstract

<abstract abstract-type="main" xml:lang="en"> <title> <x xml:space="preserve">Abstract</x> </title> <p>Addition of excipients is a common strategy to slow protein aggregation during storage. Excipient effects on the mechanism(s) and temperature (<italic>T</italic>) dependence of aggregation for a monoclonal antibody solution were tested using size‐exclusion chromatography, differential scanning calorimetry (DSC), temperature scanning monomer loss (TSML), and laser light scattering; previous work in buffer‐only conditions had shown non‐Arrhenius behavior and implicated Fab and/or C<sub>H</sub>3 unfolding as a key step in aggregation. Excipients included citrate, amino acid salts (histidine–HCl, arginine–HCl), and polyols (mannitol and glycerol). DSC and TSML showed that Fab, rather than C<sub>H</sub>3, unfolding corresponded with the onset of aggregation for each condition. Isothermal incubation at 56.5°C, 40°C, and 2°C–8°C resulted in aggregation, while fragmentation occurred readily at only 40°C. The primary effect of the different excipients appeared to be preferential accumulation/exclusion, affecting the concentrations of partially unfolded monomer key intermediates. In addition, aggregation rates were clearly non‐Arrhenius, causing aggregation to dominate over fragmentation at high and low <italic>T</italic>, and making long‐term stability predictions problematic based on commonly employed 40°C conditions. Possible reasons for non‐Arrhenius behavior include a strong <italic>T</italic>‐dependence of the Fab unfolding enthalpy and/or a switch from Fab‐mediated to Fc‐mediated aggregation as one moves from high to low <italic>T</italic>. © 2013 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 102:3556–3566, 2013</p> </abstract>