Utility of a high coverage phenyl-bonding and wide-pore superficially porous particle for the analysis of monoclonal antibodies and related products.

A wide-pore silica-based superficially porous material with a high coverage phenyl bonding was evaluated for the analysis of monoclonal antibodies and antibody-drug conjugates. This new material is based on 2.7 μm particles having a shell thickness of 0.40 μm and average pore size of approximately 450 Å. Various important features of this reversed phase column technology were explored, including kinetic performance for large biomolecules (i.e. speed of analysis, efficiency and peak capacity), recovery of proteins, selectivity for resolving modifications, and the possibility to reduce the amount of trifluoroacetic acid in the mobile phase. A systematic comparison was also performed with other existing modern wide-pore phases possessing differences in structure/morphology and chemistry. If all these figures of merit are considered, it is clear that this phenyl bonded wide-pore superficially porous stationary phase is one of the most promising materials to have been developed in recent years. Indeed, it offers kinetic performance comparable to the most efficient wide-pore SPP column on the market. In terms of protein recovery, this new phase was found to be superior to silica-based and silica-hybrid C4 bonded materials, particularly with separations performed at sub-80 °C temperature. Under such conditions, it in fact shows recoveries that are quite similar to a divinyl benzene (DVB) polymer-based material. More importantly, due to its unique, high coverage phenyl bonding, it offers additional steric effects and potentially even π-π interactions that yield advantageous selectivity for mAb sub-unit peaks and ADC species as compared to commonly used C4 or C18 bonded phases. Last but not least, mobile phases consisting of only 0.02-0.05% trifluoroacetic acid can be successfully used with this column, without significant loss in recovery and peak capacity.