A robust, high resolution capillary zone electrophoresis (CZE) assay was developed for the separation of monoclonal antibody charge variants. The assay provides information that is similar to capillary isoelectric focusing and cation exchange chromatography but is more rapid, with run times of less than 10 min per sample. The method uses a background electrolyte with a pH of 6.0 and a dynamic coating to prevent EOF and protein adsorption to the capillary wall. Migration times for several antibodies were measured and those times correlated well with the antibody isoelectric points. The effect of antibody formulation buffer on the resolution of charge variants was studied. Resolution was not affected by a variety of pH buffers at up to 10 mM concentration or sodium chloride at less than 20 mM. The CZE assay was incorporated into a formulation screening platform that previously had focused on physical stability measurements. We demonstrated the value and utility of the CZE assay in formulation studies using human monoclonal antibodies that were incubated at an elevated temperature. By providing information about an antibody that is orthogonal to physical stability properties, the CZE assay helps in making a better informed decision about formulation.

Analysis of monoclonal antibodies using capillary zone electrophoresis: Application to formulation screening

249th National Meeting (2015)

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