Development of an intermediate chromatography step in an insulin purification process. The use of a High Throughput Process Development approach based on selectivity parameters

Recent innovations in designing purification processes for biopharmaceutical production have enabled initial screening (optimization) of chromatographic conditions for binding to be performed in miniaturized batch format. The present report demonstrates the possibility of using this format to screen for selectivity and illustrates the need for careful adjustment of protocols when highly abundant, tightly-binding impurities are present in the sample. This batch format approach was used to choose a chromatography medium (resin) from a selection of available resins for the purification of recombinant insulin expressed in E. coli and to screen binding and elution conditions. Subsequent optimization was performed in small packed columns using a Design of Experiments (DoE) approach with statistical modeling before scaling up to a small pilot scale experiment. In this study insulin was effectively purified from the more tightly-binding C-peptide, and a reduction in insulin variants was also noted using the optimized conditions.