Purification of Protein by HIC: Mechanistic Modeling for Improved Understanding and Process Optimization

Hydrophobic interaction chromatography (HIC) is a separation technique widely used for the purification of therapeutic proteins. The main leverages identified to operate HIC processes are solution pH and ionic strength. In this article, the authors show that simplistic mathematical models derived from statistical analysis cannot describe the impact of pH and ionic strength observed in HIC processes. A new mechanistic model accounting for the protein charge in solution (varying with pH) and the solution non-ideality (activity coefficient varying with the ionic strength) is proposed here. This simple model is shown to accurately describe experimental data and paves the way for numerical optimization of HIC processes.
Hydrophobic interaction chromatography (HIC) is widely used for the purification of therapeutic proteins (1,2), in particular for aggregate removal (3). Designing a HIC process requires determining numerous operating parameters such [...]