Updating the European Pharmacopoeia impurity profiling method for cetirizine and suggesting alternative column, using design space comparison

The goal of the present study was to develop a generic workflow to evaluate the chromatographic resolution in a design space and find replacement column for the new method. To attain this objective, a limited number of initial experiments have been performed, and a modeling tool was employed to study and compare design spaces obtained with different columns. By overlaying the different individual resolution maps (design spaces), it is possible to quickly identify a robust zone where the different columns meet a given resolution criterion. This new feature of the modeling tool is very useful for finding alternative columns for a given separation, rather than the usual column tests. It was also demonstrated that two different columns can be used as equivalents (replacement columns), providing sufficient resolution at the same working point and with a high degree of robustness.