Automatization for development of HPLC methods.

Within the frame of inprocess analytics of the synthesis of pharmaceutical drugs a lot of HPLC methods are required for checking the quality of intermediates and drug substances. The methods have to be developed in terms of optimal selectivity and low limit of detection, minimum running time and chromatographic robustness. The goal was to shorten the method development process. Therefore, the screening of stationary phases was automated by means of switching modules equipped with 12 HPLC columns. Mobile phase and temperature could be optimized by using Drylab after evaluating chromatograms of gradient elutions performed automatically. The column switching module was applied for more than three dozens of substances, e.g. steroidal intermediates. Resolution (especially of isomeres), peak shape and number of peaks turned out to be the criteria for selection of the appropriate stationary phase. On the basis of the "best" column the composition of the "best" eluent was usually defined rapidly and with less effort. This approach leads to savings in manpower by more than one third. Overnight, impurity profiles of the intermediates were obtained yielding robust HPLC methods with high selectivity and minimized elution time.