Selecting a reversed phase liquid chromatographic (RP-LC) column with suitable selectivity for a particular separation is difficult if the brand name of the column is not known. Monographs of the European Pharmacopoeia and other official compendia for drug analysis only give a general description of the stationary phase to be used for a liquid chromatographic method. A project to develop a chromatographic test procedure to characterise RP-LC C-18 columns was started earlier and resulted in a fast, simple, repeatable, and reproducible test procedure. Four column parameters allowed the characterisation and ranking of these columns. In this paper, the separations of three drug substances (amlodipine, tetracaine, and bisacodyl) from their respective impurities were examined applied on 77 RP-LC columns. It was observed, that the column ranking system was helpful in the selection of a suitable column for the separation of amlodipine and tetracaine, but also showed its limitations towards the separation of bisacodyl.
