Evaluation and comparison of various separation techniques for the analysis of closely-related compounds of pharmaceutical interest

► Various separation techniques were compared for the analysis of closely-related compounds. ► Capillary electrophoresis provided excellent results for basic compounds but generic conditions were not reached. ► Supercritical fluid chromatography was more generic and particularly adapted for neutral and acidic compounds. ► Reversed-phase LC was the most versatile strategy for any class of compounds. ► The selectivity achieved with the three separation techniques was found complementary.