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

The aim of the present work was to compare various separation techniques for the fast analysis of closely-related compounds, including structurally-related compounds, positional isomers, diastereoisomers, Z/E isomers. Three analytical techniques were evaluated, namely ultra high performance liquid chromatography (UHPLC), ultra high performance supercritical fluid chromatography (UHPSFC), both with sub-2μm particles, and capillary electrophoresis (CE) using non-aqueous solvents. To fairly compare the three analytical techniques, only two starting conditions for further method development were considered.