Applications of Two-Dimensional Liquid Chromatography for Analysis of Synthetic Pharmaceutical Materials

Characterization of contemporary synthetic pharmaceutical molecules is challenging, as exemplified by the need for separation of closely-related species, detection of low-level impurities, and fast screening of analytical conditions during method development. Two-dimensional liquid chromatography (2D-LC) methodologies provide an agile and powerful platform enabling the simultaneous determination of multiple analytical attributes in these cases. In the pharmaceutical industry, 2D-LC is emerging as a tool that can be routinely applied to solve diverse analytical problems and accelerate the time-consuming method development process. The screening of chiral and achiral conditions can be automated via the use of 2D-LC systems, and two complementary conditions identified in this screen can then be coupled for the analysis of crude reaction mixtures containing enantiomers of a target compound. 2D-LC is also commonly used to overcome the inability to directly couple mass spectrometry (MS) with separations that rely on nonvolatile mobile phase components. In some cases 2D-LC is the only viable option for the analysis of complex drug modalities containing multiple chiral centers or/and with extreme variability in physicochemical properties – for example, peptides and oligonucleotides.