Micellar electrokinetic capillary chromatography, high performance liquid chromatography and nuclear magnetic resonance - three orthogonal methods for characterization of critical drugs

Purity assessment of multicomponent drugs such as aminoglycoside antibiotics is still a challenge. For example, the high performance liquid chromatography (HPLC) method reported in the European Pharmacopoeia for gentamicin suffers from various disadvantages, i.e. missing robustness, long retention times and broad peaks. Previously an effective and robust micellar electrokinetic chromatography (MEKC) method has been described which is capable of separating all components and impurities. Since a couple of gentamicin lots collected from international markets showed a high number and high quantities of impurities NMR spectroscopy as a primary analytical method was applied in order to validate the quantification results obtained from MEKC. In this study NMR spectroscopy was found to be a very good orthogonal and complementary method. (C) 2004 Elsevier B.V. All rights reserved.