Abstract

Isolation and characterization of the zolmitriptan unknown impurity by chromatographic and mass spectroscopy

Author(s): Abhishek Miglani, Poonam Kumar, Bhawana Negi, H.D.Gautam

The control of pharmaceutical impurities is currently a critical issue to the pharmaceutical industry. In Zolmitriptan tablet one unknown impurity was observed above identification threshold as mentioned in ICH guidelines. This unknown product was analyzed by liquid chromatography tandem mass spectrometry (LC-MS/MS) to determine its molecular weight. Comparison of fragmentation pattern of the protonated species of unknown impurity and Zolmitriptanwere made us to determine the possible structure for impurity and its fragments. A detailed study was done to characterize the impurity and it was further synthesized, subsequently characterized and was co injected with the sample and was found to be co-eluting with the impurity in the sample. Impurity was subsequently isolated using preparative scale chromatography and its structure was confirmed using MS/ MS derived structural information combined with 1H proton, 13C-NMR&IR analysis. Based on the spectral data impurity was characterized as (4-4-[[3- [2-(Dimethyloxidoamino) ethyl]-1H-indol-5-yl]methyl-2-oxazolidinone).