Isolation, Characterization of Unknown Impurity in Brimonidine Tartrate by Auto Purifier, NMR, LC/MS/MS and HPLC

The four impurities in Brimonidine Tartrate bulk drug substances were detected by newly developed gradient reverse phase high performance liquid chromatography (HPLC) method. These impurities were named as Brimonidine Impurity- A, B, C, and D. The Brimonidine Impurity-A, Brimonidine Impurity-B, Brimonidine Impurity-C were process impurities, while Brimonidine Impurity-D is degradation impurity. The degradation Brimonidine Impurity-D was isolated by semi preparative HPLC. Structural elucidation of unknown impurities was carried out by means of (conformed by) spectral studies like IR, NMR and Mass synthesized authentic compounds.