A High Sensitive LC-MS/MS Method for the Simultaneous Determination of Potential Genotoxic Impurities Carboxy Phenyl Boronic Acid and Methyl Phenyl Boronic Acid in Lumacaftor

A simple, rapid, and highly sensitive LC-MS/MS method has been developed for the simultaneous and trace level quantification of underivatized boronic acids in lumacaftor active pharmaceutical ingredient. Chromatographic separation of boronic acids and lumacaftor achieved using Agilent Poroshell HPH C18 150 × 4.6 mm 2.7 μ column with 0.1% ammonia in water as mobile phase A and 100% acetonitrile as mobile phase B at a flow rate of 0.25 ml/min. Gradient elution was used with a total method run time of 14 minutes. Boronic acids were successfully ionized and quantified without derivatization using electrospray ionization in negative mode using tandem quadrupole mass spectrometry in multiple reactions monitoring mode. Method validation was performed as per ICH guidelines with good linearity over the concentration range of 0.05 ppm to 5 ppm of Lumacaftor test concentration for both the boronic acids with a correlation coefficient of >0.99. Recoveries were found good at different concentration levels and within the range of 80% - 120%. The developed method can be successfully used for the routine quantification of boronic acids at a concentration level of 20 ng/ml (1 ppm with respect to 20 mg/ml lumacaftor).