Development and Validation of LC-MS method for determination of Genotoxic Impurity N, O-Dimethyl Hydroxylamine by Chemical Derivatization in Investigational Drug Substance

Background: Conventional chromatographic techniques and direct analysis pose challenges in detecting certain potential genotoxic impurities, primarily due to factors such as the absence of a chromophore, low molecular weight, and insufficient chromatographic retention caused by high polarity. One such compound, N, O-Dimethyl Hydroxylamine, is of particular concern due to its structural similarity to Hydroxylamine, a recognized genotoxic impurity. Method: In response to this challenge, this article proposes a rapid derivatization approach utilizing Dansyl Chloride, coupled with Liquid Chromatography-Mass Spectrometry (LC-MS) for the detection of the derivatized product in the investigational drug substance. To preserve confidentiality, the specific name and structure of the drug substance have not been disclosed. Results: The developed method exhibits a reliable range of detection spanning from 5 ppm to 60 ppm with respect to a nominal drug substance concentration of 10 mg/mL. Throughout the method validation process, it demonstrated specificity, sensitivity, linearity, accuracy, and repeatability. Conclusion: This methodology presents a versatile solution applicable in scenarios where N, ODimethyl Hydroxylamine serves as a reagent in the synthesis process of drug substances.