Applications of TiCl₃ as a Diagnostic Reagent for the Detection of Nitro- and N-Oxide-Containing Compounds as Potentially Mutagenic Impurities Using Ultrahigh-Performance Liquid Chromatography Coupled with High-Resolution Mass Spectrometry

Abstract

The ICH has strict guidelines for limiting the presence of potentially mutagenic impurities (PMIs) in marketed drugs. Therefore, it is important to fully characterize and quantitate all possible PMIs that could arise during the process of synthesizing and developing a drug. Two important and prevalent examples of PMIs are compounds containing N-oxide and nitro functional groups. TiCl 3 derivatization is an established method for determining the presence or absence of N-oxide metabolites by reduction to the corresponding amine. In this study, we demonstrate a novel application of TiCl 3 reduction combined with high-resolution UHPLC/HRMS to analyze PMIs. The results indicate that a variety of N-oxide-and nitrocontaining compounds can be readily characterized by this facile platform method. In addition, we show that this chemical derivatization method can be utilized to enhance the ionization of nitro-containing compounds for LC/MS analysis.

Extending (Q)SARs to incorporate proprietary knowledge for regulatory purposes: is aromaticN-oxide a structural alert for predicting DNA-reactive mutagenicity?*

“…An assessment of impurities, metabolites, extractable and leachables showed that many contain aromatic N-oxides (15). For example, aromatic N-oxide-containing compounds are used as reagents (16).…”

Highly sensitive LC‐MS method for stereochemical quality control of a pharmaceutical drug substance intermediate

“…[9][10][11][12][13][14][15] In addition, LC-MS/MS methods used alone or in conjunction with derivatization techniques have been the preferred options for low-level analysis of potential mutagenic impurities (PMI). [16][17][18][19][20][21][22][23][24][25] However, direct analysis by single-quadruple mass spectrometry has been rarely used for this purpose, 7,26,27 although LC-MS method in conjunction with derivatization technique has been reported. 28 This paper discusses a chiral reversed-phase LC method coupled with single-quadruple mass spectrometry in selected ion monitoring mode (LC-MS SIM) 29 for direct stereoisomer analysis, which provided sufficient chiral quality control at low ppm level.…”

“…Chiral liquid chromatography coupled with tandem mass spectrometry (LC‐MS/MS) has been widely used for low‐level detection in environmental7, 8 and pharmaceutical analysis, especially in the area of drug metabolism studies 9–15 . In addition, LC‐MS/MS methods used alone or in conjunction with derivatization techniques have been the preferred options for low‐level analysis of potential mutagenic impurities (PMI) 16–25 . However, direct analysis by single‐quadruple mass spectrometry has been rarely used for this purpose, 7,26,27 although LC‐MS method in conjunction with derivatization technique has been reported 28 .…”

Identification of Protonated Primary Carbamates by Using Gas-Phase Ion–Molecule Reactions Followed by Collision-Activated Dissociation in Tandem Mass Spectrometry Experiments

“…Gas chromatography coupled with electron ionization mass spectrometry (MS) has been commonly used to identify and quantitate different PMIs in complex mixtures. , However, this method often requires derivatization of the compounds, which is time-consuming and can lead to complications. Although high-performance liquid chromatography coupled with soft ionization mass spectrometry has become the gold standard for mixture analysis, ,, authentic compounds are required to unambiguously identify the compounds in the mixture.…”