Novel Potential Genotoxic Impurity Identification and Quantification by Using Quality by Design Approach in Angiotensin II Receptor Blocker

ABSTRACT This study reports the identification and quantification of three potential genotoxic impurities such as 3‐methyl‐4‐nitrobenzoic acid (MNBA), N‐methyl‐2‐nitroaniline (MNA), and methyl‐4‐butyramido‐3‐methyl‐5‐nitrobenzoate (MBMN) in telmisartan active pharmaceutical ingredient (API) using a robust liquid chromatography‐tandem mass spectrometry (LC‐MS/MS) method. These impurities, originating during the synthesis of telmisartan, are of regulatory concern due to their electrophilic nature and potential to cause DNA damage. A multiple‐reaction monitoring (MRM) mode was employed on a Zorbax SB‐Phenyl column (150 mm × 4.6 mm, 3.5 µm) under gradient conditions using 0.1% formic acid in water (Mobile Phase A) and methanol (Mobile Phase B), at a flow rate of 0.8 mL min −1 . The method achieved limits of detection (LOD) of 3 ng mL −1 (MNBA), 1.6 ng mL −1 (MNA), and 0.6 ng mL −1 (MBMN), and corresponding limits of quantification (LOQ) of 9, 5, and 2 ng mL −1 , respectively. Accuracy results ranged between 70%–130%, aligning with ICH and USP guidelines. Method robustness was validated using a quality by design (QbD) approach through design of experiments (DoE) methodology. Environmental impact was assessed using four green chemistry metrics: National Environmental Methods Index (NEMI), Analytical Eco‐Scale, Green Analytical Procedure Index (GAPI), and AGREE. The AGREE and Eco‐Scale scores were 0.62 and 67, respectively, indicating a high level of environmental compliance. This validated LC‐MS/MS method demonstrates high sensitivity, specificity, and eco‐friendliness, making it suitable for routine analysis of potential genotoxic impurities in telmisartan APIs.