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Rationale: Enasidenib (EDB) is an orally active selective mutant isocitrate dehydrogenase‐2 enzyme inhibitor approved by the U.S. Food and Drug Administration to treat acute myeloid leukemia. It lacks a reported forced degradation study and a stability‐indicating assay method (SIAM). This study addresses this gap by establishing a degradation profile in accordance with the International Council for Harmonisation Q1A and Q1B (R2) guidelines and developing a validated SIAM for EDB. Methods: EDB was exposed to forced degradation under various conditions (hydrolytic, photolytic, oxidative, and thermal stress). Degradation samples were analyzed using high‐performance liquid chromatography on an Agilent ZORBAX Eclipse Plus C18 column with a mobile phase consisting of 0.1% formic acid in Milli‐Q water and acetonitrile at a flow rate of 1 mL/min and detection at 270 nm. Liquid chromatography‐quadrupole time‐of‐flight‐high‐resolution mass spectrometry (LC/Q‐TOF HRMS) was used for the identification and characterization of degradation products. Nitrosamine risk assessment was conducted using a modified nitrosation assay procedure (NAP) test due to the presence of a secondary amine group in the drug, which is liable to forming nitrosamine drug substance–related impurities (NDSRI). Results: The drug exhibited significant degradation under acidic, basic, photolytic, and oxidative conditions in the solution state. A total of nine degradation products (DP) were formed (DP‐I, DP‐III, and DP‐IV: acidic conditions; DP‐I and DP‐III: basic conditions; DP‐II, DP‐V, DP‐VI, and DP‐VII: oxidative stress; and DP‐VII, DP‐VIII, and DP‐IX: photolytic conditions), which were separated and identified using reversed‐phase high‐performance liquid chromatography and characterized using liquid chromatography–tandem mass spectrometry. The mechanism behind the formation of EDB degradation products has been discussed, and this study was the first to develop a degradation pathway for EDB. In addition, the possibilities of NDSRI formation for EDB were studied using a modified NAP test, which can contribute to the risk assessment of the drug. Conclusions: Forced degradation studies were conducted by establishing a SIAM for EDB. All the degradation products were characterized by mass spectral data obtained using LC/Q‐TOF‐HRMS. [ABSTRACT FROM AUTHOR]

Several regulatory organizations encourage the quantitative analysis of potentially genotoxic impurities in finished pharmaceutical preparation. For the first time, a sensitive, accurate, and reliable reversed phase‐high‐performance liquid chromatography method was developed and validated for two antihypertensive drugs, three genotoxic impurities of Amlodipine namely methyl benzene sulfonate, ethyl benzene sulfonate, and ethyl‐p‐toluene sulfonate, as well as N‐methyl O‐phenylenediamine dihydrochloride as genotoxic impurities of Telmisartan that is marketed in a single pill combination. reversed phase‐high‐performance liquid chromatography method was developed using a C18 column Agilent (Zorbax C18; 250 × 4.6 mm internal diameter, 5 μm) along with 50 mM ammonium acetate (pH 4.5) and ACN as a mobile phase in gradient mode to achieve the retention of all analytes. The new method's sensitivity allowed the quantification of namely methyl benzene sulfonate, ethyl benzene sulfonate, and N‐methyl‐O‐phenylenediamine dihydrochloride at test concentrations as low as 0.025%. Amlodipine and Telmisartan each had a test concertation of 100 and 800 μg/ml, respectively. The developed analytical method was validated for different applications, that is, for assay and related substance methods. The calibration curves for genotoxic impurities were linear in the range of the Limit of quantitation to 1.2% of the test concentration of the respective drugs. Forced degradation investigations were conducted on selected drugs, and targeted analytes were then quantified. The stability of both drugs in acid and basic hydrolysis was improved compared to when they were evaluated separately, although Amlodipine showed an inverted degradation pattern in a more recent investigation when combined with Telmisartan under oxidative degradation conditions. The validated method was successfully applied for the quantification of the genotoxic impurities of Amlodipine and Telmisartan in finished pharmaceutical preparation. [ABSTRACT FROM AUTHOR]