Identification and characterization of forced degradation products of sertraline hydrochloride using UPLC, ultra-high-performance liquid Chromatography-Quadrupole-Time of flight mass spectrometry (UHPLC-Q-TOF/MS/MS) and NMR.

The present study focused on the forced degradation behavior of sertraline hydrochloride (SRT), selective serotonin reuptake inhibitor (SSRI). The drug was exposed to different stressed conditions (hydrolytic, oxidative, thermal and photolytic) according to ICH Q1A (R2) guidelines. The study revealed that SRT was stable in hydrolytic (acidic, basic and neutral) and thermal degradation conditions. In contrast, five degradation products (DPs) were formed under oxidative and photolytic degradation conditions. The chromatographic separation of drug substance and its DPs was achieved on an Acquity HSS T3 column (100 × 2.1 mm, 1.7 μ) using 0.1% formic acid and acetonitrile as the mobile phase in gradient mode using a UHPLC-DAD system. The DPs were identified and characterized by high-resolution LC/MS and LC/MS/MS in ESI positive mode. Two DPs (DP-I and DP-II) were formed when SRT was exposed to oxidative degradation conditions. Three DPs formed (DP III-V) when exposed to photolytic degradation conditions. All the five major DPs were isolated using Preparative HPLC. The structures of major DPs formed were further confirmed using NMR technique (1D and 2D). The proposed mechanism for the formation of the SRT DPs via the photolytic/oxidative stress degradation pathway are discussed and outlined.

Grover P ，Bhardwaj M ，Mukherjee D 《-》

LC and LC-MS/MS studies for identification and characterization of new degradation products of ibrutinib and elucidation of their degradation pathway.

Forced degradation/stress degradation studies of ibrutinib drug were done in hydrolytic (acidic, alkaline and neutral), thermal, photolytic and oxidative degradation conditions in different temperature conditions as per International Conference on Harmonization (ICH) guideline Q1A(R2) in order to identify and characterize degradation products (DPs) of ibrutinib. The study revealed that ibrutinib is extremely sensitive to oxidative degradation even at room temperature. The drug substance is highly sensitive to alkaline hydrolysis and susceptible to acidic hydrolysis at 80 °C temperature condition, whereas found stable in neutral, photolytic and thermal stress conditions. Successful separation of ibrutinib and its ten degradation products formed during stress degradation condition were observed using Waters Acquity UPLC C-18 stationary phase (100 mm × 2.1 mm, 1.7 μm) with gradient elution using mobile phase consisting of Eluent-A: ammonium acetate (20 mm, pH-6) and Eluent-B: acetonitrile. The detection was carried out at 215 nm wavelength. Flow rate was set at 0.3 mL/min with injection volume of 5 μL. The drug substance degraded to one degradation product (DP-I) in acidic hydrolysis, five DPs (DP-I, DP-II, DP-V, DP-VIII and DP-IX) in basic hydrolysis and five DPs (DP-III, DP-IV, DP-VI, DP-VII and DP-X) in oxidative degradation condition. A novel and highly sensitive HRMS/MS/TOF method was developed to identify and characterize all the ten DPs formed during stress study. All the DPs were characterized using ESI positive mode. Except DP-I, all the degradation products formed were found to be new degradation impurities and their fragmentation pathways have never been reported earlier. The proposed mechanism and pathway of degradation products of ibrutinib were discussed and outlined.

Mehta L ，Naved T ，Grover P ，Bhardwaj M ，Mukherjee D ... -  《-》

LC/Q-TOF-MS-based structural characterization of enasidenib degradation products and establishment of a stability-indicating assay method: Insights into chemical stability.

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. 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). 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. 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.

Chakkar A ，Chaturvedi S ，Rajput N ，Sengupta P ，Sharma N ... -  《-》

Validated stability indicating assay method of olaparib: LC-ESI-Q-TOF-MS/MS and NMR studies for characterization of its new hydrolytic and oxidative forced degradation products.

Olaparib (OLA) is a poly ADP ribose polymerase (PARP) enzyme inhibitor used to treat prostate, ovarian and breast cancer. The drug substance OLA was subjected to forced degradation as per ICH prescribed guidelines. It was degraded in hydrolytic (acidic and basic) and oxidative stress conditions and yielded four degradation products (DPs) while it remained stable in neutral hydrolytic, dry heat and photolytic stress conditions. A stability indicating assay method was developed to separate OLA and its DPs using InertSustain C18 column (250 × 4.6 mm, 5 μm) with a gradient mobile phase of 10 mM ammonium acetate (pH 4.5) and acetonitrile (ACN) at a flow rate of 1 mL min-1. The characterization of DPs was carried out by using liquid chromatography-electrospray ionization-quadrupole-time of flight tandem mass spectrometry (LC-ESI-Q-TOF-MS/MS). Major degradation products (DP-1 and DP-2) were isolated by using preparative HPLC and structures were further confirmed by using NMR spectroscopy. All the obtained DPs were new and not reported previously. The developed chromatographic method was validated as per ICH Q2 (R1) guideline and USP general chapter on method validation.

Thummar M ，Kuswah BS ，Samanthula G ，Bulbake U ，Gour J ，Khan W ... -  《-》

Forced degradation study of racecadotril: Effect of co-solvent, characterization of degradation products by UHPLC-Q-TOF-MS/MS, NMR and cytotoxicity assay.

Racecadotril, an enkephalinase inhibitor, was subjected to hydrolysis (acidic and alkaline), oxidation, photolysis and thermal stress, as per ICH specified conditions. The drug showed extensive degradation under acidic, basic hydrolysis and oxidative stress conditions whereas, it was stable under other stress conditions. A total of seven degradation products (DPs) were observed. The chromatographic separation was optimized on Acquity HSS Cyano (100×2.1mm, 1.8μ) column using 0.1% formic acid and acetonitrile as mobile phase in gradient mode. Six DPs were characterised by LC-MS/MS and DP1 by GC-MS. The major DPs (DP 2 and DP 5) were isolated and characterised by NMR. This is a typical case of degradation where co solvent methanol reacts with racecadotril leading to the formation of pseudo DPs, DP 6 and DP 5. Interestingly the MS/MS spectra of protonated drug, DP 4 and DP 7 showed product ions which were formed due to intramolecular benzyl migrations. In vitro cytotoxic activity studies on isolated DP 2 and DP 5 revealed that the former has no cytotoxic nature, whereas the latter has potential pulmonary and hepatic toxicity.

Chiguru V ，Lingesh A ，R S ，N S ... -  《-》