LC-HRMS and NMR studies for the characterization of degradation impurities of ubrogepant along with the in silico approaches for the prediction of degradation and toxicity

Ubrogepant is the first oral calcitonin gene-related peptide (CGRP) receptor antagonist which is used for the acute treatment of migraine in adults. The present study employs liquid chromatography-high resolution mass spectrometry (LC-HRMS) and nuclear magnetic resonance spectroscopy (NMR) techniques for the identification and characterization of degradation impurities of ubrogepant. The forced degradation study of ubrogepant was performed as per the International Council for Harmonisation (ICH) Q1A and Q1B guidelines. The in silico degradation profile of ubrogepant was predicted by Zeneth. It was observed that ubrogepant was labile to acidic hydrolysis, basic hydrolysis, and oxidative degradation conditions (H2O2), although it was stable in neutral hydrolysis and photolytic (UV light and visible light) conditions. Eight degradation impurities were formed, which were separated on reversed-phase HPLC with a gradient program on an InertSustain C8 column (4.6 × 250 mm, 5 µm) using 10 mM ammonium formate (pH unadjusted) and acetonitrile as the mobile phase. The structures of all the degradation impurities were characterized using the exact masses obtained from the HRMS/MS. Further, NMR studies were conducted on two major degradation impurities (UB-4 and UB-7). A plausible mechanism was proposed to support the structures of all the degradation impurities of UBR. In silico toxicity and mutagenicity assessment were done by DEREK Nexus, SARAH Nexus, and ProTox-II.

Covalent organic frameworks: spotlight on applications in the pharmaceutical arena

Covalent organic frameworks (COFs) have much potential in the field of analytical separation research due to their distinctive characteristics, including easy modification, low densities, large specific surface areas and permanent porosity. This article provides a historical overview of the synthesis and broad perspectives on the applications of COFs. The use of COF-based membranes in gas separation, water treatment (desalination, heavy metals and dye removal), membrane filtration, photoconduction, sensing and fuel cells is also covered. However, these COFs also demonstrate great promise as solid-phase extraction sorbents and solid-phase microextraction coatings. In addition to various separation applications, this work aims to highlight important advancements in the synthesis of COFs for chiral and isomeric compounds.

Discerning the stability behaviour of mavacamten availing liquid chromatography-mass spectrometry and nuclear magnetic resonance spectroscopy: In silico toxicity and mutagenicity prediction of degradation products

The present study aimed to separate, identify, and characterise the degradation products formed when mavacamten is exposed to stress degradation as well as the stability of the drug in various environments and also to understand its degradation chemistry. Prediction of in silico toxicity and mutagenicity was aimed at the observed degradation products. Stress degradation along with stability studies and degradation kinetics were performed on mavacamten, and separation of degradation products was carried out by high-performance liquid chromatography. Tandem mass spectrometry studies were executed to characterise the structures of degradation products using product ion fragments. Orthogonally, nuclear magnetic resonance experiments were conducted to elucidate the structures having ambiguity in characterising them. Deductive Estimation of Risk from Existing Knowledge and Structure Activity Relationship Analysis using Hypotheses software were used to establish in silico toxicity and mutagenic profiles of mavacamten and its degradation products. Two degradation products of mavacamten found in acidic hydrolytic stress conditions were separated, identified, characterised, and proposed as 1-isopropylpyrimidine-2,4,6(1H,3H,5H)-trione and 1-phenylethanamine. Mavacamten was found to be stable under different pH and gastrointestinal conditions. The degradation kinetics of mavacamten under 1 N acidic condition followed zero-order kinetics, and it was degraded completely within 6 h. In silico toxicity and mutagenicity studies revealed that 1-phenylethanamine can be a skin sensitiser. A high-performance liquid chromatography method was developed for the separation of degradation products of mavacamten and characterised by liquid chromatography-tandem mass spectrometry and nuclear magnetic resonance. During the manufacturing and storage of drug product, precautions need to be taken when dealing with acidic solutions as the drug is prone to hydrolysis in acidic conditions. The formation of 1-phenylethanamine under these conditions is to be monitored as it is a skin sensitiser.

Forced degradation study of baricitinib and structural characterization of its degradation impurities by high-resolution mass spectrometry and nuclear magnetic resonance spectroscopy

RATIONALE

Baricitinib (BARI), an inhibitor of Janus kinases 1 and 2 (JAK 1/2), is used for the treatment of rheumatoid arthritis and COVID-19. The present study focuses on establishing the forced degradation behavior of BARI under different degradation conditions (hydrolysis, oxidation, and photolysis) following International Council for Harmonization (ICH) guidelines of Q1A (R2)-Stability testing of new drug substances and products and Q1B-Photostability testing of new drug substances and products. This study helps in monitoring the quality and safety of BARI and its product development.

METHODS

Prior to conducting the study, the in silico degradation profile of BARI was predicted by Zeneth. Reversed-phase high-performance liquid chromatography employing a gradient program was used for the identification and separation of degradation impurities with an InertSustain C8 column (4.6 × 250 mm, 5 μm). The mobile phases used were 10 mM ammonium formate (pH 2.89) and acetonitrile. High-resolution mass spectrometry (HRMS) was used for the structural elucidation of the degradation impurities.

RESULTS

BARI was labile to hydrolytic (acidic, basic, and neutral) and photolytic degradation conditions which yielded 10 new degradation impurities and it was stable under oxidative (H2 O2 ) conditions. The separated degradation impurities were characterized by HRMS and the respective degradation pathways were proposed. The generated information helped to propose a mechanism for the formation of the degradation impurities. Additionally, one-dimensional and two-dimensional nuclear magnetic resonance spectroscopy were used for the characterization of two major degradation impurities.

CONCLUSION

The forced degradation study of BARI was carried out in accordance with ICH Q1A and Q1B guidelines, which resulted in the formation of 10 new degradation impurities. In our analysis, three degradation impurities were matching with the Zeneth predictions. In silico tools, DEREK Nexus® and SARAH Nexus®, were used for predicting the toxicity and mutagenicity of BARI and its degradation impurities. Overall, this study sheds light on BARI's safety monitoring and storage circumstances.

Chromatographic separation of tiropramide hydrochloride and its degradation products along with their structural characterization using LC-QTOF-MS/MS and NMR

Tiropramide HCl, an antispasmodic drug was subjected to various stress conditions (hydrolytic, oxidative, photolytic and thermal) as per ICH guidelines. The drug is widely used as an antispasmodic agent but there were no comprehensive degradation studies reported on it. Hence, forced degradation studies of tiropramide HCl were carried out to establish the degradation profile and the storage conditions to maintain its quality attributes during the shelf life and usage. A selective HPLC method was developed to separate the drug as well as its degradation products using Agilent C18 (250×4.6 mm; 5 μm) column. The mobile phase of 10mM ammonium formate at pH 3.6 (solvent A) and methanol (solvent B) with gradient elution at a flow rate of 1.00 mL/min was used. Tiropramide was susceptible to acidic, basic hydrolytic exposure and oxidative stress conditions in the solution. This drug was found to be stable in neutral, thermal and photolytic conditions in both solution and solid-state. Five degradation products were detected under different stress conditions. The mass spectrometric fragmentation pattern of tiropramide and its degradation products was extensively studied using LC-Q-TOF-MS/MS for their structural characterization. The position of the oxygen atom in the N-oxide degradation product was confirmed by NMR studies. The knowledge gained by these studies was used to predict drug degradation profiles which will be helpful in analysing any impurities in dosage form.

In Silico Tools to Thaw the Complexity of the Data: Revolutionizing Drug Research in Drug Metabolism, Pharmacokinetics and Toxicity Prediction

In silico tool is the flourishing pathway for Researchers and budding chemists to strain the analytical data in a snapshot. Traditionally, drug research has heavily relied on labor-intensive experiments, often limited by time, cost, and ethical constraints. In silico tools have paved the way for more efficient and cost-effective drug development processes. By employing advanced computational algorithms, these tools can screen large libraries of compounds, identifying potential toxicities and prioritizing safer drug candidates for further investigation. Integrating in silico tools into the drug research pipeline has significantly accelerated the drug discovery process, facilitating early-stage decision-making and reducing the reliance on resource-intensive experimentation. Moreover, these tools can potentially minimize the need for animal testing, promoting the principles of the 3Rs (reduction, refinement, and replacement) in animal research. This paper highlights the immense potential of in silico tools in revolutionizing drug research. By leveraging computational models to predict drug metabolism, pharmacokinetics, and toxicity. Researchers can make informed decisions and prioritize the most promising drug candidates for further investigation. The synchronicity of In silico tools in this article on trending topics is insightful and will play an increasingly integral role in expediting drug development.

Stability behaviour of antiretroviral drugs and their combinations. 4: Characterization of degradation products of tenofovir alafenamide fumarate and comparison of its degradation and stability behaviour with tenofovir disoproxil fumarate

In this study, stress degradation behaviour of tenofovir alafenamide fumarate (TAF), a novel prodrug of tenofovir, was investigated and compared with currently used prodrug congener, tenofovir disoproxil fumarate (TDF), whose intrinsic stability was reported by us earlier [14]. Also, pH stability and gastrointestinal stability studies were conducted on both the drugs. High performance liquid chromatography (HPLC) analysis of stressed samples of TAF revealed formation of six degradation products (DPs) against twelve characterized earlier in the case of TDF (RSC Adv. 5(2015) 96117-96129). Like TDF, characterization of DPs of TAF was done by using sophisticated hyphenated liquid chromatography-high resolution mass spectrometry (LC-HRMS) and multistage mass spectrometry (MSⁿ) tools. pH-stability studies between pH 1.2-10 revealed greater stability of TAF, except in acidic conditions, where TAF was degraded extensively. Investigation of gastrointestinal stability in simulated gastric fluid (SGF), simulated intestinal fluid (SIF) and fed state simulated gastric fluid (FeSSGF) suggested that TAF must be administered in fed state, as the drug was practically stable in FeSSGF as compared to extensive loss at acidic pH and in SGF.

Stability behaviour of antiretroviral drugs and their combinations. 1: characterization of tenofovir disoproxil fumarate degradation products by mass spectrometry

The investigation established the intrinsic degradation behaviour of tenofovir disoproxil fumarate in solid and solution states.