Isolation, identification and characterization of two novel process-related impurities in olanzapine

Risk-based in silico mutagenic assessment of benzodiazepine impurities using three QSAR tools

Benzodiazepines, widely prescribed psychoactive drugs, may contain DNA-reactive (mutagenic) impurities formed during synthesis, posing significant health risks. Owing to animal testing requirements, traditional in vitro and in vivo methods for assessing mutagenicity are time-consuming, costly, and ethically challenging. Computational approaches, particularly in silico (Q)SAR models, provide an efficient alternative for predicting toxicity based on chemical structure. This study evaluated the mutagenic potential of 88 benzodiazepine-related impurities using three freely accessible (Q)SAR tools: TOXTREE (Ames Test Alert by ISS), Toxicity Estimation Software Tool (TEST) with nearest neighbour and consensus models, and VEGA, a QSAR tool that integrates multiple mutagenicity prediction models, including the CAESAR Ames Mutagenicity Model. The tools were validated using a dataset of 99 chemicals with known Ames test results. TOXTREE exhibited the highest sensitivity (80.7 %) and accuracy (72.2 %) for predicting mutagenicity, whereas VEGA and TEST provided balanced accuracy (66.2 % and 66.7 %, respectively) and high specificity (74.5 % and 76.6 %, respectively). The risk assessment categorised 21 impurities as high risk, 11 as moderate-high risk, 28 as moderate-low risk, 22 as low risk, and 6 as equivocal, with expert review finalising classifications. The findings emphasise the integration of multiple (Q)SAR tools for early mutagenicity detection, regulatory compliance, and reduced reliance on animal testing. Further refinement of predictive models and additional computational approaches are recommended to enhance the accuracy of the risk assessment.

Isolation and Characterization of an Unknown Process-Related Impurity in Furosemide and Validation of a New HPLC Method

Furosemide is a widely used loop diuretic in the treatment of congestive heart failure and edema. During the preparation of furosemide, a new process-related impurity G in the levels ranging from 0.08% to 0.13% was detected in pilot batches by a new high performance liquid chromatography (HPLC) method. The new impurity was isolated and characterized by comprehensive analysis of FT-IR, Q-TOF/LC-MS, 1D-NMR (¹H, ¹³C, and DEPT), and 2D-NMR (¹H-¹H-COSY, HSQC, and HMBC) spectroscopy data. The possible formation pathway of impurity G was also discussed in detail. Moreover, a novel HPLC method was developed and validated for the determination of impurity G and the other six known impurities registered in the European Pharmacopoeia as per ICH guidelines. The HPLC method was validated with respect to system suitability, linearity, the limit of quantitation, the limit of detection, precision, accuracy, and robustness. The characterization of impurity G and the validation of its quantitative HPLC method were reported for the first time in this paper. Finally, the toxicological properties of impurity G were predicted by the in silico webserver ProTox-II.

Polyvinylpyrrolidone K-30-Based Crosslinked Fast Swelling Nanogels: An Impeccable Approach for Drug's Solubility Improvement

Poor solubility is a global issue of copious pharmaceutical industries as large number of drugs in development stage as well as already marketed products are poorly soluble which results in low dissolution and ultimately dosage increase. Current study is aimed at developing a polyvinylpyrrolidone- (PVP-K30-) based nanogel delivery system for solubility enhancement of poorly soluble drug olanzapine (OLP), as solubilization enhancement is the most noteworthy application of nanosystems. Crosslinking polymerization with subsequent condensation technique was used for the synthesis of nanogels, a highly responsive polymeric networks in drug's solubility. Developed nanogels were characterized by percent entrapment efficiency, sol-gel, percent swelling, percent drug loaded content (%DLC), percent porosity, stability, solubility, in vitro dissolution studies, FTIR, XRD, and SEM analysis. Furthermore, cytotoxicity study was conducted on rabbits to check the biocompatibility of the system. Particle size of nanogels was found with 178.99 ± 15.32 nm, and in vitro dissolution study exhibited that drug release properties were considerably enhanced as compared to the marketed formulation OLANZIA. The solubility studies indicated that solubility of OLP was noticeably improved up to 36.7-fold in phosphate buffer of pH 6.8. In vivo cytotoxicity study indicated that prepared PVP-K30-based formulation was biocompatible. On the basis of results obtained, the developed PVP-K30-co-poly (AMPS) nanogel delivery system is expected to be safe, effective, and cost-effective for solubility improvement of poorly soluble drugs.

An Overview of Advances in the Chromatography of Drugs Impurity Profiling

A systematic literature survey published in several journals of pharmaceutical chemistry and of chromatography used to analyze impurities for most of the drugs that have been reviewed. This article covers the period from 2016 to 2020, in which almost of chromatographic techniques have been used for drug impurity analysis. These chromatography techniques are important in the analysis and description of drug impurities. Moreover, some recent developments in forced impurity profiling have been discussed, such as buffer solutions, mobile phase, columns, elution modes, and detectors are highlighted in drugs used for the study. This primarily focuses on thorough updating of different analytical methods which include hyphenated techniques for detecting and quantifying impurity and degradation levels in various pharmaceutical matrices.

Recent Progresses in Analytical Perspectives of Degradation Studies and Impurity Profiling in Pharmaceutical Developments: An Updated Review

Forced degradation studies have been used to simplify analytical methodology development and achieve a deeper knowledge about the inherent stability of active pharmaceutical ingredients (API) and drug products. This provides insight into degradation species and pathways. Identification of impurities in pharmaceutical products is closely related to the selection of the most appropriate analytical methods like HPLC-UV, LC-MS/MS, LC-NMR, GC-MS, and capillary electrophoresis. Herein, recent trends in analytical perspectives during 2018-April 14, 2021, are discussed based on forced and impurity degradation profiling of pharmaceuticals. Literature review showed that several methods have been used for experimental design and analysis conditions such as matrix type, column type, mobile phase, elution modes, detection wavelengths, and therapeutic category. Thus, since these factors influence the separation and identification of the impurities and degradation products, we attempted to perform a statistical analysis for the developed methods according to the abovementioned factors.

Isolation and structural characterization of eight impurities in aztreonam

To comply with regulatory requirements, it is necessary to detect and separate the impurities generated during aztreonam synthesis or storage. The chromatogram of aztreonam revealed eight major impurities, which were purified through medium-pressure reversed-phase column and preparative High Performance Liquid Chromatography (HPLC). Through high resolution electrospray ionization mass spectroscopy (HRESIMS), as well as one- and two-dimensional nuclear magnetic resonance (NMR), their structures were confirmed as aztreonam acetate (Ⅰ), desulfated aztreonam (Ⅱ), anti-aztreonam (Ⅲ), open-ring aztreonam (Ⅳ), open-ring desulfated aztreonam (Ⅴ), open-ring desulfated aztreonam ethyl ester (VI), cis-deamino open-ring desulfated aztreonam (VII), and trans-deamino open-ring desulfated aztreonam (Ⅷ). Their exact concentrations were determined through quantitative nuclear magnetic resonance (qNMR) technique. Structural elucidation of the eight impurities through ¹H NMR, ¹³C NMR, the ¹H-¹H COSY, NOESY, HSQC, HMBC NMR and MS spectra was conducted. Especially, ⅥI and Ⅷ were identified as undescribed impurities here.

Isolation, structural characterization and quality control strategy of an unknown process-related impurity in sugammadex sodium

Sugammadex sodium is the first selective relaxant binding agent (SRBA) indicated for reversal of neuromuscular blockade induced by rocuronium or vecuronium during surgery. The chemical synthesis of sugammadex involved the nucleophilic substitution reaction between 6-per-deoxy-6-per-halo-γ-cyclodextrin and 3-mercaptopropionic acid under basic conditions. During the manufacture of sugammadex sodium, an unknown process-related impurity was observed in pilot batches in the range of 0.21-1.9 % based upon HPLC analysis. The same impurity was also detected in commercial Bridion® samples at the levels of more than 0.1 %. Thus this unknown impurity was enriched from the mother liquor of reaction by preparative HPLC and characterized by LC-MS/QTOF, 1D-NMR (¹H, ¹³C, DEPTQ) and 2D-NMR (¹H-¹H COSY, TOCSY, HSQC, HMBC, NOESY) techniques. Based on spectroscopic analysis and the synthetic route of sugammadex sodium, this new impurity was identified as monocyanoethyl sugammadex (impurity-I). The prospects to the formation mechanism and control strategy of impurity-I were discussed in detail. Moreover, the toxicological properties of impurity-I were evaluated using ADMET Predictor® software.

Poloxamer-407-Co-Poly (2-Acrylamido-2-Methylpropane Sulfonic Acid) Cross-linked Nanogels for Solubility Enhancement of Olanzapine: Synthesis, Characterization, and Toxicity Evaluation

Current study is focused to enhance the solubility of poorly soluble drug olanzapine (OLZ) by nanogels drug delivery system, as improved solubility is one of the most important applications of nanosystems. Poor solubility is a major issue, and 40% of marketed and about 75% of new active pharmaceutical ingredients are poorly water soluble which significantly affect the bioavailability and therapeutic effects of these drugs. In this study, nanogels, a promising system for solubility enhancement, were developed by free-radical polymerization technique. Different formulations were synthesized in which poloxamer-407 was cross-linked with 2-acrylamido-2-methylpropane sulfonic acid (AMPS) with the help of cross-linker methylene bisacrylamide (MBA). The chemically cross-linked nanogels were characterized by Fourier transform infrared spectroscopy (FT-IR), thermos gravimetric analysis (TGA), differential scanning calorimetry (DSC), X-ray diffraction (XRD), scanning electron microscopy (SEM), zeta size, swelling, sol-gel analysis, drug loading, solubility, and in vitro drug release studies. In order to determine the biocompatibility and cytotoxicity of nanogels to biological system, toxicity study on rabbits was also carried out. It was confirmed that the developed nanogels was thermally stable, safe, effective, and compatible to biological system, and the solubility of olanzapine (OLZ) was enhanced up to 38 folds as compared with reference product.

Separation and characterization of unknown impurities in latamoxef sodium by LC-Q-TOF MS and a summary of their positive-ion fragmentation regularities

A simple and sensitive method was developed for separation and characterization of seventeen impurities from commercial latamoxef sodium for injection by liquid chromatography combined with electrospray ionization and QTOF mass spectrometer (LC-ESI-QTOF MS). The chromatographic separation was performed on a Boston Green ODS-AQ C18 column (250 mm × 4.6 mm, 5 μm) under gradient mode using binary mobile phase: (A) ammonium acetate (10 mM)-methanol (99:1, v/v) and (B) ammonium acetate (10 mM)-methanol (70:30, v/v). Based on tandem multistage MS and high resolution MS data, the molecular formulas and structures of unknown impurities were inferred. A plausible formation mechanism of impurities was also proposed. In addition, the fragmentation regularity of degraded impurities in positive-ion mode was summarized.

Multi-Steps Fragmentation-Ion Trap Mass Spectrometry Coupled to Liquid Chromatography Diode Array System for Investigation of Olaparib Related Substances

A high-performance liquid chromatography-diode array-mass spectrometric (LC-DAD-MS) method was developed and validated to investigate the related substances of olaparib (OLA) in bulk form. OLA was exposed to acid–base hydrolysis, boiling, oxidation with hydrogen peroxide, and UV light followed by LC-DAD-MS analysis. OLA and OLA-related substances were simultaneously and quantitatively monitored by DAD at 278 nm and triple quadrupole mass spectrometry (QQQ-MS). The investigated compounds were auto-scanned by an ion trap MS which applied positive and negative modes separately. The fragmentation pathway was confirmed by applying multi-steps fragmentation to identify the resulted cleaved ions and their parent ion. OLA was found to be sensitive to the alkaline hydrolysis and less sensitive to UV light. Two major hydrolytic degradation products, including the protonated molar ions m/z 299 and m/z 367, were identified. Three potential impurities were also characterized. The LC-MS limit of detection (LOD) and limit of quantification (LOQ) were 0.01 and 0.05 ng/µL, respectively. The quantitative results obtained by LC-DAD was comparable with that of LC-QQQ-MS. The proposed method shows good intra-day and inter-day precision with relative standard deviation (RSD) <2%.