Neutral Hydrolysis Research Articles

A novel highly sensitive test reaction for micromixing: Acid‐base neutralization and alkaline hydrolysis of ethyl oxalate

AbstractMicromixing in chemical reactors can be characterized through test reactions that are sensitive to mixing. A new pair of parallel competitive reactions, including acid–base neutralization and diethyl oxalate hydrolysis, is proposed in this work. It has clear principles and high sensitivity to micromixing with quantitative accuracy and operational simplicity. The measurement results obtained from stopped‐flow spectra show that the alkaline hydrolysis of diethyl oxalate follows second‐order kinetics, and the rate constant conforms to the Arrhenius equation k2 = 2.331 × 108 exp(−26.92 × 103/RT) (L/mol/s). The estimated half‐life of hydrolysis is approximately 3 × 10−4 s under the selected concentration combinations, which provides significant advantages for the micromixing assessment in the strong turbulent fluid environment. In the same stirred tank, the critical feed time of new test reaction is shorter than that of the Villermaux–Dushman reaction. Overall, this work provides practical ideas for screening other desired esters for fast hydrolysis to construct more test reactions for micromixing.

Kinetics of Hydrolytic Depolymerization of Textile Waste Containing Polyester

Textile products comprise approximately 10% of the total global carbon footprint. Standard practice is to discard apparel textile waste after use, which pollutes the environment. There are professional collectors, charity organizations, and municipalities that collect used apparel and either resell or donate them. Non-reusable apparel is partially recycled, mainly through incineration or processed as solid waste during landfilling. More than 60 million tons of textiles are burnt or disposed of in landfills annually. The main aim of this paper is to model the heterogeneous kinetics of hydrolysis of multicomponent textile waste containing polyester (polyethylene terephthalate (PET) fibers), by using water without special catalytic agents or hazardous and costly chemicals. This study aims to contribute to the use of closed-loop technology in this field, which will reduce the associated negative environmental impact. The polyester part of waste is depolymerized into primary materials, namely monomers and intermediates. Reaction kinetic models are developed for two mechanisms: (i) the surface reaction rate controlling the hydrolysis and (ii) the penetrant in terms of the solid phase rate controlling the hydrolysis. A suitable kinetic model for mono- and multicomponent fibrous blends hydrolyzed in neutral and acidic conditions is chosen by using a regression approach. This approach can also be useful for the separation of cotton/polyester or wool/polyester blends in textile waste using the acid hydrolysis reaction, as well as the application of high pressure and the neutral hydrolysis of polyester to recover primary monomeric constituents.

Utilizing cutting-edge analytical techniques for the Identification, Isolation, and structural characterization of donepezil HCl forced degradation products

The current study elucidates the stress degradation behavior of donepezil HCl, a medication used to treat Alzheimer-type dementia. Using hydrolytic, oxidative, thermal, and photolytic conditions, the forced degradation investigation was conducted in accordance with ICH recommendations. In neutral hydrolysis, oxidative, thermal, and photolytic conditions, donepezil is comparatively stable; nevertheless, significant degradation was noted in acid and base hydrolysis. Using sophisticated analytical methods such as LCMS, Preparative-HPLC, NMR, and HRMS, the degradation products were identified, isolated, and their structural validity was confirmed. Degradation products 1, 2, and 3 are the three degradation products that were found and isolated during acid degradation. Conversely, products 1 and 3 generated during base hydrolysis degradation. Degradation product 1 and 3 were known products, while degradation product 2 is new compound that have not yet been documented. Using an advanced analytical approach, this is the first recorded comprehensive structural characterization of all degradation products. In the current work, high-resolution mass spectroscopy and nuclear magnetic resonance spectroscopy were employed to get specific confirmation of degradation product structures. In the future, degradation products with lower runtime will also be identified using the present LCMS technique.

Process Parameter Optimization of Waste Polyethylene Terephthalate Bottle Neutral Hydrolysis Depolymerisation Using Process Simulation and Response Surface Methodology

The global surge in plastic production has led to a concerning accumulation of durable plastic waste in landfills and the environment. To address this issue, the depolymerization of waste polyethylene terephthalate (PET) through neutral hydrolysis has been proposed as a chemical recycling solution. Despite its potential environmental benefits, the endothermic nature of this process at high temperatures has raised doubts about its commercial feasibility. In response, this study was conducted to assess optimal conditions for waste PET depolymerization using neutral hydrolysis in a continuous stirred tank reactor with zinc acetate as a catalyst. Process simulation, aimed to manufacture pure terephthalic acid (TPA) and ethylene glycol from pelletized post-consumer PET bottles, was conducted with Aspen Plus Version 11. Sensitivity analysis explored the impact of factors such as reaction temperature, reaction time, PET flake size, and catalyst to PET ratio on both PET conversion and TPA yield. The study found that PET depolymerization increased with decreasing particle size, longer reaction times, increasing catalyst to PET ratio and reaction temperatures within the range of 200–240°C. Optimizing the process through response surface modelling revealed that key parameters for neutral hydrolysis considering a mean particle size of 20 mm were the ratio of water to PET, temperature, pressure, and reaction time with optimal values of 5:1, 225°C, 30 bar, and 67.5 min respectively. The model's reliability was confirmed through variance analysis, emphasizing the significance of main and interaction effects in the regression model.

Aluminum Removal from Rare Earth Chloride Solution through Regulated Hydrolysis via Electrochemical Method

Due to the coexistence of Al3+ and RE3+ and their similar properties, the separation of aluminum from rare earths is difficult. In this study, selective precipitation was used to separate aluminum from rare earth chloride solution via electrochemical regulated hydrolysis. By controlling the current density and electrolytic time, the rate of hydroxyl ion production was regulated, and the selective separation of rare earth and aluminum was realized according to the different precipitation sequences. By altering the temperature, current density, pH value, and other parameters, the separation performance of aluminum from rare earth in mixed rare earth chloride systems was systematically investigated. The removal rate of aluminum reached 88.35%, and the loss rate of rare earth was only 5.99% under optimized conditions. Compared with traditional neutralization hydrolysis, the new process showed higher efficiency and lower rare earth loss rate. Furthermore, a kinetic analysis of aluminum precipitation revealed that the reaction adhered to pseudo-first order kinetics. Additionally, the precipitate obtained via separation and filtration was amorphous alumina hydroxide with a small amount of rare earth attached. No reagent was consumed for the new process, which was more efficient and cleaner, providing a new idea for removing aluminum impurities from rare earth solutions.

Exploratory DSC investigation on the solvolytic depolymerization of PET in varied solvent systems and in the presence of model additives and contaminants

Solvolytic depolymerization of polyethylene terephthalate (PET) is a thermo-chemical recycling route that valorizes plastic waste by recovering monomers and chemicals that can be reused for the synthesis of new polymers. This study focuses on neutral hydrolysis due to the potential environmental and economic benefits of water as depolymerization agent compared to alternative organic solvents. High-pressure crucibles were used as batch reactors in differential scanning calorimetry (DSC) to perform real-time monitoring of the thermodynamic phenomena taking place during solvolytic depolymerization of PET in varied solvent systems. PET melting point depression was found to be the main identified phenomena, with PET melting point exhibiting a drop of almost 30 °C in water and 50 °C in monoalcohol solvents like methanol and ethanol. Moreover, PET only underwent significant depolymerization prior to melting in NaOH containing systems. Gas Chromatography and Mass Spectrometry were used to study the fate of model additives and contaminants under solvolytic conditions. The uncertainty concerning these foreign substances poses a challenge for the development of PET solvolytic technologies, and the methods here provided proved to be a fast-screening technique to quantify the conversion and identify potential degradation products of model additives like 2-(2-hydroxy-5-methylphenyl) benzotriazole UV-stabilizer, 1-(methylamino) anthraquinone dye, and model contaminant (R)-(+)-limonene under hydrothermal conditions.

Recovery of high-quality terephthalic acid from waste polyester textiles via a neutral hydrolysis method

As a consequence of the extensive use of polyethylene terephthalate (PET) in the textile industry, a significant amount of PET waste is generated. To achieve environmental remediation and sustainable development, it is imperative to transform the PET waste into valuable chemical raw materials. One promising approach to managing this waste is neutral hydrolysis, which converts PET to terephthalic acid (PTA) and ethylene glycol (EG) and is environmentally friendly. However, the current technology suffers from difficulties in decolorization and purification of the PTA. Herein, we implemented a new closed-loop route for recycling waste polyester textiles, which comprises of the pre-decolorization of textile samples, neutral hydrolysis of decolorized waste polyester textiles and purification of the PTA products by reduced-pressure sublimation. Using this method, waste polyester textiles that are picked up from waste bins having various colors and compositions were successfully hydrolyzed to form PTA with a purity of up to 99.9%. The yield of the recovered PTA reached 95.1%, and the whiteness value (L*) was up to 99.9. The regenerated PET (r-PET) obtained through repolymerization of the recycled PTA exhibited similar properties to those of PET derived from petroleum-based PTA.

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.

STABILITY INDICATING UPLC METHOD FOR ESTIMATION OF BENAZEPRIL AND HYDROCHLOROTHIAZIDE IN BULK AND COMBINED DOSAGE FORM

Objective: The main objective was to develop stability indicating UPLC technique for simultaneous estimation of Benazepril and Hydrochlorothiazide in bulk and formulation. Methods: 0.1% Triethylamine phosphate: Methanol (25:75v/v) was used as the mobile phase. Benazepril linearity was found to be 4-20 µg/ml and Hydrochlorothiazide linearity was found to be 5-25 g/ml. The detection wavelength was 236 nm, and the retention period of Benazepril was 3.4 min and Hydrochlorothiazide was 5.4 min with a flow rate of 1.0 ml/min. According to the ICH guidlines, the proposed method was validated and stress studies revealed that the drugs are prone to alkali and peroxide stress conditions. Results: The calibration curve was plotted, and the regression equations for Benazepril were y = 2,01,491.67x+60,532.30 with a correlation coefficient (r2) of 0.9997 and Hydrochlorothiazide were y = 64,635.86x-74,607.10 with a correlation coefficient (r2) of 0.9994. According to the accuracy research, the percent recovery of Benazepril is 99.09-100.69 % and that of Hydrochlorothiazide is 98.27-101.88%, both of which are within the ICH recommendations. Benazepril has a limit of detection of 0.08 g/ml-0.24 g/ml and Hydrochlorothiazide has a limit of quantitation of 0.03 g/ml-0.10 g/ml. The procedure was found to be straightforward, linear, rapid, exact, repeatable, and robust. It was determined that the % RSD was within ICH norms. Stress degradation tests showed the drug's vulnerability to oxidative, thermal, photolytic, acid, basic, and neutral hydrolysis stress conditions. Under the circumstances of alkali and peroxide stress, it was discovered that the drug degraded most quickly. Conclusion: The developed chromatographic technique under consideration was suitable for the accurate, precise, and quick simultaneous measurement of hydrochlorothiazide and benazepril in both their bulk and medicinal dose forms.

Upcycling plastic wastes into high-performance nano-MOFs by efficient neutral hydrolysis for water adsorption and photocatalysis

Employing polyethylene terephthalate (PET) wastes as a linker source is a cost-effective, renewable, and sustainable approach to attain high-performance nano-MOFs for water adsorption and photocatalysis.

Correction to “Neutral Hydrolysis of Post-Consumer Polyethylene Terephthalate Waste in Different Phases”

Correction to “Neutral Hydrolysis of Post-Consumer Polyethylene Terephthalate Waste in Different Phases”

Stability-Indicating Liquid Chromatography Method for Rifaximin and LC-MS Characterization of its Potential Degradants

Rifaximin (RFX) is a structural analog of rifampin that has been shown to be a gastrointestinal-selective antibiotic with broad-spectrum antibacterial properties, a pronounced safety profile, and limited drug interactions. Crohn’s disease, diarrhea, hepatic encephalopathy, irritable bowel syndrome, and traveler’s diarrhea caused by non-invasive diarrheagenic Escherichia coli, can all be treated with rifaximin. FDA has designated RFX as an orphan drug for the treatment of hepatic encephalopathy. There is a substantial need for analytical quality monitoring of Rifaximin to ensure the safety and efficacy of treatment. To generate degradants, forced degradation study of the drug was carried out in acid, alkali, oxidative, thermal, and photolytic stress conditions. The optimum separation of the drug, and its degradants was achieved on an Inertsil ODS-3V C18 column (250 X 4.6 mm X 5 μm) under gradient elution conditions using, 10 mM potassium dihydrogen orthophosphate (pH 5.0 ± 0.05) as mobile phase A, and acetonitrile as mobile phase B, at a flow rate of 1.0 mL/min. The run time was 41 minutes and the detection wavelength was 258 nm. The method was validated in accordance with the International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human use Guidelines. The drug was stable in neutral hydrolysis, photo and dry heat degradation conditions. The percentage degradation observed during acid, alkali hydrolysis and oxidative stress conditions were 70.46, 15.11 and 24.18, respectively. The degradants were investigated by LC-MS which indicated the presence of four (m/z 784.2, 744.5, 784.3, 753.8), three (m/z 744.5, 784.3, 753.8) and five (m/z 772.4, 838.4, 744.5, 753.8, and 801.9) degradants in acid, alkali and oxidative stress conditions, respectively. The structures of degradants were elucidated using Liquid chromatography–mass spectrometry (LC-MS) and Liquid chromatography tandem mass spectrometry (LC-MS/MS) analyses.

Hydrolysis of polyethylene terephthalate by ZSM-5 combined with supercritical carbon dioxide under neutral environment

Polyethylene terephthalate (PET) is a kind of stable polyester, which is difficult to be degraded in the natural environment, and the waste PET causes severe environmental problems. To achieve efficient and environmentally friendly hydrolysis of PET, we employed ZSM-5 as a catalyst for neutral hydrolysis of PET in the presence of supercritical carbon dioxide (SCCO2). This study demonstrates that the existence of SCCO2 in the system enhances PET hydrolysis efficiency. The swelling effect of SCCO2 on PET can relax the PET segment and promote the mass transfer of water molecules in the PET bulk phase. However, excessive pressure of SCCO2 leads to plasticization of PET which increases the crystallinity of PET and hinders hydrolysis. The activation energy was measured under different pressures, revealing a decrease in activation energy with increasing pressure below 7.5 MPa. When the pressure exceeds 7.5 MPa, the activation energy increases due to plasticization. Through the density functional theory (DFT) analysis combined with the experimental results, it has been confirmed that Brønsted acid on ZSM-5 plays a more important role than Lewis acid in the system.

Identification and Structural Characterization of Forced Degradation Impurities of Sacubitril by HRMS – Development and Validation of a Stability indicating RP-HPLC method

The current work identifies and characterises the stress degradation products of the anti-hypertensive drug sacubitril. The stability profile of sacubitril was evaluated under several stress settings including hydrolytic, oxidative, thermal and photolytic conditions in accordance with ICH recommendations. The degradation products of sacubitril were separated using reverse phase liquid chromatography and structural characterization was carried out using HRMS. The chromatographic separation was carried out by Reverse Phase-High Performance Liquid Chromatography (RP-HPLC) using a Fortis C18 column (150 mm X 4.6 mm; 5μm particle size) with mobile phase A (consisting of 0.1% TFA in Milli-Q water) and mobile phase B (100% Acetonitrile) in gradient mode. With a sample injection volume of 10μL, the mobile phase flow rate was 0.7 mL/min. A quadrupole time-of-flight (Q-TOF) mass spectrometer was used for the LC-MS analysis. Sacubitril is relatively stable in oxidative, thermal and photolytic conditions; however, considerable degradation was observed in acid, base and neutral hydrolysis. Three degradation products were identified and the structural characterization of these impurities was performed using the HRMS data and mass fragmentation. The proposed RP-HPLC method was robust, precise and specific in determining the impurity profile of sacubitril under different stress conditions.

Hesperidin: Enrichment, forced degradation, and structural elucidation of potential degradation products using spectral techniques.

Hesperidin (HES) is a well-known citrus bioflavonoid phyto-nutraceutical agent with polypharmacological properties. After 2019, HES was widely used for prophylaxis and COVID-19 treatment. Moreover, it is commonly prescribed for treating varicose veins and other diseases in routine clinical practice. Pharmaceutical impurities and degradation products (DP) impact the drug's quality and safety and thus its effectiveness. Therefore, forced degradation studies help study drug stability, degradation mechanisms, and their DPs. This study was performed because stress stability studies using detailed structural characterization of hesperidin are currently unavailable in the literature. In the HES enrichment method crude HES was converted to its pure form (98% purity) using column chromatography and then subjected to forced degradation under acid, base, and neutral hydrolyses followed by oxidative, reductive, photolytic, and thermal stress testing (International Conference on Harmonization guidelines). The stability-indicating analytical method (SIAM) was developed to determine DPs using reversed-phase high-performance liquid chromatography (C18 column with methanol and 0.1% v/v acetic acid in deionized water [70:30, v/v] at 284 nm). Further, structural characterization of DPs was performed using liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) and nuclear magnetic resonance (NMR) spectroscopy. In addition, in silico toxicity predictions were performed using pKCSM and DataWarior freeware. HES was found to be susceptible to acidic and basic hydrolytic conditions and yielded three DPs in each, which were detected using designed SIAM. Of six DPs, three were pseudo-DPs (short lived), and the remaining were characterized using LC-MS/MS and NMR spectroscopy. The tentative mechanism of the formation of proposed DPs was explained. The proposed DPs were found inactive from in silico toxicity predictions. Hesperidin was labile under acidic and basic stress conditions. The potential DPs were characterized using LC-ESI-MS/MS and NMR spectral techniques. The proposed mechanism of formation was hypothesized. In addition, to identify and characterize the DPs, a SIAM, which has broad biomedical applications, was successfully developed.

HYDROLYTIC DEGRADATION STUDY OF ROXADUSTAT BY RP-HPLC AND HPTLC

Objective: Simple, rapid RP-HPLC and HPTLC methods have been developed in order to study the degradation of Roxadustat under various stress conditions. The Kinetics of hydrolytic degradation is studied. Methods: Optimum separation of Roxadustat and its degradation products was achieved using the following conditions in HPLC, Agilent eclipse XDB-C8 (150×4.6 mm) column, the mobile phase was composed of methanol: phosphate buffer (pH 5, 0.05 M) (70:30 v/v) with UV detection at 262 nm. The flow rate was at 1.0 ml/min. The RT was 4.6±0.02 min. HPTLC work for Roxadustat was performed on Aluminium plates precoated with silica gel 60 F254, (10 cm × 10 cm with 250 μm layer thickness). The mobile phase was composed of Toulene: Ethyl Acetate: Glacial acetic acid (5:5:0.5 v/v/v) and then scanned. The system was found to give a compact spot for Roxadustat (Rf value of 0.58±0.02). Results: In HPLC the calibration curves plotted were found to be linear over the concentration range of 2.5-25μg/ml, with a correlation coefficient of R2=0.9994. In HPTLC the calibration curves plotted were found to be linear over the concentration range of 500-2500 ng/band, with a regression coefficient of R2=0.9957. The analytical performance of the proposed methods was validated as per ICH Q2 (R1) guidelines. The degradant peaks were well resolved from the Roxadustat peak. Significant degradation was observed in acid hydrolysis, alkali hydrolysis, and oxidative degradation. The drug is relatively stable towards photolysis, neutral hydrolysis, and thermal conditions. Conclusion: In the current work, simple RP-HPLC and HPTLC analytical methods for the determination of Roxadustat in the presence of its degradation products have been developed. The information presented herein could be very useful while developing formulation procedures to prevent hydrolytic degradation. It can be used as a routine quality control test.

Nonenzymatic hydrolysis of 1,2:3,4‐diepoxybutane: A kinetic study including pH, temperature, and ion effects

Abstract1,3‐Butadiene is a carcinogenic and mutagenic air pollutant metabolized to butane epoxides, among which 1,2:3,4‐diepoxybutane (DEB) exhibits the highest genotoxicity. DEB is also formed by 1,3‐butadiene oxidation in the air, producing a direct environmental and occupational exposure. In this paper, we studied the kinetics of the nonenzymatic hydrolysis of DEB at a wide range of pH and temperature, including the catalytic effect of ionic species. The compound degradation involved a general and specific acid‐base catalysis of the epoxide ring hydrolysis. DEB had the greatest stability at pH 5–9, when the rates of acid‐catalyzed and base‐catalyzed hydrolysis are negligible and the neutral hydrolysis predominates. The capability of the buffer anions to accelerate the DEB decay increased in the order H2PO4− < HCO3− < CH3COO− < HPO42− < and CO32−. The Arrhenius equation well described the influence of temperature on the acid‐catalyzed, base‐catalyzed, and neutral hydrolysis rate constants. According to the obtained hydrolysis model coupled with the found thermodynamic parameters, the half‐life of DEB in natural fresh waters spans from 2 days at 30°C to 31 days at 0°C, but in the laboratory waste adjusted to pH 1or 13, the half‐life shortens to 2–3 h at 20°C. Therefore, the results of the paper help to assess the risk of exposure to the genotoxic action of DEB.

Identification, isolation, and structural characterization of novel forced degradation products of Ertugliflozin using advanced analytical techniques

The research elucidates the stress degradation behavior of Ertugliflozin, which is used for the treatment of type-2 diabetics. The degradation was conducted as per ICH guidelines and Ertugliflozin is relatively stable in thermal, photolytic, neutral, and alkaline hydrolysis conditions; however, considerable degradation was detected in acid hydrolysis and oxidative hydrolysis. Degradation products were identified by ultra-high-performance liquid chromatography-mass spectrometry, isolated by semi-preparative high-performance liquid chromatography, and structural characterization using high-resolution mass spectrometry and nuclear magnetic resonance spectroscopy. Total four degradation products were identified and isolated in acid degradation, which are degradation products 1, 2, 3, and 4. Whereas in oxidative conditions, degradation product 5 was identified. All the five degradation products formed are novel, which was not reported earlier. This is the first time documented complete structural characterization of all five degradation products by using a hyphenated analytical technique. High-resolution mass, and nuclear magnetic resonance spectroscopy were used in the present study to get concrete confirmation of degradation products structures. The current method is also used to identify degradation products with shorter runtime in the future.

Structural characterization and in silico toxicity prediction of degradation impurities of roxadustat

Roxadustat is the first drug approved for anemia due to chronic kidney disease. Drug degradation profile is very crucial for assessing the quality and safety of the drug substances and their formulations. Forced degradation studies are conducted for quick prediction of drug degradation products. Forced degradation of roxadustat was carried out as per ICH guidelines, and nine degradation products (DPs) were observed. These DPs (DP-1 to DP-9) were separated using the reverse phase HPLC gradient method with an XBridge column (250 mm × 4.6 mm, 5 µm). The mobile phase consisted of 0.1% formic acid (solvent A) and acetonitrile (solvent B) at a flow rate of 1.0 ml/min. The chemical structures of all the DPs were proposed by using LC-Q-TOF/MS. DP-4 and DP-5, the two major degradation impurities, were isolated, and NMR was used to confirm their chemical structures. Based on our experiments, the roxadustat was found stable to thermal degradation in solid state and oxidative conditions. However, it was unstable in acidic, basic, and photolytic conditions. A very remarkable observation was made about DP-4 impurity. DP-4 was generated as a common degradation impurity in alkaline hydrolysis, neutral hydrolysis as well as photolysis conditions. DP-4 has a similar molecular mass to roxadustat but is structurally different. DP-4 is chemically, (1a-methyl-6-oxo-3-phenoxy-1,1a,6,6a-tetrahydroindeno [1,2-b] aziridine-6a-carbonyl) glycine. In silico toxicity study was conducted using Dereck software to gain the best knowledge of the drug and its degradation products towards carcinogenicity, mutagenicity, teratogenicity, and skin sensitivity. A further study using molecular docking confirmed the potential interaction of DPs with proteins responsible for toxicity. DP-4 shows a toxicity alert due to the presence of aziridine moiety.

Process Simulation of Terephthalic Acid Using Neutral Hydrolysis of Polyethylene Terephthalate Bottle Waste Method

To mitigate the environment's unique challenges caused by polyethylene terephthalate [PET] bottle litter and to protect the petroleum feedstock. The chemical recycling technology was used to transform PET into practical items with a sizable and successful industrial application. In order to model the chemical neutral hydrolysis depolymerization process of PET plastic wastes utilizing a continuous stir tank reactor for the synthesis of pure terephthalic acid [TPA] and EG for commercial use, this work used ASPEN PLUS V10. The data for the modeling came from an experimental chemical recycling project employing the neutral hydrolysis process to depolymerize PET bottle trash. PET waste was degraded using excess water [H2 O] and zinc acetate [Zn [Ac]2] as the active catalyst. A mean PET particle size of 127.5 m, 1000 kg/h of PET depolymerized at an H2 O: PET [w/w] ratio of 8:1, 513.15 K temperature, 32.0 bar pressure, and 0.5 h residence time were the reaction's ideal working parameters. Regarding PET, it is a first-order reaction. The reaction yielded 782.72 kg/h of TPA, 292.43 kg/h of EG, and a depolymerization of PET of 90.54%. TPA and EG had selectivity of 0.7280 and 0.2720, respectively. Filtration, distillation, and crystallization techniques were used to separate the mixture of components. The heat from the conveyance, reaction, and separation processes was obtained. This effort increased the yield of TPA, the amount of water removed for reuse, the amount of EG generated, and the amount of processing heat required. The procedures and their operating circumstances can be used to scale up commercial processes in the future.