Degradation Of Ceftazidime Research Articles

Fabrication and characterizations of a novel Ce modified PbO2 electrode with Ti4O7-rGO as the middle layer for degradation of ceftazidime

Developing stable and high-performance electrodes for effective removal of antibiotics from wastewater remains a significant challenge. Herein, a novel Ce-doped PbO2 electrode with Ti4O7-reduced graphene oxide as the middle layer (Ti/Ti4O7-rGO/Ce-PbO2) was fabricated through drop-coating and electrodeposition for the electrocatalytic degradation of ceftazidime (CAZ). The prepared Ti/Ti4O7-rGO/Ce-PbO2 electrode exhibited more active sites, higher oxygen evolution potential, and stronger ability for hydroxyl radical (•OH) generation. In the degradation experiments, approximately 100 % of CAZ (30 mg L−1) was degraded by the Ti/Ti4O7-rGO/Ce-PbO2 electrode at 40 mA cm−2 in 0.1 M Na2SO4 solution within 90 min. The quenching test and EPR analysis indicated that the •OH played a pivotal role in the degradation process. A possible degradation mechanism of CAZ, which involved bond breaking, decarboxylation, demethylation, oxidization, and ring-opening, was proposed. The Escherichia coli inhibition experiment showed that the toxicity of CAZ was substantially reduced after electrochemical oxidation. The Ti/Ti4O7-rGO/Ce-PbO2 electrode exhibited a constant degradation efficiency (> 99 %) after 10 consecutive cycles, and its service life can reach 3000 min. Furthermore, CAZ maintained a high removal efficiency in swine wastewater. This study provides a new approach toward fabricating a Ce-PbO2 electrode with Ti4O7-rGO middle layer for the degradation of antibiotics in wastewater.

Efficient electrochemical degradation of ceftazidime by Ti3+ self-doping TiO2 nanotube-based Sb–SnO2 nanoflowers as an intermediate layer on a modified PbO2 electrode

Ceftazidime (CAZ) is an emerging organic pollutant with a long-lasting presence in the environment. Although some PbO2 materials exhibit degradation capabilities, inefficient electron transport in the substrate layer and the problem of electrode stability still limit their use. Here, an interfacial design in which TiO2 nanotube arrays generate Ti3+ self-doping oxide substrate layers and highly active 3D Sb–SnO2 nanoflowers-like interlayers was used to prepare PbO2 anodes for efficient degradation of CAZ. Interestingly, after implementing Ti3+ self-doping in the PbO2 anode base layer and introducing 3D nanoflowers-like structures, the capacity for •OH generation increased significantly. The modified electrode exhibited 5-fold greater •OH generation capacity compared to the unmodified electrode, and a 2.7-fold longer accelerated electrode lifetime. The results indicate that interfacial engineering of the base and intermediate layers of the electrodes can improve the electron transfer efficiency, promote the formation of •OH, and extend the anode lifetime of the activated CAZ system.

In-situ electrodeposition of Co/Ce-MOF-derived carbon composites as anode for electrochemical degradation of ceftazidime

Antibiotics cannot be completely removed through traditional treatment technologies, leading to their accumulation in the aquatic environment and posing a serious threat to human health. MOF-derived carbon is a promising material for the degradation of antibiotics. Herein, in this study, a novel Co/Ce-MOF electrode was rapidly prepared by one-step electrodeposition at room temperature. Then the Co/Ce-MOF electrode was carbonized to obtain MOF-derived carbon composite electrode (Co/Ce-C350Air). The ceftazidime (CAZ) degradation efficiency achieved 96.59% within 60 min under the optimum conditions ([CAZ] = 5 mg/L, [Na2SO4] = 50 mM, current density = 0.8 mA/cm2, electrode gap = 2 cm and initial pH = 5.6) and the degradation process of CAZ conformed to first-order reaction kinetics. Furthermore, the removal efficiency of CAZ maintained at 94.92% even recycling for 6 times, demonstrating the good electrochemical stability of the Co/Ce-C350Air composite anode. The synergistic effect between Co and Ce metals improved the catalytic performance and stability of the Co/Ce-C350Air electrode. Radical quenching experiments and electron paramagnetic resonance (EPR) spectra results revealed that surface hydroxyl radicals were the main active species in the degradation of CAZ. The main intermediate products were identified by high-performance liquid chromatography-mass spectrometry (HPLC-MS) and the possible degradation pathway was proposed. In addition, toxicity tests with Ecological Structure Activity Relationships (ECOSAR) software results indicated that the toxicity of the intermediate products was lower than that of CAZ. This work provided a safe and effective strategy for the degradation of antibiotics in the electrochemical oxidation system.

Efficient degradation of ceftazidime in heterogeneous electro-Fenton process with Fe/Cu bimetal MOF-derived nitrogen-doped cathode

The widespread detection and potential adverse effects of antibiotics in the aquatic environment call for effective treatment technology. Electro-Fenton is a promising strategy, but the preparation of efficient and stable cathodes is still challenging. In this study, a novel metal-organic framework (MOF)-derived N-doped cathode Fe/Cu-C400Ar was synthesized successfully for the degradation of ceftazidime (CAZ) in heterogeneous electro-Fenton (hetero-EF) system. The doping of copper could enhance electrocatalysis with a high electrochemical surface active area and low resistance. Fe/Cu-C400Ar cathode achieved CAZ removal efficiency of 99.5 ± 0.4% within 120 min, and it exhibited excellent stability after six recycle runs. Quenching experiments and electron paramagnetic resonance (EPR) tests proved that the primary species was hydroxyl radical during the CAZ degradation. In addition, the degradation pathway of CAZ was proposed including the cleavage of the pyridine ring and the shedding of the thiazole ring. Moreover, the prediction of intermediates toxicity by Ecological Structure Activity Relationships (ECOSAR) software indicated the environmentally friendly features of the CAZ degradation process. This study provided a promising cathode for the electrocatalytic degradation of antibiotic wastewater in hetero-EF system.

MOF-derived Co/Fe@NPC-500 with large amounts of low-valent metals as an electro-Fenton cathode for efficient degradation of ceftazidime

A MOF-derived carbon material containing CoFe alloy (Co/Fe@NPC-500) by calcining N-doped Co/Fe bimetallic MOF at a lower temperature was successfully synthesized as a cathode in electro-Fenton process for ceftazidime (CAZ) degradation. The presence of Co could accelerate the transfer of electrons from C atoms of carbon material to Fe, thus increasing the content of low-valent metals in the material, which had been demonstrated by characterizations and density functional theory (DFT) calculations. Thanks to the integrity of the MOF structure, the synergistic effect between Fe and Co, Co/Fe@NPC-500 cathode showed efficient removal efficiency for CAZ completely removed within 60 min and obtained a total organic carbon (TOC) removal rate of 52.1% at 90 min. Besides, based on the results of HPLC-MS and DFT calculations, the degradation pathway of CAZ was proposed. This study provides some useful information for the preparation of MOF-derived carbon materials containing low-valent metals for electro-Fenton process.

Amino acids improve aerosolization and chemical stability of potential inhalable amorphous Spray-dried ceftazidime for Pseudomonas aeruginosa lung infection

Pseudomonas aeruginosa infection is common in cystic fibrosis as well as non-cystic fibrosis bronchiectasis. The pathogen presents challenges for treatment due to its adaptive antibiotic-resistance, mainly pertaining to its biofilm-forming ability, as well as limitations associated with conventional drug delivery in achieving desired therapeutic concentration in the infection site. Hence, therapeutic approach has shifted towards the inhalation of antibiotics. Ceftazidime is a potent antibiotic against the pathogen; however, it is currently only available as a parenteral formulation. Here, spray dryer was employed to generate inhalable high dose ceftazidime microparticles. In addition, the use of amino acids (valine, leucine, methionine, phenylalanine, and tryptophan) to improve aerosolization as well as chemical stability of amorphous ceftazidime was explored. The particles were characterized using X-ray diffraction, infrared (IR) spectroscopy, calorimetry, electron microscopy, particle size analyzer, and next generation impactor. The chemical stability at 25 °C/<15% was assessed using chromatography. All co-spray dried formulations were confirmed as monophasic amorphous systems using calorimetry. In addition, principal component analysis of the IR spectra suggested potential interaction between tryptophan and ceftazidime in the co-amorphous matrix. Inclusion of amino acids improved aerosolization and chemical stability in all cases. Increase in surface asperity was clear with the use of amino acids which likely contributed to the improved aerosol performance, and potential interaction between amino acids and ceftazidime was plausibly the reason for improved chemical stability. Leucine offered the best aerosolization enhancement with a fine particle fraction of 78% and tryptophan showed stabilizing superiority by reducing chemical degradation by 51% over 10 weeks in 1:1 M ratio. The protection against ceftazidime degradation varied with the nature of amino acids. Additionally, there was a linear relationship between degradation protection and molar mass of amino acids or percentage weight of amino acids in the formulations. None of the amino acids were successful in completely inhibiting degradation of ceftazidime in amorphous spray-dried powder to prepare a commercially viable product with desired shelf-life. All the amino acids and ceftazidime were non-toxic to A549 alveolar cell line.

Facile synthesis of iron(II) doped carbonaceous aerogel as a three-dimensional cathode and its excellent performance in electro-Fenton degradation of ceftazidime from water solution

• Synthesis of iron(II) doped carbonaceous aerogel (FCA) as a three-dimensional cathode electrode for electro-Fenton (EF) system. • Degradation of ceftazidime using FCA cathode in EF process. • Optimization of the operational condition by response surface methodology. • Identification of the produced intermediates through the ceftazidime degradation. • Developing a safe, environmentally friendly, and cost-effective method by using FCA and EF process. In the present study, the electro-Fenton (EF) process has been used to remove ceftazidime (CAZ) from an aqueous solution. In the first part of this study, the iron(II) doped carbonaceous aerogel (denote as FCA) as a three-dimensional cathode was synthesized as a cathode electrode. For this purpose, resorcinol–formaldehyde polymers containing iron(II) salt were prepared by sol–gel method and after drying by ambient drying method, the resulting polymer was finally carbonized in a furnace with inert nitrogen medium at 800 °C and the resulting composite properties examined by Field Emission Scanning Electron Microscopy, Energy Dispersive X-ray, Brunaur-Emmett-Teller, X-ray Diffraction, Fourier Transform Infrared Spectroscopy, and cyclic voltammetry analyses. In the last part of this study, the prepared carbonaceous aerogel was employed as a cathode electrode in the EF system to remove CAZ from an aqueous medium. The influence of key factors such as applied current (mA), initial pH of the solution, initial CAZ concentration (mg/L), and process time (min) on the CAZ removal efficiency (RE (%)) under the EF process was assessed. The mineralization current efficiency (MCE) was found as 60.66% in 200 min. Response surface methodology (RSM) was used to optimize the process. The results showed that the optimal values for the variables of applied current intensity, pH, initial CAZ concentration, and process time were 400 mA, 4, 40 mg/L, and 110 min, respectively. The intermediates of CAZ removal were identified by gas chromatography-mass spectrometry analysis. Moreover, the possible removal mechanism of CAZ was proposed. The reusability and stability of the FCA cathode was assessed and revealed an approximately 4% decline in CAZ removal efficiency after eight consecutive cycles. The amount of organic carbon degraded by this process was investigated by chemical oxygen demand test and it was 99% after 200 min of reaction time.

Fabrication of MOF-derivated CuOx-C electrode for electrochemical degradation of ceftazidime from aqueous solution

Antibiotic contamination has already been one of hazards to aquatic environment due to the abuse of antibiotics. Metal-organic frameworks (MOFs) are known as a kind of promising porous material for solving the environmental deterioration. In this article, the physicochemical and electrochemical properties of a series of porous copper oxide carbon materials (CuOx-C) synthesized by carbonizing Cu-BTC were compared. Due to the suitable carbonization temperature, CuOx-C-550 N, whose geometric structure was similar to Cu-BTC, possessed a multiscale pore structure containing many mesopores and partial macropores in accordance with the pore size distribution curves. More copper/copper oxides were introduced toimproving the electrochemical ability, evidence by XRD, XPS, CV and EIS characterization. Moreover, the degradation of ceftazidime (CAZ) through anodic oxidation was discussed. In AO/CuOx-C-550 N system, the effects of current, solution pH, initial CAZ concentration and Na2SO4 concentration were analyzed. CAZ removal rate reached 100% within 20 min under the optimal condition and a good electrocatalytic ability with 90% CAZ removal after 20 runs indicated a good electrochemical stability of CuOx-C-550 N. Furthermore, the degradation mechanism and pathway of CAZ were proposed. The Cu(II)/Cu(I) oxidation-reduction couples on the anodic surface contribute to the efficiently selective degradation of cephalosporins for CuOx-C-550 N. Overall, this study shows a good method to design and prepare a new MOF derivative for the remediation of aquatic contamination.

High Pyridine Generation in Ceftazidime-Icodextrin Admixtures Used to Treat Peritoneal Dialysis-associated Peritonitis

PurposeTo investigate the amount of pyridine generated from degradation of ceftazidime in icodextrin peritoneal dialysis (PD) solutions. MethodsPD solutions that contained 1 and 1.5 g of ceftazidime were stored at 25 °C for 12 hours and then at 37 °C for 14 hours. An aliquot was withdrawn at predefined time points and analyzed for the concentrations of ceftazidime and pyridine. FindingsThe amount of pyridine generated was >225% and 400% of its maximum recommended daily exposure in the 1- and 1.5-g ceftazidime-PD admixtures, respectively. ImplicationsUntil these results are confirmed with appropriate in vivo studies, intermittent intraperitoneal dosing of ceftazidime admixed with icodextrin should be used with caution and appropriate clinical monitoring or a suitable alternative antibiotic should be used.

Preparation of CeO2-ZrO2 and titanium dioxide coated carbon nanotube electrode for electrochemical degradation of ceftazidime from aqueous solution

Carbon nanotubes are extensively used in energy, catalysis and environmental fields because of large specific area and superior electrochemical performances. A novel CeO2-ZrO2/TiO2/CNT anode was fabricated through sol-gel method to improve electrochemical degradation efficiency towards trace pollutant in water environment, such as ceftazidime. Surface structure and elemental compositions were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy. A uniform and compact loading of CeO2-ZrO2 and TiO2 nanoparticles were observed which is regarded to be beneficial for stability and catalytic improvement. The optimal loading amount of TiO2 and CeO2-ZrO2 was decided by electrochemical performance and the results indicated addition of 6mL tetrabutyl orthotitanate in 0.5g CNT and 3.33% atomic ratio of CeO2/C resulted in a highest removal rate of 83.47% under 3mA·cm−2. Cyclic voltammograms, electrochemical impedance spectroscopy and hydroxyl generation test were conducted, demonstrating this anode displayed superior electrochemical properties with greater yield of ·OH and lower charge transfer resistance. Moreover, kinetic parameters were optimized in this study, indicating an electrode distance of 2cm and stirring rate of 400rad·min−1 were the optimal operation condition from the perspectives of energy consumption and degradation efficiency. Finally, the degradation intermediates and pathways are proposed with HPLC-MS.

La2O3-CuO2/CNTs electrode with excellent electrocatalytic oxidation ability for ceftazidime removal from aqueous solution

Carbon nanotubes are recognized as an advanced anode material for electrocatalysis oxidation recalcitrant antibiotics in wastewater. In this study, a novel La2O3-CuO2/CNTs electrode was synthesized by solvothermal method and calcination in nitrogen atmosphere. Scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) were conducted to illustrate the structure and elemental composition, and the La and Cu bimetallic composite oxide (La3O2, Cu2O) were observed on the surface of carbon nanotubes. Cyclic voltammetry analysis showed that the modified electrode had better catalytic activity and stable working lifetime. The Tafel curves indicated that the corrosion potential of the electrode increased while the corrosion current density decreased. The degradation of ceftazidime by modified electrode was studied through optimization of five parameters, including current density, electrode space, electrolyte concentration, pH and volume of solution. The results demonstrated that La2O3-CuO2/CNTs electrode exhibited the electrochemical degradation efficiency of 90% towards 1 mg L−1 ceftazidime within 30 min, which is much higher than those of pristine CNTs and dimensional stable anode. The optimal operating conditions were: volume of 100 mL, 1 g L−1 Na2SO4 as electrolyte, current density of 0.8 mA·cm-2, and electrode space is 2 cm. The degradation intermediates and routes of ceftazidime under modified electrode were deduced by LC–MS analysis. These results suggest that La2O3-CuO2/CNTs electrodes can be considered as promising catalysts for treating bio-refractory antibiotics with relatively low concentration.

How To Minimize Toxic Exposure to Pyridine during Continuous Infusion of Ceftazidime in Patients with Cystic Fibrosis?

Ceftazidime is particularly efficient against Pseudomonas aeruginosa in cystic fibrosis patients. Thus, the spontaneous production of pyridine, which is a toxic product, raises some concern. Our aim was to examine the kinetics of degradation of ceftazidime in portable infusion pumps either at 4°C, 22°C, or 33°C and to propose some recommendations in order to reduce the pyridine exposure. Two administration models were studied in vitro. In model 1, we administered 12 g of ceftazidime infused over 23 h (once-daily infusion) compared to 6 g infused over 11.5 h in model 2 (twice-daily regimen). Samples were collected at 0 h and then every 4 and 2 h after the shaping of portable infusion pumps in models 1 and 2, respectively. Both ceftazidime and pyridine were analyzed using an ultraviolet high-performance liquid chromatograph. Production of pyridine is highly depending on the temperature. The in situ production of pyridine per day of treatment decreases at a ratio close to 1/6 and 1/3 between 33°C and 4°C in models 1 and 2, respectively. Regardless of the conditions, the production of pyridine is significantly lower in model 2, whereas the total delivery amount of ceftazidime is significantly higher at 4°C and 33°C compared to that in model 1. According to a the precautionary principle, these findings lead to three major recommendations: (i) exposing a solution of ceftazidime to over 22°C should be strictly avoided, (ii) a divided dose of 6 g over 11.5 h instead of a once-daily administration is preferred, and (iii) infusion should be administered immediately after reconstitution.

Inhibition of Human Immunodeficiency Virus Type 1 Reverse Transcriptase by Degradation Products of Ceftazidime

Previous work by Hafkemeyer et al. (1991) [ Nucleic Acids Research19: 4059–4065] indicated that a degradation product of ceftazidime, termed HP 0.35, was active against the RNase H activity of human immunodeficiency virus type 1 (HIV-1) and feline immunodeficiency virus (FIV) reverse transcriptase (RT) in vitro. Attempting to repeat these results, we isolated HP 0.35 from an aqueous degradation of ceftazidime and, after careful purification, we found HP 0.35 to be essentially inactive against both the polymerase and RNase H domains of HIV-1 RT (IC50 of &gt;100 μg mL−1). During the investigation we discovered that polymeric degradation products of ceftazidime inhibited both the polymerase and, to a greater extent, the RNase H activities of HIV-1 RT in vitro (IC50 approximately 0.1 and 0.01 μg mL−1, respectively). Subjecting HP 0.35 to conditions under which it could polymerize induced inhibitory activity similar to that of the polymeric ceftazidime degradation products. It is proposed that the previously reported activity of HP 0.35 may have resulted from the presence of low levels of polymeric material either from incomplete purification or from polymerization of HP 0.35 during storage or in vitro testing.