Novel nanostructure approach for antibiotic decomposition in a spinning disc photocatalytic reactor.

Conventional wastewater treatment processes are often unable to remove antibiotics with resistant compounds and low biological degradation. The need for advanced and sustainable technologies to remove antibiotics from water sources seems essential. In this regard, the effectiveness of a spinning disc photocatalytic reactor (SDPR) equipped with a visible light-activated Fe3O4@SiO2-NH2@CuO/ZnO core-shell (FSNCZ CS) thin film photocatalyst was investigated for the decomposition of amoxicillin (AMX), a representative antibiotic. Various characterization techniques, such as TEM, FESEM, EDX, AFM, XRD, and UV-Vis-DRS, were employed to study the surface morphology, optoelectronic properties, and nanostructure of the FSNCZ CS. Key operating parameters such as irradiation time, pH, initial AMX concentration, rotational speed, and solution flow rate were fine-tuned for optimization. The results indicated that the highest AMX decomposition (98.7%) was attained under optimal conditions of 60 min of irradiation time, a rotational speed of 350 rpm, a solution flow rate of 0.9 L/min, pH of 5, and an initial AMX concentration of 20 mg/L. Moreover, during the 60 min irradiation time, more than 69.95% of chemical oxygen demand and 61.2% of total organic carbon were removed. After the photocatalytic decomposition of AMX, there is a substantial increase in the average oxidation state and carbon oxidation state in SDPR from 1.33 to 1.94 and 3.2, respectively. Active species tests confirmed that ·OH and ·O2- played a dominant role in AMX decomposition. The developed SDPR, which incorporates a reusable and robust FSNCZ CS photocatalyst, demonstrates promising potential for the decomposition of organic compounds.

A new strategy for the treatment of middle ear infection using ciprofloxacin/amoxicillin-loaded ethyl cellulose/polyhydroxybutyrate nanofibers.

A middle ear infection occurs due to the presence of several microorganisms behind the eardrum (tympanic membrane) and is very challenging to treat due to its unique location and requires a well-designed treatment. If not treated properly, the infection can result in severe symptoms and unavoidable side effects. In this study, excellent biocompatible ethyl cellulose (EC) and biodegradable polyhydroxybutyrate (PHB) biopolymer were used to fabricate drug-loaded nanofiber scaffolds using an electrospinning technique to overcome antibiotic overdose and insufficient efficacy of drug release during treatment. PHB polymer was produced from Halomonas sp., and the purity of PHB was found to around be 90 %. Additionally, ciprofloxacin (CIP) and amoxicillin (AMX) are highly preferable since both drugs are highly effective against gram-negative and gram-positive bacteria to treat several infections. Obtained smooth nanofibers were between 116.24 and 171.82 nm in diameter and the addition of PHB polymer and antibiotics improved the morphology of the nanofiber scaffolds. Thermal properties of the nanofiber scaffolds were tested and the highest Tg temperature resulted at 229 °C. The mechanical properties of the scaffolds were tested, and the highest tensile strength resulted in 4.65 ± 6.33 MPa. Also, drug-loaded scaffolds were treated against the most common microorganisms that cause the infection, such as S.aureus, E.coli, and P.aeruginosa, and resulted in inhibition zones between 10 and 21 mm. MTT assay was performed by culturing human adipose-derived mesenchymal stem cells (hAD MSCs) on the scaffolds. The morphology of the hAD MSCs' attachment was tested with SEM analysis and hAD MSCs were able to attach, spread, and live on each scaffold even on the day of 7. The cumulative drug release kinetics of CIP and AMX from drug-loaded scaffolds were analysed in phosphate-buffered saline (pH: 7.4) within different time intervals of up to 14 days using a UV spectrophotometer. Furthermore, the drug release showed that the First-Order and Korsmeyer-Peppas models were the most suitable kinetic models. Animal testing was performed on SD rats, matrix and collagen deposition occurred on days 5 and 10, which were observed using Hematoxylin-eosin and Masson's trichrome staining. At the highest drug concentration, a better repair effect was observed. Results were promising and showed potential for novel treatment.

Efficient photodegradation of antibiotics by g-C3N4 and 3D flower-like Bi2WO6 perovskite structure: Insights into the preparation, evaluation, and potential mechanism.

Antibiotics are emerging organic pollutants that have attracted huge attention owing to their abundant use and associated ecological threats. The aim of this study is to develop and use photocatalysts to degrade antibiotics, including tetracycline (TC), ciprofloxacin (CIP), and amoxicillin (AMOX). Therefore, a novel Z-scheme heterojunction composite of g-C3N4 (gCN) and 3D flower-like Bi2WO6 (BW) perovskite structure was designed and developed, namely Bi2WO6/g-C3N4 (BW/gCN), which can degrade low-concentration of antibiotics in aquatic environments under visible light. According to the Density Functional Theory (DFT) calculation and the characterization results of X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FITR), Scanning electron microscopy - energy spectroscopy (SEM-EDS) and X-ray photoelectron spectroscopy (XPS), this heterojunction was formed in the recombination process. Furthermore, the results of 15 wt%-BW/gCN photocatalytic experiments showed that the photodegradation rates (Rp) of TC, CIP, and AMOX were 92.4%, 90.1% and 82.3%, respectively, with good stability in three-cycle photocatalytic experiments. Finally, the quenching experiment of free radicals showed that the holes (h+) and superoxide radicals (·O2-) play a more important role than the hydroxyl radicals (·OH) in photocatalysis. In addition, a possible antibiotic degradation pathway was hypothesized on the basis of High performance liquid chromatography (HPLC) analysis. In general, we have developed an effective catalyst for photocatalytic degradation of antibiotic pollutants and analyzed its photocatalytic degradation mechanism, which provides new ideas for follow-up research and expands its application in the field of antibiotic composite pollution prevention and control.

Modeling approach for Ti3C2 MXene-based fluorescent aptasensor for amoxicillin biosensing in water matrices.

Amoxicillin, a member of the penicillin family, is primarily utilized for the treatment of various bacterial infections affecting ears, nose, throat, urinary tract, and skin. Given its widespread application in medicine, agriculture, environment, and food industry, the precise and sensitive detection of amoxicillin is important. This study introduces a novel approach to developing a sensitive and selective fluorescent aptasensor relying on fluorescence resonance energy transfer (FRET) for the specific detection of amoxicillin. The carboxyfluorescein-labeled aptamer serves as a energy donor, while MXene functions as an energy acceptor, and acting as a quencher. To achieve optimal detection efficiency, a dual optimization strategy utilizing RSM-CCD and ANN-GA was used to fine-tune experimental conditions. The fluorescence measurements revealed an expansive linear range extending from 100 to 2400 ng mL-1, accompanied by an exceptionally low detection limit of 1.53 ng mL-1. Additionally, it shows an excellent selectivity towards amoxicillin over other antibiotics commonly found in water matrices. The aptasensor demonstrates good stability and reproducibility; effectiveness of the aptasensor was validated by testing in real water samples. This remarkable sensitivity and broad dynamic range affirm the efficacy aptasensor in accurately detecting varying concentrations of amoxicillin in wastewater bodies.

Efficient porphyrin integrated UiO-66 probes for ratiometric fluorescence sensing of antibiotic residues in milk.

Dual-emissive fluorescence probes were designed by integrating porphyrin into the frameworks of UiO-66 for ratiometric fluorescence sensing of amoxicillin (AMX). Porphyrin integrated UiO-66 showed dual emission in the blue and red region. AMX resulted in the quenching of blue fluorescence component, attributable to the charge neutralization and hydrogen bonds induced energy transfer. AMX was detected using (F438/F654) as output signals. Two linear relationships were observed (from 10 to 1000 nM and 1 to 100 µM), with a limit of detection of 27 nM. The porphyrin integrated UiO-66 probe was used to detect AMX in practical samples. This work widens the road for the development of dual/multiple emissive fluorescence sensors for analytical applications, providing materials and theoretical supporting for food, environmental, and human safety.

Time series-based prediction of antibiotic degradation via photocatalysis using ensemble gradient boosting.

This study aims to evaluate the effectiveness of the laboratory-made catalyst Ni2P-ZrO2 (NPZ) in the degradation of an antibiotic in an aqueous suspension when exposed to ultraviolet (UV) light. The degradation of amoxicillin (AMX) was predicted using time series forecasting through the ensemble gradient boosting model. The degradation experiments were conducted utilizing two distinct photocatalyst compositions of Nickel phosphide-zirconium dioxide (NPZ) in the proportions of 1:9 and 2:8. The most effective experimental results were obtained using a natural pH, a catalyst concentration of 0.20 g/L and reaction duration of 0.5 h after testing the different catalysts. Experimental data were used for training, validating and confirming time series predictions. The use of ensemble technique highly affected the experimental findings. The model's performance was quite satisfactory in terms of correlation coefficient (94.00%), normalized mean square error (0.01) and mean square root error (0.0911) which significantly contributed to the model's accuracy. All input variables, such as pH, catalyst dose and irradiation time, had a significant impact on the degrading efficacy. The study has demonstrated that time series forecasting can be used for predicting the degradation process precisely.

Chitosan coated graphene oxide incorporated sodium alginate hydrogel beads for the controlled release of amoxicillin.

Biopolymers are crucial in pharmaceuticals, particularly for controlled drug release. In this study, we loaded the broad-spectrum antibacterial drug amoxicillin into sodium alginate, a well-known biopolymer. Graphene oxide was incorporated into the composite, and the hydrogel beads were coated with chitosan for its mucoadhesive properties. Various composites were formulated by adjusting the weight percentage of graphene oxide (GO). The fabricated beads demonstrated controlled and sustained drug release, with 98 % of the loaded drug molecules released over 24 h at gastric pH. The antibacterial test using the disc diffusion technique confirmed the drug release, exhibiting greater effectiveness against the gram-positive bacterium S. aureus than the gram-negative bacterium E. coli. The drug release data were optimized using zero order, first order, Higuchi, and Korsmeyer-Peppas models. The experimental data were best fit to the Korsmeyer-Peppas model with a relatively higher correlation coefficient value. Biocompatibility was evaluated through a cell viability test using mouse fibroblast cell lines (L929). The MTT viability assay confirmed high levels of cytocompatibility, even at higher concentrations (100 µg/mL), with 98.15 % viable cells. These results highlight the potential of the fabricated beads as an effective amoxicillin drug delivery system with biomedical applications.

Static adsorption and photocatalytic degradation of amoxicillin using titanium dioxide/hydroxyapatite nanoparticles based on sea scallop shells.

The objective of this study is to investigate the efficiency of two processes for the amoxicillin removal through static (batch) adsorption and photocatalytic degradation onto the prepared samples. Three solid materials as photocatalyst and/or adsorbent were synthesized viz. nanotitanium dioxide (NT) prepared by the sol-gel method, scallop shells-based nanohydroxyapatite (NP), and nanotitanium dioxide/nanohydroxyapatite composite (NTP). The physicochemical and morphological properties of the prepared samples were tested by TGA, XRD, DRS, ATR-FTIR, nitrogen adsorption/desorption isotherm, zeta potential, SEM, and TEM. The major operational conditions were optimized for catalyst or adsorbent mass, pH, shaking time, initial amoxicillin (AMX) concentration, power of UV lamp, and temperature. The results illuminated that NTP achieved the highest adsorption capacity (88.46 mg/g) at 20 ℃ and AMX adsorption onto all the solid materials was well applied by Langmuir, Temkin, pseudo-second order, and Elovich models. The maximum desorption percent (98%) was attained by acetone. The degradation percent of AMX reached 85.3 and 99.5% for NT and NTP, respectively, using 0.9 g/L of catalyst dosage through 90 min. AMX photodegradation onto the catalysts' surface was well fitted by Langmuir-Hinshelwood, Arrhenius, and Eyring-Polanyi models with endothermic, physical, and nonspontaneous nature of photocatalysis process. NTP acts as a promising adsorbent and photocatalyst for the antibiotics' removal in wastewater.

Biotreatability Improvement of Antibiotic-Contaminated Waters: High Efficiency of Direct Ozonation in Comparison to Hydroxyl Radical Oxidation.

Efficiencies of direct ozonation and hydroxyl radical oxidation by Fenton process were compared, aiming to improve biotreatability of antibiotics contaminated water (tiamulin, amoxicillin and levofloxacin).  Biodegradability, COD (chemical oxygen demand) and TOC (total organic carbon) were measured before and after applying oxidative process. It was confirmed that significantly smaller molar dose of ozone (1.1 mgO3 / mgatb) against the hydrogen peroxide (17 mgH2O2 / mgatb), deliver comparable improvements of biodegradability; Tiamulin biodegraded up to 60 %, levofloxacin close to 100 %. Ozonation removed more TOC (10%, 29% and 8% for tiamulin, levofloxacin and amoxicillin, respectively) than Fenton process. This is confirming mineralization of antibiotics, not only biodegradable intermediates formation. In terms of costs, ozonation is more feasible in oxidizing complex antibiotics in water, as it targets functional groups which carry antimicrobial properties. This brings not only improved biodegradability needed for a conventional biological treatment plant, but also reduces long-term impacts of the antibiotics in the environment.

Metallic nanoparticles photodegraded antibiotics and co-application improved wheat growth and nutritional quality through stress alleviation.

Antibiotics are now considered as emerging environmental pollutants due to their persistent nature and continuous exposure through irrigation with wastewater contaminated with antibiotics. The aim of present study was to assess the potential of nanoparticles for the photodegradation of antibiotics and subsequent stress alleviation via Titania oxide (TiO2) application for improvement in crop productivity and quality in terms of the nutritional composition. In the first phase, different nanoparticles, TiO2, Zinc oxide (ZnO), and Iron oxide (Fe2O3) with varying concentrations (40-60 mg L-1) and time-periods (1-9 days) were tested to degrade amoxicillin (Amx) and levofloxacin (Lev) @ 5 mg L-1 under the visible light. Results indicated that TiO2 nanoparticles (50 mg L-1) were the most effective nanoparticles for the removal of both antibiotics with maximum degradation of 65% and 56% for Amx and Lev, respectively, on the 7th day. In the second phase, a pot experiment was conducted in which TiO2 (50 mg L-1) was applied individually and along with antibiotics (5 mg L-1) in order to evaluate the effect of nanoparticles on stress alleviation for growth promotion of wheat exposed to antibiotics. Plant biomass was reduced by Amx (58.7%) and Lev (68.4%) significantly (p < 0.05) when compared to the control. However, co-application of TiO2 and antibiotics improved the total iron (34.9% and 42%), carbohydrate (33% and 31%), and protein content (36% and 33%) in grains under Amx and Lev stress, respectively. The highest plant length, grain weight, and nutrient uptake were observed upon application of TiO2 nanoparticles alone. Total iron, carbohydrates, and proteins in grains were significantly increased by 52%, 38.5%, and 40%, respectively compared to the control (with antibiotics). The findings highlight the potential of TiO2 nanoparticles for stress alleviation, growth, and nutritional improvement under antibiotic stress upon irrigation with contaminated wastewater.

A systematic review on photo-Fenton process as an efficient advanced oxidation for degradation of amoxicillin in aqueous environments.

Amoxicillin (AMX) is one of the antibiotics in the penicillin category that is used in various fields. Considering the harmful effects of its remains, it is necessary to survey the ways to remove this compound. Advanced oxidation process (AOPs), specially photo-Fenton has been used for the removal of AMX. This study has been conducted based on PubMed, Google Scholar, DOAJ, Web of Science, and Scopus databases during the years 2008-2019. Some factors such as the aquatic solution, light source characteristics, iron, and H2O2 concentration, AMX degradation percentage, removal of total organic carbon percentage, and AMX concentration have been surveyed to optimize the process. Studies showed that the photo-Fenton process is highly dependent on pH, and in most studies, the highest efficiency has been observed in acidic pH values. Using a more energy light source can be effective in reducing the use of catalysts and oxidizers. The combined methods of AOPs such as photo-Fenton, electro-Fenton, and photo-electro-Fenton have higher efficiency in increasing mineralization than the photon process. The use of synthetic wastewater has a higher efficiency in the degradation of AMX than in real wastewater in the photo-Fenton process, which can be due to the absence of the interfering agents in synthetic environments.

New bismuth oxyiodide/chitosan nanocomposite for ultrasonic waves expedited adsorptive removal of amoxicillin from aqueous medium: kinetic, isotherm and thermodynamic investigations.

Amoxicillin (AMX) is a widely used antibiotic, which induces harmful effects to nature via bioaccumulation and persistence in the environment if discharged untreated into water bodies. In the current study, a novel bionanocomposite, bismuth oxyiodide-chitosan (BiOI-Ch), was synthesized by a facile precipitation method and its amoxicillin (AMX) adsorption capacity in the presence of ultrasonic waves has been explored. Multiple batch experiments were performed to achieve the optimum operational parameters for maximum adsorption of AMX and the obtained results were as follows: pH 3, 80 mg g-1 AMX concentration, 1.7 g L-1 adsorbent dose, temperature 298 K and ultrasonication time 20 min. Composite removed approximately 90% AMX from the solution under optimized conditions, while the maximal adsorption capacity was determined to be 81.01 mg g-1. BiOI-Ch exhibited superior adsorption capacity as compared to pure BiOI (33.78 mg g-1). To understand the dynamics of reaction, several kinetic and isotherm models were also examined. The adsorption process obeyed pseudo-second-order kinetic model (R2 = 0.98) and was well fitted to Freundlich isotherm (R2 = 0.99). The addition of biowaste chitosan to non-toxic bismuth-based nanoparticles coupled with ultrasonication led to enhanced functional groups as well as surface area of the nanocomposite resulting in superior adsorption capacity, fast adsorption kinetics and improved mass transfer for the removal of AMX molecules. Thus, this study demonstrates the synergistic effect of ultrasonication in improved performance of novel BiOI-Ch for potential application in the elimination of persistent and detrimental pollutants from industrial effluent after necessary optimization for large-scale operation.

Influence of design and material characteristics on 3D printed flow-cells for heat transfer-based analytical devices.

Redesigning 3D-printed flow cells is reported used for heat transfer based detection of biomolecules from a flow-through system to an addition-type measurement cell. The aim of this study is to assess the performance of this new measurement design and critically analyse the influence of material properties and 3D printing approach on thermal analysis. Particular attention is paid to reduce the time to stabilisation, the sample volume in order to make the technique suitable for clinical applications, and improving the sensitivity of the platform by decreasing the noise and interference of air bubbles. The three different approaches that were studied included a filament polylactic acid cell using only fused filament fabrication (FFF), a resin cell printed using stereolitography (SLA), and finally a design made of copper, which was manufactured by combining metal injection moulding (MIM) with fused filament fabrication (FFF). Computational fluid dynamic (CFD) modelling was undertaken using ANSYS Fluent V18.1 to provide insight into the flow of heat within the measurement cell, facilitating optimisation of the system and theoretical response speed.It was shown that the measurement cells using SLA had the lowest noise (~ 0.6%) and shortest measurement time (15 min), whereas measurement cells produced using other approaches had lower specificity or suffered from voiding issues. Finally, we assessed the potential of these new designs for detection of biomolecules and amoxicillin, a commonly used beta lactam antibiotic, to demonstrate the proof of concept. It can be concluded that the resin addition-type measurement cells produced with SLA are an interesting affordable alternative, which were able to detect amoxicillin with high sensitivity and have great promise for clinical applications due to the disposable nature of the measurement cells in addition to small sample volumes.

High efficiency three-dimensional electrochemical treatment of amoxicillin wastewater using Mn-Co/GAC particle electrodes and optimization of operating condition.

In this work, Mn-Co/GAC particle electrode was prepared by loading Mn and Co as catalysts on granular activated carbon (GAC) and used in a three-dimensional (3D) electrochemical system for mineralization of amoxicillin wastewater. Observation results by SEM, EDS and XRD confirmed that Mn and Co catalysts were successfully loaded onto GAC. The electrochemical properties were measured using an electrochemical workstation. Mn-Co/GAC had a much higher oxygen evolution potential (1.46V) than GAC (1.1V), which demonstrated that it could effectively reduce the oxygen evolution side reaction. In addition, Mn-Co/GAC had an electrochemically active surface area 1.34 times that of GAC and a much smaller mass transfer resistance than GAC, which could provide favorable conditions for the degradation of pollutants. The investigation of the influences of single operating parameters on total organic carbon (TOC) removal rate and electrical energy consumption (EEC) indicated that current density and treatment time had the greatest effect. In order to maximize TOC removal rate and minimize EEC, optimization of operating parameters was also carried out using response surface method in combination with central composite design. The optimal operating parameters were determined as current density of 5.68 mA/cm2, electrolyte concentration of 0.127M, particle electrode dosage of 31.14g and treatment time of 120min. Under this optimum operating condition, TOC removal rate of 85.24% and amoxicillin removal rate of 100% could be achieved with a low EEC of 0.073 kWh/g TOC. In addition, TOC removal rate and EEC were significantly improved compared to the use of bare GAC as particle electrode under the same operating conditions, demonstrating the excellent electrocatalytic ability of the new particle electrode Mn-Co/GAC. A possible mechanism of enhanced amoxicillin and TOC removal was also recommended. In summary, the 3D electrochemical method using Mn-Co/GAC particle electrodes is a suitable choice for amoxicillin wastewater treatment.

Synthesis and characterization of temperature-sensitive microspheres based on acrylamide grafted hydroxypropyl cellulose and chitosan for the controlled release of amoxicillin trihydrate.

This study deals with the preparation of temperature-sensitive chitosan/hydroxypropyl cellulose-graft-polyacrylamide (CS/HPC-g-PAAm) blend microspheres as a controlled drug release system. For this purpose, HPC-g-PAAm copolymers of hydroxypropyl cellulose (HPC) with acrylamide (AAm) were synthesized using cerium (IV) ammonium nitrate as initiator. The HPC-g-PAAm copolymers were characterized by using Fourier transform infrared spectroscopy (FTIR), elemental analysis, and differential scanning calorimetry (DSC). Lower critical solution temperatures (LCST) of the synthesized copolymers were determined. Temperature-sensitive blend microspheres of HPC-g-PAAm and chitosan were prepared by emulsion cross-linking method using glutaraldehyde (GA) as a cross-linker in the hydrochloric acid catalyst (HCl) and they were used to achieve controlled release of amoxicillin trihydrate (AMX), an antibiotic drug. The microspheres were characterized by DSC, X-ray diffraction (X-RD), and FTIR spectroscopy. In addition, surfaces of empty and drug-loaded microspheres were examined by scanning electron microscopy (SEM). The effects of variables such as CS/HPC-g-PAAm ratio, drug/polymer ratio, amount of cross-linker, and reaction time of grafting on AMX release were investigated at three different pH environments (1.2, 6.8, 7.4) at 25 °C, 37 °C, and 50 °C. The release results showed that the microspheres had temperature sensitivity and the AMX release was slightly more controlled by especially increasing graft yield (%).

Chitosan coated Fe3O4@Cd-MOF microspheres as an effective adsorbent for the removal of the amoxicillin from aqueous solution.

In this work, for the first time, a new magnetic cadmium-based MOFs (Fe3O4@Cd-MOF) was successfully synthesized in a green way and then modified with chitosan (CS) in the microsphere form (Fe3O4@Cd-MOF@CS). The obtained materials were fully characterized by several techniques. In the following, the efficiency of Fe3O4@Cd-MOF@CS was explored for the removal of amoxicillin (AMX). The outcome of the adsorption study showed that the removal efficiency is affected by CS and reaches its optimum at pH 8 and contact time of 240 min. Under optimized conditions, over 75% of AMX was removed. The kinetic and the isotherm of the adsorption were fit with the pseudo-second-order model and the Langmuir adsorption isotherm respectively. Eventually, the maximum adsorption capacity was obtained ~103.09 mg/g. Interestingly, these findings convince that the newly prepared Fe3O4@Cd-MOF@CS could be proposed as a promising magnetically separable adsorbent for antibiotic contaminants removal from the aqueous solution.

An Efficient Strategy for Enhancing the Adsorption of Antibiotics and Drugs from Aqueous Solutions Using an Effective Limestone-Activated Carbon-Alginate Nanocomposite.

Based on the adsorption performance of a porous nanocomposite with limestone (LS), activated carbon (AC) and sodium alginate (SG), a unique, multifunctional LS-AC-SG nanocomposite absorbent was designed and prepared for extracting antibiotics and drugs from aqueous solutions. The composite exhibited the following advantages: quick and simple to prepare, multifunctionality and high efficiency. Amoxicillin (AMX) and diclofenac (DCF) were chosen as the conventional antibiotic and the drug, respectively. The prepared nanocomposite's physicochemical characteristics were calculated through numerous characterization methods. The structure of the surface was made up of interconnected pores that can easily confine pollutants. The surface area was measured to be 27.85 m2/g through BET analysis. The results show that the maximum absorption capacity of amoxicillin and diclofenac was 99.6% and 98.4%, respectively, at a contact time of 40 min. The maximum removal of amoxicillin and diclofenac was reached at pH = 2. Adsorption analysis revealed that adsorption isotherm and kinetic data matched the pseudo-first-order kinetic and the Langmuir isotherm models. The results imply that the synthesized nanocomposites have the capacity to remove amoxicillin (AMX) and diclofenac (DCF) from aqueous solutions.

Determination of amoxicillin and cotrimoxazole concentrations in sputum of patients with cystic fibrosis.

In the management of cystic fibrosis, treatments against Staphylococcus aureus and Haemophilus influenzae such as amoxicillin or cotrimoxazole have to be prescribed and the antibiotherapy's efficacy may be linked to the concentration that reaches the infected site. As cystic fibrosis patients present disturbed pharmacokinetics parameters, drug monitoring would be relevant to assess the lung distribution of antibiotics and to optimize dosing regimens. In this context, the aim of the study was to develop and validate HPLC-based methods for the determination of both antibiotics in bronchial sputum from cystic fibrosis patients, in order to assess the distribution of the drugs into the lungs. Plasma proteins were precipitated by acetonitrile and amoxicillin concentrations in sputum were determined by HPLC coupled with tandem-mass spectrometry. Following liquid extraction with ethyl acetate, cotrimoxazole was quantified by HPLC using ultraviolet detection. Both methods were rapid, specific, accurate and reproducible. The method was applied to patient samples. In three treated patients, concentrations of amoxicillin in sputum were similar and below the lower limit of quantification (0.1 µg/g) and in six patients, sputum concentrations up to 11.1 and 6.4 µg/g were measured for sulfamethoxazole and trimethoprim, respectively.

Prevalence of Substandard Amoxicillin Oral Dosage Forms in the National Capital District of Papua New Guinea.

Antibiotics are commonly reported as being substandard or falsified in low- to middle-income countries, having potential to contribute to the development of antimicrobial resistance and drug-resistant infections. Amoxicillin, used to treat a number of infections and listed by the WHO as an essential medicine, presented as a good drug candidate for this study. We aimed to measure the prevalence of substandard and falsified amoxicillin oral products (tablets, capsules, and suspensions) in the National Capital District of Papua New Guinea (PNG). These oral products were surveyed in 2018 and 2019 from retail pharmacies, private and public health facilities, and the Area Medical Store, representing more than 90% of licensed medicine outlets. The product packaging was visually inspected, and the samples were analyzed for amoxicillin content using a validated high-performance liquid chromatography method. Although no falsified products were identified, 15% of the 190 products analyzed contained substandard amounts of amoxicillin. Quality varied with the dosage form (P = 0.002), with capsules exhibiting the lowest incidence of substandard content (4% in 2019) and tablets collected in 2018 experiencing the highest failure rate (50%). Suspension (40%) quality was compromised by failure to achieve homogeneity on reconstitution. A higher incidence of substandard content (P = 0.002) was associated with one major retail group. Routine testing of medicines by resource-poor countries is often unachievable, leading to the circulation of poor quality drugs, which is a global public health concern. Our study highlighted that substandard amoxicillin oral products are indeed prevalent in the NCD of PNG.

Synthesis and Biological Evaluation of Amoxicillin Loaded Hybrid Material Composite Spheres Against Methicillin-Resistant Staphylococcus aureus.

BACKGROUND: Incoherent use of antibiotics has led toward resistance in MRSA, becoming multidrug-resistant with a high rate of virulence in the community and hospital settings. OBJECTIVE: Synergistic anti-MRSA activity was investigated in this study for hybrid material composite spheres of amoxicillin, Ag nanoparticles, and chitosan, which were prepared by one-step synthesis method, and various characterizations were performed. METHODS: Antimicrobial-susceptibility assay on MRSA was achieved by disc diffusion and agar dilution techniques, while agar well diffusion was used for hybrid composite spheres. The in vitro and cytotoxicity studies were conducted on the skin abrasion mouse model and MTT assay on RD cell, respectively. RESULTS: All isolates showed resistance to the tested antibiotics except vancomycin. MIC against MRSA showed high resistance with amoxicillin from 4 to 128 mg L-1. The mean diameter of chitosan spheres and Ag nanoparticles was 02 mm and 277 nm, respectively. Morphology of spheres was uneven, varied, porous, and irregular in SEM, and Ag nanoparticles presence and formation was also seen in the micrograph. No substantial interface among drug, nanoparticles, and polymer was found in XRD, and IR showed characteristic peaks of all compounds in the formulation. The in vitro assay showed augmented anti-MRSA activity with amoxicillin loaded hybrid composite spheres (22-29 mm). A significant reduction in microbial burden (~6.5 log10 CFU mL-1) was seen in vivo with loaded hybrid composite spheres formulation. The MTT assay indicated no potential cytotoxicity with hybrid composite spheres. CONCLUSION: The synergistic effect of Amoxycillin in the current study predicts a promising hybrid formulation with enhanced anti-MRSA activity.