Green wastewater treatment of repurposed COVID-19 therapy (levofloxacin) using synthesized magnetite pectin nanoparticles, comparison with mesoporous silica nanoparticles.

RATIONALE: Antibiotics have been detected worldwide in the aquatic environment. Moreover, certain classes of antibiotics have been repurposed for the management of COVID-19, which increased their use and presence in wastewater. Their occurrence even in low concentrations leads to the development of antibiotic resistance. METHODOLOGY: Magnetite pectin nanoparticles (MPNP) were fabricated and compared to an established model of mesoporous silica nanoparticles (MSNP). Our studied adsorbate is levofloxacin, a fluoroquinolone antibiotic, commonly used in managing COVID-19 cases. RESULTS: The influence of various factors affecting the adsorption process was studied, such as pH, the type and concentration of the adsorbent, contact time, and drug concentration. The results illustrated that the optimum adsorption capacity for antibiotic clearance from wastewater using MPNP was at pH 4 with a contact time of 4 h; while using MSNP, it was found to be optimum at pH 7 with a contact time of 12 h at concentrations of 10 µg/mL and 16 g/L of the drug and nanoparticles, respectively, showing adsorption percentages of 96.55% and 98.89%. Drug adsorption equilibrium data obeyed the Sips isotherm model. DISCUSSION AND CONCLUSION: HPLC assay method was developed and validated. The experimental results revealed that the MPNP was as efficient as MSNP for removing the antibacterial agent. Moreover, MPNP is eco-friendly (a natural by-product of citrus fruit) and more economic as it could be recovered and reused. The procedure was evaluated according to the greenness assessment tools: AGREE calculator and Hexagon-CALIFICAMET, showing good green scores, ensuring the process's eco-friendliness.

The power of High Impact Amplitude Manipulation (HIAM) technique for extracting the basic spectra of two Fixed-dose combinations (FDC) -Spectrophotometric purity analysis via spectral contrast angle.

HIAM technique allows the extraction of the original constant signal of each single component out of interference signals of a mixture and further transformed into basic spectrum (D0). It includes the methods: ratio subtraction coupled with unified constant subtraction (RS-UCS), constant center (CC) and constant extraction (CE). The technique was introduced for the analysis of two pharmaceutical formulations used to treat cardiovascular diseases. The formulations are binary combinations of Amlodipine (AML) with either Atorvastatin (ATR) or Candesartan (CND) which shows interefernce absorbance signals. The technique was valid over the linearity range of (5.0-35.0 µg/ml) for AML, ATR and CND with recovery percentage 100.40 ± 1.88 , 100.00 ± 0.86 and 99.83 ± 1.07, respectively . The extracted signals were tested for its purity by spectral contrast angle (cos θ) to illustrate the efficency of the HIAM technique where cos θ values ranges from (0.9902 to 0.9986). The presented technique was fully validated regarding ICH guidelines and were statistically compared using one-way ANOVA at 95% confidence.

Appraisal for Edible Use of Vegetable Crops Cultivated in Egypt after Treatment with Selected Insecticides and Fungicides: Insights of Dissipation Rates and Pre-harvest Intervals.

An analytical investigation was carried out to study the dissipation rate of two commonly used pesticides, thiamethoxam (neonicotinoid insecticide) and propamocarb hydrochloride (carbamate fungicide), applied to four vegetable crops: cucumber, zucchini, lettuce and pepper, after open-field application. Samples were harvested according to a scheduled plan followed by QuEChERS extraction, then thiamethoxam residues were analyzed using a GC-ECD method, while propamocarb HCl residues were analyzed using an HPLC-UV method. Validation parameters were attained for both methods and the kinetic profile was studied, which fitted the first-order kinetics where k, t1/2 and t90 were calculated. The proper pre-harvest interval (PHI) was studied for each crop to ensure that the residues levels declined to reach below the maximum residue limit (MRL) where the crop is suitable for consumption. These values were found to be different from labelled values, which proves that the PHIs are greatly affected by changing weather conditions.

A validated liquid chromatography-tandem mass spectrometric method for the determination of co-administered ranitidine and metronidazole in plasma of human volunteers.

This work describes the development, optimization and validation of a liquid chromatography-tandem mass spectrometric method (LC-MS/MS) for the simultaneous analysis of co-administered ranitidine (RAN) and metronidazole (MET) in plasma of healthy human volunteers. A simple protein precipitation procedure using 1 mL acetonitrile was applied to extract both drugs and metoclopramide as an internal standard (IS) from plasma. The chromatographic separation was achieved on a C18 column with isocratic elution of the mobile phase consisting of acetonitrile and 0.1% formic acid (90 : 10, v/v) at a flow rate of 0.35 mL min-1. The positive ionization mode was used for detecting the ions, by observing the pairs of transition m/z 314.82 < 176.06 for RAN, m/z 172.03 < 127.95 for MET and m/z 299.86 < 277.10 for IS. The linearity range was from 5-600 ng mL-1 for RAN and 2-40 µg mL-1 for MET. The method was found to be sensitive and accurate with good simple extraction recovery and matrix effect, according to FDA guidelines for bioanalytical methods. The developed method could be applied for further bioavailability studies that could be useful in therapeutic drug monitoring.

Eco-friendly UPLC-MS/MS analysis of possible add-on therapy for COVID-19 in human plasma: Insights of greenness assessment.

Facing the pandemic COVID-19 is of highest priority for all researchers nowadays. Recent statistics indicate that the majority of the cases are home-treated. Two drugs of interest, Guaifenesin and Bromohexine HCl, are among the add-on therapy for treatment of COVID-19 mild cases, which has raised the need for their simultaneous determination. The analysis of the two drugs of interest was described using ultra-performance liquid chromatography-tandem mass spectrometric (UPLC-MS/MS) in plasma of healthy human volunteers using tetryzoline HCl as an internal standard (IS) after liquid-liquid extraction. The applied chromatographic conditions were Kinetex C18 (100 Å, 2.6 µm X 50 mm X 4.6 mm) column and a mixture of methanol: water (95: 5, v/v) as a mobile phase at flow rate 1 mL/min. The positive ionization mode was used for detecting the ions, by observing the pairs of transition m/z 199 < 125 for GUF, m/z 377 < 114 for BRM and m/z 201 < 131 for IS. The linearity range was from 50 to 1500 ng/mL for GUF and 0.5-50 µg/mL for BRM. Limit of detection (LOD) was found to be 35.16 and 0.43 ng/ml for GUF and BRM, respectively. The method was validated according to FDA guidance. The proposed method was assessed to be more eco-friendly versus the reported method using the greenness assessment tools: National Environmental Methods Index (NEMI), Assessment of Green Profile (AGP), Green Analytical Procedure Index (GAPI) and Eco-Scale. The proposed method was applied for the application of a pilot pharmacokinetic study.

Effective Removal of Levofloxacin from Pharmaceutical Wastewater Using Synthesized Zinc Oxid, Graphen Oxid Nanoparticles Compared with their Combination.

The presence of antibiotic traces in the aquatic system due to the inefficient treatment of the pharmaceutical wastewater represented threats, such as bioaccumulation and antibiotic-resistance, to the environment and human health. Accordingly, for the first time, the current work utilized the photocatalytic degradation and the adsorption approach for Levofloxacin (LEVO) in pharmaceutical wastewater using new designed nano aspects. Therefore, spherical Zinc oxide nanoparticles (ZnONP) sized 17 nm and ultrathin sheet-like structure graphene oxide nanosheets (GONS) with layer thickness ~5 nm were fabricated separately or in a combination between them then characterized via Transmission Electron Microscope (TEM), Scanning Electron Microscope (SEM), X-Ray Diffraction (XRD), Fourier Transforms Infrared Spectroscopy (FTIR), absorption spectra (UV-Vis) and Brunauer-Emmett-Teller (BET). Additionally, several parameters were investigated to evaluate the potential of the removal process, such as pH, the exposure time to UV radiation, the type and concentration of the nanoparticles (NPs) and the initial concentration of the drug using a mixed fractional factorial design. The most effective parameter for LEVO removal was the NPs type followed by the initial drug concentration. Furthermore, an RP-HPLC/UV method was developed and validated for measuring the percentage of removal for LEVO drug. The highest percentage removal for both 50 and 400 µg mL-1 LEVO was 99.2% and 99.6%, respectively, which was achieved using ZnONP/GONS combination at pH 9 ± 0.05 and UV light exposure time 120 min. In addition, the negative antibacterial activity of the treated wastewater sample confirmed the drug removal. The established protocol was successfully applied on wastewater samples collected from a pharmaceutical company that encouraged researchers to mainstream this design to be applied on other pharmaceutical wastewater drugs.