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A green, rapid, and simple RP-UPLC method was developed and optimized by full factorial design for the simultaneous separation of oseltamivir phosphate, daclatasivir dihydrochloride, and remdesivir, with dexamethasone as a co-administered drug. The separation was established on a UPLC column BEH C 18 1.7 µm (2.1 × 100.0 mm) connected with a UPLC pre-column BEH 1.7 µm (2.1 × 5.0 mm) at 25 °C with an injection volume of 10 µL. The detector (PDA) was set at 239 nm. The mobile phase consisted of methanol and ammonium acetate (8.1818 mM) in a ratio of 75.7: 24.3 (v/v). The flow rate was set at 0.048 mL min −1 . The overall separation time was 9.5 min. The retention times of oseltamivir phosphate, dexamethasone, daclatasivir dihydrochloride, and remdesivir were 6.323 ± 0.145, 7.166 ± 0.036, 8.078 ± 0.124, and 8.572 ± 0.166 min (eight replicates), respectively. The proposed method demonstrated linearity in the ranges of 10.0–500.0 (ng mL −1 ) and 0.5–30.0 (µg mL −1 ) for oseltamivir phosphate, 50.0–5000.0 (ng mL −1 ) for dexamethasone, 25.0–1000.0 (ng mL −1 ) and 0.5–25.0 (µg mL −1 ) for daclatasvir dihydrochlorde, and 10.0–500.0 (ng mL −1 ) and 0.5–30.0 (µg mL −1 ) for remdesivir. The coefficients of determination (R 2 ) were greater than 0.9999, with percentage recoveries greater than 99.5% for each drug. The limits of quantitation were 6.4, 1.8, 7.8, and 1.6 ng mL −1 , and the limits of detection were 1.9, 0.5, 2.0, and 0.5 ng mL −1 for oseltamivir phosphate, dexamethasone, daclatasivir dihydrochloride, and remdesivir, respectively. The proposed method was highly precise, as indicated by the low percentage of relative standard deviation values of less than 1.2% for each drug. The average content and uniformity of dosage units in the studied drugs' dosage forms were determined. The average contents of oseltamivir phosphate, dexamethasone, daclatasivir dihydrochloride, and remdesivir were nearly 93%, 102%, 99%, and 95%, respectively, while the uniformity of dosage unit values were nearly 92%, 102%, 101%, and 97%. Two novel methods were established in this work. The first method was used to assess the stability of standard solutions. This novel method was based on the slope of regression equations. The second was to evaluate the excipient's interference using an innovative instrumental standard addition method. The novel instrumental standard addition method was performed using the UPLC instrument program. It was more accurate, sensitive, time-saving, economical, and eco-friendly than the classic standard addition method. The results showed that the proposed method can estimate the tested drugs' concentrations without interference from their dosage form excipients. According to the Eco-score (more than 75), the Green Analytical Procedure Index (GAPI), and the AGREE criteria (total score of 0.77), the suggested method was considered eco-friendly.

Telmisartan (TEL) and Nebivolol (NEB) are frequently co-formulated in a single dosage form that is frequently prescribed for the treatment of hypertension, moreover, telmisartan is currently proposed to be used to treat COVID19-induced lung inflammation. Green rapid, simple, and sensitive synchronous spectrofluorimetric techniques for simultaneous estimation of TEL and NEB in their co-formulated pharmaceutical preparations and human plasma were developed and validated. Synchronous fluorescence intensity at 335 nm was used for TEL determination (Method I). For the mixture, the first derivative synchronous peak amplitudes (D 1 ) at 296.3 and 320.5 nm were used for simultaneous estimation of NEB and TEL, respectively (Method II). The calibration plots were rectilinear over the concentration ranges of 30–550 ng/mL, and 50–800 ng/mL for NEB and TEL, respectively. The high sensitivity of the developed methods allowed for their analysis in human plasma samples. NEB`s Quantum yield was estimated by applying the single-point method. The greenness of the proposed approaches was evaluated using the Eco-scale, National Environmental Method Index (NEMI), and Green Analytical Procedure Index (GAPI) methods.

For treatment of muscle spasms associated pain, combination of nonsteroidal anti-inflammatory drugs like diclofenac (DIC) and muscle relaxants as methocarbamol (MET) is usually utilized. This work represents a novel, rapid, facile, sensitive, and selective first derivative synchronous fluorescence spectroscopy (FDSFS) for the simultaneous determination of DIC and MET in their combined tablets. Factors influencing method’s sensitivity were investigated, and the best findings were accomplished applying Δ λ = 60 nm and using water as a diluting solvent. Through applying the optimized experimental conditions, DIC showed a lower detection limit of 0.15 µg/mL and a quantitation limit of 0.30 µg/mL, while MET corresponding values were 0.03 µg/mL and 0.05 µg/mL. Diclofenac was measured at 288 nm, while methocarbamol was measured at 346 nm, exhibiting linearity over the concentration ranges of 0.3–2.5 and 0.05–5.0 µg/mL, respectively. Through application to several laboratory-prepared mixtures and commercial formulation, the suggested method’s applicability was determined. When comparing the proposed method to the reported HPLC method using the student’s t -test and F -ratio test, no discernible differences were found. Due to simplicity and economical advantage of the method, it can be applied in quality control laboratories for analysis of the studied drugs. The evaluation of the method’s eco-friendliness and greenness was also performed using Analytical GREEnness (AGREE), Green Analytical Procedure Index (GAPI) and Analytical Green Star Area (AGSA) metrics. Complete validation procedures were applied to the suggested approach in compliance with the International Conference on Harmonization’s criteria.

Food and Drug Administration (FDA) recently approved co-formulated celecoxib and tramadol for the treatment of acute pain in adults. Three spectrophotometric methods were efficiently applied to estimate the co-formulated Celecoxib and Tramadol in their tablets; second derivative 2D-spectrophotometry technique (method I), induced dual-wavelength technique (method II) and dual-wavelength resolution technique (method III). The proposed methods were successfully validated following the International Council for Harmonisation (ICH) guidelines and statistically assessed based on the correlation coefficients, relative standard deviations as well as detection and quantitation limits. The obtained results revealed non-significant differences compared to the reported results as revealed by the variance ratio F test and Student t test. Moreover, the applied techniques were further assessed concerning their greenness based on the analytical eco-scale method revealing an excellent green scale with a final score of 95. The proposed spectrophotometric techniques could be applied for the routine analysis and quality control of the studied drugs in their dosage form.

This study has been proposed new, sensitive, straightforward, and validated spectrophotometric and spectrofluorimetric methods for estimating of amprolium (AMP) and triclabendazole (TCB) in laboratory prepared pharmaceutical wastewater. Both methods were based on the reaction of AMP and TCB with Eosin-Y in acidic medium, targeting the tertiary amino groups of the concerned analytes, generating an orange-red ion pair complexes. The resulting products were measured by spectrophotometric (Method I) and spectrofluorimetric (Method II) tools. Regarding method I, the absorbance was measured at 547 nm with a lower detection limit of 45 ng/mL and quantitation limit of 136 ng/mL for AMP with corresponding values of 191 ng/mL and 579 ng/mL for TCB. The proposed method exhibited a linear pattern over the concentration range of 100–5000 and 1500–10,000 ng/mL for amprolium and triclabendazole, respectively. Meanwhile in method II, the produced complex was measured at λem 552 nm for AMP or 555 nm for TCB after excitation at λex 470 nm with a lower detection limit of 142 ng/mL and quantitation limit of 429 ng/mL for AMP with corresponding values of 67 ng/mL and 202 ng/mL for TCB. The proposed method exhibited a linear pattern over the concentration range with linearity ranges of 500–2000 and 100–1500 ng/mL for amprolium and triclabendazole, respectively. The International Conference on Harmonization (ICH) requirements for linearity, accuracy, precision, specificity, and robustness were followed in the comprehensive validation of the proposed methods, allowing its application successfully to determine the studied analytes in wastewater samples.

A green and simple UPLC method was developed and optimized, adopting a factorial design for simultaneous determination of oseltamivir phosphate and remdesivir with dexamethasone as a co-administered drug in human plasma and using daclatasvir dihydrochloride as an internal standard within 5 min. The separation was established on UPLC column BEH C 18 1.7 μm (2.1 × 100.0 mm) connected to UPLC pre-column BEH 1.7 μm (2.1 × 5.0 mm) at 50 °C with an injection volume of 10 μL. The photodiode array detector (PDA) was set at three wavelengths of 220, 315, and 245 nm for oseltamivir phosphate, the internal standard, and both dexamethasone and remdesivir, respectively. The mobile phase consisted of methanol and ammonium acetate solution (40 mM) adjusted to pH 4 in a ratio of 61.5:38.5 (v/v) with a flow rate of 0.25 mL min −1 . The calibration curves were linear over 500.0–5000.0 ng mL −1 for oseltamivir phosphate, over 10.0–500.0 ng mL −1 and 500.0–5000.0 ng mL −1 for dexamethasone, and over 20.0–500 ng mL −1 and 500.0–5000.0 ng mL −1 for remdesivir. The Gibbs free energy and Van't Hoff plots were used to investigate the effect of column oven temperatures on retention times. Fluoride-EDTA anticoagulant showed inhibition activity on the esterase enzyme in plasma. The proposed method was validated according to the M10 ICH, FDA, and EMA’s bioanalytical guidelines. According to Eco-score, GAPI, and AGREE criteria, the proposed method was considered acceptable green.

The aim of this study was to investigate the stability of three major antioxidants of : thymoquinone (TQ), carvacrol (CR) and thymol (THY), under different stress conditions using HPLC and LC-MS/MS. Forced degradation for each compound was performed under different conditions, including oxidation, hydrolysis, photolysis and thermal decomposition. The results showed that both CR and THY were stable under the studied conditions, whereas TQ was not affected by acidic, basic and oxidative forced conditions but the effect of light and heat was significant. The degradation products of TQ were further investigated and characterized by LC-MS/MS. HPLC-UV method has been fully validated in terms of linearity and range, the limit of detection and quantitation, precision, selectivity, accuracy and robustness. The method was successfully applied to quantitative analysis of the principal antioxidants of TQ, CR and THY in different phytopharmaceuticals.

Medicinal plants are widely used in folk medicine to treat various diseases. Thonningia sanguinea Vahl is widespread in African traditional medicine, and exhibits antioxidant, antibacterial, antiviral, and anticancer activities. T. sanguinea is a source of phytomedicinal agents that have previously been isolated and structurally elucidated. Herein, gas chromatography combined with tandem mass spectrometry (GC-MS/MS) was used to quantify epipinoresinol, β-sitosterol, eriodictyol, betulinic acid, and secoisolariciresinol contents in the methanolic crude extract and its ethyl acetate fraction for the first time. The ethyl acetate fraction was rich in epipinoresinol, eriodictyol, and secoisolariciresinol at concentrations of 2.3, 3.9, and 2.4 mg/g of dry extract, respectively. The binding interactions of these compounds with the epidermal growth factor receptor (EGFR) were computed using a molecular docking study. The results revealed that the highest binding affinities for the EGFR signaling pathway were attributed to eriodictyol and secoisolariciresinol, with good binding energies of −19.93 and −16.63 Kcal/mol, respectively. These compounds formed good interactions with the key amino acid Met 769 as the co-crystallized ligand. So, the ethyl acetate fraction of T. sanguinea is a promising adjuvant therapy in cancer treatments.

The novelty of this work is the simultaneous analysis of sulbactam (SUL), ampicillin (AMP), and paracetamol (PARA) in human urine samples, using the environmentally benign RP-HPLC method. A C18 column was used in chromatographic separation using potassium dihydrogen phosphate (10 mmol L , pH 5)/ethanol (90 %, ) as the mobile phase; flow rate was 1.00 mL min . UV detection at 220 nm was used for quantification. The proposed method showed good linearity in the concentration ranges of 2.20–250.00 μg mL for SUL, 2.50–250.00 μg mL for PARA, and 14.50–250.00 μg mL for AMP. Direct injection of urine samples with no prior extraction was performed. This method was found successful in moving towards greener studies of drugs’ urinary excretion, by decreasing hazardous solvent consumption and waste. Moreover, the method was applied to investigate the urinary excretion of the drugs and possible interaction between ampicillin and paracetamol.

BackgroundCarbon quantum dots (CQDs) are new class of carbon nanoparticles. Recently, they have been widely used as fluorescent probes due to their easy accessibility, optical properties and chemical inertness. Many available precursors are used in the synthesis of carbon quantum dots. The electrical and optical properties of CQDs could be enhanced by doping hetero atoms such as nitrogen or sulfur into their structure.ObjectiveThe current work presents the synthesis and characterization of water-soluble nitrogen doped carbon quantum dots (N-CQDs) and their use as fluorescent nano-sensors for the spectrofluorimetric determination of furosemide in its pharmaceutical preparations and spiked human plasma.MethodsA domestic microwave was used to prepare the N-CQDs by heating a solution of sucrose and urea till complete charring (about ten minutes). The produced N-CQDs exhibit a strong emission band at 376 nm after excitation at 216 nm. Furosemide caused a quantitative quenching in the fluorescence intensity of the produced N-CQDs.ResultsThe proposed method was validated according to ICH Guidelines. The method was found to be linear over the range of 0.1–1.0 µg/mL with LOQ of 0.087 µg/ml.ConclusionEcofriendly nano fluorescent sensors (N-CQDs) were successfully synthesized. The size of N-CQDs was distributed in the range of 6.63 nm to 10.23 nm with an average of 8.2 nm. The produced N-CQDs were used as fluorescent probes for the estimation of furosemide in its pharmaceutical preparations as well as spiked human plasma samples.