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Antidepressants can cause sexual dysfunction side effects, necessitating the co-administration of phosphodiesterase type 5 inhibitors. The simultaneous determination of these drugs in biological fluids is critical for therapeutic drug monitoring. For the first time, two binary mixtures containing duloxetine with either avanafil or tadalafil were estimated utilizing simple green spectrofluorimetric methods without the need for a previous separation step. The study was based on first derivative synchronous spectrofluorimetry in ethanol using a change in wavelength difference (∆λ) of 20 and 25 nm for the first and second combinations, respectively. Duloxetine and avanafil were estimated at 297.7 and 331 nm in their binary mixture, while duloxetine and tadalafil were determined at 290.3 and 297.7 nm, respectively. The linearity was achieved over the ranges of 0.1-1.5 µg mL-1 for both duloxetine and avanafil and 0.01-0.40 µg mL-1 for tadalafil, with limits of detection of 0.013, 0.022, and 0.004 µg mL-1 for duloxetine, avanafil, and tadalafil, respectively. Successful application of the developed approaches was accomplished for the estimation of the two mixtures in dosage forms as well as human plasma with excellent percentage recoveries (96-103.75% in plasma), which supports their suitability for use in quality control laboratories and pharmacokinetic studies. Moreover, the adopted approaches' greenness was evidenced by applying three tools.
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Pirimidinas , Humanos , Tadalafila , Cloridrato de Duloxetina , Preparações Farmacêuticas , Espectrometria de Fluorescência/métodosRESUMO
Biocompatible and highly fluorescent phosphorus, nitrogen and sulfur carbon quantum dots (P,N,S-CQDs) were synthesized using a quick and ecologically friendly process inspired from plant sources. Garlic and red lentils were utilized as natural and inexpensive sources for efficient synthesis of the carbon-based quantum dots using green microwave-irradiation, which provides an ultrafast route for carbonization of the organic biomass and subsequent fabrication of P,N,S-CQDs within only 3 min. The formed P,N,S-CQDs showed excellent blue fluorescence at λem = 412 nm when excited at 325 nm with a quantum yield up to 26.4%. These fluorescent dots were used as a nano-sensor for the determination of the commonly used antibacterial and antiprotozoal drug, metronidazole (MTR). As MTR lacked native fluorescence and prior published techniques had several limitations, the proposed methodology became increasingly relevant. This approach affords sensitive detection with a wide linear range of 0.5-100.0 µM and LOD and LOQ values of 0.14 µM and 0.42 µM, respectively. As well as, it is cost-effective and ecologically benign. The MTT test was used to evaluate the in-vitro cytotoxicity of the fabricated P,N,S-CQDs. The findings supported a minimally cytotoxic impact and good biocompatibility, which provide a future perspective for the applicability of these CQDs in biomedical applications.
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Carbono , Corantes Fluorescentes , Alho , Metronidazol , Micro-Ondas , Pontos Quânticos , Pontos Quânticos/química , Alho/química , Carbono/química , Corantes Fluorescentes/química , Corantes Fluorescentes/síntese química , Metronidazol/análise , Metronidazol/química , Metronidazol/farmacologia , Humanos , Sobrevivência Celular/efeitos dos fármacosRESUMO
Vanillin is a flavouring agent that is prohibited for use in infant food products with ages lower than 6 months. Excessive vanillin usage could lead to eating disorders, nausea, headache, and vomiting. Therefore, it is essential to control the contents of vanillin in food samples, especially in infant formula. Here, we developed a highly sensitive nanosensor for vanillin based on using green synthesized highly fluorescent (QY = 29.5%) N-doped carbon quantum dots (N-CQDs) as a turn-off fluorescent nanoprobe. The N-doped CQDs synthesis was adopted using citrus bulb squeeze extract and the commonly used fertilizer, urea, as substrates. After mixing with vanillin, the fluorescence of the N-CQDs was largely quenched in a vanillin concentration-dependent manner. The sensing conditions were optimized by quality-by-design using a two-level full factorial design (22 FFD). The N-doped CQDs could detect vanillin in the range 0.1-12.0 µg/ml with a limit of detection of 0.013 µg/ml. Next, a smartphone imaging-based assay combined with a UV chamber was adopted and applied for vanillin determination. This simple detection technique showed sensitivity similar to that of the conventional fluorimetric method. Both conventional and smartphone-based methods were successfully applied for the determination of vanillin in infant milk formula and biscuits and could detect real vanillin concentrations in the analyzed samples with high % recoveries (94.5% to 105.5%). At last, the biocompatibility of the newly synthesized N-CQDs was tested, and it was found to be an excellent candidate for cancer cell imaging.
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The current study designed and applied a novel self-ratiometric fluorescent nanosensor composed of green-synthesized silver nanoparticles (Ag-NPs) to determine vanillin in adult and infant foods and human plasma. A straightforward microwave-assisted approach is proposed for synthesizing Ag-NPs in less than 1 min using a reducing agent, tailed pepper seed extract. The synthesized Ag-NPs had a strong fluorescence with an intense emission band at 360 nm and a shoulder peak at 430 nm when excited at 265 nm. Upon interaction with vanillin, the fluorescence peak of Ag-NPs at 360 nm decreases in a concentration-dependent manner while being shifted to a longer wavelength, 385 nm. Meanwhile, the shoulder fluorescence peak at 430 nm is only slightly affected by vanillin addition. Thus, a new Ag-NP self-ratiometric probe was designed and validated for vanillin determination using the peak at 385 nm and the shoulder peak at 430 as two built-in reference peaks. The optimized system accurately measured vanillin with a detection limit of 9.0 ng/mL and a linear range of 0.05-8.0 µg/mL without needing pre-derivatization or high-cost instrumentation. The method successfully measured vanillin in adult and infant milk formula, biscuits, and human plasma samples with high percentage recoveries (95.3-104.6%) and excellent precision (relative SD; ≤3.85%).
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Nanopartículas Metálicas , Humanos , Prata , Extratos Vegetais , FluorescênciaRESUMO
Naftazone is a quinone-semi carbazone drug that possesses a strong orange color, and hence it was usually analyzed colorimetrically or by HPLC-UV. However, these methods are not sensitive enough to determine naftazone in biological samples. Naftazone lacks intrinsic fluorescence and does not possess easily derivatizable functional groups. In this contribution, we introduced the first spectrofluorimetric method for naftazone assay through reduction-elicited fluorogenic derivatization through the reduction of its quinone-semicarbazone moiety to the corresponding quinol-semicarbazide derivative by potassium borohydride as a reduction probe. The solvent-dependent fluorescence of the reaction product was studied in various protic and aprotic solvents. Eventually, the fluorescence of the reduced naftazone was measured in 2-propanol at λemission of 350 nm after excitation at λecxitation of 295 nm. The relative fluorescence intensity was linearly correlated to the drug concentration (r = 0.9995) from 10.0 to 500 ng/mL with high sensitivity, where the lower detection limit was 2.9 ng/mL. Hence, the method was effectively applied for naftazone tablets quality control with a mean %recovery of 100.3 ± 1.5, and the results agreed with those of the comparison HPLC-UV method. Furthermore, a new salting-out assisted liquid-liquid extraction (SALLE) method was established for naftazone extraction from human serum, followed by its determination using the developed reduction-based fluorogenic method. The developed SALLE method showed excellent recovery for naftazone from human serum (92.3-106.5%) with good precision (RSD ≤ 6.8%). Additionally, the reaction of naftazone with potassium borohydride was kinetically monitored, and it was found to follow pseudo-first-order kinetics with an activation energy of 43.8 kcal/mol. The developed method's greenness was approved using three green analytical chemistry metrics.
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Naftoquinonas , Semicarbazonas , Humanos , Hidroquinonas , Semicarbazidas , Solventes , Espectrometria de Fluorescência , ComprimidosRESUMO
We present an environmentally friendly method for the analysis of three angiotensin-converting enzyme inhibitors and hydrochlorothiazide simultaneously using a green micellar eluent for the first time. The chromatographic separation of enalapril maleate, lisinopril dihydrate, benazepril hydrochloride, and hydrochlorothiazide was implemented on an octadecyl silica column with a solution containing sodium dodecyl sulfate (0.12 M), 1-propyl alcohol (10% v/v), triethylamine (0.3% v/v), and H3 PO4 (0.02 M) at pH 3.6 as the mobile phase and UV detection at 210 nm. Validity of the method was confirmed and it exhibited good linearity within the ranges of 5.0-50.0 µg/mL for hydrochlorothiazide and 10.0-60.0 µg/mL for the three angiotensin-converting enzyme inhibitors with a limit of detection of 0.39 to 1.15 µg/mL for all the studied drugs. The developed micellar high-performance liquid chromatography method enables the quantification of the targeted angiotensin-converting enzyme inhibitors in combined tablets with hydrochlorothiazide by isocratic elution. There is no need for special precautions to prevent broadening and splitting of their chromatographic peaks. The method fulfills the society rights for safe and green analytical methods. The retention behavior of the four studied drugs was fitted to Foley's model and their association equilibria to the micelles (KAM ) and to the surface-modified stationary phase (KAS ) were calculated.
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Inibidores da Enzima Conversora de Angiotensina/análise , Cromatografia Líquida de Alta Pressão , Hidroclorotiazida/análise , Química Verde , Micelas , Modelos Químicos , ComprimidosRESUMO
Green and efficient agro-waste-based activated carbon has been prepared utilizing peanut shells for adsorptive elimination of an industrial dye, methylene blue, and lead from polluted water. The carbonaceous biomass obtained from peanut shells was chemically activated using either NaOH, ZnCl2, or steam and characterized by scanning electron microscopy, Fourier-transform infrared spectroscopy, and N2 adsorption and desorption studies. The adsorption process was optimal for methylene blue at alkaline pH, while pH 4.5 was optimal for Pb (II) adsorption. The adsorption takes place through pseudo-second-order kinetic, and the rate-governing step of the adsorption procedure are intraparticle diffusion and film diffusion. Furthermore, the thermodynamics of the adsorption process has been studied, and the obtained Gibbs free energy (ΔG°) values are negative (- 35.90 to - 43.59 kJ mol-1) indicating the spontaneous adsorption of the investigated pollutants on the prepared activated carbon. As per the correlation coefficient, the obtained results were best fit by the Langmuir isotherm with maximum adsorption capacity of 303.03 mg g-1 for methylene blue and 130.89 mg g-1 for Pb (II). The activated carbon successfully removed methylene blue and Pb (II) with %removal exceeding 95%. The mechanisms of interaction of Pb (II) with the activated carbon is a combination of electrostatic interaction and ion exchange, while methylene blue interacts with the activated carbon via π-π interaction, hydrogen bonds, and electrostatic interaction. Thus, the prepared activated carbon has been employed to decontaminate wastewater and groundwater samples. The developed agro-waste-based activated carbon is a promising, cost-efficient, green, and accessible tool for water remediation.
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BACKGROUND: Researchers have investigated different techniques for synthesis of carbon dots. These techniques include Arc discharge, laser ablation, oxidation, water/solvothermal, and chemical vapor deposition. However, these techniques suffer from some limitations like the utilization of gaseous charged particles, high current, high temperature, potent oxidizing agents, non-environmentally friendly carbon sources, and the generation of uneven particle size. Therefore, there was a significant demand for the adoption of a new technology that combines the environmentally friendly aspects of both bio-based carbon sourcing and synthesis technique. RESULTS: Medicago sativa L (alfalfa)-derived N, S-CDs have been successfully synthesized via microwave irradiation. The N,S-CDs exhibit strong fluorescence (λex/em of 320/420 nm) with fluorescence quantum yield of 2.2 % and high-water solubility. The produced N,S-CDs were characterized using TEM, EDX, Zeta potential analysis, IR, UV-Visible, and fluorescence spectroscopy. The average diameter of the produced N, S-CDs was 4.01 ± 1.2 nm, and the Zeta potential was -24.5 ± 6.63 mv. The stability of the produced nano sensors was also confirmed over wide pH range, long time, and in presence of different ions. The synthesized N, S-CDs were employed to quantify the antibacterial drug, nifuroxazide (NFZ), by fluorescence quenching via inner filter effect mechanism. The method was linear with NFZ concentration ranging from 1.0 to 30.0 µM. LOD and LOQ were 0.16 and 0.49 µM, respectively. The method was applied to quantify NFZ in simulated gastric juice (SGJ) with % recovery 99.59 ± 1.4 in addition to pharmaceutical dosage forms with % recovery 98.75 ± 0.61 for Antinal Capsules® and 100.63 ± 1.54 for Antinal suspension®. The Method validation was performed in compliance with the criteria outlined by ICH. SIGNIFICANCE AND NOVELTY: The suggested approach primarily centers on the first-time use of alfalfa, an ecologically sustainable source of dopped-CDs, and a cost-effective synthesis technique via microwave irradiation, which is characterized by low energy consumption, minimized reaction time, and the ability to control the size of the produced CDs. This is in line with the growing global recognition of the implementation of green analytical chemistry principles.
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Biomassa , Suco Gástrico , Medicago sativa , Micro-Ondas , Nitrofuranos , Medicago sativa/química , Nitrofuranos/análise , Suco Gástrico/química , Química Verde , Hidroxibenzoatos/análise , Hidroxibenzoatos/química , Pontos Quânticos/química , Humanos , Tamanho da PartículaRESUMO
This contribution aims to design and validate a new green, cheap, and fast approach for determining the anti-GERD drug pantoprazole in different matrices. New S and N-doped carbon nanomaterials (S,N-CNMs) have been prepared via microwave irradiation of a mixture of widely available household sources. Remarkably, the utilization of a blend of carbamide and thiocarbamide with table sugar yields S,N-CNMs exhibiting the utmost quantum yield (54 %), hydrophilicity, as well as stable, homogeneous, and diminutive particle size distribution. Fourier transform infrared spectroscopy, transmission electron microscopy, spectrophotometry, and fluorescence spectroscopy were applied to characterize the S,N-CNMs. The S,N-CNMs have been used as a turn-off fluorescence probe to determine pantoprazole via a synergism of the inner filter effect and static quenching mechanisms. The fluorescence quenching is linearly correlated to pantoprazole concentration over the range of 1.0-25.0 µg/mL with a detection limit of 0.16 µg/mL. The developed probe exhibited good selectivity for pantoprazole in the presence of variability of substances. Therefore, it was applied for quality control of pantoprazole in pharmaceutical tablets and vials with an average recovery % of 100.10 ± 0.77 % and 100.33 ± 0.92 %, respectively. Moreover, it was successfully implemented to examine the content uniformity of pantoprazole in tablets. Furthermore, the prepared S,N-CNMs have been successfully used for the analysis of pantoprazole in human plasma after a simple protein precipitation step with a recovery % of 97.88 ± 5.72 %. The greenness and blueness of the developed method have been positively assessed by recent tools showing the eco-friendliness and applicability of the developed method.
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A stability-indicating micellar liquid chromatography (MLC) method was developed and validated for the assay of floctafenine (FLF) in the presence of its degradation product and main metabolite, floctafenic acid (FLA). The analysis was carried out on a CLC Shim-Pack octyl silane (C8) column (150 x 4.6 mm id, 5 microm particle size) using a micellar mobile phase consisting of 0.15 M sodium dodecyl sulfate, 10% n-propanol, and 0.3% triethylamine in 0.02 M orthophosphoric acid (pH = 3). The mobile phase was pumped at a flow rate of 1.0 mL/min with UV detection at 360 nm. The method showed good linearity for FLF and FLA over the concentration ranges of 0.5-25.0 and 0.4-10.0 microg/mL, with LODs of 0.16 and 0.12 microg/mL, respectively. The developed method was successfully applied to the determination of FLF in commercial dispersible tablets, with mean recovery of 98.87 +/- 1.37%. Also, the proposed method was specific for the analysis of FLF in presence of the co-formulated drug thiocolchicoside in laboratory-prepared tablets, with mean recovery of 100.50 +/- 1.07%. Statistical comparison of the results obtained by the proposed MLC method with those obtained by a comparison method showed good agreement. Moreover, the method was extended to study the degradation behavior of FLF under different International Conference on Harmonization recommended conditions such as alkaline, acidic, oxidative, thermal, and photolytic. The method was further applied for direct determination of FLA as the main metabolite of FLF in human plasma without prior extraction steps, with mean recovery of 110.50 +/- 6.5%.
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Cromatografia Líquida/métodos , ortoaminobenzoatos/análise , Adulto , Calibragem , Química Farmacêutica/métodos , Humanos , Concentração de Íons de Hidrogênio , Masculino , Micelas , Controle de Qualidade , Padrões de Referência , Solventes/química , Comprimidos , Fatores de Tempo , ortoaminobenzoatos/sangueRESUMO
Drug-pepsin interaction possibly affects pepsin activity, leads to undesirable shift of its functionality, and likely induces adverse effects in the gastrointestinal tract. The present study aims at exploring the interaction of pepsin with the antiprotozoal/antibacterial drug secnidazole adopting a combination of experimental spectroscopy and computational techniques. For this purpose, different spectroscopic methods including fluorescence, synchronous fluorescence, UV-Visible absorption, and infrared spectroscopy were adopted and coordinated with in silico analysis via molecular docking. The employed synchronized approaches evidenced that; pepsin interacted with secnidazole via static mechanism at stomach pH inferring some consequent conformational changes in the structure of pepsin. Thermodynamic study of drug-pepsin interaction demonstrated that the interaction is spontaneous via van der Waals and hydrogen bonding interaction and the orientation of ligand within pepsin cavity was illustrated by molecular docking. The synchronous fluorescence study proved that tyrosine amino acid residues were involved in the interaction more than tryptophan amino acid residues. Eventually, the combined experimental and molecular docking approaches suggest that secnidazole interacts with pepsin and alter its structure, that finding correlates to gastrointestinal side effects related to secnidazole oral administration.
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Anti-Infecciosos , Pepsina A , Pepsina A/química , Sítios de Ligação , Espectrometria de Fluorescência , Simulação de Acoplamento Molecular , Termodinâmica , Anti-Infecciosos/farmacologia , Aminoácidos , Percepção , Ligação Proteica , Dicroísmo CircularRESUMO
A simple, fast, and direct mix-and-read spectrofluorimetric method has been developed for the sensitive determination of naftazone (NFZ) utilizing graphene quantum dots (GQDs) as a greener and highly luminescent nanosensor. NFZ effectively quenches the strong fluorescence of GQDs at λex/λem of 350/440 nm via the inner filter effect mechanism. The nanosensor exhibits excellent linearity for NFZ over the concentration range of 0.46 to 186 µM with a limit of detection of 0.04 µM. The proposed method was validated for the successful determination of NFZ in tablets and on manufacturing equipment surfaces with good % recoveries of 98.4-101.6 and 96.3 - 102.2%, respectively. Furthermore, an integrated smartphone-based reader has been implemented and successfully applied for the determination of NFZ. The smartphone-based reader consists of a 365 nm UV torch as an excitation source, a smartphone for recording images, and smartphone-powered image analysis software for signal interpretation, together with a paper-based analytical device (PAD) utilizing filter paper as a substrate and correction fluid as a barrier for creation of detection zones. This smart platform showed excellent sensitivity with a limit of detection down to 0.12 nmol/zone, and it could be used for in-site determination of NFZ, especially for the limited resources laboratories.
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In this study, we report a one-pot, green, cost-efficient, and fast synthesis of plant-based sulfur and nitrogen self-co-doped carbon quantum dots (S,N-CQDs). By 4-min microwave treatment of onion and cabbage juices as renewable, cheap, and green carbon sources and self-passivation agents, blue emissive S,N-CQDs have been synthesized (λex/λem of 340/418 nm) with a fluorescence quantum yield of 15.2%. A full characterization of the natural biomass-derived quantum dots proved the self-doping with nitrogen and sulfur. The S,N-CQDs showed high efficiency as a fluorescence probe for sensitive determination of nitazoxanide (NTZ), that recently found wide applicability as a repurposed drug for COVID-19, over the concentration range of 0.25-50.0 µM with LOD of 0.07 µM. The nanoprobe has been successfully applied for NTZ determination in pharmaceutical samples with excellent % recovery of 98.14 ± 0.42. Furthermore, the S,N-CQDs proved excellent performance as a sensitive fluorescence nanoprobe for determination of hemoglobin (Hb) over the concentration range of 36.3-907.5 nM with a minimum detectability of 10.30 nM. The probe has been applied for the determination of Hb in blood samples showing excellent agreement with the results documented by a medical laboratory. The greenness of the developed probe has been positively investigated by different greenness metrics and software. The green character of the proposed analytical methods originates from the synthesis of S,N-CQDs from sustainable, widely available, and cheap plants via low energy/low cost microwave-assisted technique. Omission of organic solvents and harsh chemicals beside dependence on mix-and-read analytical approach corroborate the method greenness. The obtained results demonstrated the substantial potential of the synthesized green, safe, cheap, and sustainable S,N-CQDs for pharmaceutical and biological applications.
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COVID-19 , Pontos Quânticos , Humanos , Antivirais , Carbono , Corantes Fluorescentes , Hemoglobinas , Micro-Ondas , Nitrogênio , EnxofreRESUMO
A robust, stability-indicating, and eco-friendly proton nuclear magnetic resonance (1H-qNMR) method was developed for the concurrent determination of three 1,4-benzodiazepines (BDZs), namely diazepam (DZP), alprazolam (ALP), and chlordiazepoxide (CDP) and their common impurity, synthesis precursor, and degradation product; 2-amino-5-chlorobenzophenone (ACB). In the present method, a novel approach was developed for composing a green and cost-efficient solvent system as an alternative to the common NMR organic solvents utilizing 0.3 M sodium dodecyl sulfate prepared in deuterated water. The conducted method is characterized by simplicity with no need for sample pretreatment or labeling. Phloroglucinol was used as an internal standard. The chosen signals for the determinations of ALP, CDP, DZP and ACB were at 2.35 ppm (singlet), 2.84 ppm (singlet), 3.11 ppm (singlet), and 6.90 ppm (doublet of doublet), respectively. The proposed method possessed linearity over the concentration range of 0.25-15.0 mg ml-1 for DZP, ALP, CDP and of 0.5-25.0 mg ml-1 for ACB with LOD values of 0.06, 0.03, 0.07 and 0.16 mg ml-1 respectively, and LOQ values of 0.18, 0.09, 0.21 and 0.49 mg ml-1, respectively. Accuracy of the method was evidenced by excellent recovery% (99.57-99.90%) and small standard deviation (≥ 1.10) for the three analyzed drugs. Intra- and inter-day precision were determined with coefficient of variation ranging from 0.12 to 1.14 and from 0.72 to 1.67, respectively. For the studied compounds, appraisal of the method greenness was achieved via four approaches: Analytical Eco-Scale, Green Analytical Procedure Index (GAPI), Analytical greenness metric (AGREE), and RGB Additive Color Model. The results proved that the proposed method has the privilege of being a green analytical method.
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Benzodiazepinas , Benzofenonas , Diazepam , Espectroscopia de Ressonância Magnética , SolventesRESUMO
A simple and highly sensitive spectrofluorimetric method was developed and validated for determination of the antidiabetic agent repaglinide (RG) in tablets. The proposed method is based on measurement of the native fluorescence of RG in 0.1 M H(2)SO(4)/methanol medium at 360 nm after excitation at 243 nm. The method showed a linear dependence of the relative fluorescence intensity on drug concentration over the range of 0.02-0.50 µg mL(-1) with lower detection limit of 6.0 ng mL(-1) and lower quantification limit of 18 ng mL(-1). The method was successfully applied for determination of RG in different tablets and the obtained results were in good agreement with those obtained by the official method. The proposed method was extended to investigate the kinetics of oxidative degradation of the drug. A proposal for the degradation pathway was postulated.
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Carbamatos/análise , Piperidinas/análise , Espectrometria de Fluorescência/métodos , Carbamatos/química , Estabilidade de Medicamentos , Modelos Lineares , Metanol/química , Piperidinas/química , Solventes/química , Ácidos Sulfúricos/química , Comprimidos , Temperatura , Fatores de TempoRESUMO
Non-steroidal anti-inflammatory drugs (NSAIDs) are among the most detected pharmaceuticals in wastewater and likely pass to drinking water. Magnetic nanocomposite has been greenly fabricated for removal of different NSAIDs; ibuprofen (IP), ketoprofen (KP), naproxen (NX), and diclofenac sodium salt (DF); from wastewater. Solid-phase fabrication of the magnetically separable nanocomposite has been optimized using iron oxide (Fe3O4) and graphene nanoplatelets (GNP) precursors. The characterization showed the homogenous distribution of the magnetite over the GNP with a high specific surface area. Different parameters having a potential influence on the removal of the NSAIDs from wastewater by the Fe3O4@GNP nanocomposite were studied and optimized for efficient performance that achieves adsorption capacities of 8.76, 10.6, 14.3, and 7.63 mg/g for KP, NX, DF, and IP, respectively (296 K). The adsorption of the four NSAIDs by the Fe3O4@GNP nanocomposite followed pseudo-second-order kinetics, and it is mainly controlled by the intraparticle diffusion process. The thermodynamic and extra-thermodynamic studies demonstrated that the adsorption is endothermic and is affected by enthalpy-entropy compensation. The molecular interactions of the four drugs with the nanocomposite have been explored. Successful application of the nanocomposite for fast and efficient removal of the NSAIDs from wastewater has been accomplished with an average removal of 71.0%.
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Grafite , Cetoprofeno , Nanocompostos , Poluentes Químicos da Água , Adsorção , Anti-Inflamatórios não Esteroides , Concentração de Íons de Hidrogênio , Ibuprofeno , Cinética , Naproxeno , Percepção , Termodinâmica , Águas Residuárias , Poluentes Químicos da Água/análiseRESUMO
A simple, rapid and highly sensitive spectrofluorimetric method was developed for determination of ziprasidone hydrochloride (ZPS) in capsules. The method is based on measuring the native fluorescence of ZPS in acetate buffer of pH 4.5 at 398 nm after excitation at 315 nm. The fluorescence-concentration plot was rectilinear over the range of 0.05-0.80 µg mL(-1) with a lower detection limit (LOD) of 6.0 ng mL(-1) and quantification limit (LOQ) of 20.0 ng mL(-1). The method was fully validated and successfully applied to the determination of ZPS in its capsules with average percentage recovery of 99.7 ± 1.4. The method was extended to stability study of ZPS. The drug was exposed to acidic, alkaline, oxidative and photolytic degradation according to ICH guidelines. Moreover, the method was utilized to investigate the kinetics of the alkaline, acidic and oxidative degradation of the drug. A proposal for the degradation pathways was postulated.
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Piperazinas/análise , Tiazóis/análise , Cápsulas/química , Estabilidade de Medicamentos , Fluorescência , Estrutura Molecular , Espectrometria de FluorescênciaRESUMO
The design of a cheap, simple, and handy sensing system for rapid quantitation of pharmaceuticals becomes mandatory to ease drug development procedures, quality control, health care, etc. This work describes a simple, innovative, and easily manufactured paper-based device using a correction pen as a plotter for hydrophobic/lipophobic barriers and graphene quantum dots for recognition and quantification of the hemostatic drug carbazochrome, via fluorescence turn-off mechanism mediated by the inner filter effect. A smartphone-based all-in-one device fitted with an inexpensive 365 nm flashlight as a UV light source and a free image processing software was developed for rapid and reliable interpretation of the fluorescence change from the paper-based device upon introduction of the drug. The simple and convenient steps permit the analysis of many samples in a very short time. The smartphone-based all-in-one device featured excellent sensitivity for carbazochrome with a limit of detection equals to 12 ng/detection zone and good %recovery (100.0 ± 0.4). The reliability of the device was ascertained by favorable statistical comparison with the analogous optimized conventional fluorimetry method and a reference HPLC method. The device has been successfully applied for versatile quantitation of carbazochrome in tablets and on manufacturing equipment surfaces with excellent recoveries. The device offers many green aspects that definitely assist the implementation of the sustainability concept to analytical laboratories. The cost-efficiency, reliability, and ease of fabrication as well as the greenness and user friendship qualify the device for wide application in low-income communities.
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Pontos Quânticos , Raios Ultravioleta , Adrenocromo/análogos & derivados , Reprodutibilidade dos Testes , SmartphoneRESUMO
The retention behavior of a series of acidic drugs, namely ketoprofen (KET), naproxen (NAP), diclofenac (DIC), and ibuprofen (IBU), on the heat-resisting ZORBAX 300SB-C18 column, was studied thermodynamically using high-temperature liquid chromatography (HTLC). A perfect correlation of the compounds' lipophilicity and the calculated thermodynamic indicators evidenced its contribution to the retention behavior. Besides, the steric fitting has a subsidiary effect on IBU retention. Isocratic HTLC separation of the four compounds was achieved using an aqueous mobile phase containing 30% acetonitrile-0.2% acetic acid-0.2% triethylamine at 60 °C. This method has been utilized to monitor the adsorption efficiency of multiwalled carbon nanotubes (MWCNTs) for the removal of the four NSAIDs from water. Different variables affecting the remediation process have been optimized such as the time of contact, pH, ionic strength, temperature, and the mass of MWCNTs. The kinetics and thermodynamics of the adsorption were investigated. The adsorption was evidenced to take place via pseudo-second-order kinetics and the intraparticle diffusion is the rate-controlling step. The thermodynamic investigation showed that the adsorption process is exothermic and enthalpy-driven, and the adsorption is more extensive at a lower temperature. The MWCNTs showed excellent adsorption efficiency of about 76.4 to 97.6% at the optimum conditions. The obtained results are promising and encouraging for the full-scale application of MWCNTs for remediation of NSAIDs-related water pollution. The green analytical chemistry metric "AGREE" and the analytical eco-scale score tool confirmed that the developed protocol is greener and more favorable to the environment and user than most of the reported literature.
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Cromatografia Líquida/métodos , Temperatura Alta , Nanotecnologia/métodos , Nanotubos de Carbono/química , Preparações Farmacêuticas/isolamento & purificação , Águas Residuárias/química , Poluentes Químicos da Água/isolamento & purificação , Adsorção , Anti-Inflamatórios não Esteroides/isolamento & purificação , Difusão , Concentração de Íons de Hidrogênio , Cinética , Nanotubos de Carbono/ultraestrutura , Concentração Osmolar , Reprodutibilidade dos Testes , Soluções , Termodinâmica , Fatores de TempoRESUMO
A micellar HPLC method was developed for analysis of the antiosteoporosis drug risedronate. The analysis was carried out using a 250 x 4.6 mm id, 5 microm particle size C18 Waters Symmetry column. The mobile phase consisted of 0.02 M sodium dodecyl sulfate + 0.3% triethylamine + 10% n-propanol, prepared in 0.02 M orthophosphoric acid. The pH of the mobile phase was adjusted to pH 6.0, and it was pumped at a flow rate of 0.7 mL/min with UV detection at 262 nm. The method showed good linearity in the range of 2-80 microg/mL, with an LOD of 0.40 microg/mL (1.31 x 10(-6) M) and an LOQ of 1.21 microg/mL. The suggested method was successfully applied for the analysis of risedronate in raw material and a tablet formulation, with average recoveries of 99.91 +/- 1.30 and 101.52 +/- 0.30%, respectively. The stability-indicating capability of the proposed method was proved using forced degradation. By changing the pH of the mobile phase to 4.0, the oxidative degradation product could be separated from risedronate.