Green method by National Environmental Methods Index and Eco-Scale Assessment for evaluation of gatifloxacin-based product by HPLC.

The literature reveals gaps in the availability of green analytical methods for assessing products containing gatifloxacin (GFX), a fluoroquinolone. Presently, method development is supported by tools such as the National Environmental Methods Index (NEMI) and Eco-Scale Assessment (ESA), which offer objective insights into the environmental friendliness of analytical procedures. The objective of this work was to develop and validate a green method by the NEMI and ESA to quantify GFX in eye drops using HPLC. The method utilized a C8 column (4.6 × 150 mm, 5 µm), with a mobile phase of purified water containing 2% acetic acid and ethanol (70:30, v/v). The injection volume was 10 µL and the flow rate was 0.7 mL/min in isocratic mode at 25°C, with detection performed at 292 nm. The method demonstrated linearity in the range of 2-20 µg/mL, and precision at intra-day (relative standard deviation [RSD] 1.44%), inter-day (RSD 3.45%), and inter-analyst (RSD 2.04%) levels. It was selective regarding the adjuvants of the final product (eye drops) and under forced degradation conditions. The method was accurate (recovery 101.07%) and robust. The retention time for GFX was approximately 3.5 min. The greenness of the method, as evaluated by the NEMI, showed four green quadrants, and by ESA, it achieved a score of 88.

Ecotoxicological assessment of UV filters benzophenone-3 and TiO2 nanoparticles, isolated and in a mixture, in developing zebrafish (Danio rerio).

The increasing use of UV filters, such as benzophenone-3 (BP-3) and titanium dioxide nanoparticles (TiO2 NPs), has raised concerns regarding their ecotoxicological effects on the aquatic environment. The aim of the present study was to examine the embryo-larval toxicity attributed to BP-3 or TiO2 NPs, either alone or in a mixture, utilizing zebrafish (Danio rerio) as a model after exposure to environmentally relevant concentrations of these compounds. Zebrafish embryos were exposed to BP-3 (10, 100, or 1000 ng/L) or TiO2 NPs (1000 ng/L) alone or in a mixture (BP-3 10, 100, or 1000 ng/L plus 1000 ng/L of TiO2 NPs) under static conditions for 144 hr. After exposure, BP-3 levels were determined by high-performance liquid chromatography (HPLC). BP-3 levels increased in the presence of TiO2 NPs, indicating that the BP-3 degradation decreased in the presence of the NPs. In addition, in the presence of zebrafish, BP-3 levels in water decreased, indicating that zebrafish embryos and larvae might absorb BP-3. Data demonstrated that, in general, environmentally relevant concentrations of BP-3 and TiO2 NPs, either alone or in a mixture, did not significantly induce changes in heart and spontaneous contractions frequencies, levels of reactive oxygen species (ROS), morphological and morphometric parameters as well as mortality rates during 144 hr exposure. However, the groups exposed to TiO2 NPs alone and in a mixture with BP-3 at 10 ng/L exhibited an earlier significant hatching rate than the controls. Altogether, the data indicates that a potential ecotoxicological impact on the aquatic environment exists.

Green Method for Evaluation of Marbofloxacin Tablets by HPLC and Evaluation of Interchangeability With UV and Turbidimetric Methods.

BACKGROUND: Marbofloxacin (MAR) is a veterinary antimicrobial, marketed in injectable solution, oral suspension, and tablets. MAR has no monograph for tablet evaluation in official compendiums. High Performance Liquid Chromatography (HPLC) methods present in the literature for evaluating MAR in tablets do not follow the principles of green and sustainable analytical chemistry. OBJECTIVE: A green, clean, and sustainable method by HPLC was developed and validated to evaluate the content and stability of MAR in tablets, in addition to comparing it with other methods available in the literature. METHOD: A C8, 5 µm, 4.6 × 150 mm (ACE®) column, purified water with 0.2% formic acid-ethanol (70:30, v/v) as the mobile phase, and a flow rate of 0.7 mL/min at 296 nm were used. RESULTS: The method was linear over a concentration range of 1-10 µg/mL, selective for tablet matrix and forced degradation, precise with relative standard deviations (RDS) less than 5%, accurate with recovery of 99.99%, and robust to changes in the mobile phase, flow rate, wavelength, equipment, and column brand. The retention time for MAR was approximately 3.1 min. CONCLUSIONS: The method can be used in routine analysis of MAR in tablets in chemical-pharmaceutical laboratories. Furthermore, it can be used to verify the stability of MAR-based products and proved to be interchangeable with spectrophotometric method in the UV region and turbidimetric microbiological method. HIGHLIGHTS: A green method for evaluation of marbofloxacin tablets by HPLC was developed and validated. Additionally, it has been shown to be interchangeable with UV and turbidimetric methods.

Preclinical data on morpholine (3,5-di-tertbutyl-4-hydroxyphenyl) methanone induced anxiolysis.

Trimetozine is used to be indicated for the treatment of mental illnesses, particularly anxiety. The present study provides data on the pharmacological profile of trimetozine derivative morpholine (3,5-di-tert-butyl-4-hydroxyphenyl) methanone (LQFM289) which was designed from molecular hybridization of trimetozine lead compound and 2,6-di-tert-butyl-hydroxytoluene to develop new anxiolytic drugs. Here, we conduct molecular dynamics simulations, docking studies, receptor binding assays, and in silico ADMET profiling of LQFM289 before its behavioral and biochemical assessment in mice within the dose range of 5-20 mg/kg. The docking of LQFM289 showed strong interactions with the benzodiazepine binding sites and matched well with receptor binding data. With the ADMET profile of this trimetozine derivative that predicts a high intestinal absorption and permeability to blood-brain barrier without being inhibited by the permeability glycoprotein, the oral administration of LQFM289 10 mg/kg consistently induced anxiolytic-like behavior of the mice exposed to the open field and light-dark box apparatus without eliciting motor incoordination in the wire, rotarod, and chimney tests. A decrease in the wire and rotarod´s fall latency coupled with an increase in the chimney test´s climbing time and a decrease in the number of crossings in the open field apparatus at the dose of 20 mg/kg of this trimetozine derivative suggest sedative or motor coordination impairment at this highest dose. The attenuation of the anxiolytic-like effects of LQFM289 (10 mg/kg) by flumazenil pretreatment implicates the participation of benzodiazepine binding sites. The lowering of corticosterone and tumor necrosis factor alpha (cytokine) in LQFM289-treated mice at a single oral (acute) dose of 10 mg/kg suggests that the anxiolytic-like effect of this compound also involves the recruitment of non-benzodiazepine binding sites/GABAergic molecular machinery.

The presence of antibiotics and multidrug-resistant Staphylococcus aureus reservoir in a low-order stream spring in central Brazil.

The disposal of industrial effluents strongly influences low-order streams, which makes them fragile ecosystems that can be impacted by contamination. In central Brazil, the Extrema River spring targets the dumping of pharmaceutical products from the surrounding industries. So, this work aimed to investigate the presence of antibiotics in Extrema River spring samples and the isolation of Staphylococcus aureus, a potential multidrug-resistant bacteria, verifying the antimicrobial resistance profile of these isolates. Three campaigns were carried out in different locals (P1-P3) between October and December 2021, in the dry and rainy seasons. The high-performance liquid chromatography-tandem mass spectrometry (LCMS) approach indicated the presence of sulfamethoxazole (≥ 1 ng/L), metronidazole (< 0.5 ng/L), and chloramphenicol (< 5 ng/L) in the water samples in November (rainy season). S. aureus was isolated in P1 (n = 128), P2 (n = 168), and P3 (n = 36), with greater resistance to trimethoprim-sulfamethoxazole (90%), clindamycin (70%), and gentamicin (60%). The presence of antibiotics in the Extrema River spring may cause S. aureus antibiotic resistance development. The presence of antibiotics and the high percentage of isolated multidrug-resistant S. aureus in the Extrema River spring cause concern and indicate the clandestine dumping of effluents from nearby pharmaceutical industries. Since preserving the springs of low-order streams is important for the environment and public health, we encourage monitoring the wastewater from Extrema River's nearby pharmaceutical industries and preserving the spring of this river.

Chemical composition and chemotaxonomy of Nasutitermes spp. defensive secretion from Brazilian Cerrado for the differentiation of species.

Nasutitermes spp. soldier defensive secretion has a toxic and repellent effect against predators. Chemical profile characterization of this secretion is an interesting tool to differentiate similar termite species. This study aimed to determine defensive secretion composition of Nasutitermes spp. soldier and to apply chemotaxonomy tool for the unambiguous species identification. Fifteen volatile compounds were identified by gas chromatography-mass spectrometry. Multivariate analysis classified populations into three groups. Principal component (PCA), axis 1, was able to separate two groups: group I, colonies 1 and 2 (Nasutitermes corniger) and group II, colony 3 (Nasutitermes ephratae). Therefore, determination of defensive chemical secretion profile proved to be very useful in termite chemotaxonomy, since it was able to differentiate morphologically similar specimens.

Occupational exposure evaluation of Brazil university community to the volatile organic compounds.

Occupational exposure to volatile organic compounds (VOC) might generate serious worker health damages. Therefore, biological monitoring is essential to evaluate exposure biomarkers from highly toxic chemicals, ensuring better attention to the worker health. In this study was developed and validated a bioanalytical method based on high-performance liquid chromatography coupled to photodiode array (HPLC-PDA) for the quantification of VOC biomarkers in urine samples from Federal University of Goias (UFG) workers. Samples were collected from 30 occupationally exposed subjects after application of a questionnaire survey. The following biomarkers hippuric acid, methyl-hippuric acid, mandelic acid, phenylglyoxylic acid and phenol were quantified, representing exposition to toluene, xylene, styrene, ethylbenzene, benzene and phenol solvents, respectively. Hippuric acid levels were found close to or above the reference values, although a subject had levels higher than preconized by Biological Limit Values (BLV) guideline of 4.0 mg/g creatinine. Five subjects had 3 and 4-methylhippuric acid ranging from 0.1 to 1.0 mg/g creatinine. These results indicate a moderate to high VOC exposure from UFG workers. Multivariate analysis generated four clusters and indicated that histotechnicians and graphic workers need especial attention on occupational VOC exposure. The results from this study reinforce the need for reliable methods able to the biological monitoring as an important tool for assessing occupational exposure.

New bioanalytical method for the quantification of (-) - hydroxycitric acid in human plasma using UPLC-MS/MS and its application in a Garcinia cambogia pharmacokinetic study.

A new, rapid, selective and sensitive UPLC-MS/MS method was developed and validated for the quantification of (-) - hydroxycitric acid (HCA) in human plasma, using DL-malic acid-2,3,3-d3 as internal standard (IS) and simple protein precipitation for the sample preparations. HCA is a highly polar compound make challenging its determination in biological fluids. A specific chromatography column Acquity UPLC HSS T3 (100 × 2.1 mm, 1.8 µm), eluted with mobile phase composed of acetonitrile/ammonium hydroxide 0,1 % (15:85, v/v) were applied for the HCA quantification. The bioanalytical method showed high-throughput achieving as fast chromatographic run as 1 min per sample. No matrix effect was observed with excellent mean chromatographic peak areas ratio of 0.98 ± 0.07 and CV% of 7.17 from normal, lipemic and hemolyzed plasma lots. Calibration curves range was linear at 0.05-10 µg/mL, presenting adequate mean correlation coefficient great than 0.99. Excellent intra-assay and inter-assay precision were achieved, ranging from 5.02-12.01 % (CV%) as well as great intra- and inter-assay accuracy from 0.29-9.20 % (RE%). UPLC-MS/MS bioanalytical method was efficiently applied to the HCA pharmacokinetic study analyzing more than 670 plasma samples.

Piroxicam voltammetric determination by ultra low cost pencil graphite electrode

Piroxicam (PRX) was determined in pharmaceutical capsules with differential pulse voltammetry (DPV) in a three electrode system consisting of a pencil graphite electrode (PGE) as working electrode, a Pt wire and a reference electrode of Ag/AgCl/KCl 3 M. An irreversible oxidation peak was observed in Epa c.a. 0.6 V, which correlates to the oxidation of PRX. The coefficient of linear correlation obtained was 0.9946, with limit of detection of 2.1 µM and limit of quantification of 4.7 µM. PGE assays showed good analytical performance compared to high performance liquid chromatography and spectrophotometry, showing the potential to be further developed and employed in quick and simple analyses.

Voltammetric Evaluation of Diclofenac Tablets Samples through Carbon Black-Based Electrodes.

Diclofenac (DIC) is a non-steroidal anti-inflammatory drug of wide use around the world. Electroanalytical methods display a high analytical potential for application in pharmaceutical samples but the drawbacks concerning electrode fouling and reproducibility are of major concern. Henceforth, the aim of this work was to propose the use of alternative low-cost carbon black (CB) and ionic liquid (IL) matrix to modify the surface of pencil graphite electrodes (PGE) in order to quantify DIC in raw materials, intermediates, and final products, as well as in stability assays of tablets. The proposed method using CB+IL/PGE displayed good recovery (99.4%) as well as limits of detection (LOD) of 0.08 µmol L-1 and limits of quantification (LOQ) of 0.28 µmol L-1. CB+IL/PGE response was five times greater than the unmodified PGE. CB+IL-PGE stands as an interesting alternative for DIC assessment in different pharmaceutical samples.

Electroanalysis and laccase-based biosensor on the determination of phenolic content and antioxidant power of honey samples.

Honey is a functional food widely consumed. Thus, the evaluation of honey samples to determine its phenolic content and antioxidant capacity (AOC) is relevant to determine its quality. Usually AOC is performed by spectrophotometric methods, which lacks reproducibility and practicality. In this context, the electroanalytical methods offer higher simplicity and accuracy. Hence, the aim of this work was to use of electroanalytical tools and laccase based biosensor on the evaluation of AOC and total phenol content (TPC) of honey samples from different countries. The antioxidant power established by electrochemical index presented good correlation with the spectrophotometric FRAP (Ferric Reducing Ability of Plasma) and DPPH (2,2-Diphenyl-1-Picrylhydrazyl) radical scavenging assays. Also, TPC results obtained by the biosensor agreed with the Folin-Ciocalteu (FC) assay. In addition to the semi quantitative results, the electroanalysis offered qualitative parameters, which were useful to indicate the nature of major phenolic compounds.

Electroanalytical tools for antioxidant evaluation of red fruits dry extracts.

Red fruits are rich sources of antioxidant compounds with recognized health benefits. Since they are perishable, dried extracts emerge as more durable products and their quality control must include antioxidant capacity assays. In this study, the redox behavior of commercial dried products obtained from camu-camu, açai, acerola and cranberry red fruits was evaluated by electroanalytical approaches. The antioxidant potential was determined by 2,2-diphenyl-1-picrylhydrazyl free radical assay and the electrochemical index concept. The total phenol content was estimated by using a laccase based biosensor. A significant correlation was found between all methods and literature data. The voltammetric profile (cyclic, differential and square wave) obtained for each type of dried extract showed distinguishable features that were correlated with their main major markers, being also useful for identification purposes. The electrochemical methods were cheaper and more practical for evaluation of antioxidant properties and total phenol content in dried powders obtained from different red fruits.

Electrochemical behavior and determination of major phenolic antioxidants in selected coffee samples.

The redox behavior of commercial roasted coffee products were evaluated by electroanalysis, whereas high performance liquid chromatography (HPLC) was used for determination of cinnamic acid markers, the total phenolic content (TPC) was achieved by Folin-Ciocalteu assay, and the traditional DPPH (1-diphenyl-2-picrylhydrazyl) method for antioxidant power determination. In turn, an optimized electrochemical index was proposed to estimate the antioxidant power of different samples and it was found a great correlation between all methods. The voltammetric profile of all coffee samples was quite similar, presenting the same number of peaks at the same potential values. Minor differences on current levels were in agreement with the total phenolic and major markers content, as well as, to the antioxidant power. Therefore, the electrochemical methods showed to be practical, low cost and very useful to evaluate the antioxidant properties of coffee samples, which is a relevant quality parameter of this widely consumed beverage.

Um método simplificado para análise de cotinina em urina usando CG-EM / A simplified method for the analysis of urinary cotinine by GC-MS

Cotinine is the major metabolite of nicotine and, being very stable and having a long biological half-life, it can be used as a biomarker for tobacco exposure. The aim of this study was to develop an analytical GC-MS technique to measure levels of cotinine in the urine of active and passive smokers and to compare the results with reference values. The extraction of cotinine to generate the calibration curve was performed by mixing urine (250 ?L) with 50 ?L of a cotinine standard, 50 ?L of an internal standard of deuterated cotinine (15μgμmL-1) and 50 μL of 10% NH4OH solution. Next, 2 mL of a mixture of MTBE:dichloromethane:ethyl acetate (30:30:40 by volume) was added and the whole was vortexed, then centrifuged at 3000 rpm. Finally, 1.6 mL of the organic layer was evaporated under a stream of dry air at 50 °C. The resulting extract was dissolved in methanol and injected into the GC-MS system. The LOQ and LOD for cotinine were 100 and 20 ng.mL-1, respectively. The curve was linear over the whole tested range of 100 - 5000 ng.mL-1 and the method achieved 50% recovery. The intra and inter-day precisions were 1.62 ? 7.28% and 0.86 - 2.68%, respectively. Accuracy was determined at three concentrations (low, medium and high), with six replicates (95.24- 97.67%). The validation of this cotinine assay by GC-MS showed that it exhibited satisfactory limits and the assay could be performed with a one-step liquid-liquid extraction. The technique presented here can thus be used for the quantitation of cotinine levels in the urine of passive and active smokers.

A cotinina é o metabólito principal da nicotina, é muito estável e tem uma elevada meia-vida biológica e pode ser usado como biomarcador da exposição ao tabaco. O objetivo deste estudo foi desenvolver uma técnica analítica em CG-EM para medir os níveis de cotinina na urina de fumantes ativos e passivos e comparar os resultados com valores de referência. A extração da cotinina para construir a curva de calibração foi desenvolvida misturando 250 μL de padrão de cotinina em urina, 50 μL de padrão interno (cotinina deuterada 15 ?g?mL-1) e 50 μL de solução aquosa de NH4OH 10%. Em seguida, 2 mL da mistura MTBE:diclorometano:acetato de etila (30:30:40 v/v) foi adicionada, agitada em vórtex e centrifugada a 3000 rpm. Finalmente, 1,6 mL da camada orgânica foi evaporada sob ar seco a 50 °C. O extrato resultante foi dissolvido em metanol e injetado no sistema CG-EM. Os limites de quantificação e de detecção foram 100 e 20 ng?mL-1, respectivamente. A curva de calibração foi linear no intervalo de concentração testado (100 - 5000 ng?mL-1), com 50% de recuperação. Os valores de precisão intra-dia e inter-dia foram 1,62 ? 7,28% e 0,86 - 2,68%, respectivamente. A exatidão (95,24 - 97,67%) foi determinada sob 3 concentrações (baixa, média e alta), com 6 replicatas. A validação deste procedimento para análise de cotinina por CG-EM demonstrou valores satisfatórios, numa única etapa de extração líquido-líquido, podendo ser utilizada para a quantificação dos níveis de cotinina em amostras de urina de fumantes ativos e passivos.