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.

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.

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.