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Graphite carbon nitride (g-C3N4) is a two-dimensional nano-sheet with electronic properties, which shows unique characteristics with high chemical and thermal stability in its structure. The functionalization of these compounds through covalent bonding is an important step towards significantly improving their properties and capabilities. To achieve this goal, a novel strategy for the covalent functionalization of Fe3O4@g-C3N4 with thiamine hydrochloride (vitamin B1) via cyanuric chloride (TCT), which is a divalent covalent linker, was presented. The efficiency of Fe3O4@gC3N4@Thiamine as a heterogeneous organic catalyst in the synthesis of spirooxindole-pyran derivatives and 2-amino-4H-pyran under solvent-free conditions was evaluated and the yields of high-purity products were presented. In addition, easy recycling and reuse for seven consecutive cycles without significant reduction in catalytic activity are other features of this catalyst. Moreover, the performance of the prepared sorbent in the microextraction technique (herein, magnetic solid phase extraction) was studied. The tebuconazole was selected as the target analyte. The target analyte was extracted and determined by HPLC–UV. Under the optimum condition, the linear range of the method (LDR) was estimated in the range of 0.2–100 μg L−1 (the coefficient of determination of 0.9962 for tebuconazole). The detection limit (LOD) of the method for tebuconazole was calculated to be 0.05 µg L−1. The limit of quantification (LOQ) of the method was also estimated to be 0.16 µg L−1. In order to check the precision of the proposed method, the intra-day and inter-day relative standard deviations (RSD%) were calculated, which were in the range of 1.5- 2.8%. The method was used for the successful extraction and determination of tebuconazole in tomato, cucumber, and carrot samples. [ABSTRACT FROM AUTHOR]

BACKGROUND: Obesity is recognized as a lifestyle‐related disease and the main risk factor for a series of pathological conditions, including cardiovascular diseases, hypertension and type 2 diabetes. Citrus limon is an important medicinal plant, and its fruits are rich in flavonoids investigated for their potential in managing obesity. In the present work, a green extraction applied to lemon squeezing waste (LSW) was optimized to recover pancreatic lipase (PL) inhibitors. RESULTS: The microwave‐assisted procedure yielded an extract with higher lipase inhibitory activity than those obtained by maceration and ultrasound. The main compounds present in the extract were identified by high‐performance liquid chromatographic–mass spectrometric analysis, and hesperidin, eriocitrin and 4′‐methyllucenin II were isolated. The three compounds were evaluated for in vitro PL inhibitory activity, and 4′‐methyllucenin II resulted in the most promising inhibitor (IC50 = 12.1 μmol L−1; Ki = 62.2 μmol L−1). Multispectroscopic approaches suggested the three flavonoids act as competitive inhibitors and the binding studies indicated a greater interaction between PL and 4′‐methyllucenin II. Docking analysis indicated the significant interactions of the three flavonoids with the PL catalytic site. CONCLUSION: The present work highlights flavonoid glycosides as promising PL inhibitors and proposes LSW as a safe ingredient for the preparation of food supplements for managing obesity. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

This study evaluated the presence of the three pesticides methomyl (MET), carbendazim (CBZ) and chlorpyrifos-ethyl (CPE), as well as the degradation product of CPE (3,5,6-trichloro-2-pyridinol; TCP), in 44 honey samples from all 12 regions of Morocco. With a validated HPLC-UV method occurrence frequencies of 63.6% for MET, 54.5% for CBZ, 95.1% for CPE and 34.1% for TCP were obtained, even at concentrations higher than the maximum residue limits for MET, CPE and TCP. Based on the predominant pesticide, principal component analysis separated sampling regions into three groups. Risk assessment indicated that ingestion of these pesticides, alone or in combination, in honey did not pose a risk to consumers (HQ and HI < 1). [ABSTRACT FROM AUTHOR]

α‐Bisabolol (α‐BIS) is a sesquiterpene alcohol present in chamomile essential oil [Chamomilla recutita (L.) Rauschert]. Despite its numerous pharmacological effects, its pharmacokinetics remain understudied. An analytical method capable of quantifying α‐BIS in plasma is crucial to enable pharmacokinetic analysis. Presently, only one study has quantified it using mass spectrometry. Administering α‐BIS requires a nanoemulsion for intravenous injection. This study aimed to develop and validate a bioanalytical method using high‐performance liquid chromatography with an ultraviolet detector to quantify α‐BIS in rat plasma. The method employed acetonitrile and ultrapure water (80:20, v/v) as the mobile phase, with a flow rate of 1 ml/min and concentrations ranging from 465 to 29.625 μg/ml. All US Food and Drug Administration‐designated assays were successful, indicating the method's precision, accuracy, sensitivity and linearity in determining α‐BIS in rat plasma. The developed nanoemulsion, assessed through dynamic light scattering analysis, the ensemble collection of particles and polydispersity index evaluation, proved safe and effective for intravenous administration. The pharmacokinetic parameters such as volume of distribution, clearance and half‐life indicated that α‐BIS tends to persist in the body. This study provides a foundation for further research to explore α‐BIS's potential pharmaceutical applications in the future. [ABSTRACT FROM AUTHOR]

A novel simple and cost effective HPLC technique was presented for the quantification of selexipag (SLP) in human plasma sample and the technique's applicability to a pharmacokinetic investigation. Chromatographic separation was achieved with C18 (5 µm × 4.6 mm × 150 mm) column, at 30 °C with isocratic elution, mobile phase composed of solution A (acetonitrile), and solution B (0.5% formic acid) (65:35 v/v) at flow rate 1.2 mL min−1. The linearity range is 10–150 ng mL−1. As sample preparation step human plasma was precipitated with acetonitrile and the detection was provided at 300 nm. The retention time is 8.20 ± 0.02 min. LOD is found to be 3.3 ng mL−1 for drug. The method was applied to the analysis of SLP in human plasma with good recovery as 97.83%. Validation of the studied methods was carried out according to EMA guideline. The new method applied on a prototype pharmacokinetic study by administration of 800 μg SLP to a healthy volunteer and parameters like AUC0–24, AUC0–∞, Cmax, tmax, and t1/2 were assessed. [ABSTRACT FROM AUTHOR]

Comparative study of phenolic compound composition was performed by HPLC-UV and HPLC-MS techniques using raw materials of Hedysarum alpinum L. plants introduced into the dendrological ecosystem of the Siberian Botanical Garden of Tomsk State University as well as the callus culture of the same species. The callus culture of Hedysarum alpinum was obtained on Murashige and Skoog nutrient medium with the addition of 1.0 mg/L 2,4-D and 0.1 mg/L 6-benzylaminopurine (6-BAP) and was subsequently cultivated on the medium containing α-NAA (2.0 mg/L) and 6-BAP (0.5 mg/L). The culture was characterized by activated phenylpropanoid pathway, which gave rise to the formation of flavonoids, isoflavones, xanthones, and other substances. The total content of flavonoids (calculated on a per quercetin basis) and formononetin in the extracts of callus culture was lower than in the extracts from introduced plants by 35 and 11%, respectively, whereas the content of mangiferin in callus extracts was more than 50% higher than in the extracts of aerial plant parts. [ABSTRACT FROM AUTHOR]

Bacterial respiratory tract infections (e.g., in patients with cystic fibrosis) may be treated with the intravenous infusion of a piperacillin/tazobactam (P/T) solution through an elastomeric device. In the present work, we combined a 24-h drug stability study with an assessment of the drug solution flow rate during an in vitro simulated infusion. Experiments were performed in triplicate with two excipient-free generic P/T solutions and an excipient-containing proprietary P/T solution in saline (all 50/6.25 mg/mL) released from an elastomeric infusion device at 32 °C. The P/T solutions' stability was assessed by an HPLC-UV assay, pH and osmolality measurements, a visual assessment, and particle counting. Before these analyses, a forced degradation study was performed. To assess the flow rate, a precision scale was used to weigh the solution collected at the infusion line outlet. The stability criteria were <10% degradation and a flow rate within ± 15% of the nominal value over the 24-h infusion period: all three P/T solutions were found to be stable. The actual flow rate was lower than the expected flow rate; this difference was probably due to the drug solution's high viscosity and must be taken into account in clinical use. [ABSTRACT FROM AUTHOR]

Introduction. The introduction of devices – analogues of GIS (hereinafter–- Gastro-intestinal simulator) is one of the current ways to develop in-vitro assessment of the quality of solid dosage forms. Testing on a physiologically relevant test device (hereinafter referred to as PRT) makes it possible to predict pharmacokinetic profiles due to more relevant conditions, including the use of biorelevant dissolution media, physiological volumes of the gastrointestinal tract, as well as transit between them.Aim. Conduct a study of cladribine tablets on a physiologically relevant tester in order to predict the behavior of the drug in the human gastrointestinal tract.Materials and methods. The objects of the study are "Mavenclad®, tablets, 10 mg" (series 2200754, expiration date until 04.2025, NERPHARMA, S.r.L., Italy) and "Cladribine, tablets, 10 mg" of domestic production with valid expiration date. During the study, the reagents necessary for the preparation of biorelevant dissolution media and quantitative determination by HPLC. Physiologically relevant test were carried out using an apparatus of our own production, consisting of a DT-6 dissolution tester (ERWEKA GmbH, Germany), a water bath equipped with a Thermomix WB-4 heating element (B. Braun, Germany), and peristaltic pumps (Kamoer, China). The quantitative content of released cladribine was assessed using a highly efficient liquid chromatograph "Khromatek-Kristall HPLC 2014" (ZAO SKB "Khromatek", Russia) using a validated method at a wavelength of 252 nm, analysis time – 7 min, column – Grace HPLC Column Platinum C18-EPS, 250 × 4.6 mm, 5 mm (Grace, USA), temperature – 35 °C, elution mode – isocratic (A : B 80 : 20), mobile phase A – 0.1 % H3PO4 solution, phase B – acetonitrile.Results and discussion. Profiles were obtained to assess the dynamics and degree of release of the studied drugs in various parts of the human gastrointestinal tract. Despite the expected degradation of cladribine in an acidic environment (pH1.2), under physiologically relevant conditions, the drug reached the third section (small intestine model) without degradation. Complete release of cladribine from the test and reference dosage forms was observed. Also, in the future, based on the data obtained, it is possible to predict pharmacokinetic profiles using physiologically based pharmacokinetic modeling approaches.Conclusion. A PSF study was conducted for the drugs "Mavenclad®, tablets, 10 mg" and "Cladribine, tablets, 10 mg". Quantitative determination was carried out by HPLC-UV method. The test results showed complete release of both drugs and reaching the intestinal tract, indicating the absence of degradation of cladribine in the region simulating the stomach.

Abstract Graphite carbon nitride (g-C3N4) is a two-dimensional nano-sheet with electronic properties, which shows unique characteristics with high chemical and thermal stability in its structure. The functionalization of these compounds through covalent bonding is an important step towards significantly improving their properties and capabilities. To achieve this goal, a novel strategy for the covalent functionalization of Fe3O4@g-C3N4 with thiamine hydrochloride (vitamin B1) via cyanuric chloride (TCT), which is a divalent covalent linker, was presented. The efficiency of Fe3O4@gC3N4@Thiamine as a heterogeneous organic catalyst in the synthesis of spirooxindole-pyran derivatives and 2-amino-4H-pyran under solvent-free conditions was evaluated and the yields of high-purity products were presented. In addition, easy recycling and reuse for seven consecutive cycles without significant reduction in catalytic activity are other features of this catalyst. Moreover, the performance of the prepared sorbent in the microextraction technique (herein, magnetic solid phase extraction) was studied. The tebuconazole was selected as the target analyte. The target analyte was extracted and determined by HPLC–UV. Under the optimum condition, the linear range of the method (LDR) was estimated in the range of 0.2–100 μg L−1 (the coefficient of determination of 0.9962 for tebuconazole). The detection limit (LOD) of the method for tebuconazole was calculated to be 0.05 µg L−1. The limit of quantification (LOQ) of the method was also estimated to be 0.16 µg L−1. In order to check the precision of the proposed method, the intra-day and inter-day relative standard deviations (RSD%) were calculated, which were in the range of 1.5- 2.8%. The method was used for the successful extraction and determination of tebuconazole in tomato, cucumber, and carrot samples.

Aim: Ashwagandha is a widely recognized medicinal plant in Ayurveda, a traditional Indian system of medicine. These extracts, which are concentrated forms of the root, contain specified withanolides (WLs) at a 5% median concentration on their packaging. Given the visual similarity between the capsule contents of these dietary supplements and authentic pulverized Ashwagandha root, there is a growing suspicion that these so-called extracts may be merely pulverized roots. To address these concerns, a procedure for evaluating Ashwagandha root extracts is presented that offers simplicity, cost-effectiveness, and the ability to provide a valid estimation. Methods: The procedure incorporates microscopic investigations to facilitate the identification of plant fragments, which should be absent in properly prepared extracts. High-performance liquid chromatography (HPLC) with ultraviolet detection is employed to check whether the supplements are more than 10-fold concentrated compared to the powdered root, as claimed on the product labels. Results: In the analyzed Ashwagandha root extracts, plant fragments and starch granules were detected, which could be attributed to the root in terms of size and shape. HPLC analysis of both root extracts and roots revealed nearly identical chromatograms with respect to peak patterns and signal intensity. Quantitative analysis indicated a WL content of approximately 0.15% in all tested Ashwagandha root extracts, considerably lower than the claimed 5% median content but consistent with published data for Ashwagandha root. Conclusions: Notably, none of the 10 dietary supplements labeled as Ashwagandha root extracts fulfilled the manufacturers’ claims. These findings emphasize the need for practical and simple evaluation procedures, such as those proposed in this study. Such methods enable the evaluation of Ashwagandha root extracts without requiring the complex coupling of HPLC to mass spectrometry, making them accessible and feasible.

Introduction. Search for new plant species containing biologically active substances (hereinafter – BAS) is one of the leading tasks of pharmacognosy as a science. The search for flavonoid glycosides in plant raw materials is especially relevant, since they have anti-inflammatory, antioxidant, immunostimulating, as well as weak fungicidal and bacteriostatic action. Staphylea pinnata L. is an endemic plant of the Caucasus, cultivated not only in Georgia, but also in the Russian Federation in the Northern and Northwestern Caucasus. In foreign literature there are studies of antioxidant, antiproliferative and cytotoxic activity of leaf extracts of several species of S. pinnata L., as well as inhibitory activity of COX-1, COX-2 and LTB4 formation. Meanwhile, no serious Russian-language scientific studies on either the chemical composition or pharmacological action of generative organs of S. pinnata were found in the literature. This work is part of a comprehensive phytochemical study of S. pinnata. The aim of the work is to study the qualitative and quantitative composition of flavonoids in the studied object.Aim. To isolate, identify and quantify flavonoids in flowers and buds of Staphylea pinnata L.Materials and methods. Alcohol-water extracts from dried generative organs of the studied plant were used as analyzed solutions. Solutions were analyzed on a spectrophotometer SF-2000 (LLC "OKB Spectr", Russia) after sample preparation with aluminum chloride and on an HPLC Nexera-i LC-2040 (Shimadzu Corporation, Japan) equipped with a column and sample thermostat, degasser and autosampler using an individually selected elution gradient of the mobile phase (0.1 % orthophosphoric acid/acetonitrile solution). The primary data were processed using LabSolutions Single LC software (Shimadzu Corporation, Japan). Compounds from the flavonoid group were identified by retention times. Detection was carried out using a UV detector with an absorption wavelength of 365 ± 2 nm.Result and discussion. Alcohol-water extracts from flowers and buds of S. pinnata L. were obtained. Quantitative evaluation by spectrophotometry for flavonoid content was carried out. A gradient elution mode for HPLC was selected for simultaneous determination of 7 flavonoid glycosides. These chromatographic conditions allowed the identification and quantification of astragaline, cynaroside, cosmosiin, narcissin and rutin in flowers and buds of Staphylea pinnata L. Flavonoid glycosides: raponticin and kaempferol were not detected.Conclusion. Flavonoid glycosides were isolated from the generative organs of S. pinnata L., a technique for quantitative determination of flavonoid glycosides in alcohol-water extracts was developed, astragalin, cynaroside, cosmosiin, narcissin and rutin were detected and quantified.

The aim of this study was to validate an HPLC-UV method to assess vitamin D status by determining the linearity and precision of the 25-hydroxyvitamin D3 (25(OH)D3) calibration curve, the limits of detection, quantitation and robustness of the method, and its accuracy. A second stock solution of 25(OH)D3 was prepared (500 ng/mL), and working dilutions (5, 10, 20, 30, 40, and 50 ng/mL) were prepared for a calibration curve. The HPLC equipment had a UV-Vis diode-array detector and utilized an AcclaimTM 120 C18 column (5 µm, 4.6 × 250 mm) with a flow rate of 1.2 mL/min, a column temperature of 30 °C, and the standards and samples were maintained at 4 °C, with an injection volume of 100 µL. Detection of 25(OH)D3 was determined at 265 nm, with a retention time of 4.0 min. The validation was conducted according to the FDA Validation of Analytical Procedures: Guidance for Industry. Vitamin D was extracted from plasma samples using acetonitrile (ACN)–0.1% formic acid (2:1 v/v), and the percentage of recovery was calculated. The proposed method conditions gave excellent linearity (R2 = 0.9989) and the linearity coefficient was R2 > 0.99 for 25(OH)D3. The detection and quantification limits were 1.1703 ng/mL and 3.5462 ng/mL, respectively. Decreasing or increasing the reading temperature by 1 °C decreased the response units (AU) of vitamin D, 25(OH)D3. When the current flow rate decreased by 0.2 mL/min (1.0 mL/min), the retention time increased to 4.913 min, whereas an increase of 0.2 mL/min of the proposed flow rate (1.4 mL/min) decreased the retention time to 3.500 min. The percentage of recovery varied from 92.2% to 97.1%. The proposed method to quantify a vitamin D metabolite (25(OH)D3) in human plasma samples was reliable and validated. [ABSTRACT FROM AUTHOR]

The extraction of nandrolone as a steroid hormone using fast methods is of high importance. This was done by dispersive micro-solid phase extraction in the presence of two widely used organometallic frameworks (MIL-53(Al) and ZIF-8). The extraction steps were optimized by an extensive study on the main factors affecting the absorption/desorption efficiency. The optimum conditions were obtained by design of experiments for the extraction and determination of nandrolone in a blank human plasma matrix. Maximum extraction of nandrolone was achieved in 8.5 min by 2.5 mg of MIL-53(Al) in the solution with 0.89% (w/v) salt concentration, while the maximum extraction by ZIF-8 as another sorbent required 10 min, 4.5 mg of sorbent, and 0.60% (w/v) of salt concentration. Batch experiments were carried out to find appropriate kinetic and isotherm models. Finally, the analytical validation of the proposed method was investigated. The dynamic range of the method was from 0.05 to 1 µg/mL. The precision (expressed as the relative standard deviation, RSD) and accuracy (expressed as the percentage error) of extraction by MIL-53(Al) were found 3.90 and 3.39%, respectively, while those by ZIF-8 were calculated as 4.59 and 4.50%, respectively. The proposed method was successfully applied for the determination of nandrolone in spiked samples, achieving high recovery rates of approximately 96% and 94% using MIL-53(Al) and ZIF-8. [ABSTRACT FROM AUTHOR]

A simple and reliable HPLC‐ultraviolet (HPLC‐UV) method was developed and validated for the quantification of pritelivir in the samples of medium from the experiments utilizing the ex vivo technique of dual perfusion of the human placental lobule. Phenacetin was used as an internal standard (IS) in our HPLC‐UV method. Chromatographic separation of pritelivir and phenacetin was achieved on a Waters Symmetry C18 HPLC column (100 × 2.1 mm, 3.5 μm) at ambient temperature (22–25°C). The mobile phase was composed of 50% methanol in deionized water (v/v), the flow rate for isocratic elution was established at 0.25 mL/min, and the detection wavelength for pritelivir and IS was set at 254 nm. Pritelivir and IS were extracted with the protein precipitation method using methanol as a solvent. The calibration curve for pritelivir exhibited linearity (r2 > 0.99) within the concentration range from 0.155 to 6.62 μg/mL. Within‐ and between‐day accuracy ranged from 97% to 110% with relative standard deviation (RSD) values not exceeding 10%. The extraction recovery of pritelivir and IS ranged from 89% to 91% with RSD not exceeding 7%. Pritelivir was stable under the storage and sample handling conditions. This validated HPLC‐UV method was utilized to quantify pritelivir in the placental perfusion medium samples, and the resulting concentrations were authenticated with incurred sample reanalysis to confirm the reliability of the method. [ABSTRACT FROM AUTHOR]

In this study, the analytical and developed method was successfully validated for the simultaneous determination of benzoic acid (BA) and Sorbic acid (SA) by natural deep eutectic solvent (DES) composed of thymol/water and dispersive liquid–liquid microextraction (DLLME) followed by HPLC/UV in orange juice samples. A response surface methodology (RSM) based on a central composite design (CCD) was applied for optimization of the main variables. The significant parameters including DES volume (600 µL), dispersive solvent volume (THF) (709 µL), sample volume (11.1 mL), salt amount (5% w/v), and vortex time (10 min) were optimized. Under the optimal conditions, the limits of detection (LOD) and limits of quantifications (LOQ) were obtained 0.468 and 1.419 mg L−1 for BA and 2.517 and 7.628 mg L−1 for SA, respectively. The recovery values were between 94 and 97%. R2 of BA and SA were 0.9940 and 0.9921, respectively. [ABSTRACT FROM AUTHOR]

In the present review, we discuss the occurrence of ellagitannins (ETs) and ellagic acid (EA) and methods for their isolation from plant materials. We summarize analytical methods, including high-performance liquid chromatography–ultraviolet (HPLC–UV) and liquid chromatography–mass spectrometry (LC–MS), for the determination of ETs, EA and their bioactive metabolites urolithins (Uros) in samples of plant and food origin, as well as in biological samples, such as plasma, urine and feces. In addition, the current interest in the bioactivities of Uros is discussed in brief. [ABSTRACT FROM AUTHOR]

An amide‐based covalent organic framework (COF) was successfully synthesized using the reaction between 1,3,5‐trimesoyl chloride and ethylenediamine. The structure and morphology of the COF were characterized using Fourier‐transform infrared spectra, nuclear magnetic resonance spectroscopy, X‐ray diffraction, scanning electron microscopy, energy‐dispersive X‐ray spectroscopy, and Brunauer‐Emmett‐Teller surface area analysis. The COF was employed as a solid‐phase extraction adsorbent for the sampling and preconcentration of chlorophenols from industrial wastewater samples prior to high‐performance liquid chromatography with ultraviolet detection. The experimental parameters influencing the extraction efficiency including type and volume of eluent solvent, sample solution volume, salt concentration, sample flow rate, and sample solution pH were investigated and optimized using a response surface methodology employing Box‐Behnken‐design. Under optimized conditions, calibration curves exhibited good linearities over the range of 0.003–10 µg/mL with determination coefficients (R2) ranging from 0.9982 to 0.9999. The method's limits of detection ranged from 0.001 to 0.01 µg/mL. Good repeatability was achieved with relative standard deviations below 4.7%. The developed procedure utilizing the COF adsorbent was successfully applied to determine chlorophenols accurately and precisely in various industrial wastewater samples. [ABSTRACT FROM AUTHOR]

Flavonoids are a prominent group of plant phenolics (polyphenol group) extensively present in the human diet and associated with health promotion. Flavonoids are essential in various pharmaceutical, nutraceutical, and cosmetic applications. To collect and categorize these compounds, we comprehensively assessed High-performance liquid chromatography (HPLC) techniques published to analyze flavonoids in various matrices. Most documented methods employed liquid chromatography with ultraviolet detection (HPLC-UV) and tandem mass spectrometry (LC-MS/MS) methods. Among chromatographic techniques, reversed-phase liquid chromatography remains the predominant and efficient method for separating various analytes. This review explores the primary chromatographic methods used to separate and quantify flavonoids in herbs, fruits, and biological samples. This article examines recent literature on applying liquid chromatography with different detection methods for analyzing flavonoids. To examine recent literature on applying liquid chromatography with different detection methods for analyzing flavonoids. It offers valuable insights to researchers as they prepare to develop quantification methods. [ABSTRACT FROM AUTHOR]

Background and Objectives: Gemcitabine has been used to treat various solid cancers, including, since 1997, metastatic pancreatic cancer. Here, we developed an HPLC-UV method to determine serum gemcitabine levels and use it in pharmacokinetic studies. Materials and Methods: The analysis was performed after a single protein precipitation step on a reversed-phase column, isocratically eluted with sodium phosphate buffer and methanol. For the pharmacokinetic study, NOD/SCID mice received a single dose of gemcitabine at 100 mg/kg by either subcutaneous (SC) or intraperitoneal (IP) administration. Blood samples were collected at 5, 15, and 30 min and 1, 2, 4, and 6 h after the administration of gemcitabine for further analysis. Results: The duration of the analysis was ~12.5 min. The calibration curve was linear (r2 = 0.999) over the range of 1–400 μM. The mean recovery of GEM was 96.53% and the limit of detection was 0.166 μΜ. T1/2, Tmax, Cmax, AUC0–t, and clearance were 64.49 min, 5.00 min, 264.88 μmol/L, 9351.95 μmol/L*min, and 0.0103(mg)/(μmol/L)/min, respectively, for the SC administration. The corresponding values for the IP administration were 59.34 min, 5.00 min, 300.73 μmol/L, 8981.35 μmol/L*min and 0.0108(mg)/(μmol/L)/min (not statistically different from the SC administration). Conclusions: A simple, valid, sensitive, and inexpensive method for the measurement of gemcitabine in serum has been developed. This method may be useful for monitoring gemcitabine levels in cancer patients as part of therapeutic drug monitoring. [ABSTRACT FROM AUTHOR]

Each year, new psychoactive substances appear on the global drug market leading to constant changes. Most of these compounds with stimulating effect possess a chiral center, thus leading to two enantiomers with presumably different pharmacological properties. Among them, synthetic cathinones, often misleadingly traded as "bath salts," play an important role. There is little knowledge about the distinct effect of the enantiomers. The aim of this study was to test a commercially available Lux® i‐Amylose‐3 column by HPLC‐UV for enantiorecognition of cathinone derivatives. Overall, 80 compounds were tested in normal phase mode, where 75 substances were separated under initial conditions. After method optimization, at least partial separation was achieved for the remaining compounds. The same set of substances was measured in polar‐organic mode, where 63 analytes were resolved into their enantiomers under initial conditions with very short retention times. Both modes showed complementary results for the individual compounds. Furthermore, the tested methods proved to be suitable for differentiation of positional isomers, which can be useful for drug checking programs. All measurements were carried out under isocratic conditions, and intraday and interday repeatability tests were performed. [ABSTRACT FROM AUTHOR]

Dibenzoazecines are a new class of potential neuroleptics with a high potential for the treatment of schizophrenia. Initial stress tests indicated that the lead compound, LE404, decomposes when exposed to oxygen and sunlight. In this follow-up study, the influence of oxidative stress and photosensitivity was investigated in accordance with the ICH guidelines. These studies are of great importance for new APIs, as phototoxic and photoallergic reactions pose a significant risk to patients, especially with long-term medication, as it is not possible to completely avoid exposure to sunlight. Furthermore, the identification and prediction of the chemical lability of LE404 can be used to determine suitable storage conditions to prevent compound degradation. The effects of exposure of LE404 to a light source similar in spectrum and intensity to natural sunlight were investigated according to ICH-Q1B. Furthermore, the influence of oxidizing agents was investigated under exclusion of light. Two degradation products were identified. The extent and rate of degradation were continuously monitored using RP-HPLC–UV. Chromatographic separations were performed with a phenomenex™ Gemini 5 µm C18 (250 × 4.60 mm) column and acetonitrile/KH2PO4 buffer (4 mmol L−1, pH 2.5) as mobile phase at 220 nm. The photodegradation product was isolated using semi-preparative RP-HPLC. The oxidation product was obtained by quantitative conversion of LE404 in hydrogen peroxide and subsequent purification by preparative TLC. The structures of both degradation products were elucidated using HR-MS/MS, 1D- and 2D-NMR as well as FT-IR spectroscopy. The characterization of the degradation products serves as the basis for subsequent investigations into their toxicity. [ABSTRACT FROM AUTHOR]

Furfural compounds, including 5-hydroxymethylfurfural, furfural, and 5-methylfurfural, are common in foods and pose health risks. This study presents a pipette-tip solid-phase extraction with in-situ derivatization (PT-KF-SPE/ISD) method for rapid analysis of furfural compounds in various food matrices. Utilizing natural kapok fiber as an efficient adsorbent, this method integrates extraction and derivatization into a single step via a simple pull-push operation. Derivatization with 2,4-dinitrophenylhydrazine increases the hydrophobicity and ultraviolet absorption of furfural compounds, enabling sensitive liquid chromatography-ultraviolet detection. The method shows good linearity, sensitivity, and reproducibility, with limits of detection in ranges of 3.9–6.0 ng/mL. Real sample analysis confirms its applicability in detecting furfural compounds in beverages and herbal products, offering a reliable and eco-friendly solution for food safety and quality control. Five greenness assessment metrics demonstrate the method's excellent environmental friendliness. This approach highlights the advantages of combining natural adsorbents with in-situ derivatization for efficient food analysis.

A solid-phase microextraction (SPME) Arrow and high-performance liquid chromatography-UV detector (HPLC-UV, detection at 225 nm) based method was developed for the selective determination of nine alkylphenols (APs) in milk. The functionalized mesoporous UiO-66 (4-meso-UiO-66) was utilized as the new coating material, which was synthesized by post-modification of pore-expanded UiO-66-NH2 by an esterification reaction with 4-pentylbenzoic acid. It was fully characterized by X-ray photoelectron spectroscopy (XPS), fourier transformation infrared spectrometry, nitrogen sorption-desorption test, scanning electron microscopy, transmission electron microscopy, and X-ray diffractometer. The characterization results showed the ester groups and benzene rings were introduced into the 4-meso-UiO-66, and the mesoporous structure was predominant in the 4-meso-UiO-66. The extraction mechanism of 4-meso-UiO-66 to APs is the synergistic effect of Zr-O electrostatic interaction and the size exclusion effect resulting from XPS, selectivity test, and nitrogen sorption-desorption test. The electrospinning technique was utilized to fabricate the 4-meso-UiO-66 coated SPME Arrow and polyacrylonitrile (PAN) was used as the adhesive. The mass rate of 4-meso-UiO-66 to PAN and the electrospinning time were evaluated. The extraction and desorption parameters were also studied. The linear range of this method was 0.2–1000 μg L–1 with a coefficient of determination greater than 0.9989 under the optimal conditions. The detection limits were 0.05–1 μg L–1, the inter-day and intra-day precision (RSD) were 2.8–11.5%, and the recovery was 83.6%–112%. The reusability study showed that the extraction performance of this new SPME Arrow could be maintained after 80 adsorption-desorption cycles. This method showed excellent applicability for the selective determination of APs in milk. [ABSTRACT FROM AUTHOR]

Herein, Polymethyldopamin@Fe3O4 (PMDP@Fe3O4) has been synthesized using a very simple, easy, cost-effective, efficient, and fast method. First, magnetic nanoparticles (Fe3O4) were synthesized. It was followed by accommodating polymethyldopamin (PMDP) on the prepared Fe3O4. The prepared PMDP@Fe3O4 was utilized as a sorbent in the Magnetic Solid Phase Extraction (MSPE) of six selected Polycyclic Aromatic Hydrocarbons (PAHs) including anthracene, fluoranthene, fluorene, naphthalene, phenanthrene, and pyrene. The extracted model analytes were desorbed by a Deep Eutectic Solvent (DES) and were analyzed by High-Performance Liquid Chromatography-Ultraviolet detection (HPLC-UV). The method is validated according to ICH guidelines with respect to precision, accuracy, linearity, specificity, robustness, and limits of detection and quantification. Under the optimized condition, the linearity of the method was in the range of 0.1–500 µg L−1 for the selected analytes. The calibration curves showed a determination of coefficient (r2) higher than 0.9986. The limits of detection (LODs) and limits of quantification (LOQs) were calculated to be between 0.03–0.14 and 0.09–0.46 µg L−1, respectively. The inter-day and intra-day relative standard deviations (RSDs%) were determined to be in the range of 1.7–4.2% in three concentrations. Furthermore, the enrichment factors were found to be 76, 61, 65, 78, 69, and 67 for anthracene, fluoranthene, fluorene, naphthalene, phenanthrene, and pyrene, respectively. Moreover, the calculated absolute recoveries were between 61 and 78%. The results of the real sample analysis and the obtained recoveries indicated that the method was useful and applicable in complicated real samples. PMDP@Fe3O4 nanoparticles were used for the extraction and determination of PAHs. DES was synthesized and used as a desorption solvent. The prepared sorbent showed high extraction performance, high stability, satisfactory reproducibility, and easy preparation. PMDP@Fe3O4 nanoparticles revealed satisfactory extraction recoveries for the MSPE of the PAHs. The method is effective, sensitive, cost-effective, and has wide LDRs and low LODs. [ABSTRACT FROM AUTHOR]

This study aimed to investigate antibiotic residues such as oxytetracycline, ciprofloxacin, enrofloxacin and levofloxacin, in both pasteurised and raw cow’s milk. A method using high-performance liquid chromatography with a UV detector (HPLC-UV) was developed and validated following International Conference on Harmonization (ICH) guidelines for simultaneous detection and quantification of these residues. The technique demonstrated linearity, with r2 values ranging from 0.999 to 1.00 within the 1.3–15.0 μg ml−1 range for each antibiotic. Thirty cow’s milk samples, raw and pasteurised, from Dhaka’s local markets were analysed, revealing the presence of enrofloxacin and levofloxacin, while oxytetracycline was absent in all samples. Notably, pasteurised milk samples contained enrofloxacin, levofloxacin and oxytetracycline, with groups P6 and P7 exceeding the Maximum Residue Limit for enrofloxacin, levofloxacin and ciprofloxacin (121 µg l−1). This study emphasises antibiotic residues in milk, with a validated method holding promise for routine analysis in industries requiring simultaneous quantitation of multiple antibiotics. [ABSTRACT FROM AUTHOR]

The aim of this study was to rapidly determine the presence of anthelmintic drugs in sheep meat using the optimized high‐performance liquid chromatography‐ultraviolet (HPLC‐UV) method with modified QuEChERS (quick, easy, cheap, effective, rugged, safe) technology. Fifty fresh sheep meat samples from different slaughterhouses were collected. A double extraction procedure (QuEChERS/HPLC‐UV technology) was used to extract the target analytes. A multilevel calibration curve from 1 to 1000 g/kg was used to establish instrument linearity for rafoxanide, albendazole, and closantel, whereas 0.1–100 μg/kg was used for ivermectin, levamisole, and oxyclozanide to find the lowest concentration, maximum residue limit (MRL), and occupied range for targeted analytes. The concentration levels were used to investigate the linearity, whereas several certified reference materials were applied to determine accuracy. The process was linear for all combinations, from the limit of quantification (LOQ) to the maximum concentration. The LOQ was established at 0.5 μg/kg for ivermectin, levamisole, and oxyclozanide and 10 μg/kg for rafoxanide, albendazole, and closantel. Recovery values were 70%–120%, and repeatability/reproducibility stated in relative standard deviation was obtained at less than 20%. QuEChERS method revealed that most meat samples contained anthelmintic drug residues, of which the majority exceeded the MRLs. Thus, the drugs should be used correctly in animals to avoid residues in food for human consumption. [ABSTRACT FROM AUTHOR]

In this study, phenolic acid compositions in fourteen taxa of Boraginaceae were analyzed by HPLC-UV to obtain informative chromatographic data. In general, 9 phenolic acid compounds were identified in different studied taxa. m-coumaric acid (1.80-1962.09 mg/kg), salicylic acid (13.22-867.35 mg/kg), ferulic acid (0.00-661.69 mg/kg), and pcoumaric acid (12.10-392.48 mg/kg) were characterized as the main compounds of the studied taxa. The results indicated that m-coumaric acid was the main phenolic acid in Heterocaryum rigidium, Myosotis sylvatica, and Solenanthus stamineus. Furthermore, salicylic acid was the main phenolic acids of Myosotis sylvatica and Nonnea caspica. Also, the highest amounts of ferulic acid and p-coumaric acid were detected in Myosotis sylvatica and Heliotropium europaeum, respectively. The qualitative and quantitative evaluation of these compounds was used for the characterization of the taxa and for revealing their phytochemical similarity and differentiation. Hierarchical cluster analysis showed that the studied taxa were classified into two main clusters (I and II) based on main phenolic acid compounds. Cluster I included Heterocaryum rigidum, Solenanthu stamineus, and Lappula microcarpaa, and the rest studied taxa grouped in cluster II. The chemotaxonomic significance of the isolated compounds was discussed. [ABSTRACT FROM AUTHOR]

Onions (Allium cepa L.) contain various flavonols, including quercetin, kaempferol, anthocyanin, luteolin, and myricetin. Quercetin in onions is considered the primary bioactive component. To assess the impact of quercetin on hyperuricemia in healthy Wistar albino rats, this study used high‐performance liquid chromatography with ultraviolet (HPLC‐UV) to identify and measure quercetin in onion powder. Twenty‐four 160 ± 10 g, six wistar albino male rats in each group were kept: NC (control sample, no onion powder), OT1, OT2, and OT3, which contained 11.13, 14.84, and 18.61 g/100 g onion powder, respectively. The treatment lasted 28 days, during which the last 7 days were for urine, feces, and blood collection. The results showed a trend of decreasing levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase, total bilirubin, total cholesterol, and low‐density lipoprotein in rats fed OT1, OT2, and OT3 diets. Improvements were observed in feed, water, and nutrient intake, feed conversion ratio, feed efficiency ratio, nutrient digestibility, nitrogen balance, body weight, blood urea nitrogen, creatinine, and uric acid levels (p ≤.05). In contrast, high‐density lipoprotein, triglycerides, serum total protein, neutrophils, and lymphocytes did not change (p ≥.05). White blood cells, red blood cell count, platelet count, hemoglobin, and monocytes showed an upward trend. Based on our calculations, we determined the optimal human dosage from the most effective amount of onion powder. By taking into account the ratio of human‐to‐rat surface area, we estimate that the equivalent human dose of onion is 181.04 grams with 204 mg of quercetin. Additionally, when factoring in the dry matter content, the recommended dose of onion is 29.19 grams with 220 mg of quercetin. [ABSTRACT FROM AUTHOR]

In the production of doxofylline, the common occurrence of toxic p‐toluene sulfonate generation prompted the development and validation of a method using HPLC with ultraviolet detection (HPLC‐UV). This method is designed for detecting four potential genotoxic impurities (PGIs) present in both doxofylline drug substance and tablets, with a focus on the UV‐absorbing group p‐toluene sulfonate. The four impurities were methyl 4‐methylbenzenesulfonate (PGI‐1), ethyl 4‐methylbenzenesulfonate (PGI‐2), 2‐hydroxyethyl 4‐methylbenzenesulfonate (PGI‐3), and 2‐(4‐methylphenyl)sulfonyloxyethyl 4‐methylbenzenesulfonate (PGI‐4). In this method, chromatographic separation was achieved using a Waters Symmetry C18 column (250 mm × 4.6 mm, 5 μm). The mobile phases consisted of 20% acetonitrile as mobile phase A and pure acetonitrile as mobile phase B, operating in gradient elution mode at a flow rate of 1.0 mL/min. According to the guidelines of the International Conference on Harmonization, it was determined that this method could quantify four PGIs at 0.0225 μg/mL in samples containing 60 mg/mL. The validated approach demonstrated excellent linearity (R2 > 0.999) across the concentration range of 30%–200% (relative to 0.075 μg/mL doxofylline) for the four PGIs. The accuracy of this method for the four PGIs ranged from 94.8% to 100.4%. The reverse‐phase‐HPLC‐UV analytical method developed in this study is characterized by its speed and precision, making it suitable for the sensitive analysis of benzene sulfonate PGIs in doxofylline drug substances and tablets. [ABSTRACT FROM AUTHOR]

Bacterial respiratory tract infections (e.g., in patients with cystic fibrosis) may be treated with the intravenous infusion of a piperacillin/tazobactam (P/T) solution through an elastomeric device. In the present work, we combined a 24-h drug stability study with an assessment of the drug solution flow rate during an in vitro simulated infusion. Experiments were performed in triplicate with two excipient-free generic P/T solutions and an excipient-containing proprietary P/T solution in saline (all 50/6.25 mg/mL) released from an elastomeric infusion device at 32 °C. The P/T solutions’ stability was assessed by an HPLC-UV assay, pH and osmolality measurements, a visual assessment, and particle counting. Before these analyses, a forced degradation study was performed. To assess the flow rate, a precision scale was used to weigh the solution collected at the infusion line outlet. The stability criteria were

A technique for quantitative determination of biapenem in human blood plasma using HPLC with UV detection was developed to provide therapeutic drug monitoring in a hospital setting. Detection was made spectrophotometrically at 300 nm. The chromatographic procedure lasted 15 min. Precipitation with MeCN was used for sample preparation. The lower limit of quantification was 0.2 μg/mL. The methodology was validated for the main parameters. Linearity was observed over a wide concentration range from 0.5 to 100 μg/mL. The results made it possible to use the developed method for rapid determination of the biapenem content in patient blood plasma, which enabled personalization of the drug doses and increased the efficiency and rationality of antibacterial therapy. [ABSTRACT FROM AUTHOR]

An efficient method is presented for simultaneous enantioselective determination of three chiral triazole fungicides (namely paclobutrazol, hexaconazole, and diniconazole) in water samples by DSPE-HPLC–UV. The perfect chiral separation of the enantiomers was achieved on a Chiralpak IH column within 15 min. In order to adsorb and enrich the analytes from water matrices, a cross-linked hydroxypropyl β-cyclodextrin polymer was synthesized. The prepared material exhibited good adsorption capacity, which was assessed by adsorption kinetic and adsorption thermodynamic experiments. One-variable-at-a-time and the response surface methodology were used to optimize the extraction parameters. Under the optimum sample preparation conditions, good linearity (2.0 ~ 800 µg L−1, R2 ≥ 0.9978), detection limits (0.6 to 1.0 µg L−1), quantitation limits (2.0 to 3.2 µg L−1), recoveries (86.7 ~ 105.8%), and the relative standard deviation (intra-day RSD ≤ 3.7%, inter-day RSD ≤ 5.1%) were obtained, satisfying the requirements of pesticides residues determination. These results demonstrated that the proposed method was applicable for routine determination of chiral triazole fungicide residues in water samples. [ABSTRACT FROM AUTHOR]

Owing to ergosterol content, after UV irradiation yeast become a well-known source of ergocalciferol (vitamin D2). Additionally, pharmaceutical yeast-based supplements may represent a suitable option for treating hypovitaminosis, especially in patients adhering to a vegan diet. Using the high-performance liquid chromatographyultraviolet (HPLC-UV) methodology our study sought to analyse three commercially available yeast-based vitamin D2 supplements while comparing the effect of UV-C irradiation (254 nm) on yeast biomass derived from the brewing process and pure ergosterol. The two compounds were precisely separated under the described conditions in an efficient and quick manner with a retention time (Rt) of 4.152 ± 0.018 minutes for vitamin D2 and 5.097 ± 0.013 minutes for ergosterol. However, when approaching the quantitative analysis, based on our findings, it appears that the pharmaceutical supplements deviate from the declared amount of substance indicated on the label. 15 minutes of UVC irradiation generates vitamin D2 in yeast biomass with a conversion rate of 1.78%. Also, high content of ergosterol, beside vitamin D2 formation after irradiation, may trigger the appearance of secondary products such as tachysterol. [ABSTRACT FROM AUTHOR]

This study aimed to develop a fast, accurate, and precise high‐performance liquid chromatography with UV detection method for simultaneous analysis of underivatized phenylalanine (Phe) and tyrosine (Tyr) in biological samples. Separation of the analytes was accomplished using a Discovery HS F5‐3 column, which offered better retention and peak symmetry for the tested analytes. Chromatographic conditions were optimized using central composite experimental design, and three factors were investigated: the concentration of ammonium acetate (A), the acetonitrile proportion in the mobile phase (B) and the column oven temperature (C). The approach was verified using β‐expectation tolerance intervals for total error measurement that did not exceed 15%. Optimal settings were A = 50 mm, B = 24% and C = 28°C. The method applicability was determined using human plasma from 75 volunteers. The limits of detection and quantification of the technique were satisfactory at 9 and 29 μm for Phe and 4 and 13 μm for Tyr. The mean analytical bias in spiking levels was acceptable, ranging from −1.649 to +1.659% for both substances, with RSD <5% in all instances. The suggested approach was successfully used to analyze Phe and Tyr in human blood samples and calculate the Phe/Tyr ratio. [ABSTRACT FROM AUTHOR]

This work aimed to characterise the morphological traits of olives and physico-chemical of oil issued from 10 endemic cultivars harvested in the north-east of Algeria. The pomological parameters of the fruits showed a very significant difference (p < 0.0001) between the studied cultivars. Quality indices indicated that olive oil varieties belong to the extra virgin and virgin categories. Highly significant differences (p < 0.0001) were noted between the 10 varieties studied for the analytical parameters examined (fatty acid composition, total phenol, chlorophyll, and carotenoid content). Boughenfous showed the highest values in oleic acid with (75.15%) and in total phenols with 435.88 (mg of Gallic acid/kg of olive oil). Phenolic compounds (hydroxytyrosol, tyrosol, oleocanthal, total phenolic compounds) have shown important differences between varieties. The principal component analysis carried out on the profile of total fatty acids distinguishes 5 groups, group 2 and 3 proved to be the most interesting in terms of nutritional characteristics, they include three cultivars, characterised by the highest levels of oleic acid and MUFA and the MUFA/PUFA ratio. These results confirm the importance of the varietal character in determining the chemical characteristics of the oil. To enhance the olive sector, this characterisation must be extended to other secondary olive cultivars that are unexplored. [ABSTRACT FROM AUTHOR]

Monosodium glutamate is a food additive that gives sweetness, sourness, bitterness, and saltiness tastes together. In the present study, a simple and accurate high-performance liquid chromatography with ultraviolet spectrophotometer detector method was developed for the determination of monosodium glutamate in both dried and moist food samples. This method was carried out on different eleven food samples including potato chips, soups, and vegetable concentrates from the local market in Jordan. The approach was based on the derivatization step of MSG with 1-fluoro-2,4-dinitrobenzene. A good chromatographic separation is obtained by using a 5-micro meter particle size octadecyl column and one-to-one methanol: water mixture as mobile phase. The results in the calibration curve were linear with a correlation coefficient R2 was 0.9533. The tested food samples contained various MSG contents (the highest content was in the Mexicana chips sample 353 ± 7 ppm). The contents of monosodium glutamate in most investigated food samples were between 170 and 350 ppm. These contents are allowed according to the general standards of the codex Alimentarius Commission for food additives. [ABSTRACT FROM AUTHOR]

Green leafy vegetables are a rich source of micronutrients but can usually contain contaminants such as pesticides and toxic heavy metals. In this work, we have evaluated the effectiveness of washing with tap water, vinegar-acidified water and basified water with sodium bicarbonate in eliminating three pesticides (methomyl, deltamethrin and lambda-cyhalothrin) and some exogenous heavy metals. The HPLC-UV method was validated for pesticides analysis in vegetable matrices using the QuEChERS method extraction. The results showed that a ca. of 57 to 71% and 73 to 97% of the 3 pesticides are removed after washing with acidified and basified water, respectively. On the other hand, the ICP-MS method was used for analysing heavy metals and essentials elements in spinach. Washing with both acidic and alkaline water removed a part of toxic heavy metals. The decrease in metals concentrations indicated that, probably, the metals contamination of vegetables was mainly through the foliar deposition. Acidified and basified water solubilise small particles containing these exogenous metals In conclusion, the performance of washing with the basic medium was better to remove pesticides and some of exogenous toxic heavy metals from the surfaces of spinach leaves and to preserve the essential elements of the plant. [ABSTRACT FROM AUTHOR]

Olaparib is a small-molecule inhibitor of poly(ADP)-ribose polymerase (PARP) used as maintenance therapy for recurrent ovarian cancer and newly diagnosed advanced ovarian cancer after initial chemotherapy. An exposure-toxicity correlation has been reported between the probability of anemia, a common adverse event associated with olaparib, and the steady-state minimum plasma concentration (Cmin) as well as the predicted maximum plasma concentration (Cmax). On the other hand, olaparib exhibits high interpatient variability with regard to the area under the concentrationtime curve, Cmax, and Cmin. Therefore, we developed a simple and sensitive assay based on highperformance liquid chromatography with ultraviolet light (HPLC-UV) for the therapeutic drug monitoring of olaparib. The analysis was performed on an octadecylsilyl column with a mobile phase consisting of 0.5% KH2PO4 (pH 4.5) and acetonitrile (71:29, v/v), at a flow rate of 0.8 mL/min. Olaparib and an internal standard (imatinib) were well separated from the co-extracted material, with retention times of 13.6 and 11.5 min, respectively. The calibration curve for olaparib showed linearity over the concentration range of 0.10-10.0 μg/mL (r² = 0.9998). The intra- and interday validation coefficients ranged from 1.79 to 4.13% and 1.37 to 3.55%, respectively. Measurement accuracy ranged from - 6.07 to 3.26%, with a recovery rate of more than 91.06%. The developed method was then applied to evaluate the plasma olaparib concentrations in patients with ovarian cancer. Our findings demonstrate that HPLC-UV is an economical, simple, and sensitive method for clinical application and holds promise for the effective drug monitoring of olaparib during ovarian cancer treatment. [ABSTRACT FROM AUTHOR]

Animal products are a major source of human exposure to steroids, this resulted in a critical request for applicable methods for the determination of these steroid hormones in pure form and in different matrices such as hen eggs, chicken liver and water. The aim was to develop a reliable LC-UV and LC-MS/MS for the determination of selected steroid hormones in edible samples, using SFE and LLE for sample preparation. LC-MS/MS method was validated for separation and quantification of selected steroid hormones; Ethinyl oestradiol, testosterone, 17 alpha methyltestosterone, and progesterone, using mobile phase of methanol and 0.1% Formic in ratio (70:30) at different m/z ratios. The developed method has satisfactory linearity and the spiking recoveries of the steroid hormones were between 90.25% and 99.45% with RSDs lower than 5%. The results demonstrated that the developed approach has high sensitivity and repeatability and can be helpful in the determination of steroid residues in complex food matrices. [ABSTRACT FROM AUTHOR]

Amphotericin B (AMB) is a polyene macrolide antifungal agent used for treating invasive fungal infections. Liposomal AMB is a lipid dosage form, available as AmBisome, which reduces the toxicity of the drug. A simple HPLC‐UV method was developed for the determination of AMB in plasma to study its pharmacokinetic profile in a critical patient receiving AmBisome and treated with extracorporeal replacement therapies. Sample preparation was performed using plasma deproteinization and drug release from liposome by the addition of acetonitrile (ACN)/zinc sulfate and ultrasonication. Chromatographic separation was performed using a C18 column and a mobile phase consisting of phosphate buffer (pH 3.0)/ACN (65/35, v/v). The UV detector was set at 407 nm. The total run time analysis was 23 min. The method was validated according to the standard guidelines and applied to study the pharmacokinetics of AMB in a critical patient. The total run time analysis obtained was shorter than that of the previously reported methods, being useful for therapeutic drug monitoring or pharmacokinetic profile research. [ABSTRACT FROM AUTHOR]

Citrus fruits exert various beneficial health effects due to the large amount of polyphenols they contain. Citrus peels, often considered food waste, contain several health-promoting polyphenols. Among these, flavonoids have long been quantified through colorimetric assays which, if not adequately applied, can lead to conflicting results. Flavonoids possess strong antioxidant properties and can decrease circulating free radicals, thereby reducing oxidative stress phenomena. Quantifying flavonoids and properly estimating their antioxidant capacity allows us to predict plausible beneficial effects of citrus fruits on human health. The aim of this research was to analyze the advantageous phenolic compounds found in the peels of citrus fruits commonly found in the Mediterranean region. The objective was to measure their antioxidant capacity and ability to neutralize free radicals. To achieve this purpose, UV-visible spectrophotometric analyses, liquid chromatography (LC) and Electron Paramagnetic Spectroscopy (EPR) were utilized and compared, finally suggesting an innovative approach for assessing the overall flavonoid content by the nitrite-aluminum assay. HPLC data demonstrated that hesperidin was the most abundant flavonoid in all peel extracts except for orange peels, in which naringin was the predominant flavonoid. The total flavonoid content was greater than 1.3 mg/mL in all extracts, with tangerine and orange yielding the best results. Citrus peel polyphenols exerted strong antioxidant and free radical scavenging effects, inhibiting up to 75% of the free radicals used as reference in the EPR analyses. [ABSTRACT FROM AUTHOR]

COVID-19 is a serious virus that can have a lot of effects, one of which is a secondary bacterial infection that can be more life-threatening and even lethal than the initial viral infection. Hence a fast and sensitive HPLC/UV method was developed and validated for the first estimation of a binary mixture of molnupiravir (MOL) and ertapenem (ERT) as a co-administrated medicine for the management of COVID-19 in pharmaceutical dosage forms, and human plasma samples. The drug combination was separated within 5 min via RP-ODS column using isocratic elution with a mobile phase of 0.05 M phosphate buffer (pH 3.5): acetonitrile with a 76: 24% ratio v/v. The presented method provided a linear response ranging from 0.03 to 17.0 and 0.05–20 µg mL−1 with LOD values of 0.009 and 0.008 µg mL−1 for MOL and ERT respectively. The good separation and high sensitivity of the HPLC method provide the determination of the cited drugs in human plasma without matrix interference with a percent of recovery ranging from 94.97 ± 2.05 to 98.44 ± 1.92. Based on the results, this method could be utilized to monitor cited drugs in quality control and therapeutic laboratories. [ABSTRACT FROM AUTHOR]

Polysaccharide fractions were isolated from the aerial part of Serratula centauroides. The monosaccharide compositions of the polysaccharide fractions were determined by HPLC-UV. The quantitative contents of free sugars in the aerial part and subterranean organs of S. centauroides growing in the Republic of Buryatia were determined by capillary electrophoresis. The effect of mechanically activated milling of the aerial part of S. centauroides on the sugar yield was studied. [ABSTRACT FROM AUTHOR]

Abstract We developed poly-ε-caprolactone (PCL)-based nanoparticles containing D-α-tocopherol polyethylene glycol-1000 succinate (TPGS) or Poloxamer 407 as stabilizers to efficiently encapsulate genistein (GN). Two formulations, referred to as PNTPGS and PNPol, were prepared using nanoprecipitation. They were characterized by size and PDI distribution, zeta potential, nanoparticle tracking analysis (NTA), GN association (AE%), infrared spectroscopy (FT-IR), and differential scanning calorimetry (DSC). PNTPGS-GN exhibited a particle size of 141.2 nm, a PDI of 0.189, a zeta potential of -32.9 mV, and an AE% of 77.95%. PNPol-GN had a size of 146.3 nm, a better PDI than PNTPGS-GN (0.150), a less negative zeta potential (-21.0 mV), and an AE% of 68.73%. Thermal and spectrometric analyses indicated that no new compounds were formed, and there was no incompatibility detected in the formulations. Cellular studies revealed that Poloxamer 407 conferred less toxicity to PCL nanoparticles. However, the percentage of uptake decreased compared to the use of TPGS, which exhibited almost 80% cellular uptake. This study contributes to the investigation of stabilizers capable of conferring stability to PCL nanoparticles efficiently encapsulating GN. Thus, the PCL nanoparticle proposed here is an innovative nanomedicine for melanoma therapy and represents a strong candidate for specific pre-clinical and in vivo studies.