HPLC-UV Method Research Articles

Ruhao Dashi granules exert therapeutic effects on H1N1 influenza virus infection by altering intestinal microflora composition.

Antiviral medications for influenza could be ineffective due to the emergence of resistant influenza virus strains. Ruhao Dashi (RHDS) granules possess anti-inflammatory and antibacterial effects. The present study aimed to determine the efficacy of RHDS granules in treating influenza-infected mice and the mechanism underlying this treatment as well as its effect on the intestinal flora composition of the infected mice. The HPLC-UV method was used to identify the active components of RHDS granules. ICR mice were infected with influenza A virus (IAV) H1N1 subtype through a nasal drip. After the influenza mice model was successfully established, the pathological changes in the lungs were observed for 5 days after gavage treatment with 0.9% sterile saline and low, medium, and high doses (0.07, 0.14, and 0.28 g/mL, respectively) of RHDS granules. The serum levels of the cytokines IL-6 and TNF-α and sIgA were detected by ELISA. Real-time fluorescence quantitative PCR and western blotting assay were performed to determine the expression levels of the tight junction (TJ) proteins claudin-1, occludin, and zonula occludens-1 (ZO-1) in colon tissues. Furthermore, 16S rRNA gene sequencing of feces samples was conducted to assess the effect of RHDS granules on the gut microbiota. RHDS granules exerted a protective effect on the lung tissues of IAV-infected mice; moreover, the granules reduced the synthesis of proinflammatory cytokines and increased the relative expression levels of claudin-1, occludin, and ZO-1 in colon tissues. Furthermore, RHDS granule treatment increased the relative abundance of Lactobacillus, Akkermansia, and Faecalibaculum and decreased the relative abundance of Muribaculaceae; thus, RHDS granules could stabilize the intestinal microbiota to some extent. RHDS granules exert a therapeutic effect on IAV-infected mice probably by modifying the structural composition of their intestinal microbiota.

Method Development and Validation of Stability-Indicating HPLC-UV Method for Determination of 5 -Fluorouracil

Introduction: In the realm of pharmaceutical analysis, the development and validation of a High-Performance Liquid Chromatography with Ultraviolet Detection (HPLC-UV) method for the precise determination of 5-FU stand as a crucial endeavor. Methods: This study outlines the systematic process of method development, optimization, and subsequent validation to ensure the reliability and applicability of the method in pharmaceutical quality control. Method optimization included the selection of an appropriate stationary phase, mobile phase composition, and chromatographic conditions to achieve optimum resolution, sensi-tivity, and run time. Results: A speedy, simple, and dependable HPLC technique for quantifying 5-FU on a C18 (250 4.6 mm, 5m particle size) column with solvent A included 10 mM phosphate buffer with pH 3.0 and solvent B with acetonitrile as the mobile phase. At 250 nm, the effluent was measured. Fur-ther, 5-FU had a retention time of 1.698 minutes. Conclusion: According to ICH criteria, the devised technique was validated for precision, accu-racy, linearity range, robustness, and ruggedness.

Assessing pharmacokinetics and drug-drug interactions of the combination therapy of myelofibrosis with ruxolitinib and lenalidomide by a new eco-friendly HPLC method for their simultaneous determination in plasma.

Ruxolitinib (RUX), a Janus kinase 2 (JAK2) inhibitor, and lenalidomide (LEN), an immunomodulatory agent, have recently been proposed as a combined treatment for myelofibrosis (MF). This combination has demonstrated improved efficacy, safety, and tolerability compared to monotherapy. To further refine these findings, an efficient analytical tool is needed to simultaneously determine RUX and LEN concentrations in blood plasma. This tool would enable the study of their pharmacokinetics, drug-drug interactions, and therapeutic monitoring during MF therapy. Unfortunately, such a method has not been existed in the literature. This study presents the first HPLC method with UV detection for the simultaneous quantitation of RUX and LEN in plasma. The method was validated according to the ICH guidelines for bioanalytical method validation. It exhibited linearity in the concentration ranges of 10 to 3150 ng mL- 1 for RUX and 80 to 5200 ng mL- 1 for LEN. The limits of quantitation were determined to be 25 and 90 ng mL- 1 for RUX and LEN, respectively. All other validation parameters were satisfactory. The HPLC-UV method was successfully employed to study the pharmacokinetics and drug-drug interactions of RUX and LEN in rats following oral administration of single doses. The results demonstrated that the pharmacokinetics of both drugs were changed substantially by their coadministration. LEN exhibited synergistic effects on the maximum plasma concentration (Cmax) and total bioavailability of RUX, meanwhile it exhibited diminishing effect on the values of volume of distribution (Vd) and clearance (CL). Additionally, RUX decreased the Cmax and total bioavailability of LEN, meanwhile it increased its Vd and CL. These data suggest that the use of RUX, as a combination with LEN, is a better therapeutic approach for MF, compared with RUX as a monotherapy. The effects of LEN on the pharmacokinetics of RUX should be considered and can be useful in determining the appropriate RUX dosage and dosing regimen to achieve the desired therapeutic effect when used as a combination therapy with LEN. The method's environmental friendliness was confirmed through three comprehensive tools. This method represents a valuable tool for determining the appropriate dosage and dosing regimen of RUX in combination therapy with LEN to achieve the desired therapeutic effect. Furthermore, it can aid in predicting drug distribution in different patients and assessing the drug accumulation or insufficient drug levels in specific body compartments.

Development and Validation of a Simple UV-HPLC Method to Quantify the Memantine Drug Used in Alzheimer's Treatment.

Memantine, a non-competitive NMDA receptor antagonist, is used to treat Alzheimer's disease. Therefore, loading memantine in nanoparticles (NPs) could be an essential tool to improve the treatment effectiveness while reducing drug toxicity. Even though some approaches have been described to quantify memantine, none reported optimized methods using high-performance liquid chromatography resorting to ultraviolet detection (UV-HPLC) to determine encapsulation in NPs. The present research developed a HPLC method using pre-column derivatization for quantitatively analyzing memantine hydrochloride in NPs. Memantine was derivatized using 9-fluorenylmethyl chloroformate (FMOC). The developed method was fully validated regarding suitability, specificity, linearity, sensitivity, precision, accuracy, and robustness according to the International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use guidelines. The retention time of memantine was 11.393 ± 0.003 min, with a mean recovery of 92.9 ± 3.7%. The new chromatographic method was validated and found to respond linearly over 5-140 μg/mL, with a high coefficient of determination. Intraday precision lay between 3.6% and 4.6%, and interday precision between 4.2% and 9.3%. The stability of memantine was also tested at 4 °C and -20 °C, and no signs of decay were found for up to 6 months. The new method was properly validated and proved simple, sensitive, specific, accurate, and precise for determining memantine encapsulation efficiency in lipid NPs. Greenness was evaluated, presenting a final score of 0.45. In the future, this methodology could also be applied to quantify memantine in different nanoformulations.

Performing a physiologically relevant test for cladribine tablets

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.

Development and Validation of HPLC-UV Method for the Determination of Levothyroxine in Orodispersible Minitablets for Pediatric Application

Background: Thyroid hormones play an important role in cognition and brain development. The determination of the content of levothyroxine, as well as related substances and dissolution test analysis, should be carried out by methods that are selective and highly sensitive due to the low concentration used in low dose orodispersible minitablets Objectives: This study aims to develop and validate an analytical method by HPLC-UV for the quantification of levothyroxine and its related substances in pharmaceutical formulations; looking forward to being this method suitable for a future dissolution test analysis using tandem mass spectrometry detector. Methods: A Hypersil GOLD C18 (100 x 2.1 mm, 3 μm) column was used with 25°C column temperature, 5 μL injection volume, 0.3 mL/min flow rate and detection at 225 nm. The mobile phase consisted of methanol: 0.05% formic acid (55:45). The developed method was validated for specificity, linearity, precision, accuracy and robustness. Results: The method is linear within the range of 2-20 μg mL-1 (R2=0.9982), which makes the method suitable for the evaluation of levothyroxine in pharmaceuticals formulations. LOQ was 0.17 μg/mL (0.85 ng on column) and LOD 0.05 μg/mL (0.25 ng on column) of LT4. Therefore, in terms of efficiency (1671), retention factor, k (6.79), Tailing factor, T (1.09) and resolution, Rs (5.11) the chromatographic method was found to be suitable according to USP 43. Conclusion: The HPLC UV method was found to be linear, specific, precise, accurate and robust, therefore it is suitable for the quality control of levothyroxine in pharmaceutical ODMTs..

Long-Term Stability of Glycopyrrolate Oral Solution Galenic Compound at Different Storage Conditions.

Glycopyrrolate is a competitive muscarinic receptor antagonist used in the treatment of sialorrhea, especially in pediatrics. Degradation research was conducted to better understand the stability of the active pharmaceutical ingredient (API). Using an HPLC-UV method, we evaluated the chemical stability of the oral solution of the galenic compound glycopyrrolate 0.5 mg/mL under different storage conditions. Method validation was performed according to the International Council for Harmonization (ICH) Q2(R2) guidelines. The results of the stability study of the galenic compound in different storage conditions, with the exception of those stored in glass containers at 45 °C for more than 3 months, were stable (100 ± 10% of the nominal concentration). The aim of this work was to study the stability of the galenic compound glycopyrrolate in two different types of containers and at three different storage temperatures. Glycopyrrolate showed degradation beyond the limits only in glass at 45 °C and after 2 months of storage. The results indicate that oral liquid dosage forms of glycopyrrolate are stable for at least 210 days when stored at room temperature or at 4 °C, in glass or PET, for at least 7 months, maintaining product quality according to the standards established by the European Pharmacopoeia, ensuring long-term coverage for pediatric patient therapies.

Chemical detection and analysis of Astragalus-Cassia twig drug pair using UHPLC-Q-TOF-MS and HPLC-UV methods

The classic Astragalus-Cassia twig drug pair has a long history of proven efficacy. However, a fewer studies on material basis of the Astragalus and Cassia twig decoction (ACD) was researched at present. The method of UPLC-Q-TOF-MS for classifying and identifying the main chemical components of ACD was established and the differences in composition between single decoction and co-decoction were compared by using HPLC-UV. The therapeutic role of ACD on type 2 diabetes (T2D) rats was investigated. Thirty-five compounds were resolved from the ACD. Fifteen compounds were deduced from the decoction of Astragalus, whereas nine compounds were identified from Cassia twig. Pairing of herbs make a significant effect on the chemical composition of herbal decoction. ACD can play a more obvious role in alleviating the symptoms of T2D rats, compared to the application of single herb.

Facile preparation of covalent-organic framework composites for magnetic solid-phase extraction of naphthaleneacetic acid in food prior to HPLC-UV analysis

Novel magnetic covalent organic frameworks (COFs) were prepared by one-pot synthetic strategy and employed as an efficient adsorbent for magnetic solid-phase extraction (MSPE) of naphthaleneacetic acid (NAA) in food samples. Depending on the predesigned the hydrogen bonding, π-π and hydrophobic interactions of magnetic COFs, the efficient and selective extraction process for NAA was achieved within 15 min. The magnetic COFs adsorbent combined with HPLC-UV was devoted to develop a novel quantitative method for NAA in complex food. The method afforded good coefficient in range of 0.002–10.0 µg mL-1 and low limit of detection was 0.0006 µg mL-1. And the newly established method afforded less adsorbent consumption, wider linearity and lower LODs than the reported analytical methods. Ultimately, the method was successfully applied to determine NAA in fresh pear, tomato and peach juice. The magnetic COFs based MSPE coupled with HPLC-UV method provided a simple, efficient and dependable alternative to monitor trace NAA in food samples.

Development and validation of a HPLC-UV method for the quantification of major phospholipids in milk

Phospholipids have gained increased interest in the past decades because of their numerous health benefits. Due to the amphiphilic nature of phospholipids, their quantitative analysis requires lengthy procedures. Hydrophilic interaction liquid chromatography (HILIC) with UV detector was used in the present study to effectively separate the major classes of phospholipids found in milk. Phospholipids were effectively separated on a diol-HILIC column using a gradient elution method using acetonitrile and 10 mM ammonium acetate (pH 5 adjusted using acetic acid). Good chromatographic separation of major phospholipid classes: phosphatidylethanolamine (PE), phosphatidylcholine (PC), and sphingomyelin (SM) was possible at 203 nm. The developed method was validated for both phospholipid standards and milk fat. The correlation coefficient for phospholipids using a linear regression equation for 1–50 μg/mL standard solutions and milk fat were >0.99 and >0.98, respectively. The relative standard deviation for intra-day and inter-day repeatability of phospholipids were less than 6 %, and recoveries fell within the 75-120% range. The developed method was applied for the quantification of phospholipids (PC, PE, and SM) in milk from indigenous and crossbred cattle. Gir, Sahiwal, and Karan Fries cows had no significant difference in PE and PC, while Gir cows exhibited significantly higher levels of SM.

An HPLC-UV Method to Assess Human Plasma 25(OH)D3.

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.

Quantification of the Plasma Concentration of Vadadustat by High-Performance Liquid Chromatography with Ultraviolet Detection and Ultra-Performance Liquid Chromatography-Tandem Mass Spectrometry.

An inexpensive, simple, and accurate plasma concentration measurement system is needed to actively conduct pharmacokinetic and pharmacodynamic analyses of vadadustat, hypoxia-inducible factor-prolyl hydroxylase inhibitor, in clinical settings. In this study, the authors aimed to develop a method for measuring vadadustat in human plasma that could be applied for therapeutic drug monitoring using high-performance liquid chromatography with ultraviolet detection (HPLC-UV) in a clinical setting. Plasma samples (100 μL) were pretreated with acetonitrile using butyl paraoxybenzoate as an internal standard. Chromatographic separation was performed on a SunShell PFP C18 column (2.6 μm, 4.6 mm × 150 mm). The mobile phase consisted of (A) 20 mM of phosphate buffer (pH 2.4) and (B) acetonitrile (60:40, v/v), delivered isocratically at a flow rate of 1 mL/min. The analytes were detected by UV absorbance at a wavelength of 220 nm, and the column temperature was 40°C. To evaluate the applicability of HPLC-UV in a clinical setting, blood samples were collected at 19 time points from 7 patients who had been taking vadadustat. The calibration curve was linear over the concentration range of 0.2-150 mcg/mL (R2 > 0.99). Intra-assay and interassay accuracy, precision, and stability met the Food and Drug Administration recommendations. The vadadustat plasma concentrations of patients analyzed using the current HPLC-UV method were almost equal to those measured using ultra-performance liquid chromatography-tandem mass spectrometry (mean difference: 0.13 mcg/mL). Large variability in the dose-adjusted plasma concentrations of vadadustat at 12 hours after administration was observed between patients (coefficient of variation = 57.6%). This HPLC-UV method is a simple, accurate quantification method for evaluating plasma concentrations in patients taking vadadustat in a clinical setting.

Validation of a bioanalytical HPLC-UV method to quantify Α-Bisabolol in rat plasma applied to pharmacokinetic pilot study with the drug nanoemulsion.

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 1ml/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.

Neuroprotective Effect of Boswellia serrata against 3-NP Induced Experimental Huntington’s Disease

Objectives:: The study aimed to assess the neuroprotective effect of Boswellia serrata against 3-NP-induced experimental Huntington’s disease. Background:: Previous studies have shown Boswellia to have sedative, analgesic, and anti-tumour effects. Boswellia serrata yields four pentacyclic triterpene acids and boswellic acid, a bioactive substance that prevents leukotriene biogenesis. Methods:: The potential neuroprotective effect of Boswellia serrata against 3-nitro propionic acid (3-NP)-induced Huntington's disease (HD) was examined at oral doses of 45 mg/kg, 90 mg/kg, and 180 mg/kg. In this study, HD was induced by 3-NP at a dose of 10 mg/kg in Wistar rats. The study used 56 Wistar rats (8 per group) for biochemical (inflammatory markers, acetylcholinesterase activity) and behavioural (elevated plus maze, Y-maze, open-field, tail suspension tests, etc.) assessments. Additionally, a histological examination of the brain was carried out. In addition, the analysis of Boswellia serrata extract was performed by different analytical techniques, like UV spectrophotometer, FTIR, and HPLC methods. Results:: In the brain, succinate dehydrogenase is a mitochondrial enzyme irreversibly inhibited by 3-NP. Administration of 3-NP resulted in HD with altered behavioural and motor changes in rats. Treatment with Boswellia serrata resulted in remarkable protection of rats against 3-NP-induced behaviour and motor deficits in a dose-dependent manner. Moreover, in rats administered with 3-NP, Boswellia serrata improved memory performance and lowered levels of inflammatory biomarkers. These results have also been supported by histopathological analysis. Acetyl-11-keto-p-boswellic acid was found to be the main active component of Boswellia serrata extract. Conclusion:: Boswellia serrata at a dose of 180 mg/kg exhibited better protection compared to the other doses against HD induced by 3-NP. More detailed studies based on molecular targets are needed for the Boswellia serrata to transition from the bench to the bedside for use as an adjuvant in HD patients.

HPLC-UV method for the quantification of a novel indole-thiazole derivative (CS08) in nanoparticles

BackgroundValidation of an analytical method for the quantification of a drug candidate molecule is the first step. The quantification method is fundamental in the pharmaceutical industry, as it allows the development of a pharmaceutical product, such as encapsulation in nanocarriers. ObjectiveTo validate the quantification method of a novel indole-thiazole derivative (CS08) by HPLC-UV in nanoparticles. MethodsWe developed a quantification method using an HPLC coupled to a UV detector, and evaluated the method for its selectivity, linearity, precision, accuracy, LOD, LOQ, and robustness. With the method, we evaluated the stability of CS08 in different pHs simulating biological media and quantified the encapsulation rate in dextran- or fucoidan-coated nanoparticles. ResultsIt was possible to quantify CS08 using the method in different matrices, proving to be a selective, linear, precise, accurate, and robust method in the determined concentrations (1–20 µg.mL−1). The LOD and LOQ were low on a microgram scale, which facilitates the quantification of CS08 for the development of pharmaceutical formulations, showing confidence in the results obtained from the rate of encapsulation in nanoparticles. ConclusionThe validated method proved to be adequate for the quantification of CS08 in different matrices, allowing the evaluation of its encapsulation rate in nanoparticles.

Phytochemical composition and antitumor activity of a new arctic lichen Anamylopsora pakistanica

For the first-time, chemical composition and in vitro antitumor activity was investigated of a newly described lichen Anamylopsora pakistanica Usman & Khalid from the second highest plateau of the world (Deosai Plains, Pakistan). HPLC–UV method was used for identification of secondary metabolites and the acetone extract had higher values of TPC (41.90 mg GA/g) and TFC (75.37 mg RE/g) as compared to methanol extract. As chemical constituents 5,7-dihydroxy-6-methylphthalide, haematommic acid and alectorialic acid, were identified as major compounds. Atranol, alectorialin, gyrophoric acid and usnic acid were detected as minor substances. Acetone and methanol extracts induced a dose-dependent and time-dependent decrease in the viability of three types of tumour cells HeLa, HCT116 and MDA-MB-231. This lichen extract can induce S phase arrest in HeLa as compared to the untreated cells. Extract of this unique lichen, A. pakistanica, can be used safely as a significant source of biologically active compounds.

Ceftobiprole quantification in human serum by HPLC-UV to implement routine TDM in clinical practice

Background and aimsCeftobiprole is a recent 5th generation parenteral cephalosporin with antibacterial activity against a large range Gram+ and Gram− bacteria. Therapeutic drug monitoring (TDM) is an essential tool for maintaining plasma concentrations of antibiotics above the MIC by the end of the dosing interval, thus preventing the resistant strain diffusion. TDM is already recommended for other cephalosporins, and it is a reasonable tool contributing to the safety and efficacy of these drugs. During the treatment of patients in real-life, a number of pharmacokinetic (PK) changes not normally seen in healthy volunteers can occur which can impair the pharmacokinetic/pharmacodynamic target attainment.We aimed to develop simple and rapid HPLC-UV method for determination of ceftobiprole in human serum to implement TDM in clinical practice and support PKs and pharmacokinetic/pharmacodynamic (PK/PD) studies. Materials and methodsSamples preparation of calibration standards, QC, and anonymous patients serum samples was performed by protein precipitation by adding 0.01 ml of sulphosalicylic acid at 30 % to 0.1 ml of each sample. Then samples were vortexed and the centrifuged at 12,000 rpm for 10 min at 4 °C. Fifty microlitres of clear supernatant were diluted 1:1 with mobile phase and transferred into HPLC autosampler held at 8 °C. Chromatographic separation was carried out in a gradient mode at 35 °C on an ultra-Biphenyl column using a Thermo Scientific chromatographic system with a Diode array. Data management was performed with Chromeleon 7.4 software. ResultsThe HPLC-UV method proved to be linear over wide concentration ranges (0.5–50.0 mg/L) and was accurate and reproducible in the absence of matrix effects, allowing for robust, specific, and rapid quantification of ceftobiprole from a low amount of serum (0.1 mL). The mean steady state Ctrough and Cend values measured in the anonymous patients’ samples were 6.26 ± 3.81 mg/L and 22.56 ± 15.69 mg/L, respectively. ConclusionsWe report a broadened simple and fast HPLC with UV detection method for quantification of ceftobiprole in human serum to implement ceftobiprole TDM as clinical routine, and support future (PK/PD) studies in special patients’ population.

Pesticide residues in traditional and industrial honey marketed in Morocco and potential health risk

ABSTRACT 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).

Xác định acetamiprid bằng phương pháp quang học sử dụng dung dịch nano vàng được ổn định bằng Polydiallyldimethylammoni clorua

On this research, the development of a simple, cost-efective and highly sensitive spectrophotometric method for acetamiprid detection based on the localized surface plasmon resonance of polydiallyldimethylammonium chloridestabilized gold nanoparticles. By naked eyes, one can detect acetamiprid by the visual change of gold solution color from red to purple, corresponding to the shift of maximum absorbance wavelength in the UV-Vis spectrum. Quantification of acetamiprid is possible through a linear relationship between the maximum absorbance wavelength and the acetamiprid concentrations in the range of 8×10-8 -2×10-6 M. Under the optimum conditions including pH 5, NaCl concentration of 0.02 M and incubation time 20 min, the present method has high precision (RSD &lt; 5%), very low limit of detection (LOD) of 2.7×10-8 M, limit of quantification (LOQ) of 8.2×10-8 M. This method has been successfully applied to determine acetamiprid in several pesticide samples and vegetable samples. The measurement results of acetamiprid in the pesticide samples of the research method with the HPLC-UV method showed a difference of &lt; 2%, while for the vegetable sample, the difference between the research method and the LC-MS/method method/ MS &lt; 5% shows that the method has high accuracy and reliability.

Development and Validation of a Simple and Reliable HPLC-UV Method for Determining Gemcitabine Levels: Application in Pharmacokinetic Analysis.

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.