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1.
Biomed Chromatogr ; 34(10): e4925, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32557742

RESUMO

Concentrations of fluoroquinolones, which are used in the treatment of many bacterial infections, should be monitored in biological fluids as they exhibit concentration-dependent bactericidal activity. In this study, a liquid chromatography method for the determination of levofloxacin, ciprofloxacin, moxifloxacin and gemifloxacin in human urine and plasma was developed for the first time. The efficiency of five different columns for the separation of these fluoroquinolones was compared. Experimental parameters that affect the separation, such as percentage of organic solvent, pH, temperature, gradient shape and detector wavelength, were optimized by a step-by-step approach. Using a pentafluorophenyl core-shell column (100 × 4.6 mm, 2.7 µm), the separation of four analytes was accomplished in <7.5 min. The developed method was validated for the determination of analytes in both urine and plasma with respect to sensitivity, specificity, linearity (r ≥ 0.9989), recovery (79.46-102.69%), accuracy, precision and stability (85.79-111.07%). The intra- and inter-day accuracies were within 89.55-111.94% with relative standard deviations of 0.35-8.05%. The feasibility of method was demonstrated by analyzing urine and plasma samples of patients orally receiving levofloxacin, ciprofloxacin or moxifloxacin. The developed method is suitable for therapeutic drug monitoring of these fluoroquinolones and can be applied to pharmacokinetic and toxicological studies.


Assuntos
Cromatografia Líquida de Alta Pressão/instrumentação , Cromatografia Líquida de Alta Pressão/métodos , Fluoroquinolonas/sangue , Fluoroquinolonas/urina , Monitoramento de Medicamentos , Fluorbenzenos/química , Humanos , Modelos Lineares , Fenóis/química , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
2.
J Chromatogr Sci ; 58(2): 127-135, 2020 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-32154562

RESUMO

A rapid, precise and robust HPLC separation procedure has been developed and optimized for the determination of a series of drugs of different therapeutic classes: chlortetracycline, oxitetracycline, cefoperazone, diclofenac, tiamphenicol, marbofloxacin, ciprofloxacin, danofloxacin, enrofloxacin and flumequine. The chromatographic method used a monolithic C18 column and both diode array and fluorescence detection. This procedure was validated for the analysis of drugs in cow urine, using a simple and fast procedure with methanol/acetonitrile, allowing the simultaneous and efficient extraction of most of the studied drugs. The proposed method was successfully applied to the determination of enrofloxacin in cow urine, collected after the administration of this antibiotic.


Assuntos
Antibacterianos/urina , Cromatografia Líquida de Alta Pressão/métodos , Drogas Veterinárias/urina , Animais , Enrofloxacina/urina , Fluoroquinolonas/urina
3.
Biomed Chromatogr ; 33(7): e4532, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30861568

RESUMO

WCK 771 is an l-arginine salt of levonadifloxacin (LND) being developed in intravenous dosage form and has recently completed a phase III trial in India. The pharmacokinetics of WCK 771, a novel anti-MRSA fluoroquinolone, were examined in mice, rats, rabbits, dogs, monkeys and humans after systemic administration during pre-clinical and clinical investigations. Urine and serum were evaluated for identification of metabolites. It was observed that LND mainly follows phase II biotransformation pathways. All of the species showed a different array of metabolites. In mice, rabbit and dog, the drug was mainly excreted in the form of O-glucuronide (M7) and acyl glucuronide (M8) conjugates, whereas in rat and human major metabolite was sulfate conjugate (M6). Monkeys exhibited equal distribution of sulfate (M6) and glucuronide conjugates (M7, M8). In addition to these three major phase II metabolites; five phase I oxidative metabolites (M1, M2, M3, M4 and M5) were identified using liquid chromatography tandem mass spectrometry. Out of these eight metabolites M2, M3, M5, M7 and M8 are reported for the first time.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Fluoroquinolonas/farmacocinética , Fluoroquinolonas/urina , Espectrometria de Massas em Tandem/métodos , Animais , Cães , Fluoroquinolonas/química , Fluoroquinolonas/farmacologia , Haplorrinos , Humanos , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Camundongos , Coelhos , Ratos
4.
J Chromatogr A ; 1587: 42-49, 2019 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-30558844

RESUMO

In the present work, the preparation of a new selective molecularly imprinted polymer (MIP) for the family of fluoroquinolones (FQs) in the pores of polypropylene hollow fibers (HFs) is proposed. The resulting MIP-HFs, which combine solid-phase microextraction (SPME) and molecular imprinting technologies, were used to develop a selective microextraction methodology (MIP-HFM) to determine selected FQs danofloxacin, norfloxacin, enrofloxacin and ciprofloxacin in real samples of environmental and biological interest. Measurements during the optimization of the MIP-HFM and its application to the analyses of real samples were performed by HPLC-UV and HPLC-MS/MS. In order to establish optimum rebinding conditions, the effect of key experimental parameters such as loading media, extraction time and stirring-rate were studied. The developed MIP composites exhibited recognition properties towards the selected hydrophilic antibiotics in non-polar media (toluene) and in polar protic systems such as methanol and methanol/water solutions, up to 20% water content. Recoveries by the developed method for all FQs tested in surface water, groundwater and urine spiked with the analytes of interest at two different concentration levels were within 9.4-24.5 %, with a relative standard deviation, generally <20% (n = 3). The detection limits were within 0.1-10 µg L-1, depending upon the antibiotic and the type of sample.


Assuntos
Antibacterianos/isolamento & purificação , Fluoroquinolonas/isolamento & purificação , Impressão Molecular , Microextração em Fase Sólida/métodos , Antibacterianos/análise , Cromatografia Líquida de Alta Pressão , Fluoroquinolonas/análise , Fluoroquinolonas/urina , Humanos , Limite de Detecção , Polímeros/química , Espectrometria de Massas em Tandem , Tolueno/química , Urina/química , Água/química
5.
BMC Res Notes ; 11(1): 497, 2018 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-30029611

RESUMO

OBJECTIVE: The present study analyzed whether renally eliminated antibiotics achieve sufficient urinary concentrations based on their pharmacokinetic/pharmacodynamic principles to effectively eradicate organisms deemed resistant by automated susceptibility testing. RESULTS: Lower median minimum inhibitory concentrations against enterobacteriaceae were noted for ceftriaxone, cefepime, and doripenem when comparing Etest® to Vitek®. All Pseudomonas aeruginosa isolates were susceptible to cefepime, ciprofloxacin, and doripenem with both susceptibility methods, but higher median minimum inhibitory concentrations were observed with Etest®. Urine concentrations/time profiles were calculated for standard doses of ceftriaxone, cefepime, doripenem, and ciprofloxacin. The data presented in the current study suggests high urine concentrations of antibiotics may effectively eradicate bacteria which were determined to be resistant per in vitro susceptibility testing.


Assuntos
Antibacterianos/urina , Farmacorresistência Bacteriana , Pseudomonas aeruginosa/efeitos dos fármacos , Adolescente , Adulto , Ciprofloxacina/urina , Fluoroquinolonas/urina , Humanos , Testes de Sensibilidade Microbiana
6.
Artigo em Inglês | MEDLINE | ID: mdl-30007902

RESUMO

A novel optical sensors for lomefloxacin based on the plasma resonance properties of silver nanoparticles (AgNPs) for the first time. The hydrogen bonds and electrostatic force between the lomefloxacin and AgNPs could induce the change in color and absorption spectra of AgNPs suspension, which provided a theoretical basis for the optical detection of lomefloxacin. In addition, we made the AgNPs-lomefloxacin detection system reach the critical point of discoloration by adding cystine to improve the sensitivity. Furthermore, the influence of some factors such as temperature, reaction time and pH on the AgNPs-lomefloxacin detection system was investigated. The results of UV-vis spectra showed that the absorption ratio (A520/A395) was linear with the concentration of lomefloxacin in the range from 0.2 to 5 µmol/L with linear coefficients of 0.991. The proposed method can be applied to detecting lomefloxacin with an ultralow detection limit of 0.6 µmol/L without any complicated instruments and complex pretreatment. The selectivity of AgNPs-lomefloxacin detection system is proved excellent by comparing with other ions and analytes in urine. The method in our study is appropriate to be used to monitor quantitatively entecavir in human urine owing to its rapid response rate, visible color changes, wide linear range and excellent selectivity.


Assuntos
Colorimetria/métodos , Cistina/química , Fluoroquinolonas/urina , Nanopartículas Metálicas/química , Prata/química , Humanos , Limite de Detecção , Modelos Lineares , Reprodutibilidade dos Testes
7.
Artigo em Inglês | MEDLINE | ID: mdl-29518680

RESUMO

In this paper, novel univariate and multivariate regression methods along with model-updating technique were developed and validated for the simultaneous determination of quaternary mixture of imatinib (IMB), gemifloxacin (GMI), nalbuphine (NLP) and naproxen (NAP). The univariate method is extended derivative ratio (EDR) which depends on measuring every drug in the quaternary mixture by using a ternary mixture of the other three drugs as divisor. Peak amplitudes were measured at 294nm, 250nm, 283nm and 239nm within linear concentration ranges of 4.0-17.0, 3.0-15.0, 4.0-80.0 and 1.0-6.0µgmL-1 for IMB, GMI, NLP and NAB, respectively. Multivariate methods adopted are partial least squares (PLS) in original and derivative mode. These models were constructed for simultaneous determination of the studied drugs in the ranges of 4.0-8.0, 3.0-11.0, 10.0-18.0 and 1.0-3.0µgmL-1 for IMB, GMI, NLP and NAB, respectively, by using eighteen mixtures as a calibration set and seven mixtures as a validation set. The root mean square error of predication (RMSEP) were 0.09 and 0.06 for IMB, 0.14 and 0.13 for GMI, 0.07 and 0.02 for NLP and 0.64 and 0.27 for NAP by PLS in original and derivative mode, respectively. Both models were successfully applied for analysis of IMB, GMI, NLP and NAP in their dosage forms. Updated PLS in derivative mode and EDR were applied for determination of the studied drugs in spiked human urine. The obtained results were statistically compared with those obtained by the reported methods giving a conclusion that there is no significant difference regarding accuracy and precision.


Assuntos
Fluoroquinolonas/análise , Mesilato de Imatinib/análise , Nalbufina/análise , Naftiridinas/análise , Naproxeno/análise , Calibragem , Fluoroquinolonas/urina , Gemifloxacina , Humanos , Mesilato de Imatinib/urina , Análise dos Mínimos Quadrados , Nalbufina/urina , Naftiridinas/urina , Naproxeno/urina , Espectrofotometria/métodos , Espectrofotometria/estatística & dados numéricos
8.
J Clin Pharmacol ; 58(4): 514-521, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29251785

RESUMO

Delafloxacin, a fluoroquinolone, has activity against gram-positive organisms including methicillin-resistant Staphylococcus aureus and fluoroquinolone-susceptible and -resistant gram-negative organisms. This study was conducted to determine delafloxacin pharmacokinetics after a single intravenous infusion or oral dose administration in subjects with varying degrees of renal function. The study was an open-label, parallel-group crossover study in subjects with normal renal function or with mild, moderate, or severe renal impairment. Subjects received 300 mg delafloxacin intravenously, placebo intravenously, and 400 mg delafloxacin orally in 3 periods separated by ≥14-day washouts. Blood and urine pharmacokinetic parameters were calculated using noncompartmental methods. Delafloxacin total clearance decreased with decreasing renal function, with a corresponding increase in AUC0-∞ . After intravenous administration, mean total clearance was 13.7 and 7.07 L/h, and mean AUC0-∞ was 22.6 and 45.0 µg·h/mL in normal and severe renal subjects, respectively. Mean renal clearance as determined by urinary excretion was 6.03 and 0.44 L/h in normal and severe renal impairment subjects, respectively. Total clearance exhibited linear relationships to eGFR and CLCR . Similar observations were found after oral administration of delafloxacin. Single doses of delafloxacin 300 mg intravenously and 400 mg orally were well tolerated in all groups. In conclusion, renal insufficiency has an effect on delafloxacin clearance; a dosing adjustment for intravenous dosing is warranted for patients with severe renal impairment (eGFR < 30 mL/min).


Assuntos
Antibacterianos/farmacocinética , Fluoroquinolonas/farmacocinética , Insuficiência Renal/metabolismo , Administração Oral , Idoso , Antibacterianos/efeitos adversos , Antibacterianos/sangue , Antibacterianos/urina , Estudos Cross-Over , Feminino , Fluoroquinolonas/efeitos adversos , Fluoroquinolonas/sangue , Fluoroquinolonas/urina , Humanos , Infusões Intravenosas , Masculino , Pessoa de Meia-Idade
9.
Biosens Bioelectron ; 87: 1065-1070, 2017 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-27736686

RESUMO

A new sensitive simple electrochemical sensor for Moxifloxacin Hydrochloride (MOXI) detection has been successfully performed. The sensor built on carbon paste (CP) modified with silver nanoparticles (AgNPs). AgNPs are biocompatible stable noble materials especially in biological sensing. The silver nanoparticles modified carbon paste electrode (SNMCPE) displayed high electrocatalytic activity towards oxidation of 1.0mM MOXI in Britton Robinson (BR) buffer of pH range (2.0-9.0). The techniques used to do this work are cyclic voltammetry (CV), linear sweep voltammetry (LSV), chronoamperometry (CA) and electrochemical impedance spectroscopy (EIS). Surface characteristics were achieved using scanning electron microscopic (SEM) and Energy Dispersive X-Ray Analysis (EDX) techniques. The effect of changing MOXI concentration (7.0×10-7 to 1.8×10-4M) was studied in BR buffer (pH =7.4) at a scan rate of 50mV/s using SNMCPE. The detection and quantification limits were found to be 2.9×10-9M and 9.6×10-8M, respectively. In order to assess the applicability of MOXI detection method in real samples; this method was tested in Delmoxa tablet and human urine sample. Good sensible results were attained for MOXI detection.


Assuntos
Antibacterianos/urina , Técnicas Eletroquímicas/métodos , Fluoroquinolonas/urina , Nanopartículas Metálicas/química , Prata/química , Antibacterianos/análise , Carbono/química , Técnicas Eletroquímicas/economia , Técnicas Eletroquímicas/instrumentação , Desenho de Equipamento , Fluoroquinolonas/análise , Humanos , Limite de Detecção , Moxifloxacina
10.
J Chromatogr B Analyt Technol Biomed Life Sci ; 1033-1034: 27-39, 2016 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-27517523

RESUMO

A simple method using HPLC-DAD was developed for the determination of fluoroquinolones in human urine including ciprofloxacin (CIPRO), enrofloxacino (ENRO), marbofloxacino (MARBO) and norfloxacin (NOR). In addition, it was studied the extraction of fluoroquinolones in human urine samples using pipette tip-based molecularly imprinted polymers solid phase extraction (PT-MIPs-SPE). With the goal of finding the best procedure for extraction of four fluoroquinolones in human urine, several parameters that are likely to affect the efficiency of extraction during sample preparation, including the washing solvent, type and volume of eluent, amount of material, the volume of the sample, pH and the ionic strength were systematically optimized. Chromatographic separations of fluoroquinolones were hit within 10min using a Synergi(®) C18 (250×4.6mm, 4µm) column and mobile phase consisting of water (10mM of phosphoric acid, the pH adjusted at 3.29 with triethylamine) : acetonitrile (85.7: 14.3, v/v) at a flow rate of 1.5mLmin(-1). Detection was performed at 290nm. The average extraction recoveries/standard deviation relative to ENRO, CIPRO, NOR and MARBO were 96.40±5.51%, 42.47±4.81%, 41.82±7.99% and 87.49±4.70, respectively. The method was liner from 39 to 1260ngmL(-1) for each fluoroquinolone with correlation coefficient of 0.9904, 0.9910, 0.9914 and 0.9919, to ENRO, CIPRO, NOR and MARBO, respectively. The assays of within-day and between-day precision and accuracy for all analytes were studied at three concentration levels and were lower than 15%. The method was successfully employed in a preliminary cumulative urinary excretion study after administration of CIPRO to a healthy volunteer.


Assuntos
Fluoroquinolonas/urina , Impressão Molecular/métodos , Extração em Fase Sólida/métodos , Cromatografia Líquida de Alta Pressão , Estabilidade de Medicamentos , Fluoroquinolonas/química , Fluoroquinolonas/isolamento & purificação , Humanos , Limite de Detecção , Modelos Lineares , Reprodutibilidade dos Testes
11.
J Enzyme Inhib Med Chem ; 31(sup3): 110-116, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27444953

RESUMO

We developed and validated an analytical method based on microextraction packed sorbent (MEPS) and high-performance liquid chromatography (HPLC) coupled to photodiode array (PDA) detector to simultaneously quantify multiple nonsteroidal anti-inflammatory drugs (NSAIDs) and fluoroquinolones (FLQs), which may provide as combination several adverse reactions in nephrology and neurology. The linearity range from LOQs (0.1 µg/mL) to 10 µg/mL, and LODs values were 0.03 µg/mL for both NSAIDs and FLQs. The validation was performed according to international guidelines and the accuracy was tested measuring the precision, intermediate precision and trueness. The drugs stability was tested under different storage conditions (+4 °C and -20 °C) and after three different cycles of freezing and thawing. The method can be a suitable tool to simultaneously detect a possible association of drugs in human biological samples and provide several potentialities for clinical applications, bioequivalence studies, pharmacodynamics and toxicodynamics of different pharmaceutical dosage forms showing NSAIDs and FLQs.


Assuntos
Anti-Inflamatórios não Esteroides/sangue , Anti-Inflamatórios não Esteroides/urina , Fluoroquinolonas/sangue , Fluoroquinolonas/urina , Microextração em Fase Líquida , Anti-Inflamatórios não Esteroides/administração & dosagem , Cromatografia Líquida de Alta Pressão , Fluoroquinolonas/administração & dosagem , Voluntários Saudáveis , Humanos , Estrutura Molecular
12.
Br J Clin Pharmacol ; 81(6): 1078-90, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-26774055

RESUMO

AIM: To examine whether strict control of clinical trial conditions could reduce apparent differences of pharmacokinetic (PK) parameters among ethnic groups. METHODS: Open-label, single dose PK studies of moxifloxacin, simvastatin and meloxicam were conducted in healthy male subjects from three East Asian populations (Japanese, Chinese and Koreans) and one Caucasian population as a control. These three drugs were selected because differences in PK parameters have been reported, even though the backgrounds of these East Asian populations are similar. Moxifloxacin (400 mg) was administered orally to 20 subjects, and plasma and urine levels of moxifloxacin and its metabolite (M2) were measured. Simvastatin (20 mg) was given to 40 subjects, and plasma levels of simvastatin and simvastatin acid were measured. Meloxicam (7.5 mg) was given to 30 subjects and its plasma concentration was determined. Intrinsic factors (polymorphism of UGT1A1 for moxifloxacin, SLCO1B1 for simvastatin, and CYP2C9 for meloxicam) were also examined. RESULTS: AUCinf values for moxifloxacin, simvastatin and meloxicam showed no significant differences among the East Asian groups. Cmax values of moxifloxacin and simvastatin, but not meloxicam, showed significant differences. There were no significant differences of data for M2 or simvastatin acid. Genetic analysis identified significant differences in the frequencies of relevant polymorphisms, but these differences did not affect the PK parameters observed. CONCLUSIONS: Although there were some differences in PK parameters among the three East Asian groups, the present study performed under strictly controlled conditions did not reproduce the major ethnic differences observed in previous studies.


Assuntos
Povo Asiático/genética , Fluoroquinolonas/farmacocinética , Sinvastatina/farmacocinética , Tiazinas/farmacocinética , Tiazóis/farmacocinética , População Branca/genética , Adulto , Citocromo P-450 CYP2C9/genética , Fluoroquinolonas/sangue , Fluoroquinolonas/urina , Glucuronosiltransferase/genética , Humanos , Transportador 1 de Ânion Orgânico Específico do Fígado/genética , Masculino , Meloxicam , Moxifloxacina , Polimorfismo Genético/genética , Sinvastatina/sangue , Tiazinas/sangue , Tiazóis/sangue , Adulto Jovem
13.
Spectrochim Acta A Mol Biomol Spectrosc ; 157: 244-250, 2016 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-26774816

RESUMO

A novel colorimetric nanomaterial-assisted optical sensor for pazufloxacin mesilate was proposed for the first time. Pazufloxacin mesilate could induce the aggregation of glucose-reduced gold nanoparticles (AuNPs) through hydrogen-bonding interaction and electrostatic attraction, leading to the changes in color and absorption spectra of AuNPs. The effect of different factors such as pH, the amount of AuNPs, reaction time and reaction temperature was inspected. Under the optimum condition, UV-vis spectra showed that the absorption ratio (A670/A532) was linear with the concentration of pazufloxacin mesilate in the range from 9×10(-8) mol L(-1) to 7×10(-7) mol L(-1) with a linear coefficient of 0.9951. This method can be applied to detecting pazufloxacin mesilate with an ultralow detection limit of 7.92×10(-9) mol L(-1) without any complicated instruments. Through inspecting other analytes and ions, the anti-interference performance of AuNP detection system for pazufloxacin mesilate was excellent. For its high efficiency, rapid response rate as well as wide linear range, it had been successfully used to the analysis of pazufloxacin mesilate in human urine quantificationally.


Assuntos
Antituberculosos/urina , Colorimetria/métodos , Fluoroquinolonas/urina , Ouro/química , Mesilatos/urina , Nanopartículas Metálicas/química , Oxazinas/urina , Humanos , Limite de Detecção , Nanopartículas Metálicas/ultraestrutura
14.
Anal Chim Acta ; 885: 114-21, 2015 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-26231896

RESUMO

In-tube magnetic solid phase microextraction (in-tube MSPME) of fluoroquinolones from water and urine samples based on the use of sodium dodecyl sulfate (SDS) coated Fe3O4 nanoparticles packed tube has been reported. After the preparation of Fe3O4 nanoparticles (NPs) by a batch synthesis, these NPs were introduced into a stainless steel tube by a syringe and then a strong magnet was placed around the tube, so that the Fe3O4 NPs were remained in the tube and the tube was used in the in-tube SPME-HPLC/UV for the analysis of fluoroquinolones in water and urine samples. Plackett-Burman design was employed for screening the variables significantly affecting the extraction efficiency. Then, the significant factors were more investigated by Box-Behnken design. Calibration curves were linear (R(2)>0.990) in the range of 0.1-1000µgL(-1) for ciprofloxacin (CIP) and 0.5-500µgL(-1) for enrofloxacin (ENR) and ofloxacin (OFL), respectively. LODs for all studied fluoroquinolones ranged from 0.01 to 0.05µgL(-1). The main advantages of this method were rapid and easy automation and analysis, short extraction time, high sensitivity, possibility of fully sorbent collection after analysis, wide linear range and no need to organic solvents in extraction.


Assuntos
Antibacterianos/isolamento & purificação , Antibacterianos/urina , Fluoroquinolonas/isolamento & purificação , Fluoroquinolonas/urina , Nanopartículas de Magnetita/química , Dodecilsulfato de Sódio/química , Microextração em Fase Sólida/instrumentação , Cromatografia Líquida de Alta Pressão , Ciprofloxacina/isolamento & purificação , Ciprofloxacina/urina , Enrofloxacina , Humanos , Limite de Detecção , Magnetismo/instrumentação , Magnetismo/métodos , Ofloxacino/isolamento & purificação , Ofloxacino/urina , Microextração em Fase Sólida/métodos
15.
Bioprocess Biosyst Eng ; 38(9): 1803-10, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26104538

RESUMO

Silver nanoparticles have been synthesized and were utilized for the enhanced luminometric estimation of moxifloxacin antibiotic. During the experimental procedure, it was clearly found that the addition of silver nanoparticles intensifies the weak chemiluminescence signal intensity of calcein-KMnO4 system by several folds. It was also obvious that the intensity enhancement was linearly proportional to the moxifloxacin concentration and this phenomenon was further utilized for the quantitative determination of target analyte. Effects of the different chemical variables during the experiment were studied to achieve best chemiluminescence signal. Under the optimized experimental parameters, the linear calibration graph was established over the moxifloxacin concentration range of 6.0 × 10(-8) M to 2.5 × 10(-6) M with coefficient of correlation (r (2)) value 0.9998. The lower detection limit was found to be 5.6 × 10(-9) M. The percentage relative standard deviation calculated from five replicate chemiluminescence measurements was found to be 2.63 %. The developed chemiluminescence technique was successfully applied to the determination of moxifloxacin in tablet formulation and spiked human urine sample.


Assuntos
Análise de Injeção de Fluxo/métodos , Fluoroquinolonas/análise , Medições Luminescentes/métodos , Nanopartículas Metálicas/química , Prata/química , Urinálise/métodos , Antibacterianos/análise , Antibacterianos/urina , Fluoresceínas/química , Fluoroquinolonas/urina , Glucosídeos/química , Humanos , Compostos de Manganês/química , Moxifloxacina , Óxidos/química , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Comprimidos , Tecnologia Farmacêutica/métodos
16.
Food Chem ; 185: 7-15, 2015 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-25952835

RESUMO

A follow-up of antibiotics (tetracyclines, fluoroquinolones, cephalosporins, penicillins and amphenicols) in the bovine urine is important for two reasons: to understand if they are still present in organism, and whether their occurrence in urine might be considered as an environmental risk. A validated HPLC-MS/MS method (Decision 2002/657/EC) for antibiotics determination in bovine urine was developed. CCα and CCß were in the range of 0.58-0.83 and 0.55-1.1 ng mL(-1), respectively. Recoveries were 92-108%, with inter-day repeatability below 12%. Analysis of bovine urine revealed frequent presence of tetracyclines, which was related with animal's age. The cause, most presumably, might be found in different therapeutic protocols applied for veal calves and young bulls enrolled in this study. Most abundant was oxytetracycline with highest level in veal calves (1718 ng mL(-1)) vs. young bulls (2.8 ng mL(-1)). Our results indicate the necessity of antibiotics monitoring in bovine urine before animals undergo further processing in the food industry.


Assuntos
Antibacterianos/urina , Drogas Veterinárias/urina , Animais , Bovinos , Cefalosporinas/urina , Cromatografia Líquida de Alta Pressão , Fluoroquinolonas/urina , Masculino , Penicilinas/urina , Espectrometria de Massas em Tandem , Tetraciclinas/urina
17.
Artigo em Inglês | MEDLINE | ID: mdl-25754393

RESUMO

Silver nanoparticles have been utilized for the enhanced chemiluminogenic estimation of fluoroquinolone antibiotic gatifloxacin. It has been found that the weak chemiluminescence intensity produced from the reaction between calcein and KMnO4 can further be strengthened by the addition of silver nanoparticles in the presence of gatifloxacin. This phenomenon has been exploited to the quantitative determination of gatifloxacin. Under the optimum experimental conditions, the calibration curves are linear over the range of 8.9×10(-9)-4.0×10(-6) M, while the limits of detections were found to be 2.6×10(-9) M with correlation coefficient value (r(2)) 0.9999. The relative standard deviation calculated from six replicate measurements (1.0×10(-4) M gatifloxacin) was 1.70%. The method was applied to pharmaceutical preparations and the results obtained were in reasonable agreement with the amount labeled on the formulations. The proposed method was also used for the determination of gatifloxacin in spiked urine samples with satisfactory results. No interference effects from some common excipients used in pharmaceutical preparations have been found.


Assuntos
Análise de Injeção de Fluxo/métodos , Fluoroquinolonas/urina , Medições Luminescentes/métodos , Nanopartículas Metálicas/química , Prata/química , Adulto , Química Farmacêutica , Fluoresceínas/química , Gatifloxacina , Humanos , Nanopartículas Metálicas/ultraestrutura , Pessoa de Meia-Idade , Oxidantes/química , Permanganato de Potássio/química , Hidróxido de Sódio/química , Espectrofotometria Ultravioleta
18.
J Infect Chemother ; 21(4): 290-5, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25640533

RESUMO

The purpose of this study was to evaluate which of blood or urine has the greater effect on bladder tissue concentrations of fluoroquinolones important for the treatment of urinary tract infections by measuring concentrations of fluoroquinolones in the vesical tissue (chemically and immunohistochemically) and intravesical space (chemically). Thirty-minute incubation of isolated rat bladders with fluoroquinolones showed only a 1.9-fold difference in transferability among norfloxacin, levofloxacin, ciprofloxacin and sparfloxacin. Intravesical instillation of norfloxacin and sparfloxacin in rats yielded similar vesical tissue distributions. Thus, there were no large differences in vesical tissue transfer among the four fluoroquinolones. The bladder tissue/plasma concentration ratios of norfloxacin (high urinary excretion-type) and sparfloxacin (low urinary excretion-type) at 1 h after a single oral dose (10 mg/kg) to rats were 15.4 and 1.3, respectively. The bladder tissue/plasma concentration ratios of norfloxacin after an intravenous injection (10 mg/kg) to ureter-catheterized and sham-operated rats were 1.36 and 57.8. Thus the bladder tissue distribution was significantly higher in the urine-exposed bladder. Immunohistochemical examination of the vesical tissue localization of norfloxacin in rats given a single intravenous dose revealed the presence of the drug-positive image in the cytoplasm of surface layer cells (both in umbrella and cover cells) of the bladder transitional epithelium. In conclusion, the results suggest that norfloxacin and other fluoroquinolones are excreted into urine and then transferred to the surface layer of the bladder transitional epithelium. Therefore, the urine levels have a greater effect on the vesicle tissue distribution of fluoroquinolones than the plasma levels in rats.


Assuntos
Antibacterianos/farmacocinética , Fluoroquinolonas/farmacocinética , Bexiga Urinária/metabolismo , Animais , Antibacterianos/urina , Fluoroquinolonas/urina , Imuno-Histoquímica , Masculino , Ratos , Ratos Sprague-Dawley , Distribuição Tecidual , Bexiga Urinária/química , Bexiga Urinária/citologia , Cateterismo Urinário
19.
Artigo em Inglês | MEDLINE | ID: mdl-25660716

RESUMO

Herein, we developed a novel integrated device to perform phase separation based on ultrasound-assisted salt-induced liquid-liquid microextraction for determination of five fluoroquinones (FQs) in human body fluids. The integrated device consisted of three simple HDPE components used to separate the extraction solvent from the aqueous phase prior to retrieving the extractant. A series of extraction parameters were optimized using the response surface method based on central composite design. Optimal conditions consisted of 945µL acetone extraction solvent, pH 2.1, 4.1min stir time, 5.9g Na2SO4, and 4.0min centrifugation. Under optimized conditions, the limits of detection (at S/N=3) were 0.12-0.66µgL(-1), the linear range was 0.5-500µgL(-1) and recoveries were 92.6-110.9% for the five FQs extracted from plasma and urine. The proposed method has several advantages, such as easy construction from inexpensive materials, high extraction efficiency, short extraction time, and compatibility with HPLC analysis. Thus, this method shows excellent prospects for sample pretreatment and analysis of FQs in human body fluids.


Assuntos
Cromatografia Líquida/métodos , Fluoroquinolonas , Microextração em Fase Líquida/métodos , Feminino , Fluoroquinolonas/sangue , Fluoroquinolonas/química , Fluoroquinolonas/isolamento & purificação , Fluoroquinolonas/urina , Humanos , Limite de Detecção , Masculino , Reprodutibilidade dos Testes , Sonicação , Temperatura
20.
Spectrochim Acta A Mol Biomol Spectrosc ; 136 Pt B: 618-24, 2015 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-25315874

RESUMO

In the present work, the analytical performance of three multi-way algorithms has been evaluated. The proposed analytical problem was the simultaneous determination of moxifloxacin and ciprofloxacin in human urine samples using fluorescence spectroscopy. Parallel factor analysis (PARAFAC), self-weighted alternating trilinear decomposition (SWATLD) and unfolded partial least squares combined with the residual bilinearization procedure (U-PLS/RBL) have been compared, regarding their ability to solve the proposed problem. In this study, "second-order advantage" was also exploited for the mentioned algorithms through different calibration strategies. The three-way data was obtained via fluorescence spectroscopy, so that excitation-emission matrices (EEM) of the samples were recorded as the analytical signals. The accuracy and precision of each individual algorithm for analyzing the drugs in urine samples were compared using root mean square error of prediction (RMSEP), recovery and elliptical joint confidence region (EJCR) plots. The results revealed that each of the three algorithms could be applied for determination of moxifloxacin and ciprofloxacin, despite different EEM subsets and calibration strategies. However, better analytical performances were observed through PARAFAC and U-PLS/RBL modeling for MOX and CIP, respectively. So, by coupling the multi-way decomposition algorithms with fluorescence spectroscopy, a main part of preliminary sample preparation steps can be eliminated and experimental procedure might be significantly simplified, while achieving desirable analytical performance.


Assuntos
Antibacterianos/urina , Ciprofloxacina/urina , Fluoroquinolonas/urina , Espectrometria de Fluorescência , Algoritmos , Calibragem , Humanos , Análise dos Mínimos Quadrados , Limite de Detecção , Moxifloxacina , Espectrometria de Fluorescência/métodos
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