Chemiluminescence methods for the determination of ofloxacin

Ofloxacin is a synthetic fluoroquinolone antibiotic that has been used in the treatment of respiratory tract, urinary tract and tissue-based infections. Methodology for the determination of ofloxacin based on chemiluminescence detection can be divided into: direct oxidation with tris(2,2′-bipyridyl)ruthenium(III) or permanganate; and enhancement of the emission from either the oxidation of sulfite or the reaction between sodium nitrite and hydrogen peroxide. In this paper, we compare the analytical methodology and evaluate the light-producing pathways that have been proposed for these reactions.

Microbiological assay for gatifloxacin in pharmaceutical formulations

A simple, sensitive and specific agar diffusion bioassay for the antibacterial gatifloxacin was developed using a strain of Bacillus subtilis ATCC 9372 as the test organism. Gatifloxacin could be measured in tablets and raw material at concentration ranging 4-16 mu g ml(-1). The calibration graph for gatifloxacin was linear from 4.0 to 16.0 mu g ml(-1). A prospective validation of the method demonstrated that the method was linear (r(2) = 0.9993), precise (R.S.D. = 1.14%) and accurate. The results confirmed its precision and did not differ significantly from others methods described in the literature. The validated method yielded good results in terms of the range, linearity, precision, accuracy, specificity and recovery. We concluded that the microbiological assay is satisfactory for in vitro quantification of the antibacterial activity of gatifloxacin. (c) 2005 Elsevier B.V. All rights reserved.

Enrofloxacin assay validation and pharmacokinetics following a single oral dose in chickens

The pharmacokinetics of enrofloxacin (ENRO), a fluoroquinolone antimicrobial agent, was studied in male broiler chickens (Cobb) after single oral administration of 10 mg of ENRO/kg b.w. A high-performance liquid chromatography-photodiode array detector (DAD) (HPLC-DAD) method was developed and validated and used for quantitation of ENRO and its major metabolite ciprofloxacin in plasma. The HPLC analyses were carried out using a cationic-octadecyl mixed column and 0.05 mol/L phosphate buffer (pH 2.5)/acetonitrile as mobile phase. The sample preparation of plasma consisted of the precipitation of proteins followed by solid phase extraction on cationic-octadecyl mixed cartridges. The method was validated considering linear range, linearity, selectivity, sensitivity, limit of detection (LOD), limit of quantitation (LOQ), intra- and inter-day precisions and accuracy. The LOD and LOQ for both fluoroquinolones were 60 and 200 ng/mL for plasma. The plasma concentration vs. time graph was characteristic of a two-compartment open model. The maximal plasma concentration of 1.5 +/- 0.2 mg/mL was achieved at 9 +/- 2 h. The elimination half-life and the mean residence time of ENRO were 1.5 +/- 0.2 and 15.64 h, respectively. The area under the concentration-time curve was calculated as 35 +/- 4 mg(.)h/mL.

Esparfloxacino e as fluorquinolonas: Uma revisao de sua classificacao, atividade antibacteriana, mecanismo de acao, caracteristicas farmacocineticas, tolerabilidade e perspectivas farmaceuticas

A revision was accomplished in the literature on the quinolones, antibacterial class that presents wide action spectrum, focusing, mainly, the sparfloxacin, third generation fluorquinolone which has potente activity against Gram positive organisms, including Streptococcus pneumoniae and methicillin-resistant Staphylococcus aureus (MRSA), Gram negative organisms, Legionelia spp, Mycoplasma spp, Chlamydia spp and Mycobacterium spp, including multidrug resistant organisms.

Development and validation of an UV spectrophotometric method for determination of gatifloxacin in tablets

A simple, sensitive and accurate spectrophotometric method was developed for the assay of gatifloxacin in raw material and tablets. Validation of the method yielded good results concerning range, linearity, precision and accuracy. The absorbance was measured at 287 nm for gatifloxacin tablet solutions. The linearity range was found to be 4.0-14.0 μg/mL for gatifloxacin. It was also found that the excipients in the commercial tablets did not interfere with the method.

Photodegradation of sparfloxacin and isolation of its degradation products by preparative HPLC

Sparfloxacin, a third generation fluoroquinolone derivative, is a potent antibacterial agent active against a wide range of Gram-positive and Gram-negative organisms including Streptococcus pneuinoniae, Staphylococcus aureus, methicillin resistant S. aureus, Legionella spp., Mycoplasina spp., Chlamydia spp. and Mycobacterium spp. A drawback of fluoroquinolones is their photoreactivity. Sparfloxacin has been studied in terms of therapeutic activities. However, there are few published of analytical methods being applied to sparfloxacin. The aim in this study was to determine the photodegradation products of sparfloxacin, when submitted to UV light, and to characterize two of these products, designated SPAX-PDP1 and SPAX-PDP2. An accelerated study of stability in methanol solution was carried out by exposing a solution of sparfloxacin to UV light (peak wavelength 290 nm) for 36 hours at room temperature. The products were analyzed by NMR spectrophotometry, IR spectrometry and mass spectrophotometry. The results suggest that the products isolated here could be used to estimate the degradation of sparfloxacin in a stability study. However, the low activity exhibited by UV-irradiated sparfloxacin is a source of concern that demands further investigation of the mechanism of its photodegradation mechanism.

Análise térmica de esparfloxacino

Sparfloxacin, a third-generation fluoroquinolone, is a potent antibacterial agent against a wide range of Gram-positive and Gram-negative organisms, for example Streptococcus pneumonias, Staphylococcus aureus (including methicillin-resistant strains), Legionella spp., Mycoplasma spp., Chlamydia spp. and Mycobacterium spp. This compound has been submitted to thermal analysis and the results are presented here. The DSC curve of sparfloxacin has an endothermic peak that indicates a melting point at 276.5 °C. The DTA curve of the sample in synthetic air shows two exothermic peaks, at 341.6 and 579.2 °C, attributed to compound decomposition. In the TG curve, the loss of mass can be seen to occur in two steps between 285.5 and 645.3 °C. The DTA curve obtained in a nitrogen atmosphere shows an exothermic peak, with decomposition of sparfloxacin at 340.0 °C; from the corresponding TG plot, the loss of mass starts at 254.4 °C.

Development and validation of a microbiological agar assay for determination of orbifloxacin in pharmaceutical preparations

Orbifloxacin is a fluoroquinolone with broad-spectrum antimicrobial activity, and belongs to the third generation of quinolones. Regarding the quality control of medicines, a validated microbiological assay for determination of orbifloxacin in pharmaceutical formulations has not as yet been reported. For this purpose, this paper reports the development and validation of a simple, sensitive, accurate and reproducible agar diffusion method to quantify orbifloxacin in tablet formulations. The assay is based on the inhibitory effect of orbifloxacin upon the strain of Staphylococcus aureus ATCC 25923 used as test microorganism. The results were treated statistically by analysis of variance and were found to be linear (r = 0.9992) in the selected range of 16.0-64.0 μg/mL, precise with relative standard deviation (RSD) of repeatability intraday = 2.88%, intermediate precision RSD = 3.33%, and accurate (100.31%). The results demonstrated the validity of the proposed bioassay, which allows reliable orbifloxacin quantitation in pharmaceutical samples and therefore can be used as a useful alternative methodology for the routine quality control of this medicine. © 2011 by the authors; licensee MDPI, Basel, Switzerland.

Orbifloxacin: A Review of Properties, Its Antibacterial Activities, Pharmacokinetic/Pharmacodynamic Characteristics, Therapeutic Use, and Analytical Methods

Orbifloxacin is a third generation of fluoroquinolone that exhibits increased antibacterial activity against the Enterobacteriaceae, gram-negative and gram-positive bacteria, anaerobes, and mycobacteria. This drug was synthesized in 1987 and developed as a veterinary chemotherapeutic to use for livestock and domestic pets. Orbifloxacin is labeled for the treatment of skin, soft tissue, and urinary tract infections in dogs, and skin and soft tissue infections in cats, but in some countries, orbifloxacin has been given for the treatment of gastrointestinal and respiratory infections in cattle and swine and other animals. The in vitro activity and clinical efficacy of orbifloxacin against naturally occurring bacterial infections of the skin, ear, soft tissue, udder, and gastrointestinal and respiratory systems in different animals have been evaluated and good responses have been found. The minimum inhibitory concentration of orbifloxacin has been determined in various different pathogens and the results found in the literature are shown in this work. The pharmacokinetics of orbifloxacin has been evaluated by different routes of administration in goats, horses, pigs, rabbits, dogs, cats, camels, cattle, sheep, and fish. Orbifloxacin exhibits excellent pharmacokinetic parameters that suggest that this drug may have good clinical effects on various bacterial infections in these species. All methods described in the scientific literature for determination of orbifloxacin in different matrices were collected and discussed. © 2013 Copyright Taylor and Francis Group, LLC.

Análise químico-farmacêutica de norflocacino comprimidos e estudos de complexação com β-Ciclodextrina e polimorfismo

Pós-graduação em Ciências Farmacêuticas - FCFAR

Desenvolvimento de um método simples, limpo e rápido para a determinação de fluoroquinolonas em formulações farmacêuticas

Pós-graduação em Química - IQ

Development of biomimetic sensor for fast and sensitive detection of Norfloxacin

A biomimetic sensor is proposed as a promising new analytical method for determination of norfloxacin (NF) in pharmaceuticals. The sensor was prepared by modifying a glassy carbon electrode surface with a Nafion® membrane doped with poly(copper phthalocyanine) complex [poly-CuPc]. Amperometric measurements carried out with the sensor under an applied potential of -0.05 V vs Ag|AgCl in 0.1 mol L-1 acetic acid containing 1.5 × 10-3 mol L-1 hydrogen peroxide showed a linear response range from 2.0 × 10-4 to 1.2 × 10-3 mol L-1. Selectivity and interference studies were also performed. A sensor response mechanism is proposed, based on the experimental evidence. Recovery studies were carried out using environmental samples, in order to evaluate the sensor’s potential for use with these sample classes. Finally, sensor performance was evaluated using analyses of commercial formulations.

High precision and selectivity for quantitation of enrofloxacin and ciprofloxacin in five chicken tissues using solid phase extraction and ESI LC-MS/MS for application in monitoring residues

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Opportunistic pathogens and elements of the resistome that are common in bottled mineral water support the need for continuous surveillance

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)