Analysis of antibiotics by capillary electrophoresis

Co-based Nanozymatic Profiling: Advances Spanning Chemistry, Biomedical, and Environmental Sciences

Nanozymes, next-generation enzyme-mimicking nanomaterials, have entered an era of rational design; among them, Co-based nanozymes have emerged as captivating players over times. Co-based nanozymes have been developed and have garnered significant attention over the past five years. Their extraordinary properties, including regulatable enzymatic activity, stability, and multifunctionality stemming from magnetic properties, photothermal conversion effects, cavitation effects, and relaxation efficiency, have made Co-based nanozymes a rising star. This review presents the first comprehensive profiling of the Co-based nanozymes in the chemistry, biology, and environmental sciences. The review begins by scrutinizing the various synthetic methods employed for Co-based nanozyme fabrication, such as template and sol-gel methods, highlighting their distinctive merits from a chemical standpoint. Furthermore, a detailed exploration of their wide-ranging applications in biosensing and biomedical therapeutics, as well as their contributions to environmental monitoring and remediation is provided. Notably, drawing inspiration from state-of-the-art techniques such as omics, a comprehensive analysis of Co-based nanozymes is undertaken, employing analogous statistical methodologies to provide valuable guidance. To conclude, a comprehensive outlook on the challenges and prospects for Co-based nanozymes is presented, spanning from microscopic physicochemical mechanisms to macroscopic clinical translational applications.

Supramolecular interaction of Moxifloxacin and β-cyclodextrin spectroscopic characterization and analytical application

The supramolecular interaction of Moxifloxacin (Moxi) and β-cyclodextrin (β-CD) has been examined by UV-VIS, FTIR, H(1)NMR, SEM and fluorescence spectroscopy. The formation of inclusion complex has been confirmed on the base of changes of spectroscopy properties. The results showed that β-CD reacted with Moxi to form an inclusion complex. The Moxi and β-CD complex formed a host-guest complex in 1:1 stoichiometry and inclusion constant (K=3.95×10(2) L mol(-1)) was ascertained by the typical double reciprocal plots. Furthermore, the thermodynamic parameters (ΔH°, ΔS° and ΔG°) associated with the inclusion process were also determined. Based on the significant enhancement of the fluorescence intensity of Moxi produced through complex formation, a simple, accurate, rapid and highly sensitive spectrofluorometric method for the determination of Moxi in pharmaceutical formulation was developed. The measurement of relative fluorescence intensity was carried out at 464 nm with excitation at 289 nm. The factors affecting the inclusion complex formation were studied and optimized. Under the optimum reaction conditions, linear relationships with good correlation coefficients (0.99973) were in the concentration range of 10-60 ng/mL for spectrofluorimetry. The limit of detection (LOD) was found to be 1.6 ng/mL. The proposed method was successfully applied to the analysis of Moxi in pharmaceutical preparation.

Recent advances in CE analysis of antibiotics and its use as chiral selectors

Antibiotics are a class of therapeutic molecules widely employed in both human and veterinary medicine. This article reviews the most recent advances in the analysis of antibiotics by CE in pharmaceutical, environmental, food, and biomedical fields. Emphasis is placed on the strategies to increase sensitivity as diverse off-line, in-line, and on-line preconcentration approaches and the use of different detection systems. The use of CE in the microchip format for the analysis of antibiotics is also reviewed in this article. Moreover, since the use of antibiotics as chiral selectors in CE has grown in the last years, a new section devoted to this aspect has been included. This review constitutes an update of previous published reviews and covers the literature published from June 2011 until June 2013.

Development and validation of stability-indicating high performance liquid chromatography method to analyze gatifloxacin in bulk drug and pharmaceutical preparations

Quantitative determination of gatifloxacin in tablets, solid lipid nanoparticles (SLNs) and eye-drops using a very simple and rapid chromatographic technique was validated and developed. Formulations were analyzed using a reverse phase SUPELCO® 516 C-18-DB, 50306-U, HPLC column (250 mm × 4.6 mm, 5 μm) and a mobile phase consisting of disodium hydrogen phosphate buffer:acetonitrile (75:25, v/v) and with orthophosphoric acid pH was adjusted to 3.3 The flow rate was 1.0 mL/min and analyte concentrations were measured using a UV-detector at 293 nm. The analyses were performed at room temperature (25 ± 2 °C). Gatifloxacin was separated in all the formulations within 2.767 min. There were linear calibration curves over a concentration range of 4.0-40 μg.mL(-1) and correlation coefficients of 0.9998 with an average recovery above 99.91%. Detection of analyte from different dosage forms at the same Rt indicates the specificity and stability of the developed method.

Screening and determination of sulphonamide residues in bovine milk samples using a flow injection system

A new, simple, rapid and sensitive flow injection spectrophotometric method was developed for the screening and determination of sulphonamides in bovine milk samples. The method is based on the condensation of sulphathiazole, sulphamethazine, and sulphadimethoxine with p-dimethylaminobenzaldehyde (p-DAB) in acid medium, in the presence of sodium dodecyl sulphate (SDS), producing a yellow compound (λmax=465 nm). Optimisation of the experimental parameters was performed using a multivariate methodology. The linear range was 90-500 μg/L and the limits of detection and quantification were in the ranges 25-29 μg/L and 84-88 μg/L, respectively. The procedure was applied for the determination of sulphonamide antibiotics in bovine milk samples submitted to a prior extraction procedure based on QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) methodology. Recoveries of 60.5-70.5% were achieved for milk samples spiked with 0.09, 0.1, 0.2, and 0.3 μg/g of each sulphonamide.

High-sensitivity detection of oxytetracycline using light scattering agglutination assay with aptasensor

We present an aptamer-based biosensor (aptasensor) for rapid and high-sensitive detection of oxytetracycline (OTC) antibiotic in PBS inside a Y-channel PDMS microfluidic device. The detection was made by real-time monitoring of the agglutination assay of ssDNA aptamer-conjugated polystyrene latex microspheres with proximity optical fibers. The agglutination assay was performed with serially diluted OTC antibiotic solutions using highly carboxylated polystyrene particles of 920 nm diameter conjugated with OTC-binding ssDNA aptamer. Proximity optical fibers were used to measure the increase in 45° forward light scattering of the aggregated particles by fixing them around the viewing cell of the device with stable angle and distance to the detector. The detection limit was around 100 ppb for the current aptasensor system with the detection time less than 3 min.

A sensitive spectrophotometric method for the determination of sulfonamides in pharmaceutical preparations

A new, simple and sensitive spectrophotometric method for the determination of some sulfonamide drugs has been developed. The method is based on the diazotization of sulfacetamide, sulfadiazine, sulfaguanidine, sulfamerazine, sulfamethazine, sulfamethoxazole, and their coupling with 8-hydroxyquinoline in alkaline media to yield red coloured products with absorption maxima at 500 nm. Beer's law is obeyed from 0.1-7.0 microg mL-1. The limits of quantification and limits of detection were 0.11-0.18 and 0.03-0.05 microg mL-1, respectively. Intraday precision (RSD 0.1-0.5%) and accuracy (recovery 97.3--100.8%) of the developed method were evaluated. No interference was observed from common adjuvants. The method has been successfully applied to the assay of sulpha drug in pharmaceutical formulations.

Simultaneous separation of five fluoroquinolone antibiotics by capillary zone electrophoresis

A novel methodology has been developed for simultaneous separation of ciprofloxacin (CPFLX), gatifloxacin (GTFLX), levofloxacin (LVFLX), moxifloxacin (MFLX) and sparfloxacin (SPFLX) fluoroquinolone antibiotics (FQs), using capillary zone electrophoresis (CZE) with UV detection at 282 nm. Electrolyte composition was optimized through the variation of the Tris/hydrochloride and sodium tetraborate buffer mixture. The electrolyte consisted of a 25 mmol L(-1) Tris/hydrochloride and 15 mmol L(-1) sodium tetraborate buffer mixture resulting in pH 8.87. All analytes were separated in less than 3 min. The proposed method was applied to the separation of FQs in pharmaceutical formulations, and the assay results were within 95-105% of the label claim.

Recent advances in the analysis of antibiotics by capillary electrophoresis

In this review, the main aspects related to the separation of different groups of antibiotics by CE as well as the different applications reported in the literature from the beginning 2003 till May 2005 will be provided to the readers. Firstly, the experimental conditions employed to achieve the analysis of antibiotics by CE are given. Then, the main applications performed in the pharmaceutical, clinical, food, and environmental fields have been reviewed making emphasis on sample preparation requirements needed in each case. Finally, the main conclusions and future prospects in this field are presented.

Quantitative determination of gatifloxacin, levofloxacin, lomefloxacin and pefloxacin fluoroquinolonic antibiotics in pharmaceutical preparations by high-performance liquid chromatography

The objective of this research was to develop and validate analytical methods for quantitative determination of fluoroquinolones of third generation. Simple and rapid chromatographic method was developed and validated for quantitative determination of four quinolone antibiotics in tablets and injection preparations. The fluoroquinolones studied were gatifloxacin (GAT), levofloxacin (LEV), lomefloxacin (LOM) and pefloxacin (PEF). The quinolones were analyzed by using a LiChrospher 100 RP-18 column (5 microm, 125 mm x 4 mm) and a mobile phase constituted of water:acetonitrile (80:20, v/v) with 0.3% of triethylamine and pH adjusted to 3.3 with phosphoric acid. The flow rate was 1.0 mL/min and the analyses were performed using UV detector with wavelengths varying from 279 to 295 nm. The analyses were performed at room temperature (24 +/- 2 degrees C). All fluoroquinolones were separated within 5 min. The calibration curves were linear (r>or=0.9999) over a concentration range from 4.0 to 24.0 microg/mL. The relative standard deviation (R.S.D.) was < 1.0% and average recovery was above 99.54%.

Determination of the purity of ampicillin by micellar electrokinetic chromatography and reversed phase liquid chromatography on a monolithic silica column

A micellar electrokinetic chromatographic (MEKC) method and a fast reversed-phase liquid chromatographic one have been developed for determining the purity of ampicillin. MEKC separation of ampicillin and its related substances was performed with the use of an untreated fused-silica capillary and 40 mM phosphate-borate buffer, pH 7.5 containing 75 mM SDS. The HPLC method employed a monolithic silica C18 column and a mobile phase composed of phosphate buffer, pH 5.2 and ACN, the flow rate being 4.0 mL/min. Both methods were successfully validated. Linearity, relative response factors, limits of quantitation, intermediate precision, and accuracy were evaluated. The methods proved to be fast, reliable, and sufficiently sensitive and, accordingly, well-suited for control of purity of ampicillin substance, injections, and capsules. A combination of both methods can be very useful in the confirmation of impurity profiles.

Iminodibenzyl as a novel coupling agent for the spectrophotometric determination of sulfonamide derivatives

A rapid, selective and simple spectrophotometric method for the determination of sulfa-drugs is described. The method is based on the formation of violet colored azo product by the diazotization of sulfonamides, viz. sulfathiazole (SFT), sulfadiazine (SFD), sulfacetamide (SFA), sulfamethoxazole (SFMx), sulfamerazine (SFMr), sulfaguanidine (SFG) and sulfadimidine (SFDd) followed by a coupling reaction with iminodibenzyl in alcohol medium. Absorbance of the resulting violet azo product is measured at 570-580 nm and is stable for 24 h at 27 degrees C. Beer's law is obeyed in the concentration range of 0.05-6.0 microg ml(-1) at the wavelength of maximum absorption. The method is successfully employed for the determination of sulfonamides in various pharmaceutical preparations and common excipients used as additives in pharmaceuticals do not interfere in the proposed method. The method offers the advantages of simplicity, rapidity and sensitivity without the need for extraction or heating. A reaction mechanism is proposed for the formation of the violet azo product.

Analysis of quinolone residues in edible animal products

A comprehensive review on the analysis of quinolone antibacterials is presented. The review covers most of the methods described for the determination of quinolone residues in edible animal products. Sample handling, chromatographic conditions and detection methods have been discussed. A summary of the most relevant information about the analytical procedures has been included.

Biomedical applications of capillary electrophoresis with laser-induced fluorescence detection

Capillary electrophoresis (CE) is a high-efficiency analytical technique that has had a great impact as a tool in biomedical research, clinical and forensic practice in the last ten years. Only in one of the applications, the DNA analysis, it has had an explosive exponential growth in the last few years. This impact is expressed in an enormous amount of CE articles and many reviews. The CE advantages with respect to other analytical techniques: the required very small sample volume, rapid analysis, great resolution power and low costs, have made this technique ideal for the analysis of a numerous endogenous and exogenous substances present in biological fluids. The different modes of CE have been coupled to different detection techniques such as UV-absorbance, electrochemical, mass spectrometry and laser-induced fluorescence detection (LIFD) to detect different nature and molecular size separated analytes. This review focuses mostly on the applications of CE-LIFD, to measure drugs and endogenous neuroactive substances such as amino acids and monoamines, especially in microdialysis samples from experimental animals and humans. CE-LIFD trends are discussed: automated faster analysis with capillary array systems, resolution power improvement, higher detection sensitivity, and CE systems miniaturization for extremely small sample volume, in order to make CE easier and affordable to the lab bench or the clinical bed.

Current methodologies for the analysis of aminoglycosides

The aminoglycosides are a large and diverse class of antibiotics that characteristically contain two or more aminosugars linked by glycosidic bonds to an aminocyclitol component. Structures are presented for over 30 of the most important members of this family of compounds. The use of aminoglycosides in clinical and veterinary medicine and in agriculture is described. Qualitative methods for aminoglycoside analysis include X-ray crystallography, nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry (MS). The major part of this article comprises a comprehensive review of quantitative methods for the determination of aminoglycosides. These are microbiological assay, radiochemical assay, radioimmunoassay, enzyme immunoassay, fluoroimmunoassay and other immunoassays, spectrophotometric and other non-separative methods, gas chromatography (GC), thin-layer chromatography (TLC), high-performance liquid chromatography (HPLC), and capillary electrophoresis (CE). Simple spectrophotometric methods may be adequate for the assay of bulk pharmaceuticals and their formulations. Microbiological assays make useful semi-quantitative screening tests for the analysis of veterinary drug residues in food, but rapid enzyme immunoassays are more suitable for accurate measurements of aminoglycosides in complex matrices. Automated immunoassays are the most appropriate methods for serum aminoglycoside determinations during therapeutic drug monitoring. HPLC techniques provide the specificity and sensitivity required for pharmacokinetic and other research studies, while HPLC-MS is employed for the confirmation of veterinary drug residues. The potential for further development of chromatographic and CE methods for the analysis of biological samples is outlined.

Determination of quinolones in animal tissues and eggs by high-performance liquid chromatography with photodiode-array detection

A rapid, specific reversed-phase HPLC method is described, with solid-phase extraction, for assaying five quinolones (ciprofloxacin, difloxacin, enrofloxacin, norfloxacin and marbofloxacin) with confirmative diode-array detection in samples of bovine kidney, muscle and eggs. The least efficient extraction was marbofloxacin from kidney tissue (64%). The lower detection limit for each quinolone was: enrofloxacin and ciprofloxacin, 1 ng; norfloxacin and difloxacin, 2 ng; marbofloxacin, 4 ng injected. The intra-day relative standard deviations were lower than 7.9% and lower than 8.6% for inter-day assays. These results indicate that the developed method had an acceptable precision.

Analysis of antibiotics by capillary electrophoresis

The broad category of antibiotics encompasses some of the most widely prescribed pharmaceuticals in the world. As is the case with any pharmaceutical, an antibiotic must be characterized in terms of its potency and the presence and quantity of impurities. Additionally, any residue or metabolite that may be present as a result of its use must be monitored. Many capillary electrophoretic techniques have been utilized in the analysis of antibiotics, addressing the various aspects of quantifying, profiling, and monitoring. Some of the more recent applications are summarized in this review article.

Capillary electrophoresis of drugs: current status in the analysis of pharmaceuticals

The current status of capillary electrophoresis (CE) in pharmaceutical analyses is reviewed with about 300 references, mainly from 1996 until 1999. This article covers the use of CE for assay and purity determination of the main component, analysis of natural medicines, antisense DNA, peptides, and proteins. Analysis of hydrophobic and/or electrically neutral drugs by electrokinetic chromatography, capillary electrochromatography and nonaqueous CE is critically evaluated. Detailed techniques for the separation of enantiomers are given in the text with some actual applications. Furthermore, this review includes sensitivity and regulatory aspects for the actual use of CE in new drug applications (NDA). The analytical validation required for CE in NDA is also treated.

Overview of capillary electrophoresis and capillary electrochromatography

This paper provides an overview on the current status of capillary electrophoresis (CE) and capillary electrochromatography (CEC). The focus is largely on the current application areas of CE where routine methods are now in place. These application areas include the analysis of DNA, clinical and forensic samples, carbohydrates, inorganic anions and metal ions, pharmaceuticals, enantiomeric species and proteins and peptides. More specific areas such the determination of physical properties, microchip CE and instrumentation developments are also covered. The application, advantages and limitations of CEC are covered. Recent review articles and textbooks are frequently cited to provide readers with a source of information regarding pioneering work and theoretical treatments.

Drug analysis by capillary electrophoresis and laser-induced fluorescence

This review briefly presents the different laser-induced fluorescence detectors, outlines the different dyes used to derivatize molecules which are used with capillary electrophoresis/laser-induced fluorescence (CE-LIF), and provides an overview and current status of CE-LIF in drug analysis.