Simple, fast, and precise reversed-phase (RP)-high-performance liquid chromatography (HPLC) and two ecofriendly spectrophotometric methods were established and validated for the simultaneous determination of moxifloxacin HCl (MOX) and flavoxate HCl (FLX) in formulations. Chromatographic methods involve the separation of two analytes using an Agilent Zorbax SB C18 HPLC column (150 mm × 4.6 mm; 5 µm) and a mobile phase consisting of phosphate buffer (50 mM; pH 5): methanol: acetonitrile in a proportion of 50:20:30 v/v, respectively. Valsartan was used as an internal standard. Analytes were monitored by measuring the absorbance of elute at 299 nm for MOX and 250 nm for FLX and valsartan. Two environmentally friendly spectrophotometric (first derivative and ratio first derivative) methods were also developed using water as a solvent. For the derivative spectrophotometric determination of MOX and FLX, a zero-crossing technique was adopted. The wavelengths selected for MOX and FLX were −304.0 nm and −331.8 nm for the first derivative spectrophotometric method and 358.4 nm and −334.1 nm for the ratio first-derivative spectrophotometric method, respectively. All methods were successfully validated, as per the International Conference on Harmonization(ICH) guidelines, and all parameters were well within acceptable ranges. The proposed analytical methods were successfully utilized for the simultaneous estimation of MOX and FLX in formulations.
Background: Diclofenac Sodium (DCL) and Moxifloxacin HCl (MOX) were simultaneously used after cataract surgery to reduce the post-operative inflammation and to control infection respectively. Objectives: Three simple, accurate, eco-friendly and reproducible UV spectroscopic methods were established for concurrent determination of diclofenac sodium and moxifloxacin in ophthalmic preparation without prior separation. Methods: The first technique was established on the measurement of a peak amplitude of the first derivative spectra at the zero-crossing wavelength of one analyte. The second method was the determination of peak amplitude difference between peak and trough of ratio spectra. The third method involves the measurement of the peak amplitude of the first derivative of ratio spectra. Water has been used as a solvent. Results: The analytes exhibited good linearity in the range of 1-15 µg/mL for DCL and 1-18 µg/mL for MOX with excellent correlation coefficient (r 2 >0.999). Low percent relative standard deviation confirmed the precision of the methods. Excellent recovery with low percent relative error proved the accuracy of the methods. The specificity of the methods was evaluated by analyzing the laboratory prepared solutions of DCL and MOX. Conclusion: Proposed three techniques were effectively utilized for the simultaneous determination of DCL and MOX from ophthalmic preparation. The outcomes of the proposed procedures were compared with the earlier described methods and no statistical difference was found between the methods in terms of accuracy and precision.
The Middle East Respiratory Syndrome (MERS) is an emerging disease caused by a recently identified human coronavirus (CoV). Over 2494 laboratory-confirmed cases and 858 MERS-related deaths have been reported from 27 countries. MERS-CoV has been associated with a high case fatality rate, especially in patients with pre-existing conditions. Despite the fatal nature of MERS-CoV infection, a comprehensive study to explore its evolution and adaptation in different hosts is lacking. We performed codon usage analyses on 4751 MERS-CoV genes and determined underlying forces that affect the codon usage bias in the MERS-CoV genome. The current analyses revealed a low but highly conserved, gene-specific codon usage bias in the MERS-CoV genome. The codon usage bias is mainly shaped by natural selection, while mutational pressure emerged as a minor factor affecting codon usage in some genes. Other contributory factors included CpG dinucleotide bias, physical and chemical properties of encoded proteins and gene length. Results reported in this study provide considerable insights into the molecular evaluation of MERS-CoV and could serve as a theoretical basis for optimizing MERS-CoV gene expression to study the functional relevance of various MERS-CoV proteins. Alternatively, an attenuated vaccine strain containing hundreds of silent mutations could be engineered. Codon de-optimization will not affect the amino acid sequence or antigenicity of a vaccine strain, but the sheer number of mutations would make viral reversion to a virulent phenotype extremely unlikely.
A rapid, synchronized liquid chromatographic method was established for the estimation of hydrochlorothiazide (HCZ), amlodipine (AMD), olmesartan (OLM), telmisartan (TEL), and irbesartan (IRB) in binary and ternary coformulations using the same chromatographic conditions. Five analytes were separated on a Zorbax C18 column using isocratic elution with a mobile phase consisting of acetonitrile, methanol, and 20 mM phosphate buffer (pH 3.5) in a ratio of 45:20:35% v/v. The analytes were detected at a wavelength of 230 nm at ambient temperature. Furthermore, the proposed liquid chromatographic procedure was validated for linearity, precision, accuracy, stability, and robustness using an experimental design. Analytes were separated with good resolution within 3.5 min. Analytes showed good linearity in a concentration satisfactory to analyze the different ratios of these analytes in the formulations. Pareto charts showed that the flow rate and mobile phase composition have a significant effect on the peak area of analytes and hence need to be carefully controlled, however, the method is robust. Finally, the different formulations consisting of HCZ, AMD, OLM, TEL, and IRB in different ratios were analyzed with high accuracy using an optimized HPLC method and compared with reported methods. Furthermore, the reported HPLC procedure is simple, rapid, and accurate and therefore can used for regular quality control of binary and ternary formulations using the same stationary and mobile phase.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.