Norfloxacin analysis

The synthesis and antibacterial properties of norfloxacin (2a) were described in 1980 [65]. In this key paper in the evolution of quinolone antibacterial agents, a series of 6,7,8-polysubstituted-l-ethyl-l,4-dihydro-4-oxoquinoline-3-carb-oxylic acids (13) was synthesized, employing previously developed quantitative structure-activity relationships (QSAR) for the corresponding 6-, 7- and 8-monosubstituted derivatives versus Escherichia coli. The QSAR analysis... 

Fig. 3 Chromatograms obtained in the analysis of a soil sample extract spiked with 0.1 pg g 1 of the selected fluoroquinolones (a) with and (b) without performing MISPE. Peak assignment 1 = enoxacin (ENO), 2 = norfloxacin (NOR), 3 = ciprofloxacin (CIP), 4 = danofloxacin (DAN), 5 = enrofloxacin (ENR) [43]...

An IPC-ESI-MS/MS method allowed the simultaneous determination of neomycin and bacitracin in human and rabbit sera [79] and the analysis of aminoglycoside antibiotics in human plasma [80]. IPC was recently validated for the estimation of bulk and formulated gatifloxacin [81]. The IPC determination of norfloxacin in diverse matrices worked as a stability indicating method [82], A CI2 stationary phase with embedded polar group successfully achieved IPC baseline tetracycline separation simply by using a phosphate as the IPR [83], A practical IPC method for the quality control of fosfomycin calcium and its related substances was recently suggested [84],... 

If analysis of the frequency of adverse events is based on prescription event monitoring (PEM), the rates of adverse events are usually substantially lower. In one study, over 11 000 patients taking each antibiotic were monitored (19). Among the fluoroquinolones, ciprofloxacin, norfloxacin, and ofloxacin were used. Adverse events resulted in withdrawal of norfloxacin or ofloxacin in under 1% of patients (19). 

More recently Brochot et al. [89] reported an extension of the isobolographic approach to interaction studies for convulsant interaction among pelloxacin, norfloxacin, and theophylline in rats. Their contribution is unique in that they started out by explaining pharmacodynamic interactions for two drugs, but then extended the approach to derive an isobol for three drug interaction. In addition they included Bayesian analysis and developed a population model with Markov chain Monte Carlo methods. 

Barbate, F. Morrica, P. Seccia, S. Ventriglia, M. High performance liquid chromatographic analysis of quinolone antibacterial agents. Farmaco, 1994, 49, 407-410 [simultaneous cinoxacin, ciprofloxacin, flumequine, nalidixic acid, norfloxacin, ofloxacin, oxolinic acid, pefloxacin, piromidic acid]... 

The same parabolic relationship for a-p electronic interactions is seen with E. coli, but it may be biased for the reasons already discussed. In contrast, the LFER model for Ps. aeruginosa (Table XXII, Eq. 4) indicates that only lipophilicity and molar refractivity of the substituents at position 7 are important determinants of activity. In the initial analysis for this subset using the Ps. aeruginosa test system, A34 (norfloxacin) was an outlier. Because it is the only compound showing such high activity, it was deleted. The latter s calculated activity was 1.96 versus the observed 1.64. 

Schneider, M.J. Donoghue, D.J. Multiresidue analysis of fluoroquinolone antibiotics in chicken tissue using liquid chromatography-fluorescence-multiple mass spectrometry, J.Chromatogr.B, 2002, 780, 83 92. [ciprofloxacin norfloxacin danofloxadn enrofloxacin orbifloxacin sarafloxacin difloxacin LOQ 10 n g]... 

Table 4 Most Abundant Ion Fragment Clusters (> 500 Daltons) Derived from MALDI Analysis of the Products from the Reaction of Zirconcene Dichloride and Norfloxacin ...

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