The effect of some fluoroquinolone family members on biospeciation of copper(II), nickel(II) and zinc(II) ions in human plasma.

The speciation of Cu2+, Ni2+ and Zn2+ ions in the presence of the fluoroquinolones (FQs) moxifloxacin, ofloxacin, levofloxacin and ciprofloxacin, in human blood plasma was studied under physiological conditions by computer simulation. The speciation was calculated using an updated model of human blood plasma including over 6,000 species with the aid of the program Hyss2009. The identity and stability of metal-FQ complexes were determined by potentiometric (310 K, 0.

Evaluation of matrix effect in determination of some bioflavonoids in food samples by LC-MS/MS method.

In the present work the LC-MS/MS method with solid phase extraction for simultaneous determination of bioflavonoids rutin, quercetin, hesperidin, hesperetin and kaempferol in some food samples (red onion, orange peel and honey) was developed and the matrix effect accompanying this determination was quantified. The matrix effect evaluated using a postextraction addition method was found to be negative in the range -44 to -0.5%, indicating ionization suppression and strongly depended on bioflavonoid concentration.

Study of Solution Equilibria Between Gadolinium(III) Ion and Moxifloxacin.

The complex formation equilibria between gadolinium(III) ion and moxifloxacin (MOXI) were studied in aqueous solutions. The investigations were performed by glass electrode potentiometric (ionic medium: 0.1mol dm-3 LiCl, 298 K) and UV spectrophotometric measurements.

Optimization of separation and determination of moxifloxacin and its related substances by RP-HPLC.

A RP-HPLC method for the separation and determination of impurities of moxifloxacin, in its pharmaceutical forms as well as moxifloxacin degradation products, was developed with the aid of DryLab software and chemometric (response surface) approach. The separation of four synthesis-related impurities was achieved on a Waters C(18) XTerra column using a mobile phase of (water+triethylamine (2%, v/v)): acetonitrile=90:10 (v/v%); the pH of water phase being adjusted with phosphoric acid to 6.0.

Solution equilibria between aluminum(III) ion and some fluoroquinolone family members. Spectroscopic and potentiometric study.

Complex formation between aluminum(III) ion and fluoroquinolone antibacterials-either moxifloxacin (4th generation antibiotic) or fleroxacin (2nd generation antibiotic) were studied in aqueous solutions without and in the presence of sodium dodecylsulfate (SDS). The investigations were performed by glass electrode potentiometric (ionic medium: 0.1 mol/dm(3) LiCl, 298 K), UV spectrophotometric, multinuclear (1H and 13C) magnetic resonance and ESI-MS measurements.

Compounds of Mo, V and W in biochemistry and their biomedical activity.

Molybdenum, vanadium and tungsten compounds are widely applied as analytical reagents for determination of numerous pharmacologically active substances and different biochemical parameters. Recent data from the available literature pointed to a very potent biomedical activity of compounds containing these trace elements. The present paper represents a survey on the structure and chemical properties of these compounds, as well as on their biological activity, mostly based on their interaction with cations of biomolecules, such as phospholipids and proteins.

Optimization and validation of the direct HPLC method for the determination of moxifloxacin in plasma.

Moxifloxacin (1-cyclopropyl-6-fluoro-1,4-dihydro-8-methoxy-7-[(4aS,7aS)-octahydro-6H-pyrrolo-[3,4-b]pyridin-6-yl]-4-oxo-3-quinolinecarboxylic acid hydrochloride) is new, fourth generation fluoroquinolone with broaden spectrum of antibacterial activity. In the present work simple and rapid RP-HPLC method for the direct determination of moxifloxacin in human plasma is described. Separation of moxifloxacin from plasma components was achieved on Supelco LC-Hisep shielded hydrophobic phase column.

Validation of an HPLC method for the determination of fleroxacin and its photo-degradation products in pharmaceutical forms.

HPLC determination of fleroxacin in dosage forms was carried out using either reversed-phase column YMC pack ODS-AQ or Supelco LC Hisep shielded hydrophobic phase column, with UV detection at 280 nm. The mobile phase for ODS column consisted of 50:50:0.5 v/v/v and for Hisep column 15:85:0.