title: Quantitative determinations of levofloxacin and rifampicin in pharmaceutical and urine samples using nuclear magnetic resonance spectroscopy.
abstract: Rapid, specific and simple methods for determining levofloxacin and rifampicin antibiotic drugs in pharmaceutical and human urine samples were developed. The methods are based on (1)H NMR spectroscopy using maleic acid as an internal standard and DMSO-d6 as NMR solvent. Integration of NMR signals at 8.9 and 8.2 ppm were, respectively, used for calculating the concentration of levofloxacin and rifampicin drugs per unit dose. Maleic acid signal at 6.2 ppm was used as the reference signal. Recoveries of (97.0-99.4)+/-0.5 and (98.3-99.7)+/-1.08% were obtained for pure levofloxacin and rifampicin, respectively. Corresponding recoveries of 98.5-100.3 and 96.8-100.0 were, respectively, obtained in pharmaceutical capsules and urine samples. Relative standard deviations (R.S.D.) values < or =2.7 were obtained for analyzed drugs in pure, pharmaceutical and urine samples. Statistical Student's t-test gave t-values < or =2.87 indicating insignificant difference between the real and the experimental values at the 95% confidence level. F-test revealed insignificant difference in precisions between the developed NMR methods and each of fluorimetric and HPLC methods for analyzing levofloxacin and rifampicin.
authors.affiliation: Department of Chemistry, Faculty of Science, UAE University, Al-Ain 17551, UAE. asalem@uaeu.ac.ae
authors.forename: A A
authors.initials: AA
authors.lastname: Salem
authors.forename: H A
authors.initials: HA
authors.lastname: Mossa
authors.forename: B N
authors.initials: BN
authors.lastname: Barsoum
mesh_terms: D002138:Calibration; D004121:Dimethyl Sulfoxide; D004304:Dosage Forms; D006801:Humans; D064704:Levofloxacin; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008298:Maleates; D008958:Models, Molecular; D008968:Molecular Conformation; D015242:Ofloxacin / Q000032:analysis* / Q000737:chemistry / Q000652:urine; D012293:Rifampin / Q000032:analysis* / Q000737:chemistry / Q000652:urine; D012680:Sensitivity and Specificity
chemical_list: D004304:Dosage Forms; D008298:Maleates; D064704:Levofloxacin; C030272:maleic acid; D015242:Ofloxacin; D012293:Rifampin; D004121:Dimethyl Sulfoxide