title: Simultaneous determination of the combined drugs of ceftriaxone sodium, metronidazole, and levofloxacin in human urine by high-performance liquid chromatography.
abstract: OBJECTIVE
  To develop a new high-performance liquid chromatography (HPLC) method for simultaneous determination of the combined drugs (ceftriaxone sodium, metronidazole, and levofloxacin) in human urine.
  
  
  METHODS
  Ceftriaxone sodium, metronidazole, and levofloxacin were separated on a Kromasil 100-5 C18 (250 mm × 4.6 mm, 5 μm, AKZO NOBEL, Bohus, Sweden) analytical column, using the mobile phase consisted of 1.5 mM KH(2) PO(4)  (pH 4.5) with 0.0125% triethylamine-methnol (70:30, v/v). Ceftriaxone sodium, metronidazole, and levofloxacin were detected by a photodiode-array detector at 247, 320, 292 nm, respectively.
  
  
  RESULTS
  Under optimal conditions, the effective separation of ceftriaxone sodium, metronidazole, and levofloxacin was achieved. A good linearity with the correlation coefficients more than 0.999 was demonstrated. The detection limits of ceftriaxone sodium, metronidazole, and levofloxacin were 0.05, 0.01, and 0.25 μg/ml, respectively, and the average recoveries in human urine were in the range from 97.73 to 100.7% with the average relative standard deviation (RSD) in the range of 2.5% and 3.0%.
  
  
  CONCLUSIONS
  The proposed method was sensitive, accurate, and rapid. This work may provide a reference for clinical rational drug use and methodology for the pharmacokinetics study of the combined drugs.
authors.affiliation: College of Chemistry and Environmental Science, Hebei University, Key Laboratory of Analytical Science and Technology of Hebei Province, Baoding, P.R. China. hanwen@hbu.edu.cn
authors.forename: Hanwen
authors.initials: H
authors.lastname: Sun
authors.forename: Hongliu
authors.initials: H
authors.lastname: Wang
authors.forename: Xusheng
authors.initials: X
authors.lastname: Ge
mesh_terms: D002443:Ceftriaxone / Q000652:urine*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D005021:Ethylamines / Q000737:chemistry; D006801:Humans; D006863:Hydrogen-Ion Concentration; D016018:Least-Squares Analysis; D064704:Levofloxacin; D000432:Methanol / Q000737:chemistry; D008795:Metronidazole / Q000652:urine*; D015242:Ofloxacin / Q000652:urine*; D010710:Phosphates / Q000737:chemistry; D017680:Potassium Compounds / Q000737:chemistry; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D005021:Ethylamines; D010710:Phosphates; D017680:Potassium Compounds; D008795:Metronidazole; D064704:Levofloxacin; D002443:Ceftriaxone; D015242:Ofloxacin; C013216:potassium phosphate; C016162:triethylamine; D000432:Methanol