Measurement of ciprofloxacin in human plasma, whole blood, and erythrocytes by high-performance liquid chromatography.
A simple, rapid, and accurate high-performance liquid chromatographic method using fluorescence detection is described for the measurement of ciprofloxacin in plasma, whole blood, and erythrocytes. Ciprofloxacin and the internal standard difloxacin were separated on a mu-Bondapak C18 column (30 cm x 3.9 mm inside diameter, 10 microns particle size), using a mobile phase of 0.1 M phosphate buffer (pH 2.5):acetonitrile (75:25, vol/vol). The retention times were 5.1 min for ciprofloxacin and 7.9 min for difloxacin. The compounds were extracted from the three biological fluids using protein precipitation followed by a single-step liquid-liquid extraction. The assay is precise, with interassay coefficients of variation of less than or equal to 9.1% and an accuracy of less than or equal to 7.4% at 0.5 and 5.0 micrograms/ml (n = 5). The mean extraction recoveries of ciprofloxacin in plasma, whole blood, and erythrocytes were 84.4, 63.9, and 48.0%. The limit of detection for ciprofloxacin is 25 ng/ml. Ciprofloxacin concentrations in the three biological fluids were measured in patients with uncomplicated falciparum malaria to demonstrate the application of the method.
Department of Immunology and Biochemistry, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand.
P
P
Teja-Isavadharm
D
D
Keeratithakul
G
G
Watt
H K
HK
Webster
M D
MD
Edstein
D000328:Adult; D000818:Animals; D000890:Anti-Infective Agents / Q000097:blood; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D002939:Ciprofloxacin / Q000031:analogs & derivatives / Q000097:blood* / Q000627:therapeutic use; D004912:Erythrocytes / Q000737:chemistry*; D024841:Fluoroquinolones; D006801:Humans; D016778:Malaria, Falciparum / Q000097:blood / Q000188:drug therapy; D010949:Plasma / Q000737:chemistry*; D012015:Reference Standards
D000890:Anti-Infective Agents; D024841:Fluoroquinolones; D002939:Ciprofloxacin; C047225:difloxacin