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.
Teja-Isavadharm
P
P
Department of Immunology and Biochemistry, Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand.
Keeratithakul
D
D
Watt
G
G
Webster
H K
HK
Edstein
M D
MD
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