Analysis of amifloxacin in plasma and urine by high-pressure liquid chromatography and intravenous pharmacokinetics in rhesus monkeys.
An analytical method for the quantitation of amifloxacin, 6-fluoro-1,4-dihydro-1-(methylamino)-7-(4-methyl-1-piperazinyl)-4-oxo-3- quinolinecarboxylic acid, in plasma and urine has been developed. The method involves extraction with chloroform, back-extraction into 0.1 M sodium hydroxide, and subsequent analysis by reverse-phase high-pressure liquid chromatography with UV detection. The precision of the assay calculated as the overall standard deviation was +/- 4.9% in plasma and +/- 1.1% in urine. The range of mean percent differences from the nominal values was used as an estimate of accuracy and was 93.6 to 103% of the nominal values in plasma and 95.2 to 107% of the nominal values in urine. The minimum quantifiable levels were 0.032 micrograms/ml in plasma and 2.7 micrograms/ml in urine. The methods were employed in a pharmacokinetic analysis of amifloxacin after intravenous administration to rhesus monkeys. The decline in drug plasma levels was described by a biexponential process with mean rates of 8.4 h-1 and 0.32 h-1 with corresponding half-lives of ca. 5 min and 2.2 h. Amifloxacin was rapidly excreted, with ca. 53% of the dose appearing in the urine within 48 h after medication. The mean renal clearance +/- standard deviation was 4.4 +/- 1.0 ml X kg-1 X min-1 and is compatible with passive glomerular filtration in this species.
D000818:Animals; D000900:Anti-Bacterial Agents / Q000032:analysis* / Q000097:blood / Q000652:urine; D000890:Anti-Infective Agents; D002851:Chromatography, High Pressure Liquid; D002939:Ciprofloxacin / Q000031:analogs & derivatives*; D005260:Female; D024841:Fluoroquinolones; D006207:Half-Life; D007275:Injections, Intravenous; D007700:Kinetics; D008253:Macaca mulatta; D011804:Quinolines / Q000032:analysis* / Q000097:blood / Q000652:urine
D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents; D024841:Fluoroquinolones; D011804:Quinolines; D002939:Ciprofloxacin; C040691:amifloxacin