Validation of a reversed-phase LC method for quantitative analysis of intravenous admixtures of ciprofloxacin and metronidazole

The admixture ciprofloxacin-metronidazole is nowadays well known as a clini cal tool when anaerobic organisms are involved. The stability of ciprofloxa cin with metronidazole depends on several variables and this has been scarc ely studied. Thus, the aim of this study was the search for a specific, pre cise and accurate method that would allow the quantification of ciprofloxac in in the presence of metronidazole. The reversed-phase liquid chromatograp hy method is the analytical technique that has proved to be the most adequa te for stability and compatibility studies of this mixture. This method was shown to be linear (r > 0.999) in the range of concentrations of this stud y chosen, between 80 and 120% of the concentration of the commercial formul ation. It showed precision with a repeatability (within-day) of 0.62% and r eproducibility (between-day) of 1.14%, accuracy expressed as recovery perce ntage. (C) 1999 Elsevier Science B.V. All rights reserved.