Quantitative analysis of metronidazole in intravenous admixture with ciprofloxacin by first derivative spectrophotometry

Metronidazole in parenteral admixture with ciprofloxacin was analysed by fi rst-derivative spectrophotometry using the zero-crossing technique of measu rement. The procedure did not require prior separation steps. The method wa s found to be linear (r(2) > 0.999) in the range of 2.5-10 mug ml(-1) for m etronidazole in absence or presence (at constant concentration) of ciproflo xacin. The first-derivative method was applied for the analysis of intraven ous admixture of metronidazole and ciprofloxacin and proved to be rapid, ac curate and reproducible. (C) 2001 Elsevier Science B.V. All rights reserved .