Simultaneous determination of metronidazole and miconazole in pharmaceutical dosage forms by RP-HPLC

A reversed-phase high performance liquid chromatography (RP-HPLC) method with UV detection is described for the simultaneous determination of metronidazole and miconazole in pharmaceutical dosage forms. Chromatography was carried out on a C18 reversed-phase column, using a mixture of methanol-water (40+60, v/v) as a mobile phase, at a flow rate of 1.0 ml min(-1). Sulfamethoxazole was used as an internal standard and detection was performed using a diode array detector at 254 nm. The method produced linear responses in the concentration ranges 10-70 and 1-20 microg ml(-1) with detection limits 0.33 and 0.27 microg ml(-1) for metronidazole and micanozole, respectively. This procedure was found to be convenient and reproducible for analysis of these drugs in ovule dosage forms.