Spectrophotometric resolution of metronidazole and miconazole nitrate in ovules using ratio spectra derivative spectrophotometry and RP-LC

Metronidazole and miconazole nitrate in ovules was determined by ratio spec tra derivative spectrophotometry and by high-performance liquid chromatogra phy (HPLC). The first method depends on ratio spectra first derivative spec trophotometry, by utilizing the linear relationship between substances conc entration and ratio spectra first derivative peak amplitude. The ratio firs t derivative amplitudes at 242.6 ((DD242.6)-D-1), 274.2 ((DD274.2)-D-1), 26 1.8 ((DD261.8)-D-1), 273.5 ((DD273.5)-D-1) and 281.5 ((DD281.5)-D-1) nm wer e selected for the assay of metronidazole and miconazole nitrate. respectiv ely. The second method is based on high-performance liquid chromatography o n a reversed-phase column using a mobile phase of methanol-water phosphoric acid (30:70:0.20 v/v) (pH 2.8) with programmable detection at 220.0 nm. Th e minimum concentration detectable by HPLC was 0.9 mug ml(-1) for metronida zole and 0.3 mug ml(-1) for miconazole nitrate and by ratio derivative spec trophotometry 4.0 mug ml(-1) for metronidazole and 0.5 mug ml(-1) for micon azole nitrate. The proposed procedures were successfully applied to the sim ultaneous determination of metronidazole and miconazole nitrate in ovules w ith a high percentage of recovery, good accuracy and precision. (C) 2001 El sevier Science B.V. All rights reserved.