Development and Validation of an RP-HPLC Method for Simultaneous Analysis of Ofloxacin and Ornidazole in Tablets

A simple, sensitive, and inexpensive high performance liquid chromatographic method has been developed for simultaneous determination of ofloxacin and ornidazole in pharmaceutical formulations. Chromatographic separation was achieved on a BDS-C18-Hypersil column (250 mm x 4.6 mm i.d., 10 µm). Mobile phase was 80% water (containing 0.55 ml/L of triethylamine as peak modifier) and 20% acetonitrile; final pH was adjusted to 3.0 with orthophosphoric acid. Detection was done at 284 nm. Response was a linear function of concentration in the range 1–20 µg/ml for ofloxacin and 2.5-50 µg/ml for ornidazole; the correlation coefficients were 0.9998 and 0.9995, respectively. The limit of detection were 0.01 and 0.02 µg/ml for ofloxacin and ornidazole respectively, where as limit of quantitation were 0.05 and 0.1 µg/ml . The accuracy result for ofloxacin and ornidazole at eighty percent drug (80%), hundred percent (100%), and one hundred and twenty percent (120%) were ranged from 99.6-100.9%. The inter- and intra-day precision was less than 1%. Total elution time for the two components was less than 9 min.