Aim: The present article focuses on development of sensitive, simple, precise, accurate and inexpensive stability indicating assay method for the simultaneous estimation of Ofloxacin and Ornidazole in bulk was established using RPHPLC. Materials and Methods: The separation was done with C18 Phenomenex Hyperclone BDS column (250×4.6mm, 5μ) at a temperature of 25°C using a mobile phase of acetonitrile: pH 5.8 ammonium acetate buffer of ratio 25:75 with a flow rate of 1ml/min. The detection was done at 293nm and 311nm and the retention time for Ofloxacin and Ornidazole was 4.278 min and 6.750 m respectively. Results: The method was seen to be linear over the range of 2-16μg/ml for both drugs. The method was precise and robust with LOD of 0.331 and 0.360 and LOQ of 1.005 μg/ml and 1.092 μg/ml for Ofloxacin and Ornidazole respectively. The drugs were subjected to stress conditions in acidic, alkaline, oxidative, thermal and photolytic conditions. Conclusion: The method for this simultaneous estimation was found to be accurate, precise, fast and simple with a run time within 8 min. This method developed was applied with success for the assay and dissolution studies in tablet formulation.
Key words: Ofloxacin, Ornidazole, Stability indicating method, HPLC, Dissolution.