The specificity of the proposed bioassay was compared with HPLC. The HPLC assay was carried out on a system of Agilent Technol-. ogies, Series 1200, which is composed of a quaternary pump, an. autosampler, a photodiode array detector (DAD) and EZ Chrome. Elite software. The column used was a Cosmosil C18 MS II from. Thermo Electron Corporation. The mobile phase consisted of a mixture of 85 volume of buffer solution prepared by dissolving 84. volumes of 0.05 M citric acid monohydrate and 1 volume of 1 M. ammonium acetate; and 15 volumes of acetonitrile. A 0.1% (m / v). solution of Levofloxacin reference standard was prepared in 0.1 M. hydrochloric acid and 5 mL of this solution was diluted to 50 mL. with distilled water. The test solution was prepared by dissolving a. quantity containing 100 mg of the commercial sample Levoflox tablet. and dispersed in 100.0 mL of 0.1 M hydrochloric acid. 5 mL of this solution was diluted to 50 mL with distilled water. All solutions were filtered through 0.45 mm membrane filter before injection. The spectrophotometer was set at 293 nm. Flow rate was maintained as 1 mL / min and the injection volume was 10 mL.