Abstract

The objective of this work was to develop and validate simple, rapid and accurate chromatographic methods for simultaneous determination of ofl oxacin and ornidazole in solid dosage form. The fi rst method was based on reversed phase high performance liquid chromatography, on Intersil C18 column (250 mm, 4.6 i.d.), using acetonitrile:methanol: 0.025M phosphate buffer, pH 3.0 (30:10:60 % v/v/v) as the mobile phase, at a fl ow rate of 1 ml/min at ambient temperature. Quantifi cation was achieved with UV detection at 318 nm over a concentration range of 2-40 μg/ml for ofl oxacin and 5-100 μg/ml for ornidazole. The mean retention time of ofl oxacin and ornidazole was found to be 4.04 min and 5.83 min, 6.77 min (isomers), respectively. The amount of ofl oxacin and ornidazole estimated as percentage of label claimed was found to be 100.23 and 99.61%, with mean percent recoveries 100.20 and 100.93%, respectively. The second method was based on TLC separation of these drugs using silica gel 60F254 aluminium sheets and dichloromethane:methanol:25% ammonia solution (9.5:1:3 drops v/v) as mobile phase. Detection was carried out at 318 nm over the concentration range of 20-100 ng/spot for ofl oxacin and 50-250 ng/spot for ornidazole. The mean Rf value of ofl oxacin and ornidazole was found to be 0.16 and 0.56, 0.78 (isomers), respectively. The amount of ofl oxacin and ornidazole estimated as percentage of label claimed was found to be 100.23 and 99.61% with mean percent recoveries 100.47 and 99.32%, respectively. Both these methods were found to be simple, precise, accurate, selective and rapid and could be successfully applied for the determination of pure laboratory prepared mixtures and tablets.