Abstract

A high performance liquid chromatographic method for the determination of ornidazole in human serum using tinidazole as internal standard is described. Protein precipitation is used for the preparation of sample. Mobile phase consisting of 0.002 M phosphate buffer (pH-4.8), methanol and acetonitrile mixture (70:10:20 v/v/v) was used at the flow rate of 1ml/min on a C18 column. The eluate was monitored using an UV/Vis detector set at 318 nm. Ratio of peak area of analyte to internal standard was used for quantification of serum samples. The absolute recovery was greater than 90% over a concentration range of 1 to 20 0 μg/ml and the limit of quantitation was 0.05 μg/ml. The inter- day relative standard deviation ranged from 1.02 to 3.70 at 1 μg/ml, 0.96 to 3.62 at 2 μg/ml, 3.33 to 5.01 at 10 μg/ml and 1.16 to 5.03 at 20 μg/ml and for intra-day, 1.03, 2.16, 1.95 and 1.23 at 1, 2, 10, 20 μg/ml, respectively. The method was found to be simple, sensitive and could be used in the pharmacokinetic study involving human volunteers.