HPLC DETERMINATION OF DACARBAZINE, DOXORUBICIN, AND ONDANSETRON MIXTURE IN 5-PERCENT DEXTROSE INJECTION ON UNDERIVATIZED SILICA WITH AN AQUEOUS-ORGANIC MOBILE-PHASE

A high performance liquid chromatography procedure has been developed for the assay of a dacarbazine, doxorubicin, and ondansetron mixture i n 5% dextrose injection. The separation and quantitation are achieved on an 22-cm underivatized silica column at ambient temperature using a mobile phase of 60:40 v/v 6.25 mM phosphate buffer, pH 3.0-acetonitri le at a flow rate of 1.0 ml/min with detection of all three analytes a t 216 nm. The separation is achieved within 10 min with sensitivity in the ng/ml range for each analyte. It was shown that the predominant m echanism of retention for the analytes on silica was cation exchange. The method showed linearity for dacarbazine, doxorubicin, and ondanset ron in the 0.79-7.90, 0.08-1.60, and 0.06-6.00 mug/ml ranges, respecti vely. Accuracy and precision were in the 0-7% and 0.4-6% ranges, respe ctively, for all three compounds. The limits of detection for dacarbaz ine, doxorubicin, and ondansetron were 12.5. 10.0 and 8.0 ng/ml, respe ctively, based on a signal to noise ratio of 3 and a 50 mul injection.