HPLC Determination of Dacarbazine, Doxorubicin, and Ondansetron Mixture in 5% 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 in 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-acetonitrile at a flow rate of 1.0 ml/min with detection of all three analytes at 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 mechanism of retention for the analytes on silica was cation exchange. The method showed linearity for dacarbazine, doxorubicin, and ondansetron in the 0.79-7.90, 0.08-1.60, and 0.06-6.00 mug/ml ranges, respectively. Accuracy and precision were in the 0-7% and 0.4-6% ranges, respectively, for all three compounds. The limits of detection for dacarbazine, doxorubicin, and ondansetron were 12.5. 10.0 and 8.0 ng/ml, respectively, based on a signal to noise ratio of 3 and a 50 mul injection.