Determination of the antileukemia agents cytarabine and azacitidine and their respective degradation products by high-performance liquid chromatography.

A reversed-phase high-performance liquid chromatography (HPLC) system was developed for the determination of the antineoplastic agents cytarabine and azacitidine. Separations were performed on an octadecylsilane column with a mobile phase of methanol-phosphate buffer pH 7.0 (5:95). The assay methods are suitable for bulk drugs and sterile powder formulations of the agents. Specificity in the presence of analogues and decomposition products was demonstrated. UV spectra of the components of interest were obtained in the HPLC effluent, and appropriate wavelengths were employed for the various analytes. Samples of azacitidine in various solutions were analyzed as a function of time by HPLC to determine the three first-order constants associated with its decomposition.