DETERMINATION OF THE IMPURITY PROFILE OF 1,2-CYCLOHEXANEDIONE DIOXIMEBY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

High-performance liquid chromatography (HPLC) was used to determine th e impurity profile of 1,2-cyclohexanedione dioxime (CDO), a key ingred ient in the radiopharmaceutical CardioTec(R) kit (kit for the preparat ion of Tc-99m teboroxime). The HPLC assay separated CDO from potential impurities which included 1,2-cyclohexanedione, cyclohexanone monoxim e and cyclohexanedione monoxime (CDM). The method employed a mobile ph ase consisting of 0.1% phosphoric acid-acetonitrile (82:18, v/v), a Ha milton 10-mu m PRP-X100 anion-exchange column (250 x 4.1 mm I.D.), and UV absorbance detection (238 nm), and achieved a resolution (R(s)) gr eater than or equal to 1.5 for the three detected impurities: 1,2-cycl ohexanedione, cyclohexanone monoxime and cyclohexanedione monoxime (CD M) in the presence of CDO. The method was improved compared to existin g methods by achieving a rapid, simultaneous separation (15 min) of co mpounds not previously reported and quantitating impurities at the 0.2 -5% (w/w) level of sensitivity.