DETERMINATION OF MINOR IMPURITIES AND DIASTEREOMERS OF -3-OXO-3H-PYRIDO[3,2,1-KL]PHENOXAZINE-2-CARBOXYLIC ACID HYDROCHLORIDE BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

Diastereomers of the quinobenoxazine antineoplastic drug Abbott-84441. 1 and minor impurities were determined using high-performance liquid c hromatography. Manufacturing impurities, degradation products, and dia stereomers were separated using a reversed-phase system with gradient elution. Detector response was linear for Abbott-84441.1 to approximat ely 20 mu g/mL which represents 4.0% of the drug concentration. The pr ocedure provides quantitation of impurities to approximately the 0.1% level with precision (relative standard deviations) of 7.3% to 31% in typical bulk drug lots. A variety of reversed-phase columns were evalu ated for the assay method with the optimum resolution achieved using a 5-mu m Alltima C-18 packing.