Rapid determination of chlorpromazine hydrochloride and two oxidation products in various pharmaceutical samples using high-performance liquid chromatography and fluorescence detection.

A rapid, simple, and accurate high-performance liquid chromatographic procedure using an amino-bonded microparticulate column is reported for the determination of chlorpromazine hydrochloride (I) and its two oxidation products, the sulfoxide (II) and the sulfone (III), in commercially available pharmaceutical dosage preparations. Simultaneous identification and quantitation of II and III in the presence of at least 100 times the amount of parent compound were achieved with selective fluorometric detection. Identification and quantitation of I were achieved by changing the fluorescence detection mode. A typical chromatographic run was completed within 15 min. The described procedure is simpler, more sensitive, and more accurate than the USP XIX methods, particularly for the analysis of II in injectables. Quantitation of II and III at levels as low as 0.1 microgram, representing 0.1% contamination, was demonstrated.