High-performance liquid chromatographic determination of chlorpromazine and its degradation products in pharmaceutical dosage forms: a stability-indicating assay

Abstract

A high-performance liquid chromatographic method has been developed for the determination of chlorpromazine and its degradation products, chlorpromazine sulphoxide and chlorpromazine sulphone. The method utilises reversed-phase chromatography with selective fluorescence detection and internal calibration techniques. The method shows fluorescence selectivity for chlorpromazine sulphoxide and chlorpromazine sulphone at 385 nm with no interference from the chlorpromazine peak. The method has been used to study a variety of samples from sources in Zimbabwe. Tablet samples showed little degradation whereas some injection samples had levels of chlorpromazine sulphoxide in excess of 5%(i.e., greater than the maximum allowed in the USP). The developed method was compared with the official BP method for chlorpromazine determination.