The separation and determination of chlorpromazine and some of its related compounds by reversed-phase high performance liquid chromatography.

A high performance liquid chromatographic analysis is described for chlorpromazine and some of its related compounds in tablet dosage forms and biological matrices using a dimethylsilane (RP-2) reversed-phase column packing and a mobile phase consisting of ammonium carbonate, acetonitrile, and water. The method will separate and quantitate mixtures of chlorpromazine sulfone, chlorpromazine sulfoxide, desmonomethylchlorpromazine sulfoxide, chlorpromazine, and desmonomethylchlorpromazine. After incorporation of the tablet dosage form or biological matrix in a solvent mixture consisting of dilute hydrochloric acid or ammonium carbonate, acetonitrile, and water, an aliquot is chromatographed and the components are detected and quantitated by their UV spectrophotometric absorption at 254 nm. For chlorpromazine and chlorpromazine sulfoxide hydrochlorides, the data show that temperatures ranging from 30 degrees-80 degrees C may be selected without affecting this analysis except to alter elution time, but the selected temperature must be controlled to +/- 1 degree C in order to achieve precise analytical results. The response of the chromatographic system in aqueous solution is linear over a concentration range of 19.4 ng-56 microgram/ml chlorpromazine. Adequate sensitivity, good selectivity, and reproducibility are shown for the analysis of chlorpromazine in single tablets.