SIMULTANEOUS QUANTITATION OF SOME PHENOTHIAZINE DRUG SUBSTANCES AND THEIR MONOSULFOXIDE DEGRADES BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY (HPLC)

A simple liquid chromatographic procedure is presented for the simulta neous quantitation of three phenothiazine drugs, namely, perphenazine, trifluoperazine and triflupromazine and their sulphoxide degrades. Th e LC-separation was performed on a Novapak-phenyl-4 (150 x 3.9 mm id) column and a mobile phase composed of methanol + 1.5 x 10(-2) M sodium acetate buffer pH 6.5 (81:19, v/v). Isocratic elution and UV-detectio n were adopted. Satisfactory percent assay and mean recoveries with lo w relative standard deviations were obtained for each drug and its sul phoxide in bulk and in tablet dosage form. The stability-indicating ch aracteristics of LC-procedure prove its advantage over the methods use d to limit the sulphoxides.