Utilization of carbon disulphide for the analytical determination of betahistine hydrochloride and captopril in their pharmaceutical preparations

Spectrophotometric, atomic absorption spectrometric and high performance li quid chromatographic (HPLC) procedures have been developed for the determin ation of betahistine hydrochloride and captopril. The three procedures are based on the reaction of the drugs with carbon disulphide in alkaline mediu m with the formation of the dithiocarbamate or the trithiocarbonate derivat ive of betahistine (BHT) and captopril (CAP), respectively, then subsequent chelation with divalent metals. The absorbance measurement of the formed c helates or of the metal moiety of chelates was used as the basis for the sp ectrophotometric and atomic absorption spectrometric determinations. The fo rmed complexes have been used as pre-column derivatizing procedure for the HPLC determination of the two drugs. The different experimental conditions were optimized. The calibration graphs were linear over the applicable conc entration ranges. The proposed procedures were applied successfully for the determination of the two investigated drugs in their tablets dosage form. (C) 1999 Elsevier Science B.V. All rights reserved.