Phenothiazine drug poly(vinyl chloride) matrix membrane electrodes and their use in pharmaceutical analysis

Abstract

The construction and performance characteristics of ion-selective membrane electrodes for phenothiazine drugs based on their ion-pair complexes with tetraphenylborate and dinonylnaphthalene sulphonate in a poly(vinyl chloride) matrix are described. The electrodes show a near-Nernstian response over various ranges depending on the nature of the phenothiazine drug. The selectivity of these electrodes to a number of amino acids, alkaloids, neurotransmitters, quaternary ammonium compounds and other drugs or pharmaceutical excipients is reported. The standard additions method and potentiometric titrations are used to determine the phenothiazine drugs in pharmaceutical preparations with satisfactory results.