VOLTAMMETRIC DETERMINATION OF PIROXICAM IN MICELLAR MEDIA BY USING CONVENTIONAL AND SURFACTANT CHEMICALLY-MODIFIED CARBON-PASTE ELECTRODES

A method for piroxicam determination based on adsorptive stripping vol tammetric techniques, using conventional and chemically modified carbo n paste electrodes in micellar media, is described. The employed surfa ctants were sodium dodecyl sulfate (SDS), Triton X-100, Triton X-405. Tween 80 and Brij 30. However, the purpose of this paper is, at presen t, to research the use of surfactants as carbon paste modifier because one of the mechanisms of hydrophobic drugs ad-accumulation on the car bon paste electrode is based on the chemical affinity. Besides, becaus e of the water piroxicam insolubility, a special aqueous medium, such as a surfactant solution above its c.m.c. was used, this micellar medi a being very advantageous in relation to the use of organic or aqueous -organic media, in order to dissolve the studied drug and to remove th e problems derived from the organic solvents use. In addition, a pirox icam ad-accumulation increase, on surfactant modified carbon paste ele ctrode, with the surfactant mass incorporated into the electrode, was observed.