Novel Poly (vinyl chloride) Matrix Membrane Sensors for Determination of Cilostazol in Presence of Its Degradation Product and in Plasma

Three novel techniques for selective determination of cilostazol in presence of itsoxidative degradation product were described. the three techniques involve the constructionand studying of electrochemical response characteristics of novel poly (vinyl chloride) [pvc]matrix membrane sensors for cilostazolcation by using the ion-association complexes of thiscation with sodium tetraphenyl borate (natpb), phosphotungestic acid (pta) andammonium reineckate (amm.rnc) counter anions as ion exchange sites in a plasticized pvcmatrix, either as ion selective membranes, microcoated wire or as micro sized graphiteselective sensors. the preparation and full characterization of these sensors, includingcomposition, life span, usable ph range, response time and temperature were described. theelectrodes were used for potentiometric determination of cilostazol in pure form,pharmaceutical products, plasma and in presence of its oxidative degradation product. thesesensors showed near-nernstian slopes of 56.14, 58.82, 56.23, 56.7, 59.14, 56.84, 58.72, 59.44and 58.37mv over the concentration ranges of 1.0×10-7-1.0×10-2 m for natpb and ptasensors and 1.0×10-6-1.0×10-2 m for amm.rnc sensors. the electrodes show good selectivityfor cilostazol relative to a large number of inorganic cations, organic cations, sugars andamino acids. the behavior of the three sensors in presence of human plasma was also studiedand reasonable results were obtained. the methods were successfully applied fordetermination of the intact drug in bulk powder and in presence of its oxidative degradationproduct; therefore it can be used as stability indicating methods.