PVC Membrane Sensors for Potentiometric Determination of Metoclopramide in Pharmaceutical Preparations and in presence of its Degradate

Two novel polymeric membrane sensors were developed for determination of Metoclopramide (MCP), based on the use of metoclopramide-barbiturate (MCP-B) and metoclopramide-flavinate (MCP-F) ion pairs as electroactive materials in PVC matrix, in presence of o-nitrophenyloctylether (o-NPOE) as a solvent mediator, in plasticized PVC membranes. The suggested two-sensors show a near-Nernstian response for MCP over a wide concentration range of 1×10-5-1×10-2 M. The proposed sensors have a fast response time and can be used for more than 4 weeks without any considerable divergence in potentials. They exhibit comparatively good selectivity with respect to related substances, dosage forms additives, acidic-degradates, alkaline earth and some transition and heavy metal ions.