Preparation and Optimization of a Ketotifen Sensor and its Pharmaceutical Applications

A Ketotifen (KET)–selective electrode of both conventional polymer membrane and coated graphite types, based on incorporation of ketotifen–tetraphenyl borate (KETTPB) ion-pair have been constructed. The influences of membrane composition, temperature, pH of the test solution, ionic strength and foreign ions on the electrode performance were investigated. The electrode showed a Nernstian concentration range 1.0×10-5 to 1.0×10-2 M and 5.0×10-6 to1.0×10-2 M with a slope of 57.5±1.07 and 59.0±0.9 mV per decade and lower limit of determination are 1.0×10-5 M and 5.0×10-6 M for conventional and coated graphite types, respectively. The electrodes display a good selectivity for ketotifen with respect to a number of common foreign inorganic and organic species. The response not affected by pH between 2.0 and 4.9. The electrode was successfully used for determination of ketotifen both in pure solution and in pharmaceutical preparation. The solubility product of the ion-pair and also the formation constant of the precipitation reaction leading to the ion-pair formation were determined conductometrically.