Development and Validation of Potentiometric Ion Selective Screen Printed Electrode for Sensitive Determination of Linagliptin in Pure Form and in Pharmaceutical Formulation; Application to Dissolution Testing

A novel screen printed graphite ion-selective electrode (spe) was prepared and characterized for determination of linagliptin (lng) in pure form and in pharmaceutical formulation. the electrode is based on lng-tetraphenyl borate (lng-tpb) as ion exchanger and tricresyl phosphate (tcp) as a plasticizer. several parameters such as the type of solvent mediator, amount of the ion-exchanger and working ph range were studied for optimal potentiometric response. under optimal experimental conditions, the sensor exhibited a nernstian slope of 60.10±1.02 mv/decade (n=3) over the concentration range from 1.00×10^-5 to 1.00×10^-2 m (r =0.9999) with lod of 4.50×10^-6 m. the electrode can be used safely over a wide ph range from 4.0 to 8.0. the electrode showed a high selectivity for lng against common interfering substances. fast potentiometric response was obtained within 5 seconds and remained stable for at least 60 s. the electrode was applied to the analysis of lng in pure form and in pharmaceutical dosage form with high accuracy (98.00-102.00%) and precision (%rsd ≤2%). our electrode has the advantages of being inexpensive, simple, sensitive, portable and disposable.