Preparation of a Fluconazole Potentiometric Sensor and its Application to Pharmaceutical Analysis and to Drug Recovery from Biological Fluids

A novel fluconazole ion-selective electrode is prepared, characterized and used in pharmaceutical analysis. The diflucan complex with different ion-pairing agent was obtained in situ by soaking the PVC membranes in a 1 x 10(-2) M diflucan solution. Among four different solvent mediators tested, dibutyl phthalate (DBP) exhibited a proper behavior including Nernstian slope of the calibration curve, fast response time and good reproducibility of the emf values. The electrode exhibits a near Nernstian slope of 57.0 +/- 1 mV decade(-1) for fluconazole in the concentration range 5.0 x 10(-5) -5.0 x 10(-2) M with a limit of detection of 4.0 x 10(-5) M. The electrode displays a good selectivity for diflucan with respect to a number of common foreign inorganic and organic species. It can be used in a pH range 4.5-6.0. The membrane sensor was successfully applied to the determination of fluconazole in its capsules as well as in its recovery from blood serum and urine samples.