A New Screen-printed Ion Selective Electrode for Determination of Citalopram Hydrobromide in Pharmaceutical Formulation

Novel citalopram screen-printed ion selective electrodes were fabricated, characterized and used for the determination of citalopram in pharmaceutical formulations. The proposed sensors incorporated potassium tetrakis(p-chlorophenyl) borate (KTpClPB) ionophore (electrode V) and citalopram-phosphotungstate (CP-PT) ion pair complex (electrode X) as electroactive materials in screen-printed electrodes and tricresylphosphate (TCP) as solvent mediator. The fabricated electrodes demonstrated near Nernstain response over wide linear range of 4.9 × 10−7−1.0 × 10−2 M and 1.0 × 10−6−1.0 × 10−2 M citalopram with lower limit of detection of 4.9 × 10−7 M and 1.0 × 10−6 M and slope of (60.47 ± 0.80) mV decade−1 and (59.93 ± 1.45) mV decade−1 for electrode (V) and (X), respectively. The results showed that the proposed sensors had the characteristics such as fast and stable response, good reproducibility, long term stability (5 and 4 months) and applicability over a wide pH range of 2–9 and 2–8 for electrodes (V) and (X). The sensors displayed good selectivity for citalopram with respect to number of common foreign inorganic, organic species, excipients and the fillers added to the pharmaceutical preparation. The sensors were successfully applied for the determination of citalopram in tablet, urine and serum.

The static response time of the electrodes was measured after successive immersion of the electrodes in a series of CPB solutions, in each of which the CPB concentration increased 10−fold, from 4.9 × 10−7 M to 1.0 × 10−2 M. The static response time thus obtained was less than 7 and 9 s for 1.0 × 10−2 M and 1.0 × 10−3 M CPB concentration. At lower concentrations, however, the response time was little longer and reached 12 and 13 s for electrode (V) and electrode (X), respectively.Figure optionsDownload as PowerPoint slide