Ion Selective Membrane Electrodes for Determination of Citalopram Hydrobromide in Drug Product and in Presence of Its Degradation Products

This paper presents a comparative study between three sensors developed to determine Citalopram Hydrobromide (CT) in the presence of its alkaline hydrolysis and oxidation induced degradation products using different ion association complexes. Sensor 1 was fabricated using phosphomolybdic acid, Sensor 2 used phosphotungestic acid and sensor 3 used the sodium tetraphenyl borate. Linear responses of CT were obtained within the concentration ranges of 1×10−6 to 1×10−2 mol L-1 for sensor 1 and 2 and 1×10−5 to 1×10−2 mol L-1 for sensor 3 over the pH range of 3.0–6.0. The selectivity coefficients of the developed sensors indicated excellent selectivity for CT. The proposed sensors displayed useful analytical characteristics for the determination of CT in bulk powder, pharmaceutical formulation, and in the presence of its degradation products and thus could be used for stability-indicating methods. The method was validated according to ICH guidelines.Statistical comparison between the results from the proposed method and the results from the reference HPLC method showed no significant difference regarding accuracy and precision.