Direct Potentiometric Evaluation of Trazodone Hydrochloride by Novel Ion Selective Electrodes

This study improved three potentiometric sensors for measuring the drug trazodone hydrochloride. The constructive sensors were designed for the preparation of electro-active plasticized membranes representative of ion-association complexes. Trazodone cation and phosphomolybdate acid anions used a plasticized poly(vinyl chloride) membrane sensor acting as an electro-active material in a plasticized polyvinyl chloride electrode. The sensors showed agreement at near-Nernstian responses for trazodone hydrochloride-phosphotungstic acid-di-butyl phthalate and trazodone hydrochloride-phosphotungstic acid-o-Nitro phenyl octyl ether with lower detection limits of approximately 2.8×10-6 mol.L-1 and 1.1×10-6 mol.L-1, while the slopes were found to be around 55.00 and 51.70 mV/concentration decade. The pH ranges were approximately 2.0-7.5, 2.5-8.0, and 3.0-8.0 for trazodone hydrochloride-phosphotungstic acid-di-butyl phthalate, trazodone hydrochloride-phosphotungstic acid-o-Nitro phenyl octyl ether and trazodone hydrochloride-phosphotungstic acid-di-butyl phthalate, respectively. The sensor hydrochloride-phosphotungstic acid-di-butyl phthalate showed small values of the slope near the 31.20 mV/concentration decade, while the detection limit was around 5.0×10-6 mol.L-1. The three sensors indicated a high selectivity for the TRZ drug over several inorganic cations for different drug formulation samples. The dissolution profiles showed good relationships when plotted for use in the proposed sensor at optimum electrode conditions. The investigated sensors can be applied for the direct determination of TRZ in some pharmaceutical preparations, and can be used for the investigation of many TRZ tablets.