New Two Sensors PVC- Membrane and Chemically Carbon Paste for Determination of Antidepressant Drug Escitalopram Oxalate in Bulk, Cipralex and Human Fluids

Abstract

Preparation and construction of a new polyvinyl chloride PVC-membrane and chemically modified carbon paste (CMCP) sensors based on ion-pair exchanger escitalopram-silicotungstic (Es-ST) (Sensor 1) and escitalopram-silicomolybdic (Es-SM) (Sensor 2). The effect of several plasticizers and composition of ion-exchangers on the performance characteristics of the sensors was studied. Sensors(1, 2) with 1% composition and dioctyl phthalate (DOP) as plasticizer in PVC-membrane showed Nernstian slopes ranged from 57.5- 59.5 ±0.1 mV/decade over the concentration ranged from 5.0 x 10-7-1.0 x 10-2 M with the life span not less than two months and pH 2.5-7.5 with a detection limit 0.1 nM. While in (CMCP) sensors (1, 2) exhibited with 3% composition and tricresylphthalate (TCP) as binder an excellent Nernstian slopes 59.5, 60.5±0.5 mV/decade for 1 and 2 respectively and a wide concentration range from 1.0 x 10-7-1.0 x 10-2 M and pH 2.5-7.5 with a detection limit 0.5 nM. The sensors reflected high selectivity towards different anions, cations, sugars and amino acids and was recommended by IUPAC. The standard addition, the calibration curve and potentiometric titration methods were used for determination escitalopram in its bulk powder, pharmaceutical tablets Cipralex, human plasma/urine and monitoring profile for the tablet in vitro-dissolution rates. The recoveries were excellent and with good agreement compared with British Pharmacopoeia.