Electrochemical Sensors for Determination of Anticonvulsant Drug Gabapentin in Bulk Powder and Pharmaceutical Dosage Forms

Three simple, sensitive and selective sensors for determination of gabapentin (GAB) have been fabricated and validated. Plastic membrane I, coated wire II and coated graphite rod III were constructed by the incorporation of gabapentin with phosphotungstic acid (PTA) in the presence of o-nitrophenyloctylether o-NPOE as electroactive material. The influence of several parameters such as (membrane composition, kind of plasticizer, type of ion-pair, pH of the test solution, soaking time and foreign ions on the potential of the sensors was investigated and optimized. The proposed sensors clarified Nernstain response with a mean calibration slope of 57.57 +/- 0.26, 59.57 +/- 0.31 and 55.07 +/- 0.91 mV dacade(-1) over gabapentin concentration range 1.0x10(-5) -1.0x10(-2), 5.0 x10(-6)-1.0x10(-2) and 1.0x10(-5)-9.0x10(-3) mol L-1 for sensor I, II and III respectively. The fabricated sensors showed high sensitivity with detection limit of 5.0x10(-6), 2.5x10(-6) and 4.6x10(-6) mol L-1 for the above mentioned sensors, respectively. The recorded pH was 1.5-3.5 and the effect of common possible interfering species such as inorganic cations, sugars and amino acids was studied. The obtained results were statistically evaluated according to ICH guidelines.