Photoinduced oxidation of a tris(2,2'-bipyridyl)ruthenium(II)- peroxodisulfate chemiluminescence system for the analysis of mebeverine HCl pharmaceutical formulations and biological fluids using a two-chip device

A new method for the analysis of mebeverine hydrochloride (MEB) has been developed using a two-chip device. The method is highly selective, sensitive, rapid and consumes minute amount of reagents. The developed method is free of interference from the degradation products of MEB and from common ingredients present in pharmaceutical formulations. The limit of detection was 0.043 μg/mL, and the limit of quantification was 0.138 μg/mL. The short analysis time per sample (20 s) allowed a large number of analyses to be performed within a very short time. Various samples were analyzed, including two different pharmaceutical formulations and a uniformity of content analysis for 20 tablets from a known batch and two biological samples at different concentrations. In addition, the method was compared with a validated high-performance liquid chromatography (HPLC) method and the results clearly indicated the suitability of the developed method for routine analyses. A new mechanism for the tris(2,2'-bipyridyl)ruthenium(II) (Ru(bpy)₃²⁺)- peroxodisulfate (S₂O₈^2-) chemiluminescence (CL) system has also been proposed. The mechanism is based on photoinduced oxidation of Ru(bpy)₃²⁺ to Ru(bpy)₃³⁺ via the formation of Ru(bpy)₃²⁺* upon irradiation with visible light. S₂O₈^2- then oxidizes Ru(bpy)₃²⁺* to Ru(bpy)₃³⁺ and the analyte subsequently reduces the resultant Ru(bpy)₃³⁺ to Ru(bpy)₃²⁺*, which then produces the CL signal.