In this work an electrochemical behavior quantification and interaction of valsartan and glibenclamide were studied using square wave voltammetric technique. The effect of temperature on the interaction was investigated and the thermodynamic parameters (∆H, ∆S & ∆G) were calculated for the interaction and binding constant (K) also obtained. The calibration curves of each drug were linear within the range of concentration [(4.99×10-7)-(6.95×10-6)], [(5.96×10-8)-(1.15×10-6)] molar with R 2 value equal to 0.9819, 0.9926 for valsartan and glibenclamide respectively.

A square wave voltammetric technique coupled with three electrode detection system consist of hanging mercury drop electrode (HMDE) as working electrode, 1mm platinum wire as an auxiliary electrode (Pt-wire) and silver/silver chloride saturated potassium chloride (Ag/AgCl.sat.KCl) as reference electrode was used to determine the chlorpropamide indirectly through its interaction with valsartan, chlorpropamide gives no reduction peaks in the studied range. The effect of pH and the stability of the measurement were examined calibrations curve of chlorpropamide was constructed and the relation between current and concentration of chlorpropamide was linear with R2 value = 0.9944. The limit of detection for chlorpropamide was 4.89 x 10-9 M through its interaction with valsartan.

The electrochemical behavior of Eriochrome Red B (ERB) using square wave voltammetry (SWV) with three electrodes cell was studied. The cell consists of working electrodes, either graphite electrode (GE) or Poly ERB-graphite electrode (poly ERB-GE), auxiliary electrode (2mm pt wire) and reference electrode (Ag/AgCl. sat.KCl).

In this work, the interaction between theophylline (TP) which gives a stable well-defined reduction peak at (1.07) V versus Ag/AgCl. Sat. KCl/ in phosphate buffer solution (pH=7) and urea was studied using square wave voltammetry (SWV) technique. Also, the binding constant and the thermodynamics parameters have been calculated. Different temperatures (288, 293, 298, 298, 303, 308 and 310) ºK were used to study the effect of temperature on binding constant (K). The results showed that the binding constant (K) decreased with increasing temperature. This is as a result of the negative value of enthalpy (-31.07)KJ.mol-1. The negative value of Gibbs energy (-13.632 x 10 2 _-12.296 x 10 2) KJ.mol-1 indicates that the interaction is spontaneous and could be due to van der Waals forces or hydrogen bonds effect (weak interaction).