CYCLIC VOLTAMMETRIC STUDY OF SOME BIOLOGICALLY ACTIVE DRUGS

Abstract

This electrochemical study of three different biologically active compounds has been conducted using cyclic voltammetry technique at gold electrode. Losartan Potassium is an antihypertensive drug, while Gemifloxacin is antibacterial and Clarithromycin is primarily bacteriostatic and also has antimicrobial effect. Cyclic voltammetric study has been conducted by using (0.04M) Britton Robinson Buffer as supporting electrolyte with different pH range. For Losartan Potassium pH range of B-R buffer was 8-11 while for Clarithromycin and Gemifloxacin B-R buffer pH range (2-6) has been selected according to the appropriate solubility of these pharmaceutical compounds. Voltammograms of all three biologically active compounds have been recorded at six different scan rates of 20, 100, 200, 300, 400 and 500mV/s. Different electrochemical parameters such as peak potential (Ep), peak current (Ip), transfer coefficient (α), number of electron (nα), diffusion coefficient (D), and heterogeneous rate constant (K0) were determined. Moreover, diagnostics tests have also been applied to define the electrochemical properties of these compounds. Results indicate that Losartan Potassium follows electrochemically irreversible reduction process with transfer of two electrons involving adsorption controlled process on gold electrode. However, electrochemical behavior of Gemifloxacin showed quasi reversible redox process with two electron transfer and on the electrode surface some adsorption complications have been observed. In case of Clarithromycin irreversible oxidation process with two electron transfer has been identified and electrode processes were shown to be diffusion controlled. These quantitative and qualitative investigations based on cyclic voltammetry technique demonstrate that this method is very reliable, sensitive and appropriate for the determination of electrochemical properties of different biological and pharmaceutical compounds using gold electrode. Moreover, this technique can also be used for quality control and pharmacokinetics studies of biologically active compounds.