A Comparative Study of Labetalol via Electrochemical and Computational Methods

Abstract

Normodyne is the brand name of Labetalol. It has medicinal importance and well known antihypertensive drug and given to the patient in the severe hypertension condition. It is two-fold alpha and beta adrenergic antagonism and has dissimilar physiological effects in acute condition of high blood pressure. Various techniques were used to elaborate the qualitative behavior of this drug. In present work, Cyclic Voltammetry (CV) is used to determine the qualitative characteristics of Labetalol. The Glassy Carbon Electrode (GCE) is used as a working and Calomel as a reference electrode with supporting electrolyte (0.1M NaOH) at 30±1oC. In case of GCE, single anodic peak is observed which indicate that this drug showed irreversible process with transfer of one electron in the selected medium. In addition, different electrochemical parameters are also calculated including, peak current (Ip), peak potential (Ep), half peak potential (Ep/2), differential peak potential ΔEp = (Epa – Ep/2), transfer coefficient (α), diffusion coefficient (D), formal potential (Eo), heterogeneous rate constant (Ko), and Gibbs free energy (∆G). Furthermore, adsorption process is also studied. For comparative study, computational methods are employed for finding HOMO-LUMO energies and vibrational frequencies of Labetalol molecule. Both methods, electrochemical and computational are in good agreement and validate irreversible oxidation of Labetalol. This study has not been reported before and it is useful for pharmaceutical industry.