A Comparative Study of Labetalol via Electrochemical and Computational Methods

Normodyne is the brand name of Labetalol. It has medicinal importance and well known antihypertensive drug and is given to patients with severe hypertension conditions. It is the two-fold alpha and beta-adrenergic antagonism and has dissimilar physiological effects in acute conditions of high blood pressure. Various techniques were used to elaborate on the qualitative behavior of this drug. In the 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 the case of GCE, a single anodic peak is observed which indicates that this drug showed an irreversible process with the transfer of one electron in the selected medium. In addition, different electrochemical parameters are also calculated including, Anodic peak current (Ipa), Anodic peak potential (Epa), 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, the adsorption process is also studied. For comparative study, computational methods are employed for finding HOMO-LUMO energies and vibrational frequencies of the Labetalol molecule. Both methods, electrochemical and computational are in good agreement and validate the irreversible oxidation of Labetalol. This study has not been reported before and it is useful for the pharmaceutical industry.