Investigation of Electrochemical and Antioxidant Properties of Some Painkiller Drugs (Acetaminophen, Meloxicam, Tenoxicam, and Promethazine) by Computational and Cyclovoltammetry Methods

Nonsteroidal anti-inflammatory drugs are the most commonly used drugs for the treatment of articular, bone, and muscle ailments. The most famous of them are acetaminophen, meloxicam, tenoxicam, promethazine andex. These drugs have approximately the same effects, though there are slight differences, which make some of them more suitable for some patients. In recent years, electrochemical methods have become more prominent due to advances in analytical fields due to their sensitivity, low cost, and relatively short analysis time compared to other methods. In this work, using computational chemistry, which generally solves chemistry problems using mathematical and theoretical principles, the structure of acetaminophen, meloxicam, tenoxicam, and promethazine drugs was optimized using Gaussian 09 software, and the solvation-free energy was calculated. Then the half-wave potential was obtained using physical chemistry relationships, it converts to a half-wave potential. Then, by using a cyclic voltammetry device, the half-wave potential of these drugs was practically obtained and compared with the theoretical values, and the antioxidant properties of these drugs were investigated. The half-wave potential for acetaminophen in the experimental method is 195 mV and in the computational method, 213 mV for meloxicam in the experimental method of 395 mV and in the computational method is 339 mV, for tenoxicam in the experimental method of 355 mV and in the computational method 305 mV, for promethazine in the experimental method 465 mV and in the computational method 423 mV. The more negative the half-wave potential, the more anti-oxidant property. Promethazine has the most antioxidant properties among the drugs studied.