doi.org/10.36721/PJPS.2023.36.4.REG.1183-1189.1 Pak. J. Pharm. Sci., Vol.36, No.4, July 2023, pp. 1183-1189 1183 Voltammetric quantification of acetylsalicylic acid in pharmaceutical formulations utilizing copper wire electrode Mohammad Amayreh Department of Chemistry, Faculty of Science, Al-Balqa Applied University, Al-Salt, Jordan Abstract: This research describes the quantitative detection of acetylsalicylic acid (ASA) as salicylic acid (SA) in pharmaceutical formulations using electrochemical determination at copper electrode. The cyclic voltammetry (CV) technique was applied to investigate the electrochemical behavior of salicylic acid at a copper electrode. The anodic peak of salicylic acid (SA) was obtained at ~0.6V vs. Ag/AgCl quasi electrode in a phosphate buffer solution of pH 11.5. The measurement was made in a potential range of 0.00V to 0.80V, where all the reported potentials are referred to this reference electrode. The oxidation peak current was linearly dependent on the concentration of salicylic acid, which ranges between 0.05mM and 15mM with a detection limit of 14.9µM. Three different pharmaceutical formulations from three different brands were successfully analyzed for acetylsalicylic acid using the newly developed method. The acquired results and the indicated values had an RSD% of less than 2.02, which was in good agreement with the concentration of real samples. Keywords: Salicylic acid, voltammetry, copper electrode, pharmaceutical formulations. INTRODUCTION Acetylsalicylic acid (ASA) or aspirin, the well-known drug for more than 140 years, was introduced as an anti- inflammatory drug and still attracts distinct attention due to its clinical benefits for the treatment of inflammation, fever, renal function, and platelet aggregation (Fijakowski et al., 2022). Many studies have demonstrated the therapeutic benefits of aspirin when administered in specific dosages. Aspirin has a revealed effect on cardiovascular diseases, cancers, and even the occurrence of Alzheimer's disease (Fijakowski et al., 2022). ASA has an antioxidant influence as well (Abdulmajeed et al., 2021). Aspirin, however, has shown to have a number of adverse effects in the gastrointestinal (GI) tract (Li et al., 2020). A variety of analytical techniques have been applied for the quantification of acetylsalicylic acid, including high- performance liquid chromatography (HPLC) (Kim et al., 2018), colorimetric (Liang et al., 2020), UV-Vis spectrometry (Daci et al., 2020), and spectrofluorimetry (El-Olemy et al., 2021). The use of electrochemical techniques is widespread because of their exceptional merits of low cost, ease of setup and speedy analysis time with distinctive analytical performance (Tran et al., 2022). Metal electrodes were used in electrochemical analysis with and without surface modification. Although rare earth elements, like platinum, are frequently used as an electrode. Researchers are looking for more affordable and environmentally friendly alternatives due to the high cost and toxicity of chemicals (Kovendhan et al., 2019). Many metals and alloys have long been investigated for use as electrode materials in various mediums (Kovendhan et al., 2019). The catalytic performance of copper electrodes is comparable to that of carbon-coated noble metal cathodes and they are inexpensive and have a wide surface area (Kovendhan et al., 2019). Among its many unique electrocatalytic properties, copper exhibits great activity for the electrochemical reduction of nitrate and carbon dioxide (Yu et al., 2022, Chen et al., 2023). Copper is one of the most active electrode materials for nitrate reduction. Therefore, a number of recent electrochemical studies on Cu single crystals have been conducted in an effort to link the catalytic activity to the atomic surface structure (Scholten et al., 2021). For electroanalysis, copper electrodes were either used immediately or after surface modification. A low-cost copper wire (Cu-wire) electrode made of copper nanoparticles was developed in order to identify the chemical oxygen demand in water (Elfeky et al., 2022). Additionally, Velasco-Medina et al modified copper electrodes with AgHg or AgBi bimetallic particles on copper electrodes coated with a Nafion (Nf) film. The electrodes were capable of direct, precise and sensitive detection of synthesized peptides (Velasco-Medina and Espinoza-Montero., 2019). Tarantseva et al. used copper electrode for the amperometirc determination of ethanol in beverages in alkaline solutions (Tarantseva et al., 2021). Roushani et al. used a copper electrode for hydrogen peroxide determination (Roushani et al., 2019). Maria et al. utilized a copper electrode for the spectroelectrochemical determination of trichloroacetic acid (Esclapez et al., 2011). Mohammad et al. developed a new pharmacokinetic method using a copper electrode *Corresponding author: e-mail: mohammad.amayreh@bau.edu.jo