ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Expired lacosamide as a sustainable corrosion inhibitor for mild steel

Sumit Chauhan, Jasdeep Kaur, Sanjeev Kumar, Akhil Saxena, Varagunapandiyan Natarajan, Ghadah Shukri Albakri, Maha Awjan Alreshidi, Krishna Kumar Yadav, Mosab Kaseem, and Jyoti Gaur

Department of Applied Sciences, Division of Chemistry, Chandigarh University, Mohali, India

E-mail: jasdeepwarraich@gmail.com

Received: 11 December 2025  Accepted: 20 February 2026

Abstract:

The growing need for corrosion protection has encouraged the exploration of the expired drugs as environmental friendly alternatives to the toxic and conventional corrosion inhibitors. In this present study, expired Lacosamide was evaluated for its ability to decrease the pace of mild steel degradation in a 0.5 M sulfuric acid solution. Lacosamide adsorption characteristics, inhibition efficiency, and environmental sustainability are being evaluated in the research. According to weight loss (WL), Electrochemical Investigations (EIS and PDP), Lacosamide drug at 2000 ppm achieved maximum inhibition efficiencies of 88.58%, 91.44%, and 91.44%. Adsorption studies confirmed that Lacosamide obeyed the Langmuir adsorption isotherm indicating monolayer adsorption on the surface of mild steel. High inhibition efficiency also attributed to the strong interaction between drug molecules and the metal surface. This work highlights the benefits of expired drugs as effective corrosion protection as well as pharmaceutical waste valorisation, so offering a eco-friendly alternative to the traditional inhibitors.

Keywords: Corrosion inhibitor; Sustainable protection; Lacosamide expired drug; Inhibition efficiency; Green chemistry

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-026-04756-y

Chemical Papers 80 (6) 6141–6154 (2026)