Environmentally friendly electrochemical and spectrophotometric strategies for sensitive determination of nintedanib in complex matrices

Abstract

Precise quantification of nintedanib (NIN) is essential due to its widespread clinical use and the need for reliable quality control in pharmaceutical and biological samples. In this study, a sensitive electrochemical sensor based on a multi-walled carbon nanotube-modified carbon paste electrode (MWCNT/CPE) was developed for NIN determination. The electrochemical behavior of NIN was investigated using differential pulse voltammetry (DPV) in Britton–Robinson buffer (pH 2.0), producing a well-defined anodic peak. A linear response was obtained over the concentration range of 0.02–2.0 µM (R² = 0.998), with low limits of detection and quantification of 0.17 nM and 0.57 nM, respectively. The method was successfully applied to pharmaceutical formulations and biological fluids, yielding recoveries between 96.53% and 104.23% with RSD values below 3%. A UV-visible spectrophotometric method was also developed, showing good linearity over the range of 10–40 µM with a limit of detection of 0.36 µM, along with satisfactory precision and accuracy. The environmental sustainability of both methods was evaluated using the GEMAM tool, yielding scores of 6.42 and 8.058 for the electrochemical and spectrophotometric methods, respectively, confirming their excellent green characteristics. The use of water as the sole solvent, together with low reagent consumption and minimal waste generation, significantly enhances their environmental compatibility. Overall, the electrochemical method provides superior sensitivity, while the spectrophotometric method offers a simple, cost-effective, and highly sustainable alternative for routine analysis.