First voltammetric behavior study of non-narcotic analgesic drug nefopam and its reliable determination on boron-doped diamond electrodes

In the present paper, for the first time, the electrochemical behavior and determination of a highly oxidizable non-opioid painkilling medication Nefopam (NEF) has been reported. The outcomes revealed that NEF presented one diffusion-controlled anodic signal at very positive potential of about +1.7 V in 1 M HClO4 on the boron-doped diamond electrode (BDDE). The impact of the electrochemical (anodic and cathodic) pretreatment of the BDDE surface was evaluated. The cathodic pretreatment after anodic one was considered as the most suitable choice due to the improved charge transfer and the enhanced surface activity. Under optimized experimental conditions and operating parameters, the calibration curves were linear over concentration ranges of 2.00–59.7 μM and 0.99–77.1 μM with similar detection limits of 0.5 μM for differential pulse (DPV) and square-wave (SWV) voltammetry, respectively. Moreover, the electroanalytical determination of NEF in the presence of human urine matrix was also found to be possible in the linear concentration ranges from 3.8 to 64.8 μM and from 4.9 to 47.2 μM with detection limits of 1.7 μM and 1.8 μM for DPV and SWV, respectively. The practical feasibility of the introduced method was successfully confirmed by the quantification of NEF amount in commercial pharmaceutical dosage with the result in a good agreement with that specified in analytical normative documentation. The developed procedure can be easily implemented for control analysis also with the use of miniaturized thick-film BDDE without additional optimization steps. [Display omitted] •The first report on the electrochemical behavior of Nefopam•BDDE as sensitive electrochemical sensor for highly oxidizable analytes•The impact of various electrochemical pretreatments was investigated.•The method applicability in pharmaceutical, biological and environmental samples