Benzimidazoles, such as albendazole (AB) and mebendazole (MB), are common anthelmintic agents, widely used throughout the world to combat parasitic diseases. The electroanalytical sensing of AB and MB based on Perovskite-Type LaFeO₃ nanoparticles modified sonogel carbon paste electrodes has been reported for the first time. Perovskite-type LaFeO₃ nanoparticles were characterized by X-ray diffraction (XRD), fourier transform infrared (FTIR), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The XRD indicates the formation of monophase perovskite LaFeO₃ and FT-IR spectrum shows a band at 570 cm⁻¹ which is associated to the formation of lanthanum ferrite. Microscopy images show that the distribution in pore size and shape is not well defined. The particles sizes are found to be above 200 nm. It was found that sonogel carbon paste modified electrodes with Perovskite-type LaFeO₃ nanoparticles exhibit higher catalytic activity and sensitivity toward the detection of AB and MB compared to the unmodified electrode. The limits of detection for albendazole and mebendazole were reported to be 0.3 μM and 0.6 μM respectively and the limits of quantification 0.8 μM and 1.7 μM respectively. The electroanalytical protocol was successfully applied for the sensing of AB and MB in pharmaceutical formulations.

Diclofenac (DIC) is a non-steroidal anti-inflammatory drug of wide use around the world. Electroanalytical methods display a high analytical potential for application in pharmaceutical samples but the drawbacks concerning electrode fouling and reproducibility are of major concern. Henceforth, the aim of this work was to propose the use of alternative low-cost carbon black (CB) and ionic liquid (IL) matrix to modify the surface of pencil graphite electrodes (PGE) in order to quantify DIC in raw materials, intermediates, and final products, as well as in stability assays of tablets. The proposed method using CB+IL/PGE displayed good recovery (99.4%) as well as limits of detection (LOD) of 0.08 µmol L-1 and limits of quantification (LOQ) of 0.28 µmol L⁻¹. CB+IL/PGE response was five times greater than the unmodified PGE. CB+IL-PGE stands as an interesting alternative for DIC assessment in different pharmaceutical samples.