Using a Boron‐Doped Diamond Electrode in Anionic Surfactant Media as an Improved Electrochemical Sensor for the Anticancer Drug Ibrutinib

The electrochemical properties of ibrutinib (IBR), a new generation smart anti‐cancer drug, one of the Bruton's tyrosine kinase (BTK) inhibitors were investigated by a voltammetric method in the anionic surfactant (sodium dodecyl sulfate, SDS) medium with the boron‐doped diamond electrode (BDDE). IBR showed an oxidation step at about +1.56 V (vs Ag/AgCl (3.0 mol L−1 KCl) by cyclic voltammetry (CV) technique in 0.1 mol L−1 H2SO4 solution. IBR was found to be irreversible and diffusion‐controlled on the surface of the BDDE with studies of scan rate. The possible electrochemical oxidation reaction of IBR with the electroactive ring (pyrazole‐pyrimidine ring) in the structure of IBR is discussed. Square wave voltammetry (SWV) was preferred as the study method due to reproducibility for the determination of IBR in pharmaceutical and urine samples. At optimal values of SWV parameters, IBR showed good linearity in the concentration range of 0.01–2.00 μg mL−1 (5.7×10−8–2.3×10−6 mol L−1) in 0.1 mol L−1 H2SO4 with 6×10−4 M SDS. The detection (LOD) and quantification (LOQ) limits for IBR were set at 0.003 μg mL−1 (6.9×10−9 mol L−1) and 0.01 μg mL−1 (2.27×10−8 mol L−1), respectively. The relative standard deviation of the intra‐day and inter‐day repeatability of the proposed method was found 2.15 and 3.76, respectively. The necessary validation parameters have also been studied, and the recovery results obtained from both pharmaceutical dosage form and human urine samples show that the developed method is accurate and precise. The electrochemical behaviour of a new generation smart anti‐cancer drug, Ibrutinib at boron‐doped diamond electrode was investigated in the 0.1 mol L−1 H2SO4 with presence of anionic surfactant. The process was irreversible and diffusion‐controlled and the possible electrochemical oxidation reaction of Ibrutinib was discussed. The detection limit was 6.9×10−9 mol L−1 and no electroactive interferences from the excipients and endogenous substances were found in the pharmaceutical dosage forms and biological samples, respectively.