Voltammetric behavior and determination of the bronchodilator doxofylline at a boron-doped diamond electrode

The electrochemical behavior of the asthma drug doxofylline was studied at a boron-doped diamond electrode in BR buffer (pH 3.8) by square-wave voltammetry. Cyclic voltammetry revealed the oxidation of doxofylline as an irreversible diffusion-controlled process. The oxidation mechanism was proposed and the drug was studied in the presence of solubilized systems like Tween-20 (T-20), sodium dodecyl sulfate (SDS), Triton X-100 (TTN), dioxane (DO), dimethylformamide (DMF), diethyl ether (DEE), benzene and methanol (MeOH). Comparison of the current responses in the solution system explained the sensitivity of the boron-doped diamond electrode (BDDE) with a three-fold increase in the current value compared to that of a glassy carbon electrode (GCE) at a fixed concentration of doxofylline. Peak current values varied linearly with increasing concentration and the LOD and LOQ were found to be 3.48 and 10.56 µg/ml, respectively. This method was employed to investigate doxofylline in the pharmaceutical formulation.