CuO nanoparticle-enhanced electrochemical sensing of bromfenac in rabbit aqueous humor: a green analytical approach

Abstract

Electrochemical techniques, particularly voltammetry, have emerged as powerful tools for the quantitative analysis of various analytes, including pharmaceuticals. Bromfenac (BRM), a widely used anti-inflammatory eye drop, is known for its rapid penetration into ocular tissues. Herein, a novel carbon paste electrode modified with synthesized copper oxide nanoparticles (CuO-NPs) is employed to enhance the electrochemical response for BRM. Differential pulse voltammetry (DPV) is utilized to measure the oxidation current of BRM in a Britton–Robinson buffer solution (pH 4.0) within a potential range of 0.0 V–1.5 V at a scan rate of 0.0125 V s⁻¹. The developed method is validated according to ICH guidelines, and it exhibited excellent linearity in two concentration ranges: 2.00 × 10⁻⁷ M–2.00 × 10⁻⁶ M and 2.00 × 10⁻⁶ M–2.00 × 10⁻⁵ M. The accuracy of the method is found to be between 99.05% and 102.00%. The proposed voltammetric method is successfully applied for the determination of BRM in bulk powder, with a limit of detection (LOD) of 1.36 × 10⁻⁷ M and a limit of quantification (LOQ) of 1.4 × 10⁻⁷ M. This method is further extended to the quantification of BRM in a pharmaceutical ophthalmic solution and rabbit aqueous humor. To ensure the accuracy and precision of the developed method, the results of pharmaceutical formulation analysis are compared to a reported HPLC method, which showed no significant difference. Thus, this research demonstrates the potential of the developed electrochemical sensor for the accurate and reliable quantification of BRM in biological samples, providing valuable insights into its pharmacokinetics and pharmacodynamics. Eco-Scale (AES) and the Green Analytical Procedure Index (GAPI) tool are used to assess the greenness of this method, and this method proved to be environmentally friendly.