Um método analítico simples e sensível para a detecção de raloxifeno baseado na eletrodeposição de um corante sintético: aplicação em medicamentos usados no tratamento da osteoporose e amostras de urina artificial

Abstract

Raloxifene (RFN), a selective estrogen receptor modulator, is used to treat osteoporosis and prevent breast cancer, offering dual therapeutic benefits. However, its narrow therapeutic window and risks such as thromboembolic events require precise monitoring. Conventional detection methods have limitations in sensitivity, cost-effectiveness, and simplicity, particularly for pharmaceutical applications and clinical analyses. Reliable determination of RFN in these matrices is crucial to ensure therapeutic efficacy, patient safety, and regulatory compliance, underscoring the need for optimized analytical methods. In this study, we developed and characterized an electrochemical sensor based on a glassy carbon electrode modified with Alizarin Carmine, a synthetic dye, through electrodeposition and chitosan for RFN detection. The method was applied to analyze osteoporosis medications and urine samples. The electrode modification involved the electrodeposition of alizarin carmine (CA) via cyclic voltammetry (CV) across a potential range of –0.6 V to +1.5 V vs Ag/AgCl(KClsat). The influence of CA concentration was assessed by CV, revealing that 3 mmol L⁻¹ was sufficient to form a uniform and functional film. Square wave voltammetry (SWV) was used to optimize experimental parameters, perform analytical characterization, and apply the method to RFN-containing tablets and water samples. Key parameters, including pulse amplitude (0.07 V), frequency (20 Hz), buffer composition, and pH, were fine-tuned, with the best response achieved in Britton-Robinson buffer at pH 3. The sensor exhibited a detection limit of approximately 0.0089 µmol L⁻¹ and demonstrated linearity within the range of 10 nmol L⁻¹ to 10 µmol L⁻¹ (R² = 0.99). Recovery tests in artificial urine and raloxifene tablets yielded results between 96% and 106%, with relative standard deviations below 5%.