Central composite design optimized fluorescent method using dual doped graphene quantum dots for lacosamide determination in biological samples

Lacosamide is a third-generation antiepileptic drug used for the treatment of partial-onset seizures. This study investigates the development and validation of a novel analytical method for the determination of lacosamide in human plasma and pharmaceutical formulations using boron and nitrogen co-doped graphene quantum dots (BN-GQDs). The prepared BN-GQDs exhibited excellent fluorescence properties that quenches in the presence of lacosamide, allowing for its sensitive detection. Density functional theory calculations and Stern-Volmer analysis were used to elucidate the mechanism of this fluorescence quenching, which was influenced by various factors optimized using a central composite design. The proposed method was validated according to ICH M10 guidelines displaying excellent linearity in the range of 0.1-5 µg/mL, with a limit of detection of 0.033 µg/mL. Accuracy, precision, selectivity and robustness were also evaluated, and the results met the acceptance criteria of the guidelines. Hence, the method was successfully applied to quantify lacosamide in pharmaceutical formulations and pharmacokinetic studies, demonstrating its capabilities in bioanalytical applications. Assessment of the environmental impact and sustainability of the proposed method showed significant improvement, particularly in whiteness and overall performance posing its advantages for routine quality control analysis and therapeutic drug monitoring of lacosamide.