Innovative computationally designed-spectrofluorimetric method for determination of modafinil in tablets and human plasma
2022
Hosny, Noha M. | Gadallah, Mohammed I. | Gomila, Rosa M. | Qayed, Wesam S.
A novel computationally designed-spectrofluorimetric method for the determination of a unique antinarcoleptic drug; modafinil (MDF) in tablets and human plasma was theoretically and experimentally established. Firstly, a density functional theory (DFT) computations were performed to investigate MDF-Tb³⁺ complex formation and to study the affinity of Tb³⁺ to MDF in aqueous solution. The computed formation energy of [Tb (MDF)₄]³⁺ (ΔG= −246.0 kcal/mol) assured the ability of Tb³⁺ to recognize MDF in water and proved the strong nature of the Tb³⁺–O coordination bonds in addition to some contribution from inter-ligand hydrophobic interactions. Hence, a spectrofluorimetric method was optimized and validated depending on MDF quenching effect on Tb³⁺ fluorescence via fluorescence resonance energy transfer from Tb³⁺ to MDF. The formed [Tb (MDF)₄]³⁺ complex was measured at λₑₓ. 222 nm/λₑₘ. 497 nm against a reagent blank. The Tb³⁺ fluorescence was significantly reduced upon addition of MDF (linearity range= 0.5–20.0 μg/mL). Detection and quantification limits were 0.129 and 0.391 μg/mL, respectively. Good recoveries (97.47–101.92%) were obtained upon application of the proposed method for the assessment of the target drug in bulk powder, tablets and plasma. According ICH guidelines, the results of the established method were statistically analyzed and validated.
显示更多 [+] 显示较少 [-]