Abstract
The construction and development of polyvinyl chloride environmentally-friendly sensors for eletriptan hydrobromide (ELT) are developed. The sensing materials incorporated beta- or gamma-cyclodextrin as the electroactive material (sensor 1 and 2, respectively), with potassium tetrakis (4-chlorophenyl)borate as an ionic additive, polyvinyl chloride as the matrix material, and dioctyl phthalate as a plasticizer. Between pH 4 and pH 8.5, sensors 1 and 2 exhibited fast, stable, and near-Nernstian responses (58.9 and 57.5 mV/decade, respectively) over an eletriptan concentration range of 10(-2)-10(-6) M; the detection limits were 4x10(-6) and 6x10(-6) M, respectively. The selectivity coefficients of the investigated sensors were very low, which indicated that the method was free from interference. The determination of eletriptan content from its dosage form resulted in average recoveries of 97.86% and 100% and mean relative standard deviations of 2.16% and 2.42% for the beta- and gamma-cyclodextrin sensors, respectively. The determined values were similar to those obtained by an ultraviolet spectrophotometric method. Molecular modeling was used to calculate the host-guest relations between eletriptan and beta- or gamma-cyclodextrin. The lowest binding free energy was -6.15 and -7.89 kcal/mol for the host-guest complexes with a 1:1 stoichiometry of eletriptan and beta- or gamma-cyclodextrin, respectively.