Abstract

Two simple and sensitive extractive visible spectrophotometric methods (A and B) were developed for the assay of eletriptan hydro
bromide (EHB) in pure and pharmaceutical formulations based on oxidation of the EHB. When treated with known excess of
Fe(III), EHB undergoes oxidation, giving products of oxidation inclusive of reduced form of oxidant, Fe (II) from Fe(III) besides
unreacted oxidant and estimating EHB colorimetrically, which is equivalent to either reacted oxidant or reduced form of oxidant
formed. The reduced form of Fe (II) has a tendency to give a colored complex on treatment with either [Fe (CN)6]-3 in method-A,
or with O-Phenanthroline(O-Phen) in method-B. The colored products exhibit absorption λmax at 767 nm and 480 nm, Beer-Lambert
limits are in the concentration ranges (4-24) μg/ml, (4–28) μg/ml, and correlation coefficients are 0.9999 and 0.9985. The Sandell’s
sensitivities are 1.561 × 10–3, 2.462 × 10–3 (1 mole cm-1) and molar absorptivity values are 2.9688 × 105, 1.8827 × 105 (μg cm-
2), for methods A and B, respectively The proposed methods are applied to commercial available formulations and the results are
statistically compared with those obtained by the ultraviolet reference method and validated by recovery studies. These methods
offer the advantages of rapidity, simplicity, and sensitivity and low cost without the need for expensive instrumentation and reagents