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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 cm2 ), 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 |
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Key words: : Ferric Iron, Oxidation, O-Phen,
Amino group, Regression analysis. |
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