NEW SPECTROPHOTOMETRIC METHODS FOR THE QUANTITATIVE ESTIMATION OF ELETRIPTAN IN DRUG FORMULATION

Five simple, accurate, sensitive and economical UV spectrophotometric methods has been developed and subsequently validated for the determination of eletriptan in bulk and pharmaceutical formulations. The methods were based on the formulation of colored complex of eletriptan with different reagents. Absorbance of the formed color complex is measured against the reagent blank at the wavelength of maximum absorbance. In this paper, five spectrophotometric methods were proposed. Method A is based on the formation of oxidative coupling reaction involving the use of iron (III) – MBTH (3-methyl-2-benzo thiazolinone hydrazone hydrochloride). The resulting green colored chromogen complex absorbs at λmax = 520 nm. Reaction of eletriptan with ferric chloride and K3 [Fe (CN)6 ] to form a green colored species having absorption maxima at λmax =790 nm is used in Method B. Method C is based on the reaction eletriptan with FeCl3 and 1,10 phenanthroline to form a blood red colored chromogen, exhibiting absorption at λmax = 620 nm. Formation of oxidative coupling of drug with brucine in the presence of sodium meta periodate to form a purple red colored species is used in Method D which exhibits absorption maxima at λmax = 520 nm. Method E is based on the formation of complex with acidic dye WF BBL having absorption maxima at λmax = 610 nm. All these methods have different linearity ranges. Statistical analysis proves that the proposed methods are reproducible and selective for the estimation of eletriptan in bulk drug and in its tablet dosage form.