SPECTROPHOTOMETRIC DETERMINATION OF FENOTEROL IN PURE FORM AND PHARMACEUTICAL FORMULATION.

Four simple and selective spectrophotometric methods were developed for quantitative determination of Fenoterol in pure forms as well as in its pharmaceutical formulation. Method [A] is based on the nitration and subsequent complexation with a nucleophilic reagent forming a yellow colour with λ_max at 411 nm, Beer's law was obeyed in the concentration range 1-6 μg ml^-1. LOD and LOQ were found to be  0.024 and 0.08 μg ml^-1 respectively. Method [B] is based on the coupling of the drug as a phenolic compound with the diazonium salt of o-nitroaniline forming red azodye with λ_max at 505 nm. Good linearity obtained in the range of 3-21 μg ml^-1. LOD & LOQ were found to be 0.12 and 0.41, respectively. Method [C] is based on coupling with diazo reagent (method B) and subsequent chelation with copper sulphate and extraction of the resulting chelate into chloroform and measuring the chloroformic layer at 412 nm. Beer’s low was obeyed in the concentration range 3-21 μg ml^-1. LOQ & LOQ were found to be 0.056 and 0.188 μg ml^-1. respectively. Method [D] involves the reduction of follin ciocalteu's phenol reagent (FCP) by the drug to be a blue colored product which exhibited an absorption maximum at l_max 655 nm. Regression analysis of Beer's plot showed good correlation in the concentration range of 2-14 μg ml^-1. LOD & LOQ were found to be 0.011 and 0.038 μg ml^-1. respectively. The optimization of the reaction conditions was investigated, the methods were successfully applied to the analysis of  Fenoterol in its pharmaceutical formulation with good recovery.