ABSTRACT:
Fexofenadine is a new non sedating oral antinistaminic which is clinically effective in the treatment of allergic rhinitis and is not yet official in any pharmacopoeia. Literature survey has been revealed that there is no any visible spectrophotometric method has been reported for estimation of fexofenadine HCL in bulk form and in pharmaceutical formulation. Hence an attempt has been made to develop and validate a simple, economic, rapid and accurate method. In present investigation three simple and sensitive extractive spectrophotometric methods have been developed and validated for the determination of fexofenadine HCL in tablet dosage form. The developed methods involve formation of extractable ion pair complex of drug with bromophenol blue, bromocresol purple and bromocresol green dyes in acidic medium. Chloroform is used as extracting solvent for bromophenol blue and 1% v/v amyl alcohol in chloroform is used for Bromocresol purple and bromocresol green. Extractable complexes shows maximum absorption at 416 nm, 412 nm and 419 nm, the drug in the worked experimental shows linearity range for bromophenol blue, bromocresol purple and bromocresol green in concentration ranges of 0-7 ?g/ml respectively. The coloured chormophores were found to be stable for 40 min. 60 min and 30 min respectively. The effect of pH and dye concentration was also studied. The results of analysis for all the three methods have been validated statistically and by recovery studies. The proposed methods were simple, sensitive and economical for the quantitative determination of Fexofenadine HCL and were successfully employed for the estimation of bulk drug and in formulation.