Extractive Spectrophotometric and Conductometric Methods for Determination of Fexofenadine Hydrochloride in Pharmaceutical Dosage Forms

Abstract

Two simple and sensitive extractive spectrophotometric and conductometric methods have been developed for the determination of fexofenadine hydrochloride in bulk and in pharmaceutical preparations. The first method is based on the formation of colored chloroform extractable ion-association complexes (1:1) of fexofenadine with bromocresol purple (BCP) and bromophenol blue (BPB) dyes in aqueous acidic buffer pH 3.0. The extracted complex species were quantitatively measured at 411 and 415 nm for FEX-BCP and FEX-BPB, respectively (method I). The second method is based on the conductometric determination of 2.5-13.45 mg of fexofenadine by titration with sodium tetraphenylborate (TPB) in aqueous solution at 20°C (method II). All the reaction conditions for the proposed methods have been studied. Beer’s law was obeyed in the FEX concentration ranges 1.1-47.8 and 1.2-45.0 μg mL-1 with detection limit of 0.21 and 0.15 μg mL-1 for FEX-BCP and FEX-BPB, respectively. The proposed methods were applied successfully for the determination of the FEX in pharmaceutical formulations, the RSD% values were found to be 0.38, 0.24 and 0.74% for extractive spectrophotometric and conductometric methods, respectively. The results obtained were compared statistically with those obtained by the official method and showed no significant differences regarding accuracy and precision.