Atomic absorption spectrometric and colorimetric methods for determination of certain antihistaminic drugs

ABSTRACT

Two sensitive, colorimetric and atomic absorption spectrometric methods were developed for the determination of some antihistaminic drugs including acrivastine [1], fexofenadine hydrochloride [II] and cetirizine dihydrochloride [III]. The spectrophotometric method is based on the reaction of the above mentioned drugs with copper [II] to form cationic complexes, which was subsequently associated with the negatively charged rose Bengal to form ion association ternary complexes. The formed complexes were extracted with methylene chloride for acrivastine and 30% acetone in chroroform for fexofenadine hydrochloride and cetirizine dihydrochloride. The pink coloured extracts showed absorption maximum at 558 nm for [I] and 563 nm for [II] and [III]. The proposed procedures were applied over concentration ranges of [5-25], [2.5-40] and [5-50] micro g/ml for [I], [II] and [III], respectively. Molar absorptivities [epsilon], Sandell sensitivities, detection [LOD] and quantitation limits [LOQ] were calculated. Atomic absorption spectrometric method was developed, through the quantitative determination of the copper content of the complex for enhancing the sensitivity of the determination. The developed procedures were favorably applied for determination of the studied drugs in their pharmaceutical dosage forms. The obtained results were compared satisfactorily with the official and reported methods. There were no significant differences between the proposed, official and reported methods: