Abstract

COLORIMETRIC DETERMINATION OF AMLODIPINE BESYLATE AND TAMSULOSIN HYDROCHLORIDE

Ruba N. Shdeed and Imad Shdeed

Abstract

This study presents new spectrophotometric and spectrofluorimetric methods for the estimation of amlodipine besylate and tamsulosin hydrochloride in bulk and in pharmaceutical formulations. The methods depend on the coupling reaction between 4-chloro-7- nitrobenzofurazan [4-chloro-7-nitro-2,1,3-benzoxadiazole] (NBD-Cl) with amlodipine besylate and tamsulosin hydrochloride, respectively, resulting in stable colored products which can be measured spectrophotometrically and spectrofluorimetrically. For amlodipine besylate, its determination was successful by measuring the spectrophotometric absorbance, first derivative and second derivative amplitudes at 471 nm, 500.6 nm, and 495/510 nm, respectively; while the relative fluorescence intensity and its first derivative amplitudes at 533 nm and 502 nm, respectively, was used to determine amlodipine besylate. On the other hand, only spectrophotometric techniques were successful in estimating tamsulosin hydrochloride using the amplitudes of the absorbance, first derivative and second derivative at 513 nm, 512.2 nm and 507.6 nm, respectively. The described methods are simple, sensitive, selective and inexpensive and can be used in quality control analysis.

Keywords: Amlodipine besylate; Tamsulosin Hydrochloride; NBD-Cl; Spectrophotometry; Spectrofluorimetry.