M. Abdel-Hay, A. Gazy, E. Hassan
Oct 1, 2008
Citations
1
Influential Citations
27
Citations
Journal
Journal of The Chinese Chemical Society
Abstract
Two simple, rapid and reliable spectrophotometric methods are described for the resolution of the three-component mixture of amiloride hydrochloride (AMD), hydrochlorothiazide (HCT) and timolol maleate (TIM). The first method involves the use of derivative spectrophotometry with the zero-crossing technique where AMD was easily determined using its °D and 'D (AX = 6) amplitudes at 365 and 385 nm, respectively, while HCT and TIM were determined by measuring the 3 D (AX = 6) amplitude at 265 nm and the 'D (AX = 8) amplitude at 315.4 nm, respectively. The second method involves the application of the ratio-spectra zero-crossing first and second derivative spectrophotometry where two points have been used for the quantification of each compound. For the determination of AMD, HCT was used as divisor and the 1 DD (AX = 4) and 2 DD (AX = 6) values at 299.4 and 311 nm, respectively, were plotted against AMD concentration; while - by using TIM as divisor - the 2 DD (AX = 6) amplitudes at 264.2 and 290 nm were found to be proportional to HCT concentration. TIM was assayed in the mixture using its 'DD (AX = 6) amplitudes at 289.8 nm (Divisor was AMD) and 314.8 nm (Divisor was HCT). Synthetic mixtures of different proportions and laboratory-made tablets were assayed by the proposed methods and the results revealed good accuracy and repeatability of the developed methods.