%0 Journal Article
%T Spectrophotometric Method for Determination of Five 1,4-Dihydropyridine Drugs Using N-Bromosuccinimide and Indigo Carmine Dye
%A Mohamed A. El Hamd
%A Sayed M. Derayea
%A Osama H. Abdelmageed
%A Hassan F. Askal
%J International Journal of Spectroscopy
%D 2013
%I Hindawi Publishing Corporation
%R 10.1155/2013/243059
%X Indirect spectrophotometric method is described for quantification of five of 1,4-dihydropyridine (1,4-DHP) drugs using N-bromosuccinimide (NBS) with the aid of indigo carmine (INC) dye. The method is based on addition of known excess of NBS to an acidified solution of 1,4-DHP drugs and determining the residual of NBS through its ability to bleach the colour of the used dye; the amount of NBS that reacted corresponded to the amount of drugs. Beer＊s law is obeyed in the concentration range 1.25每13.00ˋ米g/mL. Good correlation coefficients (0.998-0.999) were found between the absorbance values and the corresponding concentrations. Limits of detections ranged from 0.141 to 0.500ˋ米g/mL. The proposed method was successfully applied to the analysis of dosage forms; percent of recoveries ranged from 97.31 to 99.46% without interference from any common excipients. The statistical comparison by Student＊s t-test and variance ratio F-test showed no significant difference between the proposed and official or reported methods. 1. Introduction 1,4-DHP derivatives are vasodilators with a great selectivity for vascular smooth muscles; they are primarily used for treatment of some of cardiovascular diseases such as hypertension, angina, and cardiac arrhythmias. Recently, they were used for the treatment of other pathological states, such as seizures and cerebral ischemic disorders [1, 2]. Many analytical methods were developed for determination of 1,4-DHP drugs, namely, nifedipine (NIF), nicardipine (NIC), nimodipine (NIM), felodipine (FEL), and amlodipine (AML) (Figure 1), in their pharmaceutical formulations and in biological fluids, such as titrimetric methods [3, 4], spectrometric methods (spectrophotometry [5每13] or spectrofluorimetry [12, 14每20]), electrochemical methods [21每23], liquid chromatographic methods [24每28], and gas chromatographic methods [29每32]. Figure 1: Chemical structure of the investigated 1,4-DHP drugs. Classical spectrophotometric measurements and their applications are considered as a routine analytical method in most quality control laboratories. Subsequently, the aim of this study to develop a simple, sensitive, and cost-effective method for determination of these drugs in pure and dosage forms using spectrophotometric technique. The method utilized NBS-INC reagents (Figure 2) and their developed offer the advantage of simplicity, sensitivity, speed, accuracy, and precision without the need for costly equipment/chemicals. Figure 2: Chemical structure of the chemical reagents. 2. Experimental 2.1. Instrumentation Absorbance measurements were
%U http://www.hindawi.com/journals/ijs/2013/243059/