Abdel-Wadood Hanaa M, Mohamed Niveen A, Mahmoud Ashraf M
Department of Pharmaceutical Analytical Chemistry, Faculty of Pharmacy, Assiut University, Assiut 71526, Egypt.
Spectrochim Acta A Mol Biomol Spectrosc. 2008 Aug;70(3):564-70. doi: 10.1016/j.saa.2007.07.055. Epub 2007 Aug 11.
Two simple and sensitive spectrofluorometric methods have been developed and validated for determination of amlodipine besylate (AML) in tablets. The first method was based on the condensation reaction of AML with ninhydrin and phenylacetaldehyde in buffered medium (pH 7.0) resulting in formation of a green fluorescent product, which exhibits excitation and emission maxima at 375 and 480 nm, respectively. The second method was based on the reaction of AML with 7-chloro-4-nitro-2,1,3-benzoxadiazole (NBD-Cl) in a buffered medium (pH 8.6) resulting in formation of a highly fluorescent product, which was measured fluorometrically at 535 nm (lambda(ex), 480 nm). The factors affecting the reactions were studied and optimized. Under the optimum reaction conditions, linear relationships with good correlation coefficients (0.9949-0.9997) were found between the fluorescence intensity and the concentrations of AML in the concentration range of 0.35-1.8 and 0.55-3.0 microg ml(-1) for ninhydrin and NBD-Cl methods, respectively. The limits of assays detection were 0.09 and 0.16 microg ml(-1) for the first and second method, respectively. The precisions of the methods were satisfactory; the relative standard deviations were ranged from 1.69 to 1.98%. The proposed methods were successfully applied to the analysis of AML in pure and pharmaceutical dosage forms with good accuracy; the recovery percentages ranged from 100.4-100.8+/-1.70-2.32%. The results were compared favorably with those of the reported method.
已开发并验证了两种简单且灵敏的荧光分光光度法，用于测定片剂中的苯磺酸氨氯地平（AML）。第一种方法基于AML与茚三酮和苯乙醛在缓冲介质（pH 7.0）中的缩合反应，生成绿色荧光产物，该产物在375和480 nm处分别呈现激发和发射最大值。第二种方法基于AML与7-氯-4-硝基-2,1,3-苯并恶二唑（NBD-Cl）在缓冲介质（pH 8.6）中的反应，生成高荧光产物，在535 nm（激发波长480 nm）处进行荧光测定。研究并优化了影响反应的因素。在最佳反应条件下，茚三酮法和NBD-Cl法在0.35 - 1.8和0.55 - 3.0 μg ml⁻¹的AML浓度范围内，荧光强度与AML浓度之间分别呈现良好的线性关系，相关系数为0.9949 - 0.9997。第一种和第二种方法的检测限分别为0.09和0.16 μg ml⁻¹。方法的精密度令人满意；相对标准偏差范围为1.69%至1.98%。所提出的方法成功应用于纯品和药物剂型中AML的分析，准确度良好；回收率在100.4 - 100.8±1.70 - 2.32%之间。结果与报道方法相比具有优势。
