Abdellatef Hisham E
Analytical Chemistry Department, Zagazig University, Zagazig, Egypt.
Spectrochim Acta A Mol Biomol Spectrosc. 2007 Mar;66(3):701-6. doi: 10.1016/j.saa.2006.04.014. Epub 2006 Apr 28.
This paper describes three sensitive spectrophotometric and spectrofluorimetric methods for determination of ramipril in its pure form and pharmaceutical tablets. The first method is based on the oxidation of the drug with 1-chlorobenzotriazole reagent (CBT) in strong alkaline medium followed by measuring the absorbance at 350 nm. The method obeys Beer's law over concentration range 15-50 microg ml(-1). For the second and third, both are non-extractive methods based on the formation of ternary complex between copper (II), eosin and ramipril in the presence of methylcellulose as surfactant. Spectrophotometrically, under the optimum condition, the ternary complex showed an absorption maximum at 543 nm. The method obeys Beer's law over concentration range of 20-80 microg ml(-1). A fluorescence quenching method for the determination of ramipril by forming this ternary complex was also investigated for the propose of enhance the sensitivity of the determination. The methods are simple, sensitive, and accurate. The results obtained are reproducible with a coefficient of variation less than 2%. The proposed have been successfully applied to the assay of ramipril in tablets. The results compare favorably with official method.
本文介绍了三种灵敏的分光光度法和荧光分光光度法，用于测定纯品雷米普利及其药物片剂。第一种方法基于在强碱性介质中用1-氯苯并三唑试剂（CBT）氧化该药物，然后在350nm处测量吸光度。该方法在15 - 50μg ml(-1)的浓度范围内符合比尔定律。对于第二种和第三种方法，两者均为非萃取法，基于在甲基纤维素作为表面活性剂存在下，铜（II）、曙红和雷米普利之间形成三元络合物。在分光光度法中，在最佳条件下，三元络合物在543nm处有最大吸收。该方法在20 - 80μg ml(-1)的浓度范围内符合比尔定律。还研究了通过形成这种三元络合物来测定雷米普利的荧光猝灭法，以提高测定的灵敏度。这些方法简单、灵敏且准确。所得结果具有重现性，变异系数小于2%。所提出的方法已成功应用于片剂中雷米普利的含量测定。结果与法定方法相比具有优势。
