Determination of lisinopril in pharmaceuticals by a kinetic spectrophotometric method

Abstract

A kinetic spectrophotometric method for determination of lisinopril in pharmaceuticals has been developed. The method is based on the activator action of lisinopril on Cu(II) ions catalysing the oxidation of Nile Blue A with hydrogen peroxide in borate buffer (pH 9.3). A decrease of the absorbance was recorded at 635 nm after 5 min at 25 °C. Linearity was established by application of the tangent method within the concentration range of lisinopril from 0.8-6.4 μg mL-1, the detection and quantification limits being 0.158 and 0.480 μg mL-1, respectively. The method was successfully applied to three brands of tablets containing lisinopril alone or in combination with hydrochlorothiazide.

Razvijena je kinetička spektrofotometrijska metoda za određivanje lizinoprila u farmaceutskim preparatima. Metoda se zasniva na aktivatorskom dejstvu lizinoprila na reakciju oksidacije boje nil plavog-A vodonik-peroksidom u boratnom puferu (pH 9,3), a koja je katalizovana Cu(II) jonima. Smanjenje apsorbancije mereno je na 635 nm u vremenskom periodu od 5 min na temperaturi 25°C. Linearnost je utvrđena primenom metode tangensa u opsegu koncentracija lizinoprila 0,8-6,4 μg mL-1, sa limitom detekcije 0,158 μg mL-1 i limitom određivanja 0,480 μg mL-1. Metoda je primenjena za analizu tri komercijalna preparata koja su sadržala lizinopril i lizinopril u kombinaciji sa hidrohlortiazidom.