Abstrakt

Optimization and validation of an HPLC method for determination of related compounds in enalapril maleate tablets

Miroslav Z .Milenkovi�������£, Predrag S.Sibinovi�������£, Valentina D.Marinkovi�������£, Radosav M.Pali�������£, Gordana, S.Stojanovi�������£, Dragan M.Milenovi�������£

The possibilityof optimization of an HPLC method for determination of related compounds in Enalaprilmaleate tablets described in official British Pharmacopeia (BP) was investigated. Columns with different C18 stationary phases were tried out. A full factorial design (24) was used to investigate the influence of four variables (pH of the aqueous phase in the mobile phase, acetonitrile fraction, flow rateof the mobile phase and column temperature), as BP recommends extreme column conditions regarding to pH and temperature. Nineresponses were determined in each experiment: retention time (Rt) of enalaprilat (ET) peak, retention time of enalapril diketopiperazine (DKP) peak, resolution factor between the peaks due to ET and DKP, resolution factor between the peaks due to DKP and enalapril,USP tailing of ET and DKP,capacity factor (kÂ’) of ET and DKP and retention time of enalapril. The optimal conditions for the chromatographic procedure were determined:pH of the aqueous phase in the mobile phase 2.2, acetonitrile fraction 37.5% v/v, flow rate 1.0 and column temperature 50ï‚°C.Method was found to be selective, linear, accurate and precisein the specified ranges. The limits of detection and limits of quantitation were 0.024 µg ml-1 and 0.080 µg ml-1 for ET, 0.017 µg ml-1 and 0.055 µg ml-1 for DKPand 0.181 µg ml-1 and 0.603 µg ml-1for enalapril,respectively. The presented HPLC method is to be implemented in the quality and stability testing of Enalaprilmaleate tablets 10 mg and 20 mg. 2013 Trade Science Inc. - INDIA.