Development and Validation of RP-HPLC method for the simultaneous determination of Diltiazem HCl and Enalapril Maleate

A simple, rapid, precise, sensitive and reproducible reverse phase high performance liquid chromatography (RP-HPLC) method has been developed for the quantitative analysis of Diltiazem HCl and Enalapril Maleate in pharmaceutical dosage form. Chromatographic separation of Diltiazem HCl and Enalapril Maleate was achieved on Waters Alliance-e2695 by using Inertsil ODS (250x 4.6mm, 5µ) column and the mobile phase containing Acetonitrile: 0.1% Formic acid in the ratio of 40:60% v/v. The flow rate was 1.0 ml/min; detection was carried out by absorption at 272nm using a photodiode array detector at ambient temperature. The number of theoretical plates and tailing factor for Diltiazem HCl and Enalapril Maleate were NLT 2000 and should not more than 2 respectively. % Relative standard deviation of peak areas of all measurements always less than 2.0. The proposed method was validated according to ICH guidelines. The method was found to be simple, economical, suitable, precise, accurate & robust method for quantitative analysis of Diltiazem HCl and Enalapril Maleate study of its stability.