Abstract: This paper presents a simple and sensitive kinetic
spectrophotometric method for the determination of ramipril in
commercial dosage forms. The method is based on the reaction of the
drug with 1-chloro-2,4-dinitrobenzene (CDNB) in dimethylsulfoxide
(DMSO) at 100 ± 1ºC. The reaction is followed
spectrophotometrically by measuring the rate of change of the
absorbance at 420 nm. Fixed-time (ΔA) and equilibrium methods are
adopted for constructing the calibration curves. Both the calibration
curves were found to be linear over the concentration ranges 20 - 220
μg/ml. The regression analysis of calibration data yielded the linear
equations: Δ A = 6.30 × 10-4 + 1.54 × 10-3 C and A = 3.62 × 10-4 +
6.35 × 10-3 C for fixed time (Δ A) and equilibrium methods,
respectively. The limits of detection (LOD) for fixed time and
equilibrium methods are 1.47 and 1.05 μg/ml, respectively. The
method has been successfully applied to the determination of ramipril
in commercial dosage forms. Statistical comparison of the results
shows that there is no significant difference between the proposed
methods and Abdellatef-s spectrophotometric method.