Development of a Validated Stability Indicating RP-HPLC Method for Simultaneous Determination of Benazepril, Benazeprilat, and Amlodipine in Presence of Their Degradation Products and Application to Pharmaceutical Formulation and Human PlasmaAuthor(s): Hemdan A, Omar AE, Farouk M, Shereen MT and Mostafa AS
A sensitive, reproducible, and rapid stability indicating RP-HPLC method was developed and subsequently validated for simultaneous determination of both benazepril (BENZ), benazeprilat (BENZT), and amlodipine (AML) in presence of their basic hydrolysis degradation products in bulk powder, pharmaceutical formulation, and application to human plasma using moexipril (MOX) as an internal standard (IS). The method uses Inertsil C18 column (250 mm × 4.6 mm, 5 μ) and the mobile phase used was consisting of acetonitrile-potassium hydrogen phosphate buffer pH 7 adjusted by 0.1 N NaOH (40/60 v/v) with a flow rate of 1.0 mL/min and detection at 242 nm. A detailed validation of the methods was performed following the ICH guidelines and the standard curves were found to be linear in the range of 0.5 μg/mL to 100 μg/mL, 0.5 μg/mL to 100 μg/mL and 5 μg/mL to 100 μg/mL for BENZ, BENZT, and AML, respectively. Statistical comparison was done between the proposed method and the reported one where no significant difference was found between the two methods.