Simultaneous Estimation of Amlodipine and Enalapril Maleate by Stability Indicating UHPLC Method

Objectives: The key objective of this work is to establish a stability-indicating UHPLC technique for measuring amlodipine and enalapril maleate in bulk and pharmaceutical formulations Materials and Methods: The mobile phase consisted of 0.02M KH2 PO4 buffer: Methanol (70:30 v/v). The chromatographic separation was carried out using an Analytical Technologies UHPLC-3000 equipment in conjunction with a variable wavelength programmable UV identifier and a Rheodyne injector equipped with a 5 µL fixed circle. Detection was done at 224 nm with the flow rate of 0.3 mL/min. Results: Amlodipine's retention time was determined to be 0.7 min, while Enalapril's was 1.2 min. The linearity range for Amlodipine and Enalapril was discovered to be 5–25 µg/mL. The technique has been examined in accordance with ICH (International Conference on Harmonisation) standards. A procedure is precise and accurate if the %RSD is less than two. Amlodipine's limit of detection and quantitation ranges are 0.12–0.37 µg/mL and Enalapril's range is 0.10–0.30 µg/mL, respectively. The procedure proved to be simple, linear, swift, exact, accurate, repeatable, and reliable. The drug was prone to acid, basic, and oxidation conditions, according to the stress degradation research. Conclusion: Even in actual samples, the techniques clearly distinguished between the drugs and degradation products. The method was proved as a stability indicating method and can be used in practice for bulk and the dosage forms and also to evaluate the shelf life.