A new spectrophotometric method to estimate atenolol, amlodipine, and furosemide in pharmaceutical dosages

Atenolol, amlodipine, and furosemide are the most important medications that have been used to treat cardiovascular diseases. Due to this fact, we suggested a new method to estimate these three drugs in their pure form and their pharmaceutical dosages. The suggested spectrophotometric method was based on redox reaction of the mentioned drugs at the selected wavelength 516 nm of the resulting complex from the reaction of these three drugs in step I with cerium (IV) ions as an oxidizing agent in acidic medium, step II which is occurred between unreacted cerium (IV) with the reagent safranin. The linearity of this method was obeyed Beer’s law from (0.8-34), (1.6-40), and (2-40) μg.ml^-1 of atenolol, amlodipine, and furosemide respectively, with molar absorptivity (2.66×104, 2.15×10^4, and 1.57×10^4) L.mol^-1.cm^-1 of atenolol, amlodipine, and furosemide, respectively. The limit of detection (LOD) is 0.915, 1.098, and 1.372 μg.ml−1 for atenolol, amlodipine, and furosemide, respectively. The limit of quantification (LOQ) is 3.05, 3.66, and 4.57 μg.ml^−1 for atenolol, amlodipine, and furosemide, respectively. The method reveals a good accuracy and precision and it was applied successfully to the determination of these three drugs in pharmaceutical preparations. No interferences were observed from common additives found in pharmaceutical preparations. The Reddishwine color of the product was highly stable and did not show a significant change in absorbance up to 60 min.