Development and validation of spectrophotometric methods for estimation of arrhythmias drug-dronedarone hydrochloride in pure and dosage forms

Sensitive, simple, and accurate spectrophotometric methods have been developed for the assay of arrhythmias drug-dronedarone hydrochloride (DND) in bulk drug and pharmaceutical formulations. The proposed method is based on the oxidation reaction of DND with a known excess of cerium(IV) ammonium sulfate (Ce(IV)) as an oxidizing agent in acid medium, followed by the determination of the unreacted oxidant by adding a fixed amount of dye, e.g., amaranth (AM), methylene blue (MB), and indigocarmine (IC), followed by measuring the absorbance at 520, 664, and 610 nm, respectively. The effects of experimental conditions were studied and optimized. The beer's law was obeyed in the concentration ranges of 1.0–10, 1.0–15, and 1.0–8.0 μg mL^-1 using AM, MB, and IC dyes, respectively, with a correlation coefficient ≥ 0.9992. The calculated molar absorptivity values are 3.6527 × 10⁴, 3.1212 × 10⁴, and 4.229 × 10⁴ L mol^-1 cm^-1 using AM, MB, and IC dyes, respectively. The limits of detection and quantification were 0.30 and 1.0 µg mL^-1, respectively, for the three methods. Intra-day and inter-day accuracy and precision of the methods have been evaluated. No interference was observed from the additives. The proposed methods were successfully applied to the assay of DND in tablet preparations and the results were statistically compared with those of the reported method by applying Student's t-test and F-test. The reliability of the methods was further ascertained by performing recovery studies using the standard addition method.