Optimized and validated spectrophotometric methods for the determination of ezetimibein pharmaceutical formulations using potassium permanganate

摘要

Three sensitive, accurate and validated spectrophotometric methods has been developed for estimation of ezetimibe (EZT)in pure and dosage forms. The proposed methods is based on oxidation reaction of EZT with a known excess potassium permanganate (KMnO4) as an oxidimetric reagent in acid medium followed by determination of unreacted oxidant by adding a fixed amount of amaranth (AM), orange G (OG) andmethylene blue (MB) dyes followed by measuring the absorbance at 520, 480and664 nm, respectively.The experimental conditions affecting the reaction were studied and optimized. The beer’s law was obeyed in the concentration ranges of 2.0-15, 2.0-10, and 2.0-12 μg mL-1 using AM, OG and MB dye, respectively with a correlation coefficient ≥ 0.9992. The calculated molar absorptivity values are 1.7012 × 104, 3.0117 × 104and 1.5321 × 104L mol-1 cm-1 using AM, MB and OG dyes, respectively. The limits of detection and quantification were reported. Intra-day and inter-day accuracy and precision of the methods have been evaluated. No interference was observed from the additives and the applicability of the method was tested by analyzing the pharmaceutical preparations containing the investigated drug. The proposed methods were successfully applied to the assay of EZT 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.