Applications of New Validated RP-HPLC Method for Determination of Indomethacin and its Hydrolytic Degradants using Sodium Acetate Buffer

Abstract:

Objective: A New RP-HPLC method for estimation of indomethacin and its two degradant impurities 4-chlorobenzoic acid, 5-methoxy-2-methyl-indoleacetic acid was developed and validated as per ICH guidelines. Background: This new method is not only capable of identifying and quantifying the impurities but also can be used for the assay of indomethacin in marketed capsule formulations. Methods: The chromatographic conditions were optimized using Zorbax Eclipse Plus C18, 3.5 μm (4.6 mm × 100 mm) column with methanol: acetonitrile: 10 mM sodium acetate buffer pH 3, 10:50:40% v/v as the mobile phase at the flow rate of 1 ml/min and detection was carried out using UV-Visible PDA detector at 254 nm. Results: The method was linear over concentration range of 25-70 μg/ml for indomethacin, 0.25-2 μg/ml for 4-chlorobenzoic acid and 0.25- 2 μg/ml for 5-methoxy-2-methyl-indoleacetic acid. The developed method was validated as per the ICH guidelines for linearity, accuracy, precision, limit of detection, limit of quantification, robustness and specificity for indomethacin and its impurities.

Key words: RP-HPLC, Indomethacin, 4-chlorobenzoic acid, 5-methoxy-2-methylindoleacetic acid, Validation