Novel Analytical Approach for the Estimation of Oxalic Acid Content in Sodium Ascorbate by Reversed Phase-High Performance Liquid Chromatography

Abstract

A simple and novel reverse phase-high performance liquid chromatography (RP-HPLC) method employing Triart C18 column has been developed and validated for the estimation of oxalic acid content in sodium ascorbate drug substance and drug product. Forced degradation study of sodium ascorbate was performed at acid, base, oxidative, photolytic and thermal stress conditions. Oxalic acid was found as final degradants. The separation was achieved in isocratic mode using mixture of tetrabutylammonium hydroxide-phosphate buffer (pH 7.0) and acetonitrile in the ratio of 80:20; v/v as mobile phase at a flow rate of 1.0 mL min–1 using UV detector. The method was validated as per the ICH guideline (Q2R1) for accurate and precise quantification of oxalic acid content in sodium ascorbate. The obtained limit of quantification of oxalic acid was 0.034%. Mean recovery of oxalic acid was found to be 98.9 ± 8.7%. Presented method could be applied for the estimation of oxalic acid content in sodium ascorbate at pharmaceutical laboratories.