A simple and sensitive validated method for quantitation of toxic impurities-Ethylene glycol and Diethylene glycol in Pharmaceutical Ingredient-Glycerin by Gas chromatography.

Abstract

Ethylene glycol (EG) and Diethylene glycol (DEG) are hazardous compounds that can pose significant health risks if present in pharmaceutical products more than permissible limits. This study aims to develop and validate sensitive and accurate gas chromatography (GC) method for the quantification of Ethylene glycol (EG) and Diethylene glycol (DEG) in pharmaceutical ingredients. Calibration curves for EG and DEG were established over a concentration range of LOQ to 160% for Ethylene Glycol and LOQ to 160% for Diethylene Glycol demonstrating excellent linearity with correlation coefficients (r²) of 1.000.  Sensitivity analyses revealed low limits of detection (LOD) and limits of quantification (LOQ) for both components with GC-FID achieving LODs of 13 ppm for EG and 5 ppm for DEG. Precision and accuracy assessments showed that the method provided consistent results, with relative standard deviations (% RSD) below 5%. Accuracy was evaluated through recovery rates for EG and DEG, which ranged from 80% to 100%. Application of the method to various pharmaceutical ingredients such as Sorbitol NF confirmed that all tested samples contained EG and DEG levels below regulatory limits set by the FDA and EMA. The results demonstrated that the developed GC method is precise, accurate, rugged, robust, reliable, and suitable for routine quality control to ensure the safety of pharmaceutical products. These findings underscore the importance of implementing stringent quality control measures to prevent toxic contamination and safeguard public health.