The revised monograph on Propylene glycol (0430) was adopted by the European Pharmacopoeia Commission (EPC) at its 177th session held on 21 and 22 November 2023. The monograph was revised in response to the public health risk posed by the discovery of ethylene glycol (EG) and diethylene glycol (DEG) contamination in several medicinal products in African and Asian countries (WHO alerts N⁰6-7/2022, N⁰1/2023 and N⁰4-6/2023), and confirmed cases of propylene glycol adulterated with EG that led to over 190 fatalities in Indonesia.1 Consequently, the EPC decided to revise the monograph to include a test for EG and DEG.
Given the need to act swiftly on this public health issue, the EPC has decided to make the monograph immediately available on the website of the EDQM to give users advance warning of the upcoming change and the corresponding analytical procedure. The monograph will be officially published in Ph. Eur. Supplement 11.6 in July 2024 and will come into force on 1 January 2025.
The revised monograph takes into account the feedback received on the proposed EG and DEG test during public consultation in Pharmeuropa 27.3. This includes changing the limit for EG to 620 ppm to bring it in line with the requirement described in general chapter 5.4. Residual solvents and the ICH Q3C guideline. An additional system suitability criterion for the symmetry factor for the EG and DEG peaks has been included and, following thorough verification of the procedure, changes have also been made to the solution preparation method.
Further updates to the monograph include an identification test by infrared (IR) spectrophotometry and a modernised procedure for the Acidity test. Details on all changes can be found in the history section of the EDQM Knowledge Database. The revised text prescribes the use of Propylene glycol for identification CRS for the IR test which will be made available by the end of January 2024.
Propylene glycol is also on the international harmonisation work programme of the Pharmacopoeial Discussion Group (PDG) and the European Pharmacopoeia is fully committed to proceeding with harmonisation of this monograph. It is planned to republish the text for public consultation as soon as a harmonised Assay method is available.
1. Elanda Fikri, Yura Witsqa Firmansyah (2023). A Case Report of Contamination and Toxicity of Ethylene Glycol and Diethylene Glycol on Drugs in Indonesia. Environment and Ecology Research, 11(2), 378 - 384. DOI: 10.13189/eer.2023.110211.
