Since October 2022, the Word Health Organization (WHO) has issued six global medical product alerts for over-the-counter medicines contaminated with DEG/EG. The first substandard medical products were identified in The Gambia with further issues surfacing in the WHO regions of South-East Asia, Europe, Western Pacific and Eastern Mediterranean. It is estimated that there have been at least 300 fatalities in children worldwide.

Diethylene glycol (DEG) and ethylene glycol (EG) are toxic substances used as industrial solvents and antifreeze agents that can be fatal even taken in small amounts, especially for children. Gas Chromatography is a suitable and widely used analytical technique to test pharmaceutical products for DEG and EG. However, many National Quality Control Laboratories in remote and less-resourced countries do not have access to the technique. For these laboratories, a two-level approach has been developed in which suspicious samples are first screened for non-compliance using a semi-quantitative thin-layer chromatography (TLC) method. Suspected contaminations are then confirmed by gas chromatography at collaborating laboratories or regional centres. WHO recommends implementing at least the TLC method in every National Quality Control Laboratory (NQCL).

The screening by thin-layer chromatography will enable less-resourced NQCL to effectively monitor medicines in their countries and quickly identify contaminated products that pose a high risk to patients. Using this evidence, regulatory and law enforcement authorities will be able to respond quickly to suspected counterfeit and substandard medicines. This two-level approach will be included in the next edition of the International Pharmacopoeia.