FDA Issues Guidance for Testing for DEG-Contaminated Glycerin

Rockville, MD (May 1)-The US Food and Drug Administration (www.fda.gov) issued a guidance to alert pharmaceutical manufacturers, pharmacy compounders, repackers, and suppliers to the potential public health hazard of glycerin contaminated with diethylene glycol (DEG), a poison. The guidance may be found here.

FDA has received and continues to receive (most recently in October 2006) reports about fatal DEG poisoning of consumers who ingested medicinal syrups such as cough syrup or acetaminophen syrup that were manufactured with DEG-contaminated glycerin. The guidance provides recommendations to help pharmaceutical manufacturers, repackers, other suppliers of glycerin, and pharmacists who engage in drug compounding avoid using glycerin that is contaminated with DEG and prevent incidents of DEG poisoning.

To avoid using DEG-contaminated glycerin, FDA advises that certain analytical testing procedures must be performed on all lots of glycerin. These tests include a specific identity test that incorporates a limit test for DEG on all containers of all lots of glycerin before the glycerin is used in the manufacture or preparation of drug products. 

 The relevant safety limit for DEG is 0.1%, as recognized by the United States Pharmacopeia (USP) monograph for glycerin.

FDA recommends that a manufacturer perform the identity tests, including the limit test for DEG, which appears in the USP monograph for glycerin. Alternatively, a manufacturer may use an equivalent identification procedure that includes a test to detect and quantify DEG, provided it meets the relevant safety limit. One alternative procedure is a thin-layer chromatography method published in Journal of AOAC International.

FDA also advises that drug-product manufacturers know their supply chain for glycerin, including the manufacturer of the component and any subsequent distributors. The agency advises that all personnel in pharmaceutical manufacturing facilities, especially personnel directly responsible for the receipt, testing, and release of glycerin, should be made aware of the importance of proper testing and the potential hazards if the testing is not done.

The guidance further urges repackers and others who distribute and prepare glycerin for use in drug products to test glycerin that is used, sold for use, or intended for use in drug products. FDA also recommends that pharmacies that use glycerin in compounding drug products either test the glycerin for DEG content or ensure that such testing was properly done by a reliable supplier. In addition, FDA says that bulk or repackaged glycerin intended as an excipient or other component of a drug product should be tested for DEG content following good manufacturing practices.