An FDA press release, issued May 4, 2007, advised manufacturers to ?test glycerin for possible contamination. Glycerin contaminated with Diethylene Glycol (DEG) remains a potential health hazard to consumers.? The press release contains the statement: ?At the present time, FDA has no reason to believe that the US supply of glycerin is contaminated with DEG, though the agency is cognizant of reports from other countries over the past several years in which DEG-contaminated glycerin has caused human deaths.?
This is a potentially serious concern for compounding pharmacists, because glycerin frequently is used as an ingredient and as a levigating or wetting agent in extemporaneously prepared formulations. The US Pharmacopeia/National Formulary (USP/NF), not the FDA, sets pharmaceutical standards in the United States; the FDA is charged with enforcing those standards. The FDA apparently has determined that sufficient reports of adverse events (including deaths) were received from other countries, so it was time to issue a reminder.
Glycerin USP must be tested according to its USP monograph. The section of the monograph entitled ?Limit of diethyl-ene glycol and related compounds? specifies the limit as follows: ?not more than 0.1% of any individual impurity, excluding diethylene glycol?; and not more than 1.0% of total impurities, including diethylene glycol?.? (USP 30, p.2239) USP 30 <795>, Pharmaceutical Compounding?Nonsterile Preparations, and USP 30 <1075>, Good Compounding Practices, direct the compounder to ensure the identity, strength, quality, and purity of components. For USP/NF monograph materials in particular, manufacturers can supply Certificates of Analysis. In the case of Glycerin USP, the Certificate of Aunalysis will show the results of the ?Limit of diethylene glycol and related compounds,? usually as ?Pass,? because the USP permits the use of that term where the test is for a limit. In this particular case, it is also not practicable to report a specific quantity. Please visit www.pharmacytimes.com/repackagers for information regarding repackagers.
Repackagers, as registered manufacturers, must ensure conformance of received material with the USP/NF monograph where applicable. Where a manufacturer has been ?validated? by the repackager according to Good Manufacturing Practices (GMP) (21 CFR 210 and 21 CFR 211), the repackager may perform a limited set of identification tests, relying on the manufacturer?s Certificate of Analysis for the balance of the USP or NF data. Since the FDA issued the press release and guidance, some repackagers have elected to perform a validated DEG test in addition to the testing and procedures required under current GMP. The compounding pharmacist, according to the guidance associated with the press release, may elect to perform the DEG test in the pharmacy (or pay a contract analytical laboratory to perform the testing), or the pharmacist may use the evidence supplied (the Certificate of Analysis) as evidence of conformity to the USP or NF monograph.