2021 FDA Science Forum
Quantitation of Methanol, Ethanol and Isopropanol in Gel Hand Sanitizer Products by Gas Chromatography-Flame Ionization Detection (GC-FID)
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Contributing OfficeOffice of Regulatory Affairs
Abstract
The COVID-19 outbreak and pandemic resulted in an increase in the number of firms producing hand sanitizers and an increase in the numbers of hand sanitizers requiring analysis in U.S. FDA laboratories. The analysis was necessitated by initial screenings of imported hand sanitizers by Customs and Border Patrol that tested positive for methanol. Due to the anticipated workload, the Office of Medical Products Specialty Laboratory Operations determined that a single method was needed to quantitate ethanol or isopropanol active ingredients as well as to quantitate methanol adulterant if present. The analytical procedure developed uses GC-FID for quantitation of ethanol, isopropanol and/or methanol in hand sanitizer from levels as low as 0.25% v/v up to 100% v/v. The limit of detection of methanol is 0.0625% v/v. The method is an extension of the USP <611> Alcohol Determination method for ethanol, and now includes methanol and isopropanol in the analysis. This method was successfully validated using a gel hand sanitizer matrix containing a label claim of 70% ethanol, with glycerin, propylene glycol and aloe among the inactive ingredients. The correlation coefficient for linearity (r2) was ? 0.9997, spike recovery values were from 99.1-100.3%, and %RSDs were < 1% for methanol, ethanol and isopropanol. The method has been used by the FDA Pacific Southwest Medical Products Laboratory to analyze 96 imported hand sanitizers to date, all but two of which were labeled with ethyl alcohol as the active ingredient. Of those, 28 hand sanitizers were found to have actionable levels of methanol (> 630 ppm), ranging from 1.6% to 79.3% v/v. All but two of the hand sanitizers containing methanol were subpotent in ethanol (< 90% of label claim amount), indicating an economically-motivated substitution of ethanol with methanol. The details of the method will be submitted as an LIB.
