More Researchers Find Heat Forms Probable Carcinogen In Zantac
Additional researchers have found that the probable carcinogen NDMA forms in Zantac (ranitidine) when the drug is exposed to high temperatures.
Testing laboratory Emery Pharma petitioned the FDA in January to recall all drugs containing ranitidine from the U.S. market, stating that they found that NDMA forms in the drug when it is exposed to heat. Now, researchers at the National Institute of Health Sciences in Japan have come to the same conclusion.
Their study involved storing ranitidine tablets from two different brands at 40 degrees Celsius with 75% relative humidity “for up to 8 weeks.” The NDMA in one tablet increased from 0.19 to 116 ppm and the NDMA in the other tablet increased from 2.89 to 18 ppm. The acceptable daily intake limit of NDMA is 0.32 ppm. This “clearly highlights the risk of NDMA formation in ranitidine formulations when extrapolated to storage under ambient conditions,” according to the study.
The study says that it is “strongly suggested” that environmental factors like oxygen and moisture are linked with the formation of NDMA in drugs containing ranitidine. The researchers determined this after exposing ranitidine to 60 degrees Celsius for one week.
The study said that the results demonstrate the “necessity” of monitoring and controlling storage conditions as well as “controlling impurities during the manufacturing process.”
“NDMA formation observed during the storage of ranitidine tablets necessitates the use of additional measures to control stability-related nitrosamine impurities in order to mitigate the safety risk of these products throughout their lifecycle,” the study states.
The study found that “exposure of the atmosphere and nitrite produced by the self-decomposition of ranitidine may have contributed to NDMA formation during storage.”
The researchers note that they are currently “performing an in-depth analysis of the mechanism of NDMA formation by focusing on the self-decomposition of ranitidine,” noting that “it is not fully understood” yet how the self-decomposing products of ranitidine contribute to the formation of NDMA.
The FDA requested that all drugs containing ranitidine be removed from the U.S. market in April, due to contamination with NDMA. The FDA advised that people stop taking drugs containing ranitidine and to dispose of the drugs properly.
NDMA is classified as a probable human carcinogen by the International Agency for Research on Cancer and the EPA, and the World Health Organization claims there is “conclusive evidence that NDMA is a potent carcinogen” and there is “clear evidence of carcinogenicity.”