D&C RED 33 USE IN INGESTED DRUGS OKAYED BY FDA

Executive Summary

D&C RED 33 USE IN INGESTED DRUGS OKAYED BY FDA for products other than mouthwashes and dentifrices "in amounts not to exceed .75 milligrams per daily dose of the drug." According to an Aug. 30 Federal Register notice the color can also be used "in externally applied drugs, mouthwashes, and dentifrices in amounts consistent with current good manufacturing practice." The publication date coincided with the expiration of the permanent listing of the additive. The new rule takes effect Sept. 30. In reviewing the data submitted on Red 33, the agency found that the dye "has not induced cancer in any of the laboratory testing," a finding supported by the National Toxicoloby Program's Board of Scientific Counselors. Therefore, Red 33 is not subject to the provisions of the Delaney clause, FDA says. However, FDA does note that six carcinogenic impurities have been found in commercial certified batches of Red 33 -- 4-aminoazobenzene, 4-aminobiphenyl, aniline, azobenzene, benzidine, and 1,3-diphenyltriazene. The regulation sets forth manufacturing specifications limiting concentrations of the impurities in future batches. "FDA is willing to consider petitions for alternative manufacturing processes," the rule says, "but those petitions should contain evidence that demonstrates that those processes will not produce impurities that will make use of the color additive unsafe." The agency followed a similar course with Red 36, for which one impurity was identified. The Red 33 approval follows an Aug. 2 final rule permanently listing D&C Red 36. Aug. 30 was also to have been the deadline for listing of FD&C Red 3, but in a separate same-day notice, FDA published a proposal to extend that closing date to June 30, 1989. Because the final rules for both Red 33 and Red 36 are not immediately effective, their provisional listing status has been extended to Oct. 28.