The notice published in the Federal Register in April 2011 specifically addresses color regulations for D&C Red No. 6 and D&C Red No. 7 which are principally monosulfo monoazo dyes prepared by the coupling of diazotized 2-amino-5-methylbenzenesulfonic acid with 3-hydroxy-2-naphthalenecarboxylic acid in alkaline medium.
Both color additives are required to be batch certified by the FDA before they may legally be used in drugs and cosmetics marketed in the United States.
On looking into the matter, the administration has made the decision to replace the current specification for ether-soluble matter with a maximum limit of 0.015 percent for the recently identified impurity 1-[(4 methylphenyl)azo]-2-naphthalenol and by removing Appendix A in part 74, which pertains to the ether-soluble matter specification.
Based on this information, it further states that it does not have any safety concerns with the proposed amendment and concludes that the dyes will continue to be safe and suitable for their listed uses in drugs and in cosmetics.
In addition, the administration will no longer analyze the impurity by visible spectrophotometry when new samples of the color additive are submitted for batch certification. Instead, it will test the impurity using reversed-phase high performance liquid chromatography.
The final ruling is said to be effective from 7 August 2012, unless any objections or requests for a hearing are received prior to this date, by the filing of proper objections.
In the Federal Register of 1982 (47 FR 57681), the FDA published a final rule that permanently listed D&C Red No. 6 and D&C Red No. 7 for use in coloring drugs and cosmetics.
It described how the dyes contained ether-soluble matter for which the proponents of the color additives were not able to determine the chemical identity.