In December 2012, the US Food and Drug Administration's (FDA) drug regulatory body, the Center for Drug Evaluation and Research (CDER), indicated that it wanted to limit the use of some phthalates as excipients in medicines. Now two legislators have a message for the agency: There's more that needs to be done.
FDA's December 2012 guidance, Limiting the Use of Certain Phthalates as Excipients in CDER-Regulated Products, explained that the agency had found the health risks associated with exposure to Di-n-butyl phthalate (DBP) and di(2ethylhexyl)phthalate (DEHP)—two compounds widely used as plasticizers—to be concerning enough warrant a recommendation against their use in all drug products.
The two compounds have been shown be developmentally and reproductively toxic—at least in laboratory animals. Though the data for humans is a bit less clear, CDER said it would prefer to reduce human exposure to the chemical in light of its "potential risk" to humans. Such risks have been known since at least June 2000, when a National Institutes of Health (NIH) panel said it was concerned about the substance's effects on pregnant women. CDER referenced that same study in a 2012 Federal Register notice, noting that the population is widely exposed to phthalates "by multiple routes, including inhalation, ingestion, and absorption through the skin."
While phthalates aren't necessarily ubiquitous in medicines, they have historically been used in enteric coatings of solid oral drug products, FDA noted.
Under the new guidance, CDER recommends—but doesn't require—that companies stop including the two phthalates in drug products, including those under review and those already marketed to the public.
To date, the agency has not called for the mandatory removal of all phthalates from drug products.
Legislators Call for More Regulation
But now three members of the House of Representatives are calling on the agency to limit the use of phthalates further based on new information from the Consumer Product Safety Commission.
The commission's Chronic Hazard Advisory Panel (CHAP) on Phthalates recently found that the chemicals "pose significant risks" to human health, the legislators said in a letter to FDA Commissioner Margaret Hamburg.
"The CHAP’s findings are alarming," Democratic Reps. Henry Waxman, Frank Pallone and Jan Shakowsky wrote. "The hazards associated with phthalates and their ubiquity in everyday products underscore the needs for further regulatory action on and assessment of phthalates and phthalate substitutes."
The legislators explained that of 14 phthalate chemicals studied by CHAP, "Eight were found to cause reproductive abnormalities stemming from a syndrome of androgen insufficiency known as 'phthalate syndrome.'" Other phthalates were "also found to be hazardous," the legislators recounted.
The letter goes on to request that FDA assess the recommendations of the CHAP report, which includes a recommendation to limit the exposure of DEHP and DBP.
Further, the legislators ask that FDA assess whether it has sufficient statutory authority to "Address potential phthalate risks in drugs and pharmaceuticals," and to identify what steps the agency plans to take in response to the CHAP report's findings.
"The CHAP recommended FDA action on many of the studied phthalates, calling on the agency to 'conduct the necessary risk assessments with a view to supporting risk management steps' for eight phthalates," the legislators wrote.
The letter does not mention FDA's regulation of medical device products, which can also contain phthalates. FDA has previously recommended reducing exposure to DEHP in device products.
Letter to FDA on Phthalates