ALUMINUM's SAFETY AS AN ANTIPERSPIRANT INGREDIENT: FDA SEEKS COMMENTS

ALUMINUM's SAFETY AS AN ANTIPERSPIRANT INGREDIENT: FDA SEEKS COMMENTS "to determine whether further study should be required to assess the safety of aluminum antiperspirants before issuing a final monograph." In a March 24 Federal Register notice, FDA is soliciting comments on whether available safety data are "sufficient to retain aluminum-containing and aluminum zirconium- containing OTC antiperspirants in Category I" (safe and effective). FDA said it will consider the comments as it develops a final monograph for OTC antiperspirants. FDA is asking for comments on what data may be needed to support safety and, if necessary, what testing should be required. For example, FDA is seeking comment on what kinds of "absorption studies should be conducted to determine the level, if any, of aluminum [that] is absorbed through the skin and deposited in organs, such as the lungs and brain, from direct application of antiperspirant drug products." The agency points out that if aluminum-containing antiperspirants are found to be unsafe, the antiperspirant monograph will be devoid of Category I ingredients. FDA seeks comment on whether any ingredients that do not contain aluminum "may be suitable for review as OTC antiperspirant drug products." FDA placed aluminum- and aluminum zirconium-containing antiperspirant active ingredients in Category I in an August 1982 tentative final monograph for both aerosol and nonaerosol dosage forms of the products. The agency also proposed a warning for aerosol antiperspirants to "avoid excessive inhalation." However, this warning is not required to appear in labeling until publication of a final monograph. Comments received from the notice also will be used by FDA to respond to two citizen petitions on aluminum-containing antiperspirants. One petition, submitted last year by Glen Scott, MD, of Cincinnati, asked FDA to reclassify all aluminum compounds used in antiperspirants from Category I to Category III "until further absorption studies are done to determine the amount of aluminum absorbed following topical application and inhalation exposure." The petitioner argued that studies conducted since the 1982 TFM show that aluminum is a powerful neurotoxin. The petition also cites a case-control study that indicated a relationship between aluminum-containing antiperspirants and Alzheimer's disease. In response to Scott's petition, Henry Wisniewski, MD/PhD, director for trace metal studies and environmental neurotoxicology at the Institute for Basic Research in Developmental Disabilities, asserted in October 1992 remarks to the agency that current scientific information does not support the need to reclassify aluminum-containing antiperspirants. Wisniewski pointed out that Scott's petition referred mostly to findings from in vitro studies, and that physiologically impossible concentrations of aluminum were used in those studies. A second petition was forwarded to FDA on Dec. 21, 1992 by Patricia Saunders, a microbiologist in the agency's analgesic, antiperspirant and antimicrobials section of the OTC Drug Monograph Staff, who recommended that FDA revoke Category I classification of aerosol dosage forms, reclassify nonaerosol aluminum-containing dosage forms as Category III (safety and efficacy data insufficient to permit classification), and require a reevaluation of the potential for skin aborption of aluminum- containing antiperspirants as well as possible toxic effects from long-term use. Like Scott, Saunders argued that aluminum- containing antiperspirants may be linked to neurotoxicity and systemic toxicity. FDA has evaluated several aluminum compounds for use in other categories of OTC drug products. For example, the agency has deemed various aluminum salts as safe when used in astringents, skin protectants, and topical acne products. Aluminum compounds also are allowed in OTC antacids, but with a warning that "prolonged use of aluminum-containing antacids in patients with renal failure may result in or worsen dialysis osteomalacia." FDA states in the notice that for OTC hypophosphatemia drugs, "a role for aluminum in the pathogenesis of Alzheimer's disease cannot be ruled out, but the evidence supporting such a role is very weak." The agency is accepting comments on the notice until July 24.