The US Food and Drug Administration (FDA) on Tuesday issued a draft guidance encouraging drugmakers to provide detailed labeling about whether their products are made from ingredients that contain gluten.
FDA says the guidance is meant to reduce uncertainty about the presence of wheat gluten in oral drugs, and that unless a drug specifically contains wheat gluten or wheat flour as an ingredient, that it expects that most drugs would contain less wheat gluten than a gluten-free cookie.
"The amount of gluten estimated to be potentially present in a unit dose of an oral drug product (less than 0.5mg) is significantly less than the range at which gluten is estimated to be present in a gluten-free diet (5 to 50mg)," FDA writes, noting that 0.5mg is the high end of its estimate.
FDA also says it is not aware of any currently marketed oral drugs that contain wheat gluten as an intentionally added inactive ingredient, and that drugs that contained intentionally added wheat gluten would have to be labeled as such.
"We have made great strides in enhancing transparency about gluten in food labeling, but because there has been uncertainty about gluten in certain drug products, some patients may be avoiding medications that would otherwise offer a health benefit," said FDA Commissioner Scott Gottlieb.
The guidance pertains to all human drugs that pass through the small intestine, including drugs that are taken orally, topical drugs applied on or near the lips and drugs that are applied inside the mouth.
Specifically, FDA says it encourages manufacturers to include a statement that their drug "contains no ingredient made from a gluten-containing grain (wheat, barley or rye)" when such a statement is "truthful and substantiated" in the description section of the drug's prescribing information.
FDA says the guidance was developed to address concerns for patients with celiac disease and that its recommendations also apply to patients with other conditions treated with a gluten-free diet. But FDA says the guidance does not cover issues related to wheat hypersensitivity and does not apply to other FDA-regulated products, such as food, dietary supplements or cosmetics.
According to FDA, wheat gluten is "never or very rarely added as an inactive ingredient to oral drug products" and drugs that have wheat gluten intentionally added should be labeled as such.
The agency also says it may question the use of wheat gluten as an inactive ingredient on a case-by-case basis, especially for drugs with few or no alternatives or for drugs intended for long-term use to treat comorbidities associated with celiac disease.
"In the absence of more detailed information regarding wheat gluten amounts, individuals with celiac disease may choose to avoid oral drug products that are labeled as containing wheat gluten as an ingredient," FDA writes.
However, aside from wheat gluten intentionally added to drugs, FDA says that wheat gluten may be found in low levels as an impurity in ingredients such as wheat starch, wheat flour, wheat germ oil, ingredients derived from starch and ingredients produced through fermentation.
In the guidance, FDA discusses specific considerations and estimates for how much gluten may be found as an impurity per unit dose of a drug made with those ingredients.