The U.S. FDA Center for Drug Evaluation and Research (CDER) is currently proposing labeling recommendations for gluten in drugs.
What are the reasons to find gluten in drugs?
There are four possible reasons why gluten can be found in drugs:
- Wheat gluten may be an ingredient of a drug. While in the past, a few manufacturers had added wheat flour to oral drugs, wheat gluten is present “never or very rarely added as inactive ingredient” in oral drugs. Here, the opinion expressed it to clearly label such drugs to contain wheat gluten if it is added.
- Wheat gluten may be an impurity of drug ingredients that are derived from wheat. A drug ingredient that may still contain traces of gluten contain is wheat starch. Similar to wheat flour, this is nowadays only very rarely used. Starch-derivatives like maltodextrin and sorbitol however, are not uncommon in some drugs. According to data published by the European Food Safety Authority back in 2007, starch hydrolysates may contain up to 40mg/kg gluten, meaning that the amount consumed when taking a pill or capsule is below 0.5 mg gluten, and with that well below the gluten-free labelling limit of 20 mg/ kg.
- Wheat gluten as residues in wheat-driven fermentation processes. Numerous products are produced by fermentation, where specific microorganisms produce the desired compounds like citric acid, malic acid etc. These microorganisms require carbohydrates for the fermentation, and these could come from wheat. However, almost all fermentation processes are followed by a purification step which enriches the desired compound (e.g. citric acid), while eliminating others. Again, residual wheat gluten levels can be expected to be very low. U.S. Department of Health and U.S. FDA estimate that the gluten levels per pill or capsule are below 0.5 mg gluten.
- Wheat Germ Oil. Some drug formulations contain wheat germ oil. These however, tend to be applied to skin or lips and are not for oral application. In these formulations, highly refines oils tend to be used which do not contain detectable amounts of gluten. As such, even application of products to lips are not considered a health risk.
U.S. FDA estimated that even if multiple drugs (capsules or pills) containing gluten at the expected levels of 0.5 mg gluten are taken, the total amount remains well below the recommended level of 5 mg to 50 mg gluten for a gluten-free diet. However, while U.S. FDA considers taking such medication a “low risk of experiencing problems as a result of the possible presence of gluten in a drug product“, it acknowledges that persons suffering from celiac disease may want to avoid taking such drugs.
FDA Recommendation
Based on the possible sources and amounts of wheat gluten in drugs, the U.S. FDA and U.S. Department of Health recommend voluntary statements regarding the absence of gluten: “Contains no ingredient made from a gluten-containing grain (wheat, barley, or rye”. It is pointed out that any such statement needs to be supported by appropriate evidence.
U.S. FDA is currently still seeking comments on the proposed labeling recommendation.
