(AP) -- The Food and Drug Administration has issued warnings to eight companies for illegally marketing pain relief ointments containing ibuprofen.

Regulators say the companies do not have federal permission to market their products, which mix the popular drug with other ingredients. While ibuprofen is available in a variety of tablets like Advil, the FDA has not approved any ointments containing the drug.

The companies include: Tennessee-based Wonder Laboratories, New Mexico-based Meditrend and Alabama-based Progressive Emu Inc. They have 15 business days to respond to the FDA

Some of the products claim they are safer than tablets. The FDA says there is no evidence supporting those claims.

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