Specialty drug manufacturer Acella Pharmaceuticals is recalling dozens of lots of NP Thyroid tablets, a drug for treatment of hypothyroidism, after it was determined that the products did not meet potency standards, a recurring issue for the company that previously prompted FDA enforcement action.

The FDA sent a warning letter to Union City, Calif.-based drugmaker RPK Pharmaceuticals for mislabeling of a topical drug, saying the label for the drug did not match the description of the listed drug.