Individuals who suffer from thyroid disorders may be unaware that their medication has a limited shelf-life. Medicines that are past their expiration date may have decreased potency, which can affect their therapeutic value. Since thyroid hormone drugs are often prescribed in very small doses, product stability is very important.
Over the past decade, the U.S. Food and Drug Administration (FDA) has implemented strict potency standards for thyroid-related drugs, such as Synthroid, Unithroid, Levothroid, Levolet and Levoxyl. Endocrinologists have found that a patient who is being treated for hypothyroidism could experience an ineffective dose or an overdose due to the instability of levothyroxine or liothyronine.
According to the FDA, "Orally administered levothyroxine sodium is used as replacement therapy in conditions characterized by diminished or absent thyroid function, such as cretinism, myxedema, nontoxic goiter or hypothyroidism. [It] may be used to suppress the secretion of thyrotropin in the management of simple nonendemic goiter, chronic lymphocytic thyroiditis and thyroid cancer."
The FDA's effort to narrow the release date for these products provided a temporary solution, but the industry has remained unable to properly regulate product quality. In order to fix this issue, the inherent stability of the active ingredients needs to be improved.
This week, Pisgah Labs received a Notice of Allowance from the U.S. Patent and Trademark office for thyroid hormone active ingredients in salt forms, which have much greater stability. With this improvement, dosages can be more uniform from across different batches.