Pisgah Labs receives Notice of Allowance for new patent relating to thyroid hormone drugs

Aug 17 2010

Today, Pisgah Labs, Inc. (http://www.pisgahlabs.com) received a Notice of Allowance from the United States Patent and Trademark office (http://www.uspto.gov) for an important new technology patent addressing global stability problems of thyroid hormone drugs. According to the FDA (http://www.fda.gov): "Thyroid hormones effect protein, lipid, and carbohydrate metabolism, growth and development. 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. Levothyroxine sodium may be used to suppress the secretion of thyrotropin in the management of simple nonendemic goiter, chronic lymphocytic thyroiditis, and thyroid cancer."

The shelf life of important treatments, particularly for prescription drugs, is a factor that affects all patients. A medication past its expiry date has been shown to have decreased potency to the extent it may no longer exhibit therapeutic value. Drug product manufacturers in conjunction with the FDA routinely perform and monitor the stability of formulated drug products and of the active ingredients used to make those drug products. In the case of the thyroid hormones, the stability of the existing commercial drugs is inherently lacking and formulation techniques do little to correct the deficiency. Current manufacturers have responded to the FDA's insistence for safe and efficacious medications, but breakthrough technology was, until now, unavailable.

Further, the criticality of drug product stability and associated shelf life is obviously very important and well-exemplified when considering the low-dose requirements of the thyroid hormone drugs. During the past decade, the FDA implemented rigorous potency standards for thyroid-related drug products such as Synthroid®, Unithroid®, Levothroid®, Levolet® and Levoxyl®. The very low dosage needed for therapeutic effect was susceptible to potency degradation during and after manufacturing, and the low dosage challenged manufacturing techniques for provision of a uniform tablet-to-tablet dosage. Endocrinologists know a patient being treated for hypothyroidism could experience the complete range of dosing -- from an ineffective dose to an overdose -- principally due to the instability of levothyroxine (T4) or liothyronine (T3).

In response to the potency variability, manufacturers employed various formulation techniques to improve the stability of these delicate and sensitive active ingredients. Regulatory mandates can typically only serve as patches to inherent problems when invention is required to completely resolve a serious problem. The FDA's effort to narrow the release specification for these products defined an outcome, but not a means by which the desired result could be routinely obtained. Not surprisingly, the industry has remained handicapped with product quality often jeopardized. At the root of the stability and potency issue was a need to improve the inherent stability of the active ingredients prior to their formulation into dosage products.

Fortunately, Pisgah Labs has prepared thyroid hormone active ingredients in salt forms which exhibit unprecedented stability. Since the improved stability occurs at the active ingredient level, formulation demands are significantly lessened. With improved active ingredient stability, the formulation and manufacturing requirements are comparatively uncomplicated and can principally address the dosage and batch-to-batch uniformity.