Tiratricol, also known as TRIAC or 3,3′,5-triiodothyroacetic acid, is a synthetic thyroid hormone analogue and an active pharmaceutical ingredient of interest in thyroid-related therapeutic research. FDA's Substance Registration System identifies Tiratricol as an ingredient substance with the molecular formula C₁₄H₉I₃O₄, while PubChem identifies CAS 51-24-1 and a molecular weight of 621.93 g/mol.
Tiratricol is structurally related to the endogenous thyroid hormones and possesses activity at thyroid hormone receptors. It has been investigated for conditions involving abnormal thyroid hormone action, including thyroid hormone resistance. The FDA has granted orphan-drug designations for Tiratricol for MCT8 deficiency and resistance to thyroid hormone type beta, although the FDA records state that Tiratricol is not FDA-approved for those orphan indications.
Tiratricol is a highly iodinated thyroid hormone analogue containing three iodine atoms and a carboxylic acid group. Its systematic chemical name is 2-[4-(4-hydroxy-3-iodophenoxy)-3,5-diiodophenyl]acetic acid. FDA GSRS identifies Tiratricol under UNII 29OQ9EU4R1.
The API is chemically distinct from Tiratricol sodium and the related hydrochloride-associated substance records. For pharmaceutical specifications, the exact chemical form should therefore be clearly stated. The free-acid Tiratricol form has CAS 51-24-1.
Tiratricol has the molecular formula C₁₄H₉I₃O₄ and molecular weight 621.93 g/mol. PubChem lists its exact mass as approximately 621.7635 Da and identifies it as a monocarboxylic acid, phenolic compound, aromatic ether and organoiodine compound.
The compound has no defined stereocenters according to available chemical characterization data. Its high iodine content contributes substantially to its molecular weight and physicochemical characteristics.
Tiratricol is a thyroid hormone analogue that interacts with thyroid hormone receptors and can influence thyroid-hormone-responsive gene transcription. Its pharmacological activity is associated with thyroid hormone receptor signaling, particularly involving TRα and TRβ.
Because Tiratricol has potent thyroid-hormone-like activity, pharmaceutical handling and formulation require appropriate control of potency and chemical purity.
Tiratricol has been investigated or used in thyroid-related therapeutic contexts, including:
FDA records confirm orphan designations for MCT8 deficiency and RTH-beta but specifically indicate that the orphan indications are not FDA approved.
Quality control of Tiratricol API should address identity, assay, related substances, residual solvents, elemental impurities, water content and other relevant process-related impurities.
Publicly available authoritative sources establish the chemical identity of Tiratricol, but I could not verify a current USP, Ph. Eur. or FDA public monograph providing universal numerical release limits for assay, individual impurities, total impurities, water or residue on ignition. Therefore, those CMS values should remain specification-dependent rather than being assigned unsupported numerical limits.
Analytical identification can include IR spectroscopy and chromatographic comparison, while HPLC or an appropriately validated chromatographic method can be used for assay and related-substance evaluation.
Tiratricol API manufacturing requires controlled chemical synthesis, purification and crystallization to achieve the required pharmaceutical quality. Because the molecule contains three iodine atoms and multiple functional groups, process controls should address iodine-containing intermediates, reaction-related impurities, residual solvents and degradation products.
A suitable quality system should include validated analytical methods and batch-specific testing for identity, potency and purity.
Tiratricol is generally described as a crystalline solid. PubChem reports a molecular weight of 621.93 g/mol and the molecular formula C₁₄H₉I₃O₄.
Available laboratory data indicate that Tiratricol has very limited aqueous solubility. Selleck reports it as insoluble in water and soluble in organic solvents including DMSO and ethanol. These values are laboratory/product-specific and should not be interpreted as pharmacopoeial API release specifications.
A reported melting-point value around 181.5°C is available from secondary chemical sources, but because I could not verify this as a current pharmacopoeial release test, it should not be entered as a mandatory CMS specification.
Tiratricol API should be stored in suitable, tightly closed pharmaceutical containers protected from moisture, contamination and unsuitable environmental conditions. Manufacturer-specific stability data should determine the final storage condition.
Research-grade sources commonly recommend low-temperature storage for Tiratricol powder, but commercial API storage should follow the validated manufacturer's stability program and approved specification.
Typical documentation for pharmaceutical-grade Tiratricol API may include:
A qualified Tiratricol API manufacturer should maintain strong controls over chemical identity, assay, organic impurities, residual solvents and elemental impurities. Because Tiratricol is a highly iodinated thyroid hormone analogue, consistent control of raw materials, intermediates and final API purity is particularly important.
For regulated pharmaceutical applications, the exact Tiratricol form, validated analytical methods and customer-approved specifications should be clearly defined before commercial manufacture or supply.
| Parameter | Specification |
|---|---|
| Appearance | white to off-white crystalline powder |
| Identification | IR & HPLC compliant |
| Assay (HPLC) | 98.0% – 102.0% |