Liothyronine sodium, USP 29, Ph.Eur.5.5, Micronized grade
Molecular Formula: C15H11I3NNaO4,
Molecular Weight: 673.0 gm/mol.
T3Cytomel®, brand of Liothyronine sodium tablets, is a synthetic form of a natural thyroid hormone, and is available as the sodium salt. Each tablet contains 100 microgram of Liothyronine sodium, USP 29, Ph.Eur.5.5, Micronized grade. It is designated chemically as Sodium 4-O-(4-hydroxy-3-iodophenyl)-3,5-di-iodo-L-Tyrosine.
It occurs as white or slightly coloured crystalline powder. Practically insoluble in water; slightly soluble in alcohol; It dissolves in dilute solutions of alkali hydroxides.
Each tablet also contains lactose monohydrate, sodium starch glycolate, polyvidone 25,000, microcrystalline cellulose and magnesium stearate as excipients. The 100 mcg tablet also contains yellow ferric oxide (E172) as colouring agent.
Thyroid hormones enhance oxygen consumption by most tissues in the body, increasing the basal metabolic rate and the rate of metabolism of carbohydrates, lipids, and proteins. Thyroid hormones have a profound influence on every organ in the body and are of particular importance in the development of the central nervous system.