SPL Set ID: c760d0cc-2245-4914-8c67-d536c41ac90f

Levothyroxine sodium tablets, USP is L-thyroxine (T4) and contains synthetic crystalline L-3,3',5,5'-tetraiodothyronine sodium salt. Synthetic T4 is chemically identical to that produced in the human thyroid gland. Levothyroxine (T4) sodium has a molecular formula of C 15 H 10 I 4 N NaO 4 • H 2 O, molecular weight of 798.86 (anhydrous), and structural formula as shown: Levothyroxine sodium tablets, USP for oral administration are supplied in the following strengths: 137 mcg, 150 mcg, 175 mcg, 200 mcg, and 300 mcg. Each levothyroxine sodium tablet, USP contains the inactive ingredients butylated hydroxyanisole, colloidal silicon dioxide, croscarmellose sodium, gelatin, maltodextrin, mannitol, microcrystalline cellulose, povidone, and sodium stearyl fumarate. Levothyroxine sodium tablets contain no ingredients made from a gluten-containing grain (wheat, barley, or rye). Table 9 provides a listing of the color additives by tablet strength: Table 9: Levothyroxine Sodium Tablet Color Additives Strength (mcg) Color additive(s) 137 FD&C Blue No.1 150 FD&C Blue No.2 175 D&C Red No. 27, D&C Red No. 30 and FD&C Blue No. 1 200 FD&C Red No.40 300 D&C Yellow No. 10, FD&C Blue No. 1 and FD&C Yellow No. 6* * Note – FD&C Yellow No. 6 is orange in color. FDA approved dissolution method and acceptance criterion differs from the USP monograph dissolution testing. str