Synthroid (Levothyroxine Sodium) - Description

DESCRIPTION

SYNTHROID (levothyroxine sodium tablets, USP) contain synthetic crystalline L-3,3',5,5'-tetraiodothyronine sodium salt [levothyroxine (T₄) sodium]. Synthetic T₄ is identical to that produced in the human thyroid gland. Levothyroxine (T₄) sodium has an empirical formula of C₁₅H₁₀I₄N NaO₄ • H₂O, molecular weight of 798.86 g/mol (anhydrous), and structural formula as shown:

Inactive Ingredients

Acacia, confectioner's sugar (contains corn starch), lactose monohydrate, magnesium stearate, povidone, and talc. The following are the color additives by tablet strength:

Strength (mcg)	Color additive(s)
25	FD&C Yellow No. 6 Aluminum  Lake
50	None
75	FD&C Red No. 40 Aluminum Lake, FD&C Blue No. 2 Aluminum  Lake
88	FD&C Blue No. 1 Aluminum Lake, FD&C Yellow No. 6 Aluminum Lake, D&C Yellow No. 10 Aluminum  Lake
100	D&C Yellow No. 10 Aluminum Lake, FD&C Yellow No. 6 Aluminum  Lake
112	D&C Red No. 27 & 30 Aluminum  Lake
125	FD&C Yellow No. 6 Aluminum Lake, FD&C Red No. 40 Aluminum Lake, FD&C Blue No. 1 Aluminum  Lake
137	FD&C Blue No. 1 Aluminum  Lake
150	FD&C Blue No. 2 Aluminum  Lake
175	FD&C Blue No. 1 Aluminum Lake, D&C Red No. 27 & 30 Aluminum  Lake
200	FD&C Red No. 40 Aluminum  Lake
300	D&C Yellow No. 10 Aluminum Lake, FD&C Yellow No. 6 Aluminum Lake, FD&C Blue No. 1 Aluminum  Lake

Meets USP Dissolution Test 3