IR;HPLC 

Very slightly soluble in water, slightly soluble in ethanol (96 per cent). It dissolves in dilute solutions of alkali hydroxides.

Freshly prepared solution S is not more intensely coloured than reference solution BY3.

Solution S is clear and not more intensely coloured than reference solution B7or BY7.

+16°~+ 20° 

Liothyronine≤1.0% ;

β-Hydroxy-T4a≤0.15% ;

T4-Hydroxyacetic acidb≤0.15% ;

N-Formyl-T4c and T4-acetamided≤0.15% ;

N-Acetyl-T4e:≤0.2% ;

T4-Acetic acidf ≤0.30% ;

T4-Aldehydeg≤0.15% ;

T4-Benzoic acidh≤0.15%; 

Individual unspecified impurities:≤0.10% ;

Total Impurity≤2.0%  

6.0%~12.0%  

97% ~103.0% 

It can be used for hormone replacement therapy of hypothyroidism

Preserve in tight containers, protected from light. Store as stated in the labeling instructions.