Aminophylline Base from China

Aminophylline base, theophylline ethylenediamine complex, qualifies as heterocyclic nitrogen compound before salt formation considerations. U.S. note 3 product in 2933.99.79.00. Used in respiratory therapy intermediates.

Duty Rate — China → United States

6.5%

Rate breakdown

9903.03.030%Articles the product of any country, as provided for in subdivision (aa)(ii) of U.S. note 2 to this subchapter

Import Tips

Specify base vs salt form clearly with assay method documentation

Test for ethylenediamine content to confirm stoichiometric ratio

Declare moisture content affecting stability during customs valuation