Isoergosine from Mexico
Isoergosine is an isomer of ergosine from rye ergot, used in stereochemistry studies. HTS 2939.69.00.00 covers this as a rye ergot derivative; chapter note (b) includes isomers of organic compounds. Chemically defined and separate from mixtures.
Duty Rate — Mexico → United States
100%
Rate breakdown
9903.04.60100%Except as provided in heading 9903.04.61, patented pharmaceutical articles as provided for in subdivisions (c) and (d) of U.S. note 40 to this subchapter
9903.05.860%Articles provided for in subdivision (b) of U.S. note 52 to this subchapter
Import Tips
• Chiral analysis certificate essential for isomer verification
• Chapter note (b) allows isomer mixtures if same compound base
• Retail sale packing triggers Chapter 33/38 preparations