Penicillamine from Mexico
D-Penicillamine, 3-mercapto-D-valine, is a mercaptocarboxylic amino acid used in Wilson's disease treatment. The free mercapto and carboxylic functions qualify it for HTS 2930.90.4920 classification as organo-sulfur compound. Chapter 29 takes precedence over amino acid headings.
Duty Rate — Mexico → United States
110%
Rate breakdown
9903.04.6095.8%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
9903.05.5510%Except for products described in headings 9903.05.85–9903.05.92 and 9903.05.94, articles the product of Mexico, as provided for in U.S. note 52 to this subchapter
Import Tips
• Chiral HPLC certificate required showing D-isomer >99%; CAS 52-67-5
• Oxidation-sensitive; import with antioxidant stabilizer per Chapter 29 note 2(f)
• Distinguish from 2922.50 amino acid salts by free base form