Paraxanthine Reference Standard from Japan
Paraxanthine is a caffeine metabolite with a xanthine (pyrimidine-containing) structure, supplied as analytical reference material. Falls under HTS 2933.59.70.00 for aromatic pyrimidines listed in additional U.S. note 3. Used in lab research and pharma development.
Duty Rate — Japan → United States
21%
Rate breakdown
9903.04.628.5%Patented pharmaceutical articles that are the product of Japan, of a European Union member country, of South Korea, of Switzerland, or of Liechtenstein as provided for in subdivisions (c) and (f) of U.S. note 40 to this subchapter
9903.05.4912.5%Except for products described in headings 9903.05.85–9903.05.92, articles the product of Japan, with an ad valorem (or ad valorem equivalent) rate of duty under column 1 less than 12.5 percent, as provided for in U.S. note 52 to this subchapter
Import Tips
• Include stability data and intended research use declaration to avoid pharma drug scrutiny
• Use small package sizes (<1kg) typical for standards to prevent bulk chemical treatment
• Cross-check with FDA for any import alerts on xanthine metabolites