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
15%
Rate breakdown
9903.04.628.5%Pharmaceuticals: patented pharma from JP/EU/KR/CH/LI — 15% floor rate
9903.05.900%Articles already subject to Section 232 (steel/aluminum/copper + derivatives, autos + parts, wood, medium/heavy vehicles + parts, semiconductors, patented pharma) — U.S. note 52(f)
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