Mercaptoethanesulfonic Acid Sodium Salt from Mexico
Sodium 2-mercaptoethanesulfonate (mesna) contains both thiol and sulfonic acid groups but classified under HTS 2930.90.4950 based on principal organo-sulfur characteristics. Direct C-S linkages qualify; used as mucolytic and cytoprotective agent in chemotherapy.
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
• Provide sulfonic vs sulfinic acid differentiation via NMR
• Include ICH stability data for pharma grade material
• Declare bulk API status vs finished dosage to maintain Chapter 29 classification