Isradipine from Japan
Isradipine, a 1,4-dihydropyridine derivative, selectively blocks L-type calcium channels for hypertension therapy. Its nitrogen-heterocyclic aromatic structure fits HTS 2933.99.53.00 as a cardiovascular drug API. Typically imported as micronized powder for tablet coating.
Duty Rate — Japan → United States
12.5%
Rate breakdown
9903.05.4912.5%Section 301 (forced labor) — Japan (col1 rate < 12.5 percent): MFN < 12.5% → total duty capped at 12.5%
Import Tips
• D50 particle size 5-15μm critical - include laser diffraction report
• Photostability testing required due to yellowing tendency
• Single-source API often - verify supplier DMF status with FDA