The Court of International Trade ruled recently that darunavir ethanolate, a medicine for the treatment of the human immunodeficiency virus, is properly classified as a sulfonamide under HTSUS 2935.00.60 and eligible for duty-free treatment under the Pharmaceutical Appendix. The plaintiff had argued for classification as a medicament under HTSUS 3003.90.00.
According to the CIT, the Explanatory Notes to Chapter 29 clarify that in a crystal lattice (which the subject product is) the molecular species corresponds to the repeating unit cell, which in this case is comprised of four darunavir molecules linked to four ethanol molecules by hydrogen bonds. The plaintiff noted that this ratio is not constant in this product because the ethanol and water molecules can exchange positions.
However, the court said the composition of the product is defined by a constant ratio of elements regardless of whether the purity of the product decreases over time or the rate at which it does so. In light of this fact, and because the repeating unit cell can be represented by a definitive structural diagram, this product meets the criteria of a separately defined organic compound subject to Chapter 29. Further, evidence shows that the product is a sulfonamide within this chapter.
The government argued that darunavir ethanolate is not within the scope of table 1 of the Pharmaceutical Appendix because it is assigned a separate Chemical Abstract Service registry number than darunavir. However, the court said (a) the chapeau to that table states that any references to a product enumerated in that table include that product by whatever name known and (b) CAS registry numbers are not exclusive or exhaustive identifiers as to whether a named product is within the scope of that annex.