D-pantothenic acid is the biologically active enantiomer, while DL-pantothenic acid is the racemic mixture; only the D-form has full vitamin activity. Both forms are classified together under 2936240100 — the US tariff schedule does not subdivide by stereoisomer at the 10-digit level. However, the distinction is commercially significant: pharmaceutical and dietary supplement buyers typically specify the D-form (as calcium D-pantothenate) and will reject racemic material, so the certificate of analysis must confirm optical purity. This does not change the HTS classification but is critical for contract compliance and FDA labeling accuracy.

The commercial invoice and entry documentation should clearly state whether the material is intended for human dietary supplement use, pharmaceutical manufacturing, food fortification, cosmetic use, or animal feed. Each end-use triggers a different FDA regulatory pathway: dietary supplement ingredients require the foreign manufacturer to be registered with FDA; pharmaceutical-grade material requires drug establishment registration; and feed-grade material must comply with 21 CFR Part 573. Mismatched documentation — for example, a feed-grade certificate of analysis accompanying a dietary supplement import declaration — is a common cause of FDA examination and detention.