Phenobarbital is Schedule IV; butalbital is Schedule III; amobarbital and secobarbital are Schedule II. The DEA schedule level affects the stringency of quota controls and the specific import permit form required. Schedule II substances face the most restrictive annual quotas and require individual import authorization for each shipment, while Schedule III and IV substances have somewhat less restrictive procedures — though all require a valid DEA importer registration.

For DEA purposes, the importer must have a Schedule IV importer registration and a completed DEA Form 486 filed prior to shipment. For FDA purposes, the foreign manufacturer must appear on FDA's drug establishment registration, and the bulk active pharmaceutical ingredient must be accompanied by a certificate of analysis and, if applicable, a Drug Master File reference. CBP will verify both sets of documentation at entry. Consult a licensed customs broker experienced in controlled substance imports to coordinate the pre-import filings.