Comment:

This resource should not exist. "Wrappers" are not allowed in FHIR. Every resource must stand alone and be interpretable and processable without access to referenced resources. As well, identifiers, classifications, relationships, etc. belong with the item, not as part of a catalogue. A catalogue can group items, but can't change their characteristics. A medication in a catalog is a medication instance and all information about that catalogue item belongs on the Medication instance itself - the Medication instance might be catalogue-specific.

Summary:

Drop EntryDefinition