National Drug Data File	METPO	Source
https://w3id.org/metpo/0000004	http://purl.bioontology.org/ontology/NDDF/000826	LOOM
http://purl.obolibrary.org/obo/BFO_0000001	http://purl.bioontology.org/ontology/STY/T071	LOOM
https://w3id.org/metpo/0000229	http://purl.bioontology.org/ontology/NDDF/003316	LOOM
https://w3id.org/metpo/0000210	http://purl.bioontology.org/ontology/NDDF/007010	LOOM