Source:http://linkedlifedata.com/resource/umls/id/C0598322
NCI: "A special class of inhalations consisting of a drug or combination of drugs, that by virtue of their high vapor pressure, can be carried by an air current into the nasal passage where they exert their effect; the container from which the inhalant generally is administered is known as an inhaler. (NCI)",NCI: Vaporized active and/or inert ingredient(s) intended for administration by inhalation.