One of them is the following, the other source (Electronic Orange Book (EOB) Query data files) may provide additional info which I will look at later.
Anyhow,
http://www.fda.gov/Drugs/InformationOnDrugs/ucm079750.htm
supplies among its tables:
Product (Product): This table contains the products included in each application. Includes form, dosage, and route.
• ApplNo [varchar, 6] (Primary Key)
• ProductNo [varchar, 3] (Primary Key)
• Form [varchar, 255, nulls]
• Dosage [varchar, 240, nulls]
• ProductMktStatus [tinyint, 1] (1=prescription, 2=OTC, 3=discontinued, 4=tentative approval) (Primary Key)
• TECode [varchar, 100, nulls]
• ReferenceDrug [bit, 1]
• Drugname [varchar, 125, nulls]
• Activeingred [varchar, 255, nulls]
from the above table, an example of a drug that contains two molecules is
"020668","001","TABLET, EXTENDED RELEASE; ORAL","5MG;5MG",1,"",1,"LEXXEL","ENALAPRIL MALEATE; FELODIPINE"
"020668","002","TABLET, EXTENDED RELEASE; ORAL","5MG;2.5MG",3,"",0,"LEXXEL","ENALAPRIL MALEATE; FELODIPINE"
another is
"020033","001","TABLET; ORAL","5MG;6.25MG",1,"AB",0,"LOTENSIN HCT","BENAZEPRIL HYDROCHLORIDE; HYDROCHLOROTHIAZIDE"
"020033","002","TABLET; ORAL","10MG;12.5MG",1,"AB",0,"LOTENSIN HCT","BENAZEPRIL HYDROCHLORIDE; HYDROCHLOROTHIAZIDE"
"020033","003","TABLET; ORAL","20MG;25MG",1,"AB",1,"LOTENSIN HCT","BENAZEPRIL HYDROCHLORIDE; HYDROCHLOROTHIAZIDE"
"020033","004","TABLET; ORAL","20MG;12.5MG",1,"AB",0,"LOTENSIN HCT","BENAZEPRIL HYDROCHLORIDE; HYDROCHLOROTHIAZIDE"
Notice that in each case, multiple strengths can obtain approval under a single application number which is shared (non-uniquely) among these strengths and is rather like an ATC and could be mapped to an ATC. This is rather the less-granular-than-Canada (and France) case that I made, because the Canadian UID incorporates strength-within-manufacturer.
OTOH the US is potentially more granular than Canada if one combines
FDA application number + product number {1,2,3}
since this combines an ATC-equivalent with a
form;route
strength;strengths
Another drug, "Paxil" illustrates that a single drug, from a single company, can have multiple different FDA Application Numbers depending presumably when they filed for any new "formulation":
"020031","001","TABLET; ORAL","EQ 10MG BASE",1,"AB",0,"PAXIL","PAROXETINE HYDROCHLORIDE"
"020031","002","TABLET; ORAL","EQ 20MG BASE",1,"AB",0,"PAXIL","PAROXETINE HYDROCHLORIDE"
"020031","003","TABLET; ORAL","EQ 30MG BASE",1,"AB",0,"PAXIL","PAROXETINE HYDROCHLORIDE"
"020031","004","TABLET; ORAL","EQ 50MG BASE",3,"",0,"PAXIL","PAROXETINE HYDROCHLORIDE"
"020031","005","TABLET; ORAL","EQ 40MG BASE",1,"AB",1,"PAXIL","PAROXETINE HYDROCHLORIDE"
"020710","001","SUSPENSION; ORAL","EQ 10MG BASE/5ML",1,"AB",1,"PAXIL","PAROXETINE HYDROCHLORIDE"
"020936","001","TABLET, EXTENDED RELEASE; ORAL","EQ 12.5MG BASE",1,"AB",0,"PAXIL CR","PAROXETINE HYDROCHLORIDE"
"020936","002","TABLET, EXTENDED RELEASE; ORAL","EQ 25MG BASE",1,"AB",0,"PAXIL CR","PAROXETINE HYDROCHLORIDE"
"020936","003","TABLET, EXTENDED RELEASE; ORAL","EQ 37.5MG BASE",1,"",1,"PAXIL CR","PAROXETINE HYDROCHLORIDE"
These files provide no ATC or AHFS drug classifiers.
-- Jim