I'm using the "Drug and Drug Target Mapping" search engine (http://www.rcsb.org/pdb/ligand/drugMapping.do). I've noticed that there are some drugs (generic names) that if they appear in the query, the search results end in "No records to view". I've failed to find a pattern in identifying those drugs.

Any thoughts?

Thanks.

I'm using the "Drug and Drug Target Mapping" search engine (http://www.rcsb.org/pdb/ligand/drugMapping.do). 

I've noticed that there are some drugs (generic names) that if they appear in the query, the search results end in "No records to view". 

I've failed to find a pattern in identifying those drugs.

The site is no longer active.

One replacement is the 'anatomical therapeutic chemical' (ATC) classification. Information is found on RCSB, PDB, https://www.rcsb.org/docs/search-and-browse/browse-options/atc

...and WHO, https://www.whocc.no/atc/structure_and_principles/

The question remains pertinent.