Opthazel

https://www.ebi.ac.uk/chebi/searchId.do?chebiId=CHEBI:2950
http://www.hmdb.ca/metabolites/HMDB0015107
http://www.genome.jp/dbget-bin/www_bget?drug:D07483
http://www.genome.jp/dbget-bin/www_bget?cpd:C07768
https://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=2267
https://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?sid=46507582
https://www.chemspider.com/Chemical-Structure.2180.html
http://www.bindingdb.org/bind/chemsearch/marvin/MolStructure.jsp?monomerid=50341448
https://mor.nlm.nih.gov/RxNav/search?searchBy=RXCUI&searchTerm=18603
https://www.ebi.ac.uk/chebi/searchId.do?chebiId=2950
https://www.ebi.ac.uk/chembldb/index.php/compound/inspect/CHEMBL639
http://bidd.nus.edu.sg/group/cjttd/ZFTTDDRUG.asp?ID=DNC000270
http://www.pharmgkb.org/drug/PA448517
http://www.rxlist.com/cgi/generic/optivar.htm
https://www.drugs.com/cdi/azelastine-spray.html
http://www.pdrhealth.com/drug_info/rxdrugprofiles/drugs/opt1673.shtml
https://en.wikipedia.org/wiki/Azelastine