felbinac felbinac felbinac (inn, or biphenylylacetic acid) is a topical medicine, belonging to the family of medicines known as nonsteroidal anti-inflammatory drugs (nsaids) of the arylacetic acid (not arylpropionic acid) class, which is used to treat muscle inflammation and arthritis. it is an active metabolite of fenbufen. felbinacclinical dataahfs/drugs.cominternational drug namesroutes ofadministrationtopicalatc codem02aa08 (who) legal statuslegal status uk: p (pharmacy medicines) identifiers iupac name biphenyl-4-ylacetic acid cas number5728-52-9pubchem cid3332drugbankdb07477 ychemspider3215 yunii94wnj5u8l7keggd01675 ychebichebi:31597 ychemblchembl413965 ycomptox dashboard (epa)dtxsid0045389 echa infocard100.024.758 chemical and physical dataformulac14h12o2molar mass212.248 g·mol−13d model (jsmol)interactive image smiles o=c(o)cc1ccc(cc1)c2ccccc2 inchi inchi=1s/c14h12o2/c15-14(16)10-11-6-8-13(9-7-11)12-4-2-1-3-5-12/h1-9h,10h2,(h,15,16) ykey:qrzakqdhevvfrx-uhfffaoysa-n y (verify) related compounds the α-methyl acid of felbinac is called biprofen and is used to prepare bifepramide. the α-ethyl acid is called xenbucin which is used to make xenthiorate.