A monocarboxylic acid in which one of the alpha-hydrogens is substituted by a biphenyl-4-yl group. An active metabolite of fenbufen, it is used as a topical medicine to treat muscle inflammation and arthritis. ChEBI: Biphenyl-4-ylacetic acid is a monocarboxylic acid in which one of the alpha-hydrogens is substituted by a biphenyl-4-yl group. An active metabolite of fenbufen, it is used as a topical medicine to treat muscle inflammation and arthritis. It has a role as a non-steroidal anti-inflammatory drug. It is a member of biphenyls and a monocarboxylic acid. It contains a biphenyl-4-yl group. It is functionally related to an acetic acid.