#$%^&*AU2017279760A120180201.pdf#####Abstract There is described (S)-(+)-2-(2-fluoro-4-biphenylyl) propionic acid, or a salt or ester thereof, having substantially limited amounts of specific impurities associated with the synthesis and purification of the (S)-(+)-2-(2-fluoro-4-biphenylyl) propionic acid.