On the photophysical and photochemical behavior of fenbufen: a study in homogeneous media and micellar environments

Abstract

The photochemistry of fenbufen, γ-oxo-[1,1′-biphenyl]-4-butanoic acid (FB), has been investigated in homogeneous solutions and in micellar environments. The photochemical and photophysical properties of the drug are mediated by its lowest excited triplet states. The presence of a low-lying π,π* triplet is responsible for the inefficient Norrish Type I photocleavage, whereas an upper n,π* triplet promotes a large intersystem crossing yield. FB interacts with both anionic and cationic micelles. The different binding mode of the drug with the microheterogeneous environments can significantly change its photoreactivity. These changes are rationalized on the basis of “micellar cage effects”.