Photodegradation of cinnamic acid in different media

The photodegradation of cinnamic acid under UVB irradiation was evaluated in different vehicles, such as water solutions at different pH values, Tween-20 micelles, liposomes, and O/W emulsions prepared with Xalifin 15 or Montanov 68 as emulsifiers. The increase of pH decreases the photodegradation of cinnamic acid in all the vehicles studied. Micellar solutions showed a protective effect against cinnamic acid photodegradation; this property increases according to the surfactant percentage. Emulsions appeared to be the most efficient protective systems while liposomes had lower ability to protect cinnamic acid against UVB photodegradation.