title: Reducing adverse effects from UV sunscreens by zeolite encapsulation: comparison of oxybenzone in solution and in zeolites.
abstract: Oxybenzone (OXB) is one of the most widely employed sunscreen ingredients, yet its allowed load is limited to a maximum of 6% reflecting the frequency with which adverse effects are reported. From a spectroscopic point of view, OXB has excellent absorption properties in both the UVB and UVA regions. We propose that zeolite encapsulation can lead to a sunscreen composite ingredient, that we describe as a supramolecular sunscreen, that will retain the excellent spectroscopic properties of OXB, while preventing contact between the skin and the active ingredient. OXB is very photostable, with the only photodegradative pathway observed being the monophotonic photoejection of electrons that leads to trace yields of phenoxyl radicals; this trace reaction is so minor that it cannot be detected from the recovery of unreacted OXB following UV exposure. Solution, as well as powder and in vitro studies of the supramolecular sunscreen, demonstrate that the protective properties of OXB are totally preserved when encapsulated in zeolite NaY.
authors.affiliation: Department of Chemistry, Centre for Catalysis Research and Innovation, University of Ottawa, Ottawa, ON, Canada.
authors.forename: Michelle N
authors.initials: MN
authors.lastname: Chrétien
authors.forename: Eve
authors.initials: E
authors.lastname: Heafey
authors.forename: Juan C
authors.initials: JC
authors.lastname: Scaiano
mesh_terms: D001577:Benzophenones / Q000008:administration & dosage / Q000009:adverse effects* / Q000528:radiation effects; D002214:Capsules; D016503:Drug Delivery Systems / Q000379:methods*; D004355:Drug Stability; D012996:Solutions; D013473:Sunscreening Agents / Q000008:administration & dosage / Q000009:adverse effects* / Q000528:radiation effects; D017641:Zeolites
chemical_list: D001577:Benzophenones; D002214:Capsules; D012996:Solutions; D013473:Sunscreening Agents; D017641:Zeolites; C005290:oxybenzone