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Triplet Stabilization for the Enhanced Drug Photorelease from Sunscreen-Based Photocages

revised on 09.12.2020, 12:09 and posted on 10.12.2020, 06:42 by Mauricio Lineros-Rosa, Maria Consuelo Cuquerella, Antonio Francés-Monerris, Antonio Monari, Miguel Angél Miranda, Virginie Lhiaubet-Vallet

Recently, sunscreen-based drug photocages have been introduced to provide UV protection to photoactive drugs, thus increasing their photosafety. Here, combined experimental and theoretical studies performed on a photocage based on the commercial UVA filter avobenzone (AB) and on the photosensitizing non-steroidal anti-inflammatory drug ketoprofen (KP) are presented unveiling the photophysical processes responsible for the light-triggered release. Particular attention is paid to solvent stabilization of the drug and UV filter excited states, respectively, which leads to a switching between the triplet excited state energies of the AB and KP units. Most notably, we show that the stabilization of the AB triplet excited state in ethanol solution is the key requirement for an efficient photouncaging. By contrast, in apolar solvents, in particular hexane, KP has the lowest triplet excited state, hence acting as an energy acceptor quenching the AB triplet manifold, thus inhibiting the desired photoreaction.


Email Address of Submitting Author


Université de Lorraine and CNRS



ORCID For Submitting Author


Declaration of Conflict of Interest

No conflict of interest