Photodegradation mechanism of nonsteroidal anti-inflammatory drugs containing thiophene moieties: suprofen and tiaprofenic acid.

Klefah A K Musa, Leif A Eriksson

School of Science and Technology and Orebro Life Science Center, Orebro University, 701 82 Orebro, Sweden.

The journal of physical chemistry. B 2009 Aug 13

filter terms:

The photodegradation of nonsteroid anti-inflammatory drugs suprofen, 2-[4-(2-thienoyl)phenyl]propionic acid, and tiaprofenic acid, 2-(5-benzoyl-2-thienyl)propanoic acid, is studied by means of density functional theory. Besides the redox properties of the neutral species, we report on absorption spectra and degradation pathways involving excitation, intersystem crossing to the T(1) state, and spontaneous decarboxylation of the deprotonated species of each drug. The energetics and properties of the suprofen and tiaprofenic acid systems are found to be very similar to those of the highly photolabile benzyl analogue ketoprofen. Mechanisms leading to the formation of a closed-shell decarboxylated ethyl species, as well as peroxyl radicals capable of initiating lipid peroxidation reactions, are discussed.

Citation

Klefah A K Musa, Leif A Eriksson. Photodegradation mechanism of nonsteroidal anti-inflammatory drugs containing thiophene moieties: suprofen and tiaprofenic acid. The journal of physical chemistry. B. 2009 Aug 13;113(32):11306-13