This work is a contribution of theoretical chemistry to the classification of some non-steroidal anti-inflammatory drugs (NSAIDs). Indeed, research on the efficacy of NSAIDs has shown that no NSAID is recognized as the most efficient anti-inflammatory drug. We have made a theoretical study of diclofenac, bromfenac and amfenac, in order to compare their efficacy from some physicochemical properties. To do this, we used the DFT and TD-DTF methods at the B3LYP/6-311+G(d, p) level theory. The lipophilicity study shows that diclofenac and bromfenac are very lipophilic. Acidity study shows that diclofenac is more acid than bromfenac and amfenac. The results from molecular orbital and the TD-DFT calculations reveal that for the three NSAIDs, the lowest energy transition is due to the excitation from HOMO to LUMO. The absorption energy corresponding to H→L transition is comparable with the energy gap value. Our findings have shown that bromfenac is more reactive than amfenac, which is more reactive than diclofenac.

No abstract

No abstract

A comparative theoretical study of some physicochemical properties of R and S enantiomers of ibuprofen, ketoprofen and flurbiprofen is undertaken in order to understand their reactivity. To do this, DFT and TD-DFT methods at the B3LYP/6-311G(d,p) level theory are used. The partition coefficient determined is 3.72 for ibuprofen, 2.81 for ketoprofen and 4.12. for flurbiprofen. That means that these NSAIDs are characterized by a high lipophilicity. The calculated Gibbs energies show that the R enantiomer is the most stable in the case of ibuprofen and the S enantiomer in the case of ketoprofen and flurbiprofen. The study of acidity shows that S enantiomer of ibuprofen and R enantiomers of ketoprofen and flurbiprofen are the most acidic enantiomers. TD-DFT calculations show that, the absorption maxima (λmax) of ibuprofen and flurbiprofen correspond to the HOMO→LUMO transition. For ketoprofen, these are associated with the transition HOMO→LUMO+1. These results elucidate the reactivity of the investigated NSAIDs and could help to establish a classification their efficacy.