Ibuprofen and Paracetamol when They Meet: Quantum Theory of Atoms in Molecules Perspective

Ibuprofen (IBP) and paracetamol (PCM) are widely used and prescribed two drugs for particularly their effects in reducing pain and fever. For enhanced pain relief, combinations of IBP and PCM are considered another option rather than taken each drug alone. In the scope of this work, the possible structural interaction edges, some important electronic properties and the binding energy evaluations of the IBP&PCM system were examined with density functional theory (DFT) and quantum theory of atoms in molecules (QTAIM). Further, all the configurations were subjected to biological activity evaluations. It was observed that hydrogen bonding interactions are possible for the examined drug couple and configuration 4 is the most stable form whereas C1 and C6 are better inhibitors. Therefore, possible advantages and disadvantages or possible side effects must be taken into account before combining these two important drug molecules.