The present invention relates to a pharmaceutical composition of ibuprofen, tramadol, or one of the pharmaceutically acceptable salts thereof, and a basic amino acid selected from arginine, lysine and the mixtures thereof, for administration by oral route, to a process for preparing it and to the use thereof, in particular for the treatment of chronic or acute pain of moderate to severe intensity, inflammation, fever and/or other ailments wherein ibuprofen and/or tramadol are traditionally used.