The mechano-chemical activation was used to obtain a new composite of a anti-inflamatory drug (Nimesulide) and a polysaccharide carrier (beta -cyclodextrin). The original industrial process for activation, patented by Eurand Int. S.p.A., permits an improvement of the physico-chemical properties of the drug, which reaches a higher thermodynamic state (activation state). This work wants to demonstrate that the interaction between the drug and the carrier as a composite causes the thermodynamic activation of the Nimesulide as a new physical compound.