Patent ID: 8039475

Claim:
A co-crystal comprising (1S,3aR,6aS)-2-[(2S)-2-[[(2S)-2-Cyclohexyl-2-(pyrazine-2-carbonylamino)acetyl]amino]-3,3-dimethylbutanoyl]-N-[(3S)-1-(cyclopropylamino)-1,2-dioxohexan-3-yl]-3,3a,4,5,6,6a-hexahydro-1H-cyclopenta[c]pyrrole-1-carboxamide and salicylic acid, wherein said co-crystal has X-ray powder diffraction peaks at about 4.43, 7.63, 8.53, 9.63, 12.89, 14.83, 16.29 2-Theta.