The invention provides an amorphous solid of a compound of formula (I) or of a salt thereof as well as compositions comprising the amorphous solids, and methods for making and using the amorphous solids.Linvention concerne un solide amorphe dun composé de la formule (I) ou dun sel de celui-ci, ainsi que des compositions comportant les solides amorphes, et des procédés de fabrication et dutilisation des solides amorphes.