PROBLEM TO BE SOLVED: To provide a salt form and a salt polymorph having an improved pharmacological profile, particularly in vivo exposure, as compared with a free base form and/or an amorphous form. A pharmaceutically acceptable salt of a salt of Compound 1, which is a crystalline form of a 1:1:3 free base/HCl/H2O adduct. Prevention of inflammatory conditions, autoimmune diseases, proliferative diseases, allergies, graft rejection, diseases associated with reduced and/or destroyed cartilage homeostasis, congenital chondrodysplasia, diseases associated with excessive secretion of IL6 or interferon, and /Or a therapeutically useful salt of Compound 1. [Selection diagram] None【課題】遊離塩基形態及び／又は非晶質形態と比較して、薬理学的プロファイル、特にインビボ暴露が改善された塩形態及び塩の多形体の提供。【解決手段】化合物１の塩であって、結晶形態の１：１：３の遊離塩基／ＨＣｌ／Ｈ２Ｏ付加物である、医薬として許容し得る塩。炎症性病態、自己免疫疾患、増殖性疾患、アレルギー、移植片拒絶、軟骨恒常性の低下及び／又は破壊を伴う疾患、先天性軟骨形成異常、ＩＬ６もしくはインターフェロンの分泌過多に関連する疾患の予防及び／又は治療に有用な化合物１の塩。【選択図】なし
