The present invention relates to (1aS, 5aS) -2- (4- oxygen-pyrazine -2- base) -1a, 2,5,5a- tetrahydro -1H-2, the crystalline form and its pharmaceutical composition of 3- diaza-cyclopropyl simultaneously [a] pentalene -4- formic acid ((S) -1- hydroxymethyl -2,2- Dimethyl-propyl)-amide (compound 1)The crystalline form and composition adjust the activity of Cannabined receptor and therefore available what treats the receptor-mediated illness of CB2,The receptor-mediated illness of CB2 for example,Osteoarthritis； Pain； Hyperalgia； Allodynia； Inflammatory hyperalgesia； Neuropathic hyperalgesia； Acute nociception； Osteoporosis； Spasticity related with multiple sclerosis； Autoimmune conditions； Allergic response； CNS inflammation,Such as atherosclerosis； Undesirable immunocyte activity,And inflammation related with illness selected from the following: osteoarthritis,Allergic reaction,Behcet's disease,Transplant rejection,Vasculitis,Gout,Spondylitis,Viral disease,Bacteriosis,Lupus,Inflammatory bowel disease,Oneself immunity hepatitis and type 1 diabetes； Age-related macular degeneration； Cough； Leukaemia； Lymthoma； Cns tumor； Prostate cancer； Alzheimer disease； The damage of stroke induction； It is dull-witted； Amyotrophic lateral sclerosis； And Parkinson's disease.本發明涉及(1aS,5aS)‑2‑(4‑氧‑吡嗪‑2‑基)‑1a,2,5,5a‑四氫‑1H‑2,3‑二氮雜‑環丙并[a]并環戊二烯‑4‑甲酸((S)‑1‑羥基甲基‑2,2‑二甲基‑丙基)‑酰胺(化合物1)的晶形及其藥物組合物，所述晶形和組合物調節大麻素受體的活性並因此可用於治療CB2受體介導的病症，所述CB2受體介導的病症例如，骨關節炎；疼痛；痛覺過敏；異常性疼痛；炎性痛覺過敏；神經性痛覺過敏；急性傷害感受；骨質疏鬆症；與多發性硬化症有關的痙攣狀態；自身免疫性病症；變應性應答；CNS炎症，例如動脈粥樣硬化；不期望的免疫細胞活動，以及與選自以下的病症有關的炎症：骨關節炎、過敏性反應、貝切特氏病、移植排異、血管炎、痛風、脊椎炎、病毒性疾病、細菌性疾病、狼瘡、炎性腸病、自身免疫性肝炎和1型糖尿病；年齡相關性黃斑變性；咳嗽；白血病；淋巴瘤；CNS腫瘤；前列腺癌；阿爾茨海默病；卒中誘導的損傷；痴呆；肌萎縮性側索硬化；以及帕金森病。
