| 摘要 |
The present invention relates to novel crystalline forms of tapentadol oxalate of the general formula II, chemically 3-[(1R,2R)-3-(dimethylamino)-1-ethyl-2-methylpropyl]phenol oxalate. The invention further relates to a process for preparing crystalline form of tapentadol oxalate, which preparation process is characterized by dissolving a tapentadol base in a suitable solvent, adding oxalic acid or a solution thereof thereto and the thus obtained solution is let to crystallize, optionally cooled and/or antisolvent is added, and the crystallized oxalate is then isolated. |
