A FOAF recently did another xylene pull from a batch of MHRB that had been sitting around for awhile and thought to be nearly exhausted. He was blown away when close to a gram precipitated after adding FASA. However, these aren't the nice white fumarates gathered during the previous pulls. On the bottom was a layer of orange and very waxy fumarates, and on top were fluffier crystals like the white ones, but very noticeably yellow in color.
Has anyone else had this happen? Can these be used as is, or should they be further purified somehow?
Does anyone have experience using these in pharma? If so, is there any noticeable difference between those and purer crystals?
Has anyone else had this happen? Can these be used as is, or should they be further purified somehow?
Does anyone have experience using these in pharma? If so, is there any noticeable difference between those and purer crystals?