The invention relates to crystalline forms of (1r,4r)-6’-fluoro-N,N-dimethyl-4-phenyl-4’,9’-dihydro-3’H-spiro[cyclohex ane-1,1’-pyrano[3,4,b]indol]-4-amine, pharmaceutical compositions and medicaments comprising these modifications, the use of these modifications as well as to a process for the enrichment of them.本發明涉及(1r,4r)-6’-氟基-N,N-二甲基-4-苯基-4’,9’-二氫-3’H-螺[環己烷-1,1’-吡喃[3,4,b]吲哚]-4-胺之結晶形式,藥物組合物與藥劑,包含其改質、改質之使用及使其更加豐富之一種方法。