The invention relates to a novel process for the manufacture of substituted enantiopure 10hydroxy-dihydrodibenz[b,f]azepines (Ia), (Ib) wherein each of R1 and R2, independently, are hydrogen, halogen, amino or nitro; and each of R3 and R4, independently, are hydrogen or C1-C6alkyl; by transfer hydrogenation of 10-oxo-dihydrodibenz[b,f]azepines; and to novel catalysts of formula (III′a) and (III′b) wherein M is Ru, Rh, Ir, Fe, Co or Ni; L1 is hydrogen; L2 represents an aryl or aryl-aliphatic residue; and the further radicals have the meanings as defined herein; and to new crystal forms of both enantiomers of 10,11-dihydro-10 hydroxy-5Hdibenz[b,f]azepine-5-carboxamide, obtainable by the new processes, their usage in the production of pharmaceutical preparations, new pharmaceutical preparations comprising these new crystal forms and/or the use of these new crystal forms in the treatment of disorders such as epilepsy, or in the production of pharmaceutical formulations which are suitable for this treatment.