The present invention relates to the crystalline base of the well known antidepressant drug escitalopram, S-1-[3-(dimethylamino)propyl]-1-(4-fluorophenyl)-1,3-dihydro-5-isobenzo-f- urancarbonitrile, formulations of said base, a process for the preparation of purified salts of escitalopram, such as the oxalate, using the base, the salts obtained by said process and formulations containing such salts, and a process for the preparation of purified escitalopram free base or salts of escitalopram, such as the oxalate, using the hydrobromide, the salts obtained by said process and formulations containing such salts. Finally the present invention relates to an orodispersible tablet having a hardness of at least 22 N and an oral-disintegration time of less than 120 s and comprising an active pharmaceutical ingredient adsorbed onto a water soluble filler wherein the active pharmaceutical ingredient has a melting point in the range of 40-100.degree. C., as well as a method for making such an orodispersible tablet.