nsf d dsv 3 hb nsf subjected to 45 u00b0 c in dry conditions and e dsv 3 hb nsf subjected to 50 u00b0 c in dry conditions fig5 c shows the powder diffractograms obtained from the stability test for a desvenlafaxine base b co former 3 4 dhb c initial dsv 3 4 dhb nsf d dsv 3 4 dhb nsf subjected to 45 u00b0 c in dry conditions e dsv 3 4 dhb nsf subjected to 50 u00b0 c in dry conditions and f dsv 3 4 dhb nsf subjected to 40 u00b0 c with 75 relative humidity from the samples subjected to 40 u00b0 c and 75 humidity it was only possible to characterize the dsv 3 4 dhb nsf by x ray diffraction fig5 c because the other solid forms became hydrated for this reason fig5 a and 5b do not show the corresponding spectra we verified that the same phase was obtained using ethanol as the dissolution medium as an alternative to methanol fig6 a y 6 b show x ray powder diffractograms of the new amorphous solid form dsv 3 4 5 thb obtained in methanol and ethanol respectively these graphs allow confirming the reproducibility of the processes for obtaining the dsv 3 4 5 thb nsf the present invention discloses crystalline nsf formed from dsv and a co former x wherein x possesses one or several hydroxyl groups and a carboxyl group and it can form the new entity through ionic interactions or intermolecular forces such as hydrogen bonding and or van der waals 39 links as well as solvates hydrates and or polymorphs of dsv x co former x is selected from 2 hb 3 hb 4 hb 2 3 dhb 2 4 dhb 2 5 dhb 2.