process for the production of methanesulfonate ralfinamide salts or their r-enantiomers. The invention relates to a novel process for the production and / or purification of the salt of the compound 2- (4- (2-fluorobenzyloxy) benzylamino] propanamide, i.e. ralfinamide, or the respective r-enantiomer, with acid). methanesufonic in high yields and very high enantiomeric and chemical purity in the form of the crystalline anhydrous polymorph identified as form a, wherein said salt is substantially free of impurities having geotoxic effect such as (c1-c5) alkyl methanesulfonate (s), and residual solvents known as precursors thereof, such as (c1-c5) alkyl methanesulfonate (s), and residual solvents known as precursors thereof, such as (c1-c5) alkanol (s) or ester (s) thereof with alkanoic acid (s) ) lower (s). the process provides (i) salt production and / or crystallization of water, acetone, an aliphatic ketone of 4-5 carbon atoms, or mixtures thereof with water, or ii) solidification of the solid salt with (a) water, ( b) a mixture of water with acetone, or an aliphatic ketone of 4-5 carbon atoms, (c) acetone, an aliphatic ketone of 4-5 carbon atoms, or a mixture thereof, or (iii) solid salt exposure air flow having a high degree of relative humidity and, when the product obtained consists wholly or in part, of immediately crystalline pseudopolymorph form crystals, converting said product into anhydrous form crystals, subjecting them to removal of Water. The pseudopolymorph h form of crystalline ralfinamide methanesulfonate hemihydrate, or r-enantiomer, is a useful intermediate for obtaining the crystalline anhydrous polymorph free of the above impurities, having genotoxic effect and / or residual solvents known as precursors thereof, and exhibit a physicochemical profile that confers significant advantages in the design and development of solid dosage forms, in particular modified release formulations.processo para a produção de sais de ralfinamida metanossulfonato ou
