A polymorphic form referred to as the monohydrochloride of 2 - ((1 - (2 - (4-fluorophenyl) - 2-oxoethyl) piperidin-4-yl yl) methyl) - 1 - isoindolin Ona Dihydrate, also known as the () of the compound (i). Hcl.2h2o where the form includes Peaks of x-ray Powder diffraction (Theta) 2 Which are: 7.6\u00b0, 11.2\u00b0, 14.3\u00b0, 14.7\u00b0, 14.9\u00b0, 18.6\u00b0, 22.0\u00b0, 25.9\u00b0 27.5\u00b0 and 30.1\u00b0.It also relates to a Pharmaceutical composition useful for the treatment of schizophrenia.Referido a una forma polimorfica A, tal como el monoclorhidrato de 2-((1-(2-(4-fluorofenil)-2-oxoetil) piperidin-4-il)metil)isoindolin-1-ona dihidratado, denominado tambien como la Forma (A) del compuesto (I).HCl.2H2O donde dicha forma comprende picos de difraccion de rayos X en polvo 2(theta) los cuales son: 7.6°, 11.2°, 14.3°, 14.7°,14.9°, 18.6°, 22.0°, 25.9° 27.5° y 30.1°. Tambien se refiere a una formulacion farmaceutica util en el tratamiento de la esquizofrenia.
