Risperidone chloride 2.5-hydrate: a new crystalline form

The asymmetric unit of the title compound, C₂₃H₂₈FN₄O₂⁺·Cl⁻·2.5H₂O, contain one risperidone cation {systematic name: 4-(6-fluoro-1,2-benzisoxazol-3-yl)-1-[2-(2-methyl-4-oxo-3,4,6,7,8,9-hexa­hydro-2H-pyrido[1,2-a]pyrimidin-3-yl)eth­yl]piperidinium}, one Cl⁻ anion, and two and a half water mol­ecules. The piperidine ring adopts a chair conformation, while the tetra­hydro­pyridine ring has a sofa conformation. Each Cl⁻ anion and the water mol­ecules are linked to the risperidone mol­ecules via O—H⋯O, O—H⋯N, O—H⋯Cl and N—H⋯Cl hydrogen bonds which stabilize the crystal packing.