Crystal Structures of Two New Polymorphic forms of Pinaverium Bromide: a Solvate and a Dihydrate

The polymorphism of pinaverium bromide has been further explored by characterizing two novel crystalline forms: a solvate with isopropanol and a dihydrate. The crystal structures of both forms were determined using single crystal X-ray diffraction. These new forms are compared to the previously reported anhydrous polymorph [1]. All three forms exhibit distinct packing motifs, crystal systems, and intermolecular interactions. The solvate crystallizes in the triclinic system with the inclusion of two isopropanol molecules per asymmetric unit, the dihydrate adopts a triclinic arrangement involving two water molecules in a hydrogen-bonded network. Structural analysis highlights the role of solvent interactions in crystal stabilization and polymorph selection. These findings contribute to a deeper understanding of the solid-state behaviour of pinaverium bromide, a clinically used antispasmodic agent [2, 3].