Tribenzoatobismuth(III): a new -polymorph.

ABSTRACT

A new polymorph (ß) was obtained for an active pharmaceutical ingredient, bis-muth tribenzoate, [Bi(C(6)H(5)CO(2))(3)]. The new ß-polymorph is 1.05 times denser than the previously known polymorph [Rae et al. (1998 ▶). Acta Cryst. B54, 438-442]. In the ß-polymorph, the Bi atom is linked with three benzoate anions, each of them acting as a bidentate ligand, and these assemblies with C(3) point symmetry can be considered as 'mol-ecules'. The structure of the ß-polymorph has no polymeric chains, in contrast to the previously known polymorph. The 'mol-ecules' in the ß-polymorph are stacked along [001], so that the phenyl rings of the neighbouring mol-ecules are parallel to each other. Based on the pronounced difference in the crystal structures, one can suppose that two polymorphs should differ in the dissolution kinetics and bioavailability.