Polymorphism and solvation of indomethacin characterization of an indomethacin-tetrahydrofuran solvate leading to phase

Abstract

Indomethacin crystallizes from solutions in tetrahydrofuran as a solvate exhibiting the mole ratio 1 indomethacin: 2 tetrahydrofuran. Upon heating, desolvation into indomethacin phase I occurs through partial amorphization and transitory formation of a phase, which is different from the crystallographically known polymorphs. The X-ray powder diffraction pattern of the solvate was tentatively indexed on a triclinic lattice (a = 31.454(5) A, b = 17.883(3) A°, c = 10.551(2) A°, α = 70.55(2)°, ß = 105.31(2)°, y = 136.70(1)°). Assuming Z = 6 (1 indomethacin + 2 tetrahydrofuran) formula units per unit cell, the solvate's specific volume is similar to the value calculated using additivity. © 2009 Akademiai Kiado, Budapest, Hungary.