Crystal structures and simulated morphologies of two polymorphs of lornoxicam

The experimental X-ray powder diffraction patterns for two polymorphs of lornoxicam were analyzed by Materials Studio to obtain cell parameters,to establish crystal structures and then to simulate the morphologies.The results demonstrated that form I was triclinic with two kinds of inter-molecular hydrogen bonds,while form II was orthorhombic with two kinds of intra-molecular hydrogen bonds.Based on the attachment energy values calculated,the dominant growth faces were ascertained.The final morphologies of form I and form II were established to be cuboid and ellipsoid，respectively，which were consistent with their scanning electron microscope（SEM） images.