title: Polymorphism of rifampicin.
abstract: The antibiotic rifampicin shows polymorphism. Two crystalline forms, an amorphous form and four solvates (S I and S II from water; S III from tetrahydrofuran; S IV from carbon tetachloride) have been isolated and characterized by thermal analysis, infrared and X-ray powder spectroscopy. The functional I.R. bands have been interpreted as indicative of some structural features involved in the polymorphism: the intramolecular H-bonds between C23--OH and O=C--O--C25, C4--OH and O=C11, and C1--OH and O=C15. The relative physical stabilities of the various forms are reported.
mesh_terms: D003460:Crystallization; D004355:Drug Stability; D011110:Polymorphism, Genetic; D012293:Rifampin / Q000032:analysis*; D013055:Spectrophotometry, Infrared; D013696:Temperature; D014961:X-Ray Diffraction
chemical_list: D012293:Rifampin