| Polymorphism in Acitretin Luciana Malpezzia, Elisabetta Brennaa, Claudio Fugantia, Norberto Masciocchib, Cesare Pellegattac, and Gianpiero Ventimigliaa Dipartimento di Chimica, Materiali ed Ingegneria Chimica “G. Natta” del Politecnicoa, Milano, Dipartimento di Scienze Chimiche ed Ambientali, Universita dell’Insubriab, Como, and Laboratori SOLMAGc, Garbagnate Milanese (Italy)
Yellow polycrystalline powders of acitretin (CAS 54757-46-9), a synthetic retinoid for oral use, have been crystallised by different methods, and, through a combination of X-ray powder diffraction and thermal analyses, were found to generate three distinct polymorphic phases (named acitretin form I, II and III), depending on the solvent and conditions used in the precipitation process. In addition, it was found that the quantitative solid-state conversion of the standard acitretin material (acitretin form I), deposited in the European Pharmacopoeia, into one of the other polymorphs (acitretin form II) can be achieved upon moderate heating near 200 °C, under vacuum.
Key words Acitretin, polymorphism • CAS 54757-46-9 • Retinoids, X-ray powder diffraction patterns |
