Polymorphic forms α, β and γ of rifaximin

US7902206B2 · kind B2 · utility

Assignee

• ALFA WASSERMANN S.P.A. · IT

Inventors

• Giuseppe Claudio Viscomi · Monterotondo, IT
• Manuela Campana · Bologna, IT
• Dario Braga · Bologna, IT
• Donatella Confortini · Bologna, IT
• Vincenzo Cannata · Sasso Marconi, IT
• Paolo Righi · Bologna, IT
• Goffredo Rosini · Bologna, IT

Key dates

• Filing date: May 13, 2008
• Grant date: Mar 8, 2011
• Expiry date: May 13, 2028

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07B2200/13
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

Crystalline polymorphous forms of rifaximin (INN) antibiotic named rifaximin α and rifaximin β, and a poorly crystalline form named rifaximin γ, useful in the production of medicinal preparations containing rifaximin for oral and topical use and obtained by means of a crystallization carried out by hot-dissolving the raw rifaximin in ethyl alcohol and by causing the crystallization of the product by addition of water at a determinate temperature and for a determinate period of time, followed by a drying carried out under controlled conditions until reaching a settled water content in the end product, are the object of the invention.