Pharmaceutical compositions comprising polymorphic forms α, β, and γ of rifaximin

US7906542B2 · 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 15, 2011
• Expiry date: Dec 8, 2028

Classification

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

Abstract

Crystalline polymorphous forms of rifaximin (INN), referred to as rifaximin α and rifaximin β, and a poorly crystalline form referred to as rifaximin γ, useful in the production of medicaments containing rifaximin for oral and topical use and obtained by means of a crystallization process 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 fixed temperature and for a fixed period of time, followed by a drying under controlled conditions until reaching a precise water content in the end product, are the object of the invention.