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Last Updated: December 22, 2024

Claims for Patent: 8,158,781


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Summary for Patent: 8,158,781
Title:Polymorphic forms .alpha., .beta. and .gamma. of rifaximin
Abstract: Crystalline polymorphous forms of rifaximin (INN) antibiotic named rifaximin .alpha. and rifaximin .beta., and a poorly crystalline form named rifaximin .gamma., 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.
Inventor(s): Viscomi; Giuseppe Claudio (Bologna, IT), Campana; Manuela (Bologna, IT), Braga; Dario (Bologna, IT), Confortini; Donatella (Bologna, IT), Cannata; Vincenzo (Bologna, IT), Righi; Paolo (Bologna, IT), Rosini; Goffredo (Bologna, IT)
Assignee: Alfa Wassermann, S.p.A. (Bologna, IT)
Application Number:13/041,332
Patent Litigation and PTAB cases: See patent lawsuits and PTAB cases for patent 8,158,781
Patent Claims: 1. Rifaximin in polymorphic Form .alpha., wherein the rifaximin Form .alpha.has x-ray powder diffraction pattern peaks at about 7.4.degree. ; 19.7.degree. ; 21.0.degree. and 22.1.degree. 2-.theta. and wherein the rifaximin has a water content of between 3.0%-4.5%.

2. The rifaximin of claim 1, wherein the rifaximin Form .alpha. has a water content of 3.0%.

3. The rifaximin of claim 1, wherein the rifaximin Form .alpha. has a water content of 4.5%.

4. Rifaximin in polymorphic Form .beta., wherein the rifaximin Form .beta.has x-ray powder diffraction pattern peaks at about 5.4.degree. ; 9.0.degree. ; and 20.9.degree. 2-.theta. and wherein the rifaximin has a water content of between 4.5%-5.0%.

5. The rifaximin of claim 2, wherein the rifaximin Form .beta. has a water content of 5.0%.

6. Rifaximin in polymorphic Form .gamma., wherein the rifaximin Form .gamma.has x-ray powder diffraction pattern peaks at about 5.0.degree. , 7.1.degree. , and 8.4.degree. 2-.theta. and wherein the rifaximin has a water content of from between 0% to 1%.

7. The rifaximin of claim 5, wherein the rifaximin Form .gamma. has a water content of 0%.

8. The rifaximin of claim 5, wherein the rifaximin Form .gamma. has a water content of 1%.

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