Claims for Patent: 7,906,542

Summary for Patent: 7,906,542

Title:	Pharmaceutical compositions comprising polymorphic forms .alpha., .beta., and .gamma. of rifaximin
Abstract:	Crystalline polymorphous forms of rifaximin (INN), referred to as rifaximin .alpha. and rifaximin .beta., and a poorly crystalline form referred to as rifaximin .gamma., 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.
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:	12/119,622
Patent Litigation and PTAB cases:	See patent lawsuits and PTAB cases for patent 7,906,542
Patent Claims:	1. A pharmaceutical composition comprising rifaximin in polymorphic Form .alpha. and a pharmaceutically acceptable excipient or carrier, 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 after administration to a patient, the observed plasma concentration of rifaxmin is no more than about 2.6 ng/ml. 2. The pharmaceutical composition of claim 1, wherein the polymorph Form .alpha. has a water content of about 2% to about 3%. 3. The pharmaceutical composition of claim 1, wherein the excipient is selected from the group consisting of a diluting agent, a binding agent, a lubricating agent, a disintegrating agent, a coloring agent, a flavoring agent, and a sweetening agent. 4. The pharmaceutical composition of claim 1, wherein the composition is formulated for selected coated and uncoated tablets, hard and soft gelatin capsules, sugar-coated pills, lozenges, wafer sheets, pellets and powders in a sealed packet. 5. The pharmaceutical composition of claim 1, wherein after administration to a patient, the t.sub.max of the Form .alpha. is about 9.5 hours. 6. The pharmaceutical composition of claim 1, wherein after administration to a patient, the AUC.sub.0-24 h of the Form .alpha. is about 13 ngh/ml. 7. The pharmaceutical composition of claim 2, wherein after administration to a patient, the t.sub.max of the Form .alpha. is about 9.5 hours. 8. The pharmaceutical composition of claim 2, wherein after administration to a patient, the AUC.sub.0-24 h of the Form .alpha. is about 13 ngh/ml. 9. A pharmaceutical composition comprising rifaximin in polymorphic Form .beta. and a pharmaceutically acceptable excipient or carrier, 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 after administration to a patient, the observed plasma concentration of rifaximin is no more than about 1.1 ng/ml. 10. The pharmaceutical composition of claim 9, wherein the polymorph Form .beta. has a water content of from between greater than about 4.5%. 11. The pharmaceutical composition of claim 9, wherein the excipient is selected from the group consisting of a diluting agent, a binding agent, a lubricating agent, a disintegrating agent, a coloring agent, a flavoring agent, and a sweetening agent. 12. The pharmaceutical composition of claim 9, wherein the composition is formulated for selected coated and uncoated tablets, hard and soft gelatin capsules, sugar-coated pills, lozenges, wafer sheets, pellets and powders in a sealed packet. 13. The pharmaceutical composition of claim 9, wherein after administration to a patient, the t.sub.max of the Form .beta. is about 4 hours. 14. The pharmaceutical composition of claim 9, wherein after administration to a patient, the AUC.sub.0-24 h of the Form .beta. is about 11 ngh/ml. 15. The pharmaceutical composition of claim 10, wherein after administration to a patient, the t.sub.max of the Form .beta. is about 4 hours. 16. The pharmaceutical composition of claim 10, wherein after administration to a patient, the AUC.sub.0-24 h of the Form .beta. is about 11 ngh/ml. 17. The pharmaceutical composition of claim 10, wherein the intrinsic dissolution rate of the Form .beta. is about 0.014 mg/min/cm.sup.2. 18. A pharmaceutical composition comprising rifaximin in polymorphic Form .gamma. and a pharmaceutically acceptable excipient or carrier, 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 after administration to a patient, the observed plasma concentration of rifaximin is no more than about 668 ng/ml. 19. The pharmaceutical composition of claim 18, wherein the intrinsic dissolution rate of the Form .gamma. is about 0.14 mg/min/cm.sup.2. 20. The pharmaceutical composition of claim 18, wherein the polymorph Form .gamma. has a water content of from between about 1% to about 2%. 21. The pharmaceutical composition of claim 18, wherein the excipient is selected from the group consisting of a diluting agent, a binding agent, a lubricating agent, a disintegrating agent, a coloring agent, a flavoring agent, and a sweetening agent. 22. The pharmaceutical composition of claim 18, wherein the composition is formulated for selected coated and uncoated tablets, hard and soft gelatin capsules, sugar-coated pills, lozenges, wafer sheets, pellets and powders in a sealed packet. 23. The pharmaceutical composition of claim 18, wherein after administration to a patient, the t.sub.max of the Form .gamma. is about 2.3 hours. 24. The pharmaceutical composition of claim 20, wherein after administration to a patient, the t.sub.max of the Form .gamma. is about 2.3 hours. 25. The pharmaceutical composition of claim 18, wherein after administration to a patient, the AUC.sub.0-24 h of the Form .gamma. is about 4000 ngh/ml.