Valomaciclovir Polymorphs

Abstract

The present invention relates to crystalline forms of valomaciclovir, processes for preparing crystalline forms of valomaciclovir, pharmaceutical compositions thereof and methods of using thereof.

What is claimed is: 
     
         1 . Crystalline valomaciclovir having characteristic absorption peaks at 2θ angles of 22.9°+/−0.2°, 18.6°+/−0.2°, 19.5°+/−0.2°, 24.3°+/−0.2°, 20.8°+/−0.2°, 21.8°+/−0.2°, 27.0°+/−0.2°, 14.7°+/−0.2°, 15.5°+/−0.2°, 25.5°+/−0.2°, and 29.9°+/−0.2° with Cu Kα radiation in a X-ray powder diffractogram. 
     
     
         2 . A pharmaceutical composition comprising crystalline valomaciclovir according to  claim 1  and a pharmaceutically acceptable excipient or diluent. 
     
     
         3 . The crystalline valomaciclovir of  claim 1  which is at least 90% pure. 
     
     
         4 . The crystalline valomaciclovir of  claim 1  which is at least 95% pure. 
     
     
         5 . The crystalline valomaciclovir of  claim 1  which is at least 99% pure. 
     
     
         6 . A process of preparing crystalline valomaciclovir according to  claim 1 , comprising the steps of:
 dissolving valomaciclovir in a lower alkanol solvent or a mixed solvent of lower alkanols by heating to an appropriate internal temperature;   cooling the solution with stirring to effect substantial crystallization of valomaciclovir; and   collecting the crystalline valomaciclovir.   
     
     
         7 . The process of  claim 6 , wherein the lower alkanol solvent is ethanol. 
     
     
         8 . The process of  claim 6 , wherein the mixed solvent of lower alkanols is a mixture of 95:5 (v/v) ethanol/2-propanol. 
     
     
         9 . The process of  claim 6 , wherein the internal temperature is from about 65° C. to about 74° C. 
     
     
         10 . The process of  claim 9 , wherein the internal temperature is from about 68° C. to about 72° C. 
     
     
         11 . The process of  claim 6 , wherein the cooling is at a rate of from about 5° C. to about 15° C. per hour. 
     
     
         12 . The process of  claim 11 , wherein the cooling is at a rate of from about 8° C. to about 12° C. per hour. 
     
     
         13 . A method of treating or preventing a viral infection in a subject comprising administering to the subject in need thereof a therapeutically effective amount of the crystalline compound of  claim 1 . 
     
     
         14 . The method of  claim 13 , wherein the viral infection is a varicella zoster virus infection. 
     
     
         15 . The method of  claim 13 , wherein the viral infection is a herpes simplex virus infection. 
     
     
         16 . The method of  claim 13 , wherein the viral infection is a human herpes virus infection. 
     
     
         17 . The method of  claim 13 , wherein the viral infection is an Epstein Barr virus infection. 
     
     
         18 . The method of  claim 13 , wherein the viral infection is a cytomegalovirus infection. 
     
     
         19 . The method of  claim 13 , wherein the viral infection is a HIV infection.