Novel crystalline forms of gatifloxacin

Abstract

Provided are novel crystalline forms of gatifloxacin denominated forms A, B, C, D, E1, F, G, H, I, and J, and methods for their preparation. Also provided are methods for making known crystalline forms of gatifloxacin, in particular forms omega and T2RP.

1 - 98 . (canceled)  
     
     
         99 . A method of making gatifloxacin crystalline form omega comprising the steps of: 
 a) providing a filtered solution of gatifloxacin in acetonitrile, wherein the solution has a water content of about 5 wt % or less, at reflux,    b) cooling the solution to a seeding temperature of about 50° to about 56° C.    c) seeding the solution with gatifloxacin at the seeding temperature,    d) cooling the seeded solution, and    e) isolating the crystalline gatifloxacin crystalline form omega.    
     
     
         100 . The method of  claim 99  wherein the solution of gatifloxacin in acetonitrile has a water content of about 4.5 wt % or less.  
     
     
         101 . The method of  claim 99  wherein the solution is held at the seeding temperature for a seeding time of at least about 30 minutes.  
     
     
         102 . The method of  claim 99  wherein the seeded solution is cooled to a temperature of 5° C. or below.  
     
     
         103 . A method of making crystalline gatifloxacin form omega comprising the step of heating form J at about 90° to about 170° C. and atmospheric pressure.  
     
     
         104 . The method of  claim 103  wherein the heating is at about 120° C.  
     
     
         105 . A method of making gatifloxacin form omega comprising the step of heating form E1 at about 70°-170° C.  
     
     
         106 . The method of  claim 105  wherein the treating is at about 100° C.  
     
     
         107 . A method of making gatifloxacin form omega comprising the step of heating gatifloxacin form G at about 100°-150° C.  
     
     
         108 - 131 . (canceled)  
     
     
         132 . The method of  claim 99 , wherein the gatifloxacin crystalline form omega has a water content of from about 0.2 to about 0.3 percent by weight.