Polymorphic forms of fluvastatin sodium and process for preparing the same

Abstract

Disclosed herein are novel polymorphic forms of Fluvastatin sodium, wherein said polymorphic forms are designated as J F , J F1 , J F2 , J F3 and are characterized by their powder X-ray diffraction patterns, Infrared absorption spectrums, thermo gravimetric analysis and differential scanning calorimetry. The processes for preparing said polymorphic forms are also disclosed. The present invention also relates to process for preparing amorphous form of Fluvastatin sodium.

1 . Novel crystalline forms of Fluvastatin sodium wherein said crystalline forms are pure and stable polymorphic forms designated as J F , J F1 , J F2  and J F3 . 
     
     
         2 . The crystalline form according to  claim 1 , wherein said polymorphic form is J F . 
     
     
         3 . The crystalline form according to  claim 2 , wherein said polymorphic form J F  is having a powder X-ray diffraction pattern comprising characteristic peaks at about 3.3, 3.9, 10.0, 10.9, 17.1, 19.3, 20.6±0.2θ. 
     
     
         4 . The crystalline form according to  claim 2 , wherein said polymorphic form J F  is having a powder X-ray diffraction pattern essentially as depicted in  FIG. 1 . 
     
     
         5 . The crystalline form according to  claim 2 , wherein said polymorphic form J F  is having an infrared spectrum comprising one or more characteristic peaks selected from absorption bands (cm −1 ) at 3399, 2973, 1577, 1500, 1342, 1217, 1154, 1106, 974, 839, 741, 564. 
     
     
         6 . The crystalline form according to  claim 2 , wherein said polymorphic form J F  is having an infrared spectroscopy essentially as depicted in  FIG. 2 . 
     
     
         7 . A process for preparing crystalline polymorphic form J F  of Fluvastatin sodium as claimed in  claim 2 , the process comprising:
 (a) hydrolyzing a lower alkyl ester of Fluvastatin in a solution containing sodium hydroxide in a mixture consisting of water and methanol,   (b) evaporating the methanol from the mixture to obtain residue,   (c) dissolving the residue in methanol and optionally adding water,   (d) adding anti-solvent to precipitate Fluvastatin sodium Form J F , and   (e) isolating the Fluvastatin sodium Form J F .   
     
     
         8 . The process according to  claim 7 , wherein the anti-solvent is selected from ethanol or propanol or mixture thereof. 
     
     
         9 . The process according to  claim 7 , wherein the moisture content of the solution in step (c) is between 3-8% by volume. 
     
     
         10 . A process for preparing crystalline polymorphic form J F  of Fluvastatin sodium as claimed in  claim 2 , the process comprising:
 (a) dissolving Fluvastatin sodium in methanol and optionally adding water,   (b) adding anti-solvent to precipitate Fluvastatin sodium Form J F , and   (c) isolating the Fluvastatin sodium Form J F .   
     
     
         11 . The process according to  claim 10 , wherein the anti-solvent is selected from ethanol or propanol or mixture thereof. 
     
     
         12 . The process according to  claim 10 , wherein the moisture content of the solution in step (a) is between 3-8% by volume.