Process for annealing amorphous atorvastatin
Processes for annealing amorphous atorvastatin is described. Pharmaceutical compositions and formulations containing annealed amorphous atorvastatin are also described.
1. A process for annealing amorphous atorvastatin at elevated temperature comprising heating at ambient pressure amorphous atorvastatin in an essentially solvent-free system wherein no additional solvent is added to a temperature of between approximately 50° C. to approximately 140° C.; holding said temperature for approximately 30 minutes to approximately 12 hours; and cooling the resulting annealed amorphous atorvastatin.
2. The process of claim 1 , wherein said temperature is between approximately 80° C. to approximately 110° C.
3. The process of claim 1 , wherein said temperature is between approximately 90° C. to approximately 105° C.
4. The process of claim 1 , wherein said time is between approximately 1 and 6 hours.
5. The process of claim 1 , wherein said heating-holding-cooling cycle is repeated two or more times.
6. The process of claim 1 , wherein said amorphous atorvastatin is amorphous atorvastatin calcium.