Process for forming amorphous atorvastatin
A process for forming amorphous atorvastatin comprising the steps of dissolving atorvastatin in a non-hydroxylic solvent and removing the solvent by freeze-drying, as well as processes of dissolving atorvastatin in a hydroxylic solvent with a solubilizing agent or an alkalizing agent or an antioxidant and removing the solvent by freeze-drying to afford amorphous atorvastatin.
1. The process for forming amorphous atorvastatin comprising:
(a) dissolving atorvastatin in a hydroxylic solvent containing an antioxidant selected from the group consisting of: a chelating agent; a free-radical scavenger, and an oxygen scavenger, or mixture thereof; and
(b) lyophilizing the solution to afford said amorphous atorvastatin.
2. The process of claim 1 wherein the hydroxylic solvent is selected from the group consisting of: water, an alcohol, and mixture thereof.
3. The process of claim 1 wherein the chelating agent is selected from the group consisting of: a citrate; and ethylenediaminetetraacetic acid.
4. The process of claim 1 wherein the free-radical scavenger is selected from the group consisting of: butylated hydroxyanisole and butylated hydroxytoluene and wherein the oxygen scavenger is selected from the group consisting of: sodium ascorbate; and potassium ascorbate.