917805-80-2Relevant academic research and scientific papers
PROCESS FOR PREPARING AMORPHOUS ROSUVASTATIN CALCIUM FREE OF IMPURITIES
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Page/Page column 14; 16, (2008/06/13)
A pure amorphous form of rosuvastatin calcium having purity of more than 99.5%, preferably a purity of more than 99.8%, more preferably a purity of more than 99.9% as determined by HPLC area percentage, and free from any traces of alkali metal impurities is disclosed. A process of preparing said pure amorphous form of rosuvastatin calcium is disclosed, which comprises hydrolysis of C1-C5 alkyl esters of rosuvastatin, preferably terf-butyl ester of rosuvastatin, with an organic nitrogen base, e.g. guanidines, amidines, amines and quaternary ammonium hydroxides, in the presence of water, optionally containing aprotic solvent, following the conversion of thus obtained rosuvastain salt with a source of calcium to desired rosuvastatin calcium, which is then isolated. An alternative process is disclosed, which comprises the conversion of numerous novel ammonium salts of rosuvastatin, preferably tert-octylammonium salt of rosuvastatin, with the source of calcium to desired commercial rosuvastatin calcium.. Rosuvastatin calcium is HMG CoA reductase, useful in the treatment of hyperlipidemia, hypercholesterolemia and atherosclerosis.
