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US 4,904,776 AGranted
Method for producing crystalline cefadroxil hemihydrate
AssigneeRifar S.R.L.
InventorLeonardo Marsili
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Abstract
The invention relates to a method for producing crystalline cefadroxil hemihydrate. According to the method a cefadroxil solvate is slurried with a mixture methanol:isopropyl alcohol 30:70 to 70:30 by volume containing from 5% to 12% of water, a temperature from +45.degree. C. to +55.degree. C. and then isolating the so obtained crystalline compound.
Claims2
A method for producing crystalline cefadroxil hemihydrate, which comprises:
- (a) adding to an aqueous solution of cefadroxil prepared from 7-ADCA, a solvent selected from the group consisting of dimethylacetamide, N-methyl-2-pyrrolidone and monomethylformamide, while controlling the pH of the solution in the range of 5.5-6.0, to give the corresponding cefadroxil solvate which precipitates and is filtered off and dried, and
- (b) slurrying said dried solvate with a mixture of methanol:isopropyl alcohol 30:70 to 70:30 by volume containing about 5% to 12% of water, at a temperature in the range of about +45.degree. C. to +55.degree. C., wherein after the crystalline cefadroxil hemihydrate obtained is isolated from the reaction mixture.
Dependencies are inferred from the claim text.