Substantially anhydrous crystalline cefadroxil and method for producing it
AssigneeRifar S.R.L.
InventorLeonardo Marsili
Life of this patent
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Abstract
The invention relates to a substantially anhydrous crystalline cefadroxil having a water content between about 0.8% and 3.9%. Such cefadroxil is obtained slurrying a cefadroxil solvate of dimethylacetamide, or of N-methyl-2-pyrrolidone or of monomethylformamide, with isopropyl alcohol with up to 4% of water and preferably in the presence of methanol in an amount lower than 60%, at a temperature of about +45.degree. C. to +55.degree. C. and then filtering the so obtained compound.
Claims6
A crystalline cefadroxyl compound having a water content of from about 0.8% to about 3.9% and having the following X-ray diffraction data:
- ______________________________________ Spacing d(A) Relative Intensity ______________________________________ 10.42 21 8.54 100 7.06 34 6.38 15 6.05 22 5.84 25 5.12 16 4.79 26 4.58 21 4.35 44 4.26 21 4.18 24 4.02 34 3.90 11 3.78 12 3.52 9 3.46 17 3.27 8 3.18 14 3.12 22 2.93 15 2.89 18 2.82 16 2.61 12 2.55 10 2.52 7 2.35 9 2.30 9 2.18 8 2.13 7 2.08 7 ______________________________________
A method of preparing a crystalline cefadroxyl compound having a water content of from about 0.8% to about 3.9%, and having the following x-ray data:
- ______________________________________ Spacing d(.ANG.) Relative Intensity ______________________________________ 10.42 21 8.54 100 7.06 34 6.38 15 6.05 22 5.84 25 5.12 16 4.79 26 4.58 21 4.35 44 4.26 21 4.18 24 4.02 34 3.90 11 3.78 12 3.52 9 3.46 17 3.27 8 3.18 14 3.12 22 2.93 15 2.89 18 2.82 16 2.61 12 2.55 10 2.52 7 2.35 9 2.30 9 2.18 8 2.13 7 2.08 7 ______________________________________
- comprising:
- a) adding a solvent selected from the group consisting of dimethylacetamide, N-methyl-2-pyrrolidone and monomethylformamide to an aqueous solution of cefadroxyl prepared from 7-ADCA while the pH of the solution is controlled to within the range of 5.5-6 thereby forming a cefadroxyl solvate;
- b) precipitating, isolating and drying said cefadroxyl solvate;
- c) slurrying said dried cefadroxyl solvate in isopropyl alcohol containing (a) from about 2% to 4% water or (b) from 0.1% to 4% water and from 0% to 60% methanol at a temperature in the range of about +45.degree. C. to +55.degree. C.;
- and
- d) isolating said crystalline cefadroxyl compound.
A slurry mixture comprising dried cefadroxil precipitate and a solvent containing at least 40% b.v. of isopropyl alcohol.
Dependencies are inferred from the claim text.