Patent ID: 6441162
Filing Date: 2002-08-27
Classification: A61P,C07D

Abstract:
A crystalline substance of Cefditoren pivoxyl, namely 7-[(Z)-2-(2-aminothiazol) -2-methoxyiminoacetamido]-3-[(Z)-2-(4-methylthiazol-5-yl)ethenyl]-3-cephem -4-carboxylic acid pivaloyloxymethyl ester, characterized in that said crystalline substance of Cefditoren pivoxyl is of orthorhombic form and has a melting point with decomposition at a temperature in a range of 206.2Â° C. to 215.7Â° C. as evaluated from the peak of thermal absorption shown in the heat flow curve of said substance determined by a differential scanning calorimeter, that a single crystal of said crystalline substrate has a density of 1.21 to 1.23 g/cm3 and contains 4 molecules of Cefditoren pivoxyl within a unit lattice of the single crystal, that said crystalline substance has a purity of 97% to 98% for the Cefditoren pivoxyl component as measured by a liquid chromatography with using a reverse phase silica gel column and by detecting with ultra-violet ray absorption at 230 nm, and that said crystalline substance has a higher thermal stability as determined at a temperature of 60Â° for two months or at a temperature of 40Â° for four months than the known amorphous substance of Cefditoren pivoxyl.