ABSTRACT
OBJECTIVE:To isolate and purify three principal degraded impurities of mitiglinide calcium (impurity A,B,C) and identify their structures,establish HPLC method for content determination of impurity A,B,C. METHODS:Mitiglinide calci-um was used as raw material and reacted with acid;3 impurities were then separated by HPLC and their structures were elucidated by IR,MS,1H NMR,13C NMR,LC-ESI-MS and ORD. 3 impurities of 3 batches of mitiglinide calcium were determined,and the determination was performed on Agilent Extend-C18 column with mobile phase consisted of 0.01 mol/L sodium acetate solution-ace-tonitrile-triethylamine(60:40:0.1,pH=3.0)at the flow rate of 1.0 ml/min. The detection wavelength was set at 210 nm and sam-ple size was 20 μl. The response tests of 3 impurities and mitiglinide calcium were conducted. RESULTS:After treated with acid, impurity A,B,C had been obtained,and their purity were 99.05%,98.87%,99.98%,respectively after isolation and purifica-tion;after identifying the structure, 3 impurities were S-2-bezylsuccinic acid, S-2-bezylsuccinic acid-4-methyl ester, methyl (2S)-2-benzyl-3-(cis-hexahydroisoindolin-2-ylcarbonyl) propionate;methodological study of content determination of impurities were all up to the requirement. The linear range of impurity A,B,C were 0.387 5-3.875,0.395-3.95 and 0.392 5-3.925 μg/ml(all r were 1.000 0). The response value of impurity A,B,C and mitiglinide calcium were 2.316 1,2.636 1,2.617 8 and 2.620 4,re-spectively. CONCLUSIONS:The structures of 3 principal degraded impurities of mitiglinide calcium have been identified and con-firmed;the content of them can be determined by HPLC main component self-comparison method.