Determination Of Candesartan Cilexetil And Its Related Substances

A simple and rapid method has been proposed for the quantitative determination of candesartan cilexetil and related substances by HPLC. A inertsil C8-3250×4.6mm 5μ chromatographic column was used with the mobile phase of the buffer solution (0.01M/L two sodium hydrogen phosphate, adjust pH 6.0 with 10% phosphoric acid solution)-acetonitrile (30:70 v/v), determine the content of candesartan cilexetil at the detection wavelength of 254nm; This mathod is validated by some experimentation including linearity, precision, stability, repeatability, repetition and so on. At the same time the changes of the determination results with different conditions of mobile phase were evaluated, the pH of the mobile phase, proportion of mobile phase, flow rate were also evaluated. The results show that:The calibration curves of candesartan cilexetil were linear in the range of 0.05994mg-0.13986mg/mL, r=0.99998, the regression equation was y= 15896x-2.2; the average recovery rate (n=9) was 99.89%, the relative standard deviation was 0.14%. The method is a simple, accurate, rapid, high stabile method, and has successfully been applied for the determination of candesartan cilexetil. In this paper,6 kinds of impurities in synthetic mother liquor of candesartan cilexetil were analysised by liquid chromatography-mass spectrometry, infer the structure of three impurity. A method has been proposed for the determination of related substances in candesartan cilexetil.A inertsil C8-3 250 ×4.6mm 5μ. chromatographic column was used with the mobile phase of different ratios of buffer solution (A) (0.01M/L two sodium hydrogen phosphate, adjust pH 6.0 with 10% phosphoric acid solution)-acetonitrile (B).six impurity, the single largest unknown impurities and total impurities in candesartan cilexetil were determined at the detection wavelength of 215nm. In this paper, the results of different mobile phase composition, pH of the mobile phase adjustment, mobile phase gradient change situation were compared, in addition six impurities were positioning, suspicious impurities found in the experiment were analyzed and discussed. The results show that:The calibration curves of the determination of candesartan cilexetil impurities were linear in 0.3084-0.7196 (A g/mL, r=0.99985,the regression equation is y= 44.066x+0.29. peak area reproducibility of RSD is 0.94%, intermediate precision RSD is 0%. The method is simple, accurate, rapid, high stabile method,and is suitable for the determination of candesartan cilexetil six impurities, the biggest single impurities and total impurities in candesartan cilexetil...