Evaluation of Process Impurities and Degradants of Sitagliptin Phosphate by Validated Stability Indicating RP-LC Method

摘要

A new stability-indicating high-performance liquid chromatographic method has been developed for evaluation of degradants, starting materials and process related impurities during the synthesis of sitagliptin phosphate (SIT-P). Separations were achieved on a RP C_(18) column with linear gradient elution of 0.02 M phosphate buffer at pH 7 and acetonitrile as mobile phase constituents. The flow rate was 1 mL/min and photodiode array detector wavelength was set at 210 nm. Method development was carried in order to elute all starting materials, intermediates during reaction monitoring of stage wise synthesis. Sitagliptin phosphate was subjected for stress conditions like acidic and basic hydrolysis, oxidative, photolytic, neutral and thermal degradation and > 95 % mass balance was achieved, thus ensuring stability indicating capability of the method. Major degradants raised due to acid and base stress were studied by LCMS, identified as Imp-1 (m/z 193.0) and Imp-4 (m/z. 234.20), synthesized and subsequently validated along with all other process related impurities as per ICH with respect to specificity, precision, linearity, LOD, LOQ, accuracy, ruggedness and robustness.