IMPURITY PROFILING STABILITY INDICATING METHOD DEVELOPMENT AND VALIDATION OF LINAGLIPTIN AND LC-MS CHARACTERIZATION OF OXIDATIVE DEGRADATION PRODUCT.

In this research study, we developed a new rapid and simple HPLC quantitative approach for comprehensively measuring related substance impurities (LNGN N formyl; LNGN acetamide; LNGN N Boc; LNGN amino) in Linagliptin. The related substance impurities were studied by PDA detection at 225 nm after being separated on the Kromasil C18 column stationary phase. The isocratic mode elution and a flow velocity of 1.0 mL/min were performed with the 0.1% phosphoric acid having pH 2.5 and acetonitrile. The proposed approach was appropriately verified in agreement with the "International Conference on Harmonization". Linearity was demonstrated for values ranging from LOQ quantity ppm to 150% quantity ppm, with variance coefficients 0.99. The precision varied from 0.128 to 0.969% RSD and accuracy varied from 99.13% to 101.76% for four related substance impurities. The proposed approach was appropriately implemented in the quality control analysis of the linagliptin API. Stress testing on the linagliptin API is also part of this investigation. One degradant with a 10.273 min Rt was found during oxidative stress testing on linagliptin. Using LC-MS this peak was discovered to be an adduct. [ABSTRACT FROM AUTHOR]