title: Structural elucidation of potential impurities in Azilsartan bulk drug by HPLC.
abstract: During the synthesis of Azilsartan (AZS), it was speculated that 15 potential impurities would arise. This study investigated the possible mechanism for the formation of 14 of them, and their structures were characterized and confirmed by IR, NMR, and MS techniques. In addition, an efficient chromatographic method was developed to separate and quantify these impurities, using an Inertsil ODS-3 column (250 x 4.6 mm, 5 pm) in gradient mode with a mixture of acetonitrile and the potassium dihydrogen orthophosphate buffer (10 mM, pH adjusted to 3.0 with phosphoric acid). The HPLC method was validated for specificity, precision, accuracy, and sensitivity. LOQ of impurities were in the range of 1.04-2.20 ng. Correlation coefficient values of linearity were >0.9996 for AZS and its impurities. The mean recoveries of all impurities in AZS were between 93.0 and 109.7%. Thus, the validated HPLC method is suitable for the separation and quantification of all potential impurities in AZS.
authors: Wentao
authors: W
authors: Zhou
authors: Yuxia
authors: Y
authors: Zhou
authors: Lili
authors: L
authors: Sun
authors: Qiaogen
authors: Q
authors: Zou
authors: Ping
authors: P
authors: Wei
authors: Pingkai
authors: P
authors: Ouyang
mesh_terms: D001562:Benzimidazoles / Q000032:analysis* / Q000737:chemistry; D002021:Buffers; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004340:Drug Contamination; D057230:Limit of Detection; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D010069:Oxadiazoles / Q000032:analysis* / Q000737:chemistry; D013055:Spectrophotometry, Infrared
chemical_list: D001562:Benzimidazoles; D002021:Buffers; D010069:Oxadiazoles; C521273:azilsartan