title: Quantitative proton nuclear magnetic resonance for the structural and quantitative analysis of atropine sulfate.
abstract: This study assessed a general method of quantitative nuclear magnetic resonance (qNMR) for the calibration of atropine sulfate (Active Pharmaceutical Ingredient, API) as reference standard. The spectra were acquired in D2O using maleic acid as the internal standard. Conformational behaviors of tropane ring were observed and studied by means of NMR and ROESY experiments at different temperature, which showed that the azine methyl group was at equilibrium for axial and equatorial conformations at room temperature. Signal delay and monitor signals of qNMR experimentation were optimized for quantification. The study reported here validated the method's linearity, range, limit of quantification, stability and precision. The results were consistent with the results obtained from mass balance approach.
authors.affiliation: National Institute for Food and Drug Control, Beijing 100050, People's Republic of China; National Institute for Nutrition and Food Safety, Chinese Center for Disease Control and Prevention, Beijing 100050, People's Republic of China. Electronic address: shenshiss@126.com.
authors.forename: Shi
authors.initials: S
authors.lastname: Shen
authors.affiliation: National Institute for Food and Drug Control, Beijing 100050, People's Republic of China.
authors.forename: Jing
authors.initials: J
authors.lastname: Yao
authors.affiliation: National Institute for Food and Drug Control, Beijing 100050, People's Republic of China. Electronic address: shiyq@nicpbp.org.cn.
authors.forename: Yaqin
authors.initials: Y
authors.lastname: Shi
mesh_terms: D001285:Atropine / Q000737:chemistry*; D002138:Calibration; D004355:Drug Stability; D057230:Limit of Detection; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D011522:Protons
chemical_list: D011522:Protons; D001285:Atropine
keywords: Atropine sulfate; Conformational isomer; Reference standard; VT-NMR; qNMR