Structural studies of racecadotril and its process impurities by NMR and mass spectroscopy.
Three unknown impurities in racecadotril bulk drug at levels below 0.5% were detected by simple reverse phase isocratic high performance liquid chromatography (HPLC). Structures for these impurities were proposed by molecular ion information and their fragmentation pattern obtained by LC-MS and these impurities were confirmed by NMR spectroscopy. The impurities I, II and III were characterized as benzyl 2-methyl carboximido acetate, benzyl 2-phenyl ethyl carboximido acetate, and benzyl 2-(1-benzyl vinyl carboximido) acetate. These structures were further confirmed by co-injecting of synthetic standards of impurities with racecadotril. The mechanism of the formation of these process related impurities is discussed.
Reddy
K Mallikarjun
KM
Department of Analytical Research, Discovery Research, Dr. Reddy's Laboratories Ltd., Miyapur, Hyderabad, India.
Babu
J Moses
JM
Sudhakar
P
P
Sharma
M S P
MS
Reddy
G Sudershan
GS
Vyas
K
K
D002851:Chromatography, High Pressure Liquid; D004340:Drug Contamination; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D021241:Spectrometry, Mass, Electrospray Ionization; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared; D015244:Thiorphan / Q000031:analogs & derivatives* / Q000032:analysis
C049331:racecadotril; D015244:Thiorphan