Identification of impurities in ivermectin bulk material by mass spectrometry and NMR.
The identification and characterization of four process impurities in bulk ivermectin and four process impurities in bulk avermectin, using a combination of MS and NMR, are discussed herein. These process impurities were shown to be 24-demethyl H2B1a, 3'-demethyl H2B1a, 3''-demethyl H2B1a and 24a-hydroxy B2a isomer. The impurities were shown to be process impurities and are present in avermectin bulk also.
Beasley
Christopher A
CA
Pharmaceutical Research and Development, Merck Research Laboratories, Merck & Co., Inc., WP78-210, West Point, PA 19486, USA.
Hwang
Tsang-Lin
TL
Fliszar
Kyle
K
Abend
Andreas
A
McCollum
David G
DG
Reed
Robert A
RA
D004340:Drug Contamination; D007306:Insecticides / Q000032:analysis* / Q000737:chemistry; D007536:Isomerism; D007559:Ivermectin / Q000031:analogs & derivatives* / Q000032:analysis* / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D013058:Mass Spectrometry / Q000379:methods
D007306:Insecticides; D007559:Ivermectin; C019264:avermectin