Identification of a process impurity formed during synthesis of a nevirapine analogue HIV NNRT inhibitor using LC/MS and forced degradation studies.
Impurities in pharmaceutical products do not enhance the desired therapeutic effect and may, of course, have adverse effects. Impurities must therefore be limited or controlled for quality and safety considerations. Structural identification of an impurity is the first step in understanding the chemistry of its formation and subsequently controlling the impurity. In this article, the chemical structure of an unknown by-product formed during the synthesis of a nevirapine analogue HIV NNRT inhibitor was identified using a combination of low resolution, high resolution and H/D exchange LC/MS and LC/MS/MS. The origin of the impurity was investigated through a series of photo- and oxidative stress studies. It was concluded that this impurity is formed via a side-reaction of the last intermediate with the oxidant used in the synthesis.
Qiu
Fenghe
F
Department of Analytical Sciences, Boehringer Ingelheim Pharmaceuticals Inc., 900 Ridgebury Road, Ridgefield, CT 06877, USA. fenghe.qiu@boehringer-ingelheim.com
Pennino
Scott
S
Busacca
Carl A
CA
Norwood
Daniel L
DL
D002851:Chromatography, High Pressure Liquid; D004340:Drug Contamination; D008027:Light; D013058:Mass Spectrometry; D019829:Nevirapine / Q000031:analogs & derivatives* / Q000032:analysis* / Q000138:chemical synthesis; D016877:Oxidants / Q000737:chemistry; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D010777:Photochemistry; D018894:Reverse Transcriptase Inhibitors / Q000032:analysis* / Q000138:chemical synthesis; D012996:Solutions; D012997:Solvents
D016877:Oxidants; D018894:Reverse Transcriptase Inhibitors; D012996:Solutions; D012997:Solvents; D019829:Nevirapine