Identification and structural characterization of in vivo metabolites of ketorolac using liquid chromatography electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS).
In vivo metabolites of ketorolac (KTC) have been identified and characterized by using liquid chromatography positive ion electrospray ionization high resolution tandem mass spectrometry (LC/ESI-HR-MS/MS) in combination with online hydrogen/deuterium exchange (HDX) experiments. To identify in vivo metabolites, blood urine and feces samples were collected after oral administration of KTC to Sprague-Dawley rats. The samples were prepared using an optimized sample preparation approach involving protein precipitation and freeze liquid separation followed by solid-phase extraction and then subjected to LC/HR-MS/MS analysis. A total of 12 metabolites have been identified in urine samples including hydroxy and glucuronide metabolites, which are also observed in plasma samples. In feces, only O-sulfate metabolite and unchanged KTC are observed. The structures of metabolites were elucidated using LC-MS/MS and MS(n) experiments combined with accurate mass measurements. Online HDX experiments have been used to support the structural characterization of drug metabolites. The main phase I metabolites of KTC are hydroxylated and decarbonylated metabolites, which undergo subsequent phase II glucuronidation pathways.
National Centre for Mass Spectrometry, Indian Institute of Chemical Technology, Hyderabad, 500 007, India.
B
B
Raju
M
M
Ramesh
Roshan M
RM
Borkar
Raju
R
Padiya
Sanjay K
SK
Banerjee
R
R
Srinivas
D000818:Animals; D002853:Chromatography, Liquid / Q000379:methods*; D041961:Deuterium Exchange Measurement; D005243:Feces / Q000737:chemistry; D020910:Ketorolac / Q000032:analysis / Q000737:chemistry* / Q000378:metabolism* / Q000493:pharmacokinetics; D008297:Male; D008958:Models, Molecular; D051381:Rats; D017207:Rats, Sprague-Dawley; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D053719:Tandem Mass Spectrometry / Q000379:methods
D020910:Ketorolac