RT Journal Article
SR Electronic
T1 Application of hyphenated LC/NMR and LC/MS techniques in rapid identification of in vitro and in vivo metabolites of iloperidone.
JF Drug Metabolism and Disposition
JO Drug Metab Dispos
FD American Society for Pharmacology and Experimental Therapeutics
SP 951
OP 964
VO 23
IS 9
A1 A E Mutlib
A1 J T Strupczewski
A1 S M Chesson
YR 1995
UL http://dmd.aspetjournals.org/content/23/9/951.abstract
AB Iloperidone, 1(-)[4(-)[3(-)[4-(6-fluro-1,2-benzisoxazol-3-yl)-1- piperidinyl]propoxy]-3-methoxyphenyl]ethanone, is currently undergoing clinical trials as a potential antipsychotic agent. Iloperidone was found to be extensively metabolized to a number of metabolites by rats, dogs, and humans. LC/MS/MS was used to characterize and identify metabolites of iloperidone present in complex biological mixtures obtained from all three species. Identification of some of the unknown metabolites in rat bile was achieved successfully by combination of LC/NMR and LC/MS with a minimum amount of sample cleanup. The utility of coupling a semipreparative HPLC to LC/MS instrument for further characterization of collected metabolites was demonstrated. It was shown that iloperidone was metabolized by O-dealkylation processes to yield 6-fluoro-3(-)[1-(3-hydroxypropyl)-4-piperidinyl]-1,2-benzisoxazole and 1(-)[4(-)[3(-)[4-(6-fluoro-1,2-benzisoxazol-3-yl)-1- piperidinyl]propoxy]-2-hydroxyphenyl]ethanone. Oxidative N-dealkylation led to the formation of 6-fluoro-3-(4-piperidinyl)-1,2-benzisoxazole and a secondary metabolite, 3(-)[(4-acetyl-2-methoxy)phenoxy]propionic acid. Iloperidone was reduced to produce 4(-)[3(-)[4-(6-fluoro-1,2-benzisoxazol-3-yl)-1-piperidinyl]- propoxy]-3-methoxy-alpha-methylbenzenemethanol as the major metabolite in humans and rats. Hydroxylation of iloperidone produced 1(-)[4(-)[3(-)[4-(6-fluoro-1,2-benzisoxazol-3-yl)-1- piperidinyl]propoxy]-2-hydroxy-5-methoxyphenyl]ethanone and 1(-)[4(-)[3(-)[4-(6-fluoro-1,2-benzisoxazol-3-yl)-1-piperidinyl]-3 -methoxyphenyl]propoxy]-2-hydroxyethanone, the later of which was found to be the principal metabolite in dogs. The identities of all these metabolites were established by comparing the LC/MS retention times and mass spectral data with synthetic standards.