title: Quantification of phenytoin and its metabolites in equine plasma and urine using high-performance liquid chromatography.
abstract: A reliable and sensitive method for the extraction and quantification of phenytoin (5,5'-diphenylhydantoin), its major metabolite, 5-(p-hydroxyphenyl)-5-phenylhydantoin (p-HPPH) and minor metabolite, 5-(m-hydroxyphenyl)-5-phenylhydantoin (m-HPPH) in horse urine and plasma is described. The method involves the use of solid-phase extraction (SPE), liquid-liquid extraction (LLE), enzyme hydrolysis (EH) and high-performance liquid chromatography (HPLC). The minor metabolite, 5-(m-hydroxyphenyl)-5-phenylhydantoin (m-HPPH) was not present in a reliably quantifiable concentration in all samples. The new method described was successfully applied in the pharmacokinetic studies and elimination profile of phenytoin and p-HPPH following oral or intravenous administration in the horse.
authors.affiliation: University of Pennsylvania School of Veterinary Medicine Department of Clinical Studies, Kennett Square 19348, USA.
authors.forename: F
authors.initials: F
authors.lastname: Guan
authors.forename: C E
authors.initials: CE
authors.lastname: Uboh
authors.forename: L R
authors.initials: LR
authors.lastname: Soma
authors.forename: E K
authors.initials: EK
authors.lastname: Birks
authors.forename: D
authors.initials: D
authors.lastname: Teleis
authors.forename: J A
authors.initials: JA
authors.lastname: Rudy
authors.forename: A O
authors.initials: AO
authors.lastname: Watson
authors.forename: D S
authors.initials: DS
authors.lastname: Tsang
mesh_terms: D000818:Animals; D002138:Calibration; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D006736:Horses; D010672:Phenytoin / Q000097:blood / Q000493:pharmacokinetics* / Q000652:urine; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D010672:Phenytoin