Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1984-7-20
pubmed:abstractText
A gas chromatographic method was developed for the determination of the R- and S- enantiomers of the anticonvulsant, mephenytoin, and its N-demethylated metabolite, 5-phenyl-5- ethylhydantoin ( PEH ), in plasma and blood. Direct enantiomeric separation of mephenytoin and its internal standard was obtained using a chiral capillary column ( Chirasil -Val) followed by nitrogen specific detection. However, resolution of the enantiomers of PEH and its internal standard required propylation at the 3-position of the hydantoin ring prior to analysis. Similar linear and reproducible standard curves were obtained from both plasma and blood over the concentration range 50 ng/ml to 5 micrograms/ml, and above 100 ng/ml the reproducibility was less than 8% (coefficient of variation). Pronounced stereoselective differences in the plasma concentration--time curves for both mephenytoin and PEH were observed in a normal subject who received a single oral dose of 300 mg racemic mephenytoin. The peak plasma level of S-mephenytoin was only one-fifth that of the R-enantiomer and its elimination half-life was less than 3 h compared to over 70 h for R-mephenytoin. Similarly, S- PEH levels were barely detectable whereas concentrations of R-metabolite steadily increased over 4-6 days before slowly declining.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0021-9673
pubmed:author
pubmed:issnType
Print
pubmed:day
13
pubmed:volume
307
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
121-7
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1984
pubmed:articleTitle
Direct enantiomeric resolution of mephenytoin and its N-demethylated metabolite in plasma and blood using chiral capillary gas chromatography.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.