Serum concentrations of phenytoin after oral administration in rats

Phenytoin (115 mg/kg) was given orally to rats in order to determine serum concentration levels of the drug. It was found that the peak concentration in serum was 8 micrograms/ml 1 h postadministration , with little variation being noted for up to 8 h. The relevance of these findings in terms of behavioral studies is discussed.