The effects of 5,5-diphenylbarbituric acid on experimental seizures in rats: correlation between plasma and brain concentrations and anticonvulsant activity.

Diphenylbarbituric acid was administered by gavage to male albino Sprague-Dawley rats for evaluation of anticonvulsant activity and analysis of blood plasma and brain drug concentrations. A method for gas-liquid chromatographic analysis of blood plasma and brain for diphenylbarbituric acid is described. The drug was effective in the maximum electroshock test and as an antagonist to clonic seizures and death produced by pentylenetetrazol. Brain concentrations associated with 50 to 70% protection in the maximum electroshock seizure test were of the order of 2 to 6 mug/g of brain and are thus equal to values for phenobarbital in this test. Large doses of diphenylbarbituric acid (up to 2,800 mg/kg) failed to produce signs of neurotoxicity. The results of the present investigation continue to indicate that diphenylbarbituric acid exhibits promise as a potential antiepileptic agent.