BLOOD PHENYTOIN CONCENTRATIONS PRODUCED BY INGESTION OF THREE DIFFERENT PHENYTOIN PREPARATIONS

Abstract

A cross-over study was carried out, comparing the blood phenytoin concentrations produced in a series of patients by three different brands of phenytoin capsule. In general, the three preparations proved to be equivalent, but this equivalence did not apply for every individual patient. Because the composition of the excipients in the three preparations differed qualitatively and quantitatively, it seemed likely that none of the excipients was biologically active in altering phenytoin metabolism, though the excipient (calcium sulphate dihydrate) in a phenytoin preparation previously available in Australia appeared not to have been inert biologically.