Measurement of Phenytoin and Carbamazepine in an Ultrafiltrate of Saliva

Abstract

We have introduced a method of collecting a prepurified sample of saliva in the mouth for the quantitative determination of phenytoin and carbamazepine. The patient places in the mouth an osmotic device that accumulates in >8 min a volume of ∼1.2 ml clear ultrafiltrate devoid of molecules > 12,000 daltons. The concentrations of phenytoin and carbamazepine in serum (total and free fractions), whole saliva, and the salivary ultrafiltrate from patients receiving anticonvulsant treatment were measured and correlated. The correlation coefficients r (p