Clavulanate-potentiated ticarcillin: high-performance liquid chromatographic assays for clavulanic acid and ticarcillin isomers in serum and urine.

High-performance liquid chromatographic assays for the determination of clavulanic acid and ticarcillin in biological fluids are described. The clavulanic acid assay uses serum ultrafiltrate and direct injection of diluted urine with reversed-phase ion-pair/counter-ion chromatography. The ticarcillin assay allows, for the first time, the separation and quantitation of two isomers of ticarcillin. The performance of these assays has been evaluated and found to be satisfactory for routine clinical use and thus the assays have been applied to the study of the pharmacokinetics of these analytes in a subject with renal failure.