title: High performance liquid chromatographic measurement of iothalamate in human serum and urine for evaluation of glomerular filtration rate.
abstract: A simple and sensitive HPLC-UV assay was developed for the measurement of iothalamate (IOT) in human serum and urine. Chromatographic separation was achieved using an embedded-carbamate-group bonded RP18 column and mobile phase consisting of 50 mM monobasic sodium phosphate and methanol (90:10, v/v) without the addition of ion-pair reagents. The assay demonstrated a high analytical reliability within the IOT concentration range of 1-150 microg/ml in serum and 25-1500 microg/ml in urine. The relative standard deviations (RSDs) for intra- and inter-day analysis were less than 5.1% in all cases. This method has been used for the evaluation of glomerular filtration rate (GFR) in subjects participating in a phase I clinical trial of a novel antimalarial medicine. The average baseline GFR was 100.41+/-19.99 ml/min/1.73 m(2) in 119 healthy volunteers. The assay may also allow the simultaneous measurements of p-aminohippuric acid (PAH), N-acetyl PAH (aPAH), and IOT with some modification. PAH, IOT, aPAH, and beta-hydroxyethyl-theophylline internal standard peaks appeared approximately at 2.5, 3.7, 5.9, and 11.8 min, respectively, in an isocratic run.
authors.affiliation: Division of Clinical Pharmacology and Medical Toxicology, Department of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD 20819, USA.
authors.forename: Daoqin
authors.initials: D
authors.lastname: Bi
authors.forename: Kevin J
authors.initials: KJ
authors.lastname: Leary
authors.forename: Julie A
authors.initials: JA
authors.lastname: Weitz
authors.forename: Svetlana A
authors.initials: SA
authors.lastname: Cherstniakova
authors.forename: Michael A
authors.initials: MA
authors.lastname: Reil
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Roy
authors.forename: Louis R
authors.initials: LR
authors.lastname: Cantilena
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D005919:Glomerular Filtration Rate; D006801:Humans; D007483:Iothalamic Acid / Q000032:analysis*; D012015:Reference Standards; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D007483:Iothalamic Acid