title: Analysis of chlorthalidone in biological fluids by high-performance liquid chromatography using a rapid column cleanup procedure.
abstract: A high-performance liquid chromatographic assay usable for clinical monitoring of chlorthalidone in biological fluids was developed. Extraction efficiency was greater than 80% for blood and urine using a rapid, disposable column cleanup procedure. Chlorthalidone could be reliably measured in the range of 100-4,000 ng/ml in biological fluids with excellent day-to-day reproducibility and within-day precision. Chlorthalidone was found to be stable at -20 degrees C in blood and urine for at least 1 year, permitting repeat assays and large clinical studies to be conducted. The pharmacokinetics of chlorthalidone was studied in 24 subjects over a 120-h time interval following a single dose. chlorthalidone has a long terminal half-life in whole blood of 49 h, with peak concentrations occurring 8-10 h after oral dosing. During the first 12 h after dosing, chlorthalidone was rapidly excreted into urine followed by a slower phase with a half-life of 49 h.
mesh_terms: D000293:Adolescent; D000328:Adult; D002752:Chlorthalidone / Q000097:blood* / Q000652:urine; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D005615:Freezing; D006801:Humans; D007700:Kinetics; D008297:Male; D011309:Preservation, Biological; D013997:Time Factors
chemical_list: D002752:Chlorthalidone