title: High-performance liquid chromatographic determination of cicletanide, a new diuretic, in plasma, red blood cells, urine and saliva.
abstract: A sensitive, selective and easy to use high-performance liquid chromatographic method for the determination of cicletanide, a new diuretic, in plasma, red blood cells, urine and saliva is described. After extraction of cicletanide together with an internal standard with diethyl ether, or diethyl ether-n-hexane (20:80) for urine, the sample extracts are chromatographed with water-methanol-acetic acid (50:50:0.3) as eluent on to a Nucleosil C18 column. Both compounds are detected by their ultraviolet absorption at 280 nm. The calibration graph was linear between 0.2 and 20 micrograms/ml for plasma and between 0.2 and 5 micrograms/ml for the other biological fluids. The sensitivity limit was 20 ng/ml for plasma, red blood cells and saliva and 30 ng/ml for urine. The coefficients of variation of the between-day assays did not exceed 4.6% in plasma, 8.3% in red blood cells, 7.8% in urine and 4.2% in saliva for the lowest concentrations studied. The application of the method to a pharmacokinetic study of cicletanide after a single oral therapeutic dose in humans is reported.
mesh_terms: D002851:Chromatography, High Pressure Liquid; D004232:Diuretics / Q000032:analysis* / Q000097:blood / Q000652:urine; D004912:Erythrocytes / Q000032:analysis; D006801:Humans; D007700:Kinetics; D010949:Plasma / Q000032:analysis; D011725:Pyridines; D012463:Saliva / Q000032:analysis
chemical_list: D004232:Diuretics; D011725:Pyridines; C038068:cicletanine