title: Determination of aminopyrine, dipyrone and its metabolites in urine by high-performance liquid chromatography.
abstract: A readily applicable and accurate isocratic high-performance liquid chromatography method for the detection of aminopyrine, dipyrone and its metabolites in urine is described. Parent drugs and four metabolites were chloroform-extracted from 1 ml of urine after addition of the internal standard isopropylaminoantipyrine and alkalinization. The organic phase was evaporated to dryness, and the residue was reconstituted in the mobile phase, which was injected onto a Spherisorb ODS 5 microns particle-size column (250 x 4.6 mm) using as mobile phase water, methanol, triethylamine, and acetic acid. The column eluent was monitored by ultraviolet absorption at 254 nm. Excellent linearity (r > 0.99) was obtained in the range 1-150 micrograms/ml urine, either for parent drugs and metabolites. This method offers a sensitive assay for aminopyrine, dipyrone (widely consumed in some countries) and its metabolites. After oral administration and collection of 24-h urine, this method allows the in vivo study of aminopyrine metabolism, which reflects liver function.
authors.affiliation: Department of Pharmacology, Medical School, University of Extremadura, Badajoz, Spain.
authors.forename: J A
authors.initials: JA
authors.lastname: Agúndez
authors.forename: C
authors.initials: C
authors.lastname: Martínez
authors.forename: R
authors.initials: R
authors.lastname: Martín
authors.forename: J
authors.initials: J
authors.lastname: Benítez
mesh_terms: D000328:Adult; D000632:Aminopyrine / Q000493:pharmacokinetics / Q000652:urine*; D002851:Chromatography, High Pressure Liquid; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism; D003640:Dealkylation; D004177:Dipyrone / Q000493:pharmacokinetics / Q000652:urine*; D005260:Female; D006801:Humans; D007527:Isoenzymes / Q000378:metabolism; D008107:Liver Diseases / Q000201:enzymology / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D013056:Spectrophotometry, Ultraviolet
chemical_list: D007527:Isoenzymes; D000632:Aminopyrine; D004177:Dipyrone; D003577:Cytochrome P-450 Enzyme System