Abstract: AIM: To investigate the essential metabolites of azithromycin in human urine. METHODS: The urine samples of the volunteers after an oral administration of 500 mg azithromycin tablets were collected for 0-144 h, the samples were purified and separated through Strata C₁₈-E solid-phase extraction column and analyzed with liquid chromatography-mass spectrometry. The potential metabolites were analyzed through comparing the TIC and SIM chromatograms of the blank urine and sample urine, and the structure of the metabolites were identified through the correlation of the full scan MSn spectra of azithromycin and the metabolites. RESULTS: Eight metabolites were found in human urine, 4 metabolites were identified, the major metabolic pathways of azithromycin in human were Odemethylation, N-demethylation, N-desmethyl descladinose and hydroxylation. CONCLUSION: The research is possible to supply a reliable reference for further study on the metabolites of azithromycin.

Key words: liquid chromatography-mass spectrometry, azithromycin, solid-phase extraction, metabolite