title: Lachrymal concentration of norfloxacin after a single ocular instillation in humans.
abstract: Lachrymal concentrations of the fluoroquinolone norfloxacin were studied in 30 subjects (aged 24-35 years) after a single ocular instillation (0.3% solution, 50 ul) in comparison with ofloxacin instilled at the same dose. Lachrymal levels were measured by high performance liquid chromatography (HPLC). Lachrymal peak levels were comparable 5 min after instillation but norfloxacin appeared to have a longer elimination half-life than ofloxacin. The AUC (area under the curve) for norfloxacin was therefore higher than for ofloxacin (35.9 and 10.7 mg* min/ml, respectively). These data suggest that norfloxacin may have higher corneal retention than ofloxacin, so this antibiotic may be indicated in superficial infections dependent on fluoroquinolone-sensitive bacteria.
authors.affiliation: Institute of Pharmacology, University of Catania Medical School, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Drago
authors.forename: E
authors.initials: E
authors.lastname: De Bernardis
mesh_terms: D000328:Adult; D002851:Chromatography, High Pressure Liquid; D003315:Cornea / Q000378:metabolism; D005260:Female; D006801:Humans; D007765:Lacrimal Apparatus / Q000378:metabolism*; D008297:Male; D009643:Norfloxacin / Q000493:pharmacokinetics*; D015242:Ofloxacin / Q000493:pharmacokinetics; D009883:Ophthalmic Solutions; D013666:Tears / Q000378:metabolism*
chemical_list: D009883:Ophthalmic Solutions; D015242:Ofloxacin; D009643:Norfloxacin