RESUMO
PURPOSE: To determine the concentration of netilmicin in tears after eye drop administration. METHODS: A clinical study was carried out on 32 healthy volunteers. Subjects were divided into four groups and underwent tear collection at 5, 10, 20, and 60-minutes after drug administration, respectively. Tear samples were collected through capillary suction from the inferior conjunctival "cul-de-sac" and analyzed by high-pressure liquid chromatography (HPLC). RESULTS: Netilmicin concentration in tears decreased after a first order kinetics, a best-fit curve was drawn and the minimum inhibitory concentration (MIC90) intersection for the most common ocular pathogens was calculated. CONCLUSIONS: The extrapolation of the curve shows that the concentration of netilmicin on the ocular surface can be effective against microorganisms more than 120 minutes after eye drop instillation.