COMPARATIVE TEAR CONCENTRATIONS OVER TIME OF OFLOXACIN AND TOBRAMYCININ HUMAN EYES

The pharmacokinetic profiles of 0.3% ofloxacin and 0.3% tobramycin oph thalmic solutions after multiple administrations in the eyes of 160 he althy volunteers were evaluated. In human tears, ofloxacin and tobramy cin were found to have terminal half-lives of 226 and 154 minutes, res pectively. The mean residence time in the ocular tear fluid was 326 mi nutes for ofloxacin and 106 minutes for tobramycin. The mean duration of time that ofloxacin remained above the MIC90 value for five bacteri al species evaluated was 605 minutes, compared with 251 minutes for to bramycin. The mean area under the inhibitory curve for the five bacter ial species evaluated was greater for ofloxacin (2224) compared with t obramycin (1549). ne duration of time above the MIC90 for ofloxacin wa s longer compared with tobramycin for gram-positive isolates. Overall, the pharmacokinetic and pharmacodynamic profiles of ofloxacin were su perior to those of tobramycin for most parameters studied.