PHARMACOKINETIC MEASUREMENT OF DRUGS IN LUNG EPITHELIAL LINING FLUID BY MICRODIALYSIS - AMINOGLYCOSIDE ANTIBIOTICS IN RAT BRONCHI

A novel technique for in vivo intrabronchial pharmacokinetic measureme nts using microdialysis is described. The technique was applied to the measurement of tobramycin and gentamicin in the anesthetized rat. The concentration versus time profiles of the drugs in the lung epithelia l lining fluid (ELF) following intravenous bolus administration were d etermined. The mean penetration ratios into the ELF were determined an d found to be 0.36 +/- 0.06 (mean +/- SEM, n = 5) for gentamicin and 0 .56 +/- 0.09 (mean +/- SEM, n = 5) for tobramycin. The findings sugges t that the technique can be used for intrabronchial pharmacokinetic me asurement of drugs in the lung, either as an extension of the bronchoa lveolar lavage technique or as a practical alternative to it.