Abstract: AimTo investigate the tissue distribution and pharmacokinetics of hydroxycamptothecin (HCPT) after aerosol inhalation in rabbits. MethodsRP-HPLC was used to determine the concentration of HCPT in different tissues and plasma of rabbits. The tissue distribution of HCPT after aerosol inhalation or iv administration was compared. The plasma concentrations at different time after aerosol inhalation were compared with iv injection. ResultsThe HCPT concentrations in lung after aerosol inhalation at 0.5, 1 and 2 h were 13.52, 27.81 and 20.82 times higher than that of iv administration group, respectively. At the same time, concentrations in other tissues were decreased obviously. The absolute bioavailability of HCPT after aerosol inhalation was 7.38%. ConclusionAfter aerosol inhalation, HCPT is retained mostly in lung. So this administration route can raise the therapeutic index and reduce adverse effects.