Isolated lung perfusion with gemcitabine in a rat: pharmacokinetics and survival.

Background: Toxicity and pharmacokinetics of gemcitabine (GCB) were evaluated in a rat model of isolated lung perfusion (ILuP) and compared to intravenous (iv) infusion.
Materials and Methods: CC531S adenocarcinoma cells were incubated in vitro for 24 h with GCB. Cell survival was determined 4 days after GCB treatment with the sulforhodamine B test. In a first in vivo experiment, Wag/Rij rats underwent left ILuP with 20 mg/kg (n = 3), 40 mg/kg (n = 6), 80 mg/kg (n = 6), 160 mg/kg (n = 6), or 320 mg/kg (n = 6) of GCB and a control group (n = 6) with buffered starch. After 3 weeks, right pneumonectomy was performed. Furthermore, survival was determined for rats treated with iv infusion of 40 mg/kg (n = 10), 80 mg/kg (n = 10), 160 mg/kg (n = 10), or 320 mg/kg (n = 6) of GCB and a control group (n = 6) treated with saline (0.9% NaCl). In a second experiment lung and serum GCB levels were determined for rats treated with iv infusion (160 mg/kg, n = 6) and rats which had ILuP (160 mg/kg, n = 6; 320 mg/kg, n = 6).
Results: Incubation of the CC531S adenocarcinoma cells with GCB led to a 50% decrease (P < 0.05) in the number of cells compared to controls at a dose of 23.6 nM. After 90 days, the mortality for rats treated with 320 mg/kg iv GCB was 100% compared to 17% after ILuP for the same dose. ILuP with 160 and 320 mg/kg resulted in significantly higher lung levels of GCB compared to iv therapy without any systemic leakage.
Conclusions: GCB ILuP is well-tolerated to a maximum dose of 320 mg/kg and results in significantly higher GCB lung levels with undetectable serum levels compared to iv treatment.