Pharmacokinetics, toxicities, and tissue concentrations of belotecan sprayed by rotational intraperitoneal pressurized aerosol chemotherapy in a pig model.

OBJECTIVE

We evaluated the pharmacokinetics, tissue concentrations, and toxicities of belotecan during rotational intraperitoneal pressurized aerosol chemotherapy (RIPAC) in pigs.

METHODS

We sprayed belotecan in 10% and 30% of doses for intravenous chemotherapy in six pigs (cohort 1, n=3, 0.50 mg/m²; cohort 2, n=3, 1.5 mg/m²). We evaluated the time-dependent plasma concentrations of belotecan before RIPAC to 120 hours for the pharmacokinetics, tissue concentrations in twelve peritoneal regions, and hepatic and renal functions before RIPAC to 120 hours in the 2 cohorts.

RESULTS

Mean values of the peak plasma concentration (C), the time to C, the time taken for C to drop in half, and the area under the curve from time zero to the time of last quantifiable concentration were 905 and 3,700 ng/mL, 1.42 and 1.50 hours, 3.64 and 5.60 hours, and 2,260 and 17,900 pg·hr/mL in cohorts 1 and 2, respectively. Mean values of tissue concentrations were 1.5 to 15.3 times higher in cohort 1 than in cohort 2 despite the similar ratio of tissue to plasma concentration, and tissue concentrations in the two cohorts were higher in the parietal peritoneum than in the visceral peritoneum. However, hepatic and renal functions were not different before RIPAC to 120 hours in the two cohorts.

CONCLUSION

RIPAC using belotecan of 0.5 mg/m² and 1.5 mg/m² may be feasible with fewer hepatic and renal toxicities in pigs. Thus, belotecan of 1.5 mg/m² may be considered as the starting dose for RIPAC in a phase 1 trial.