Pharmacologic Effects of Oxaliplatin Instability in Chloride-Containing Carrier Fluids on the Hyperthermic Intraperitoneal Chemotherapy to Treat Colorectal Cancer In Vitro and In Vivo

Background: Oxaliplatin-based hyperthermic intraperitoneal chemotherapy (HIPEC) involves mixing oxaliplatin with 5% dextrose solution (5DW) to prevent the structural degradation of oxaliplatin in chloride-containing fluids. This study evaluated oxaliplatin degradation in carrier fluids containing different chloride ion concentrations to determine a carrier fluid that is optimal for use in oxaliplatin-based HIPEC. Methods: Five types of carrier fluids (normal saline, half saline, 5DW, Dianeal PD-2 peritoneal dialysis solution, and non-chloride Dianeal solution) were compared. An in vitro study was performed that monitored an oxaliplatin concentration of 1 ml (2 mg/ml) oxaliplatin mixed in 24 ml of each carrier fluid during 3 days to evaluate the rate of oxaliplatin degradation in each carrier fluid. An in vivo study, which subjected Sprague-Dawley rats to HIPEC for 60 min, also was performed. The efficacy of each carrier fluid for preserving oxaliplatin was evaluated using area under the curve (AUC) ratios between peritoneal fluid and plasma. Results: The degradation rate of oxaliplatin in non-chloride fluids was significantly lower than in chloride-containing fluids. However, the rate was less than 10 to 15% at 30 min. The in vivo study indicated that oxaliplatin concentrations in peritoneal fluids did not differ significantly, whereas those in plasma did differ. The AUC ratios of both normal saline and Dianeal were higher than those of 5DW and non-Cl^– Dianeal solutions. Conclusions: Chloride-containing fluids, such as normal saline or Dianeal, which display high absorption rates of oxaliplatin and acceptable degradation rates, may be more beneficial for use in oxaliplatin-based HIPEC than 5DW.