Intraperitoneal injection of dextran sulfate as an anti-adherent drug for the prevention of peritoneal metastasis of cancer shows low toxicity in animals.

Intraperitoneal dextran sulfate with a mean molecular weight of 5 x 10(5) has been developed for use in an anti-adherent therapy against peritoneal carcinomatosis. The present study examined acute toxicity of i.p. injection of dextran sulfate in mice and rabbits. The 10, 50 and 90% lethal dose values are 0.213 (0.146-0.252), 0.336 (0.291-0.405) and 0.530 mg/g (0.431-0.873 mg/g: 95% confidence interval) in mice, respectively. These are markedly larger than the efficacious dose of 0.005-0.01 mg/g obtained previously. Death or symptoms of intoxication were seen within 3 days after administration of toxic doses. Rabbits received i.p. injection of dextran sulfate at 0.02 mg/g, which was close to the efficacious dose. At 2, 4, 6, 8 and 13 days after administration, blood was taken for biochemical and hematological analyses. Dextran sulfate at 0.02 mg/g induced no remarkable abnormal findings. These results suggest that the i.p. dextran sulfate is safe as an anti-adherent agent against peritoneal metastasis of cancer.