A safety study on single intravenous dose of tetrachloro-diphenyl glycoluril [iodogen] dissolved in dimethyl sulphoxide (DMSO)

Abstract

1. Iodogen (tetrachloro-diphenyl glycoluril) dissolved in DMSO (dimethyl sulphoxide) appears indispensable in radioiodination of hypericin for a new anticancer strategy. We studied the safety of intravenously administered iodogen/DMSO in mice (n = 132).

2. Median lethal dose (LD₅₀) of iodogen/DMSO was determined with doses of 40.0, 50.0, 55.0, 60.0, 65.0 and 70.0 mg/kg. Next, toxicity of iodogen/DMSO at 30.0 mg/kg was evaluated using saline and DMSO as controls. Changes in behaviour, body weight and serum biochemistry were evaluated. Histopathology of lungs, heart, liver and kidney was performed.

3. LD₅₀ values of iodogen/DMSO were 59.5 mg/kg (95% confidence limits (CI): 54.1–65.4 mg/kg) and 61.0 mg/kg (95%CI: 56.2–66.2 mg/kg) for female and male mice, respectively. Similar to that of control groups, no animal deaths were encountered after iodogen/DMSO administration at 30.0 mg/kg. Body weights over 24 h were not altered in all groups, but significantly higher in iodogen/DMSO and DMSO groups (p < 0.05) 14 d post-injection. Blood urea nitrogen and alkaline phosphatase increased (p < 0.05) in iodogen/DMSO group without clinical symptoms. No pathologies were found by gross and microscopic inspection.

4. A single dose of iodogen/DMSO up to 30.0 mg/kg, over 3000 times the dose in potential human applications, appears safe, with an LD₅₀ doubling that dose in mice.

• Anticancer therapy
• formulation
• hypericin
• mice
• radioiodination