Subchronic Toxicity of the New Iodine Complex in Dogs and Rats.

Area of Science:

• Toxicology
• Pharmacology
• Endocrinology

Background:

• Iodine complexes like povidone-iodine are vital antiseptics but have oral administration limitations due to irritation and toxicity.
• A novel iodine complex, PA (potentiator of anticancer antibiotics), coordinated by carbohydrates and polypeptides, was developed.

Purpose of the Study:

• To evaluate the safety and toxicological profile of orally administered PA in rat and dog models.
• To compare the effects of PA on hormonal levels, hematology, clinical chemistry, and histology in different species.

Main Methods:

• Wistar rats and Beagle dogs were orally administered PA for 30 days.
• Evaluations included hormone level measurements, hematological and clinical chemistry analysis, necropsy, and histological examination.
• Maximum tolerated dose (MTD) and no-observed-adverse-effect level (NOAEL) were determined.

Main Results:

• In rats, the MTD of 2,000 mg/kg PA decreased body weight gain and altered hematological and biochemical parameters.
• Histological examination of rats revealed thyroid gland changes, including follicle alterations and colloid resorption.
• Dogs showed no significant changes in thyroid hormones (TSH, T3, T4) at doses up to half the MTD (180 mg/kg).

Conclusions:

• PA induces an inflammatory response leading to thyrotoxicosis, not hypothyroidism, in rats, confirmed by histological findings.
• The no-observed-adverse-effect level (NOAEL) for PA in dogs is 180 mg/kg, suggesting better oral tolerability in this species.
• PA's safety profile appears species-dependent, with dogs exhibiting higher tolerance than rats.