β-Cyclodextrin: 52-Week toxicity studies in the rat and dog

A 52-wk toxicity study by dietary administration was performed in Sprague—Dawley rats and in pure-bred beagle dogs with β-cyclodextrin, a starch derivative that acts as a molecular inclusion agent. Doses of 0 (control), 12,500, 25,000 and 50,000 ppm were selected for the rat study, and 0 (control), 6200, 12,500 and 50,000 ppm were selected for the dog study. The liver and kidney were identified at the histopathological examination as target organs for toxicity in the rat at doses of 50,000 and 25,000 ppm, with the hepatic changes associated with increased plasma liver enzyme and reduced plasma triglyceride concentrations. In the dog study, there was no pathological evidence of systemic toxicity, although there were minor changes in urinalysis and biochemical parameters and a slightly higher incidence of liquid faeces. These changes were considered to be of no toxicological importance. The results in these studies, therefore, indicate that the non-toxic effect level was 12,500 ppm in the rat (equivalent to 654 or 864 mg/kg/day for males or females, respectively) and 50,000 ppm in the dog (equivalent to 1831 or 1967 mg/kg/day for males or females, respectively).