Toxicology of Diethylene Glycol Butyl Ether 5. Dermal Subchronic Neurotoxicity Study in Rats

Abstract

Groups of Sprague-Dawley rats were treated dermally with the vehicle, distilled water or with diethylene glycol butyl ether (DGBE) at 10 or 30% v/v aq. solutions or undiluted (0.2, 0.6, or 2.0 g/kg body weight) for 13 weeks under occlusion 6 hr/day, 5 days/week, at the maximum attainable volume of 2 mL/kg. Male and female rats were examined using a functional observational battery (FOB) prestudy, at 1, 6, and 24 hr after the initiation of the first exposure, and prior to treatment on days 7, 14, 35, 63, and 91. Motor activity was determined prestudy and on nontreated days 34, 62, and 90. At the completion of treatment, six control and top dose group animals were perfused for neuropathology. There was no mortality, and the body weights and food consumption were unaffected. Five females in the top dose group had scab formation at the treatment site during the study. There were no other treatment-related clinical findings. The FOB and motor activity tests revealed no findings indicative of a neurotoxic effect, and there were no gross or neuropathological changes that were attributed to treatment. No neurotoxicity or other systemic toxicity was seen at the highest dose tested—2 g/kg/day.