Abstract
In order to assess the hazard potential of air-borne Polyethylene Glycol 200 (Vehicle), a repeated dose inhalation study in male and female rats was performed, following the OCSPP (OPPTS) test guidelines.
The rats were exposed to compressed air (G1) and 2.018 mg/L air (G2) for 6 h/day, 5 days/week for consecutive 4 weeks, respectively, in a 28-day study. The biological clinical chemistry, haematology, urine analysis, organ weight, and histopathology examination were performed.
In this study, microscopic lesions (kidneys: regenerative/basophilic tubules, liver: infiltration, MNC, prostate: infiltration, MNC, thyroid: ultimobranchial cyst & ectopic thymus and uterus: dilatation) were at lower rate of occurrence and with minimal to mild severity. Hence, those lesions were considered to be spontaneous or incidental in nature representing the normal physiological/metabolic/cyclical or congenital changes encountered in rats of this age kept under laboratory conditions. In the absence of clinical pathology and histopathological findings, it is concluded that repeated inhalation for 28 consecutive days did not produce any adverse effect in Wistar rats.
No Observed Adverse Effect Concentration (NOAEC) and No Observed Effect Concentration (NOEC) of Polyethylene Glycol 200 was found to be ≥2.018 mg/L air, when administered through inhalation route, for consecutive 28 days, to Wistar rats, based on the procedures and conditions followed in this study. Hence, it is concluded that Polyethylene Glycol 200 can be used as a vehicle for long term inhalation study.
