Acute dermal and ocular irritation testing of rice bran supercritical CO2 extract (RB-SCE) and 0.5% RB-SCE essence product

Abstract

This study was conducted to investigate the acute dermal and ocular irritation potential of rice bran supercritical CO2 extract (RB-SCE) and a 0.5% RB-SCE essence product in rabbits and guinea pigs. No abnormal clinical signs attributable to RB-SCE were detected. In the dermal irritation test, erythema, eschar, and edema formation was observed at 24 h of RB-SCE treatment, and the skin returned to normal after 72 h. The dermal primary irritation index (PII) of RB-SCE was 2.71; thus it was classified as a moderate irritant. In the ocular irritation test, there were no clinical signs related to the application of the RB-SCE; thus it was classified as a non-irritant according to the Draize scoring system. In a skin sensitivity test in rabbits, no abnormal clinical signs attributable to RB-SCE essence were observed and the PII was 0 because there was no evidence of erythema, eschar, or edema. In the guinea pig skin sensitivity test, no abnormal body weight changes or increased mortality was detected. Sensitization to the RB-SCE essence was 0%; thus it was classified as a very weak irritant.