Safety assessment of biotin used in cosmetics
摘要
Biotin, also known as vitamin B7, has been used as a skin- and hair-conditioning agent in cosmetic products. In acute oral toxicity studies, the lethal dose 50 (LD50) exceeded 10 g/kg in mice, indicating low acute toxicity. Dermal and eye irritation studies in rabbits showed that biotin was non-irritant. Guinea pig maximization test demonstrated no sensitizing potential of biotin. In a 28-day repeated-dose oral toxicity study in rats, dietary administration with over 0.08% biotin exhibited decreases in body weight gain, food intake, and tissue weights, while the relevance of these effects with systemic toxicity was unidentified. No significant adverse effects were observed in rats orally administered with 50 mg/rat or 16 g/kg of biotin for 10 or 5 days, respectively, and in mice fed 1 mg/mouse for 60 days. Reproductive toxicity studies in rats showed adverse effects at 50–100 mg/kg when administered by subcutaneous injection, including increased resorptions and reduced fetal and placental weights, which were partially mitigated by estrogen or progesterone co-treatment. In contrast, no adverse effects were observed even at dietary doses up to 1000 mg/kg in a mouse reproductive toxicity study. In vitro genotoxicity assays including Ames test showed negative results. In the present assessment, a systemic point of departure (PoD) and the corresponding margin of safety (MoS) could not be derived due to limitations in the available toxicological data. However, biotin is an essential vitamin and is generally recognized as safe (GRAS) when orally consumed as a food ingredient, with no evidence of significant systemic toxicity in humans. Therefore, based on the available information, there is insufficient justification to impose restrictions on the use of biotin in cosmetic products. Nevertheless, the risk assessment should be re-evaluated if new toxicological data allow the establishment of a systemic PoD.