Steiner A, Kugarajan K, Wullimann M, Ruty B, Kunze G. Margin of safety of pentylene glycol derived using measurements of cutaneous absorption and volatility.
Regul Toxicol Pharmacol 2017;
87:106-111. [PMID:
28483712 DOI:
10.1016/j.yrtph.2017.05.007]
[Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Revised: 04/12/2017] [Accepted: 05/04/2017] [Indexed: 11/30/2022]
Abstract
The safety assessment of pentylene glycol (PG) has been based on a bioavailability extrapolated from those of other 1,2-glycols or an assumed 100% absorption. To make a better safety assessment and an accurate calculation of the margin of safety (MoS), the skin penetration of PG present in a commercially available sunscreen was measured in pig skin at different exposure durations. The mass balance of PG decreased with increasing exposure durations, from 98% (1 h) to 29% (24 h) and the amount of PG detected in the skin wash decreased over time from 93% to 3%. The decrease in mass balance was attributed to an unexpected volatility of PG, which was confirmed in additional experiments. The maximum bioavailable amount of PG was 123 μg/cm2 after 24 h and was considered to be worst case scenario (10 mg/cm2 i.e. 5-fold the recommended application standard dose, 2 mg/cm2). MoS values for the application of a standard dose of sunscreen after 1-24 h exposure were 140-671 in adults and, if calculated for children ratios, 87-217 Based on the available toxicological data for PG in comparison to the amounts determined to be potentially bioavailable, PG in the test sun protection product SPF 50 + does not show any safety concerns for daily usage at the recommended dosage of 2 mg/cm2 or lower.
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