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Description of key information

In vitro metabolism studies were conducted with cell-free preparations from human, rat and mouse tissues on an isomer of 2,3-epoxypropyl neodecanoate.  Metabolic preparation were derived from liver, lung and skin.  Estimation of in vivo clearance was made from the in vitro kinetic data and scaling.  An estimation of dermal penetration was made from in vitro skin absorption studies.  
Short description of key information on absorption rate:
In an in vitro diffusion celll study the data demonstrated that an isomer of 2,3-epoxypropyl neodecanoate was metabolized by skin samples from rat, mouse and humans to the corresponding diol and ester hydrolysis product. Rat skin was most permeable to the test substance isomer. Human skin samples were approximately an-order-of-magnitude less permeable than rodent skin.

Key value for chemical safety assessment

Absorption rate - dermal (%):
0.24

Additional information

The findings from in vitro metabolism studies conducted with cell-free tissue perparations from human, rat and mouse, liver, lung and skin demonstrated that an isomer of 2,3 -epoxypropyl neodecanoate was rapidly detoxified. The predominate pathway of detoxication was epoxide hydrolase and carboxylesterase hydrolysis relative to glutathione conjugation. Estimation of in vivo clearance based on the in vitro kinetic data and scaling suggested that the human detoxication rate was approximately an-order-of-magnitude slower relative to rodents. The dermal penetration and metabolism of radio-labeled 2,3 -epoxypropyl neodecanoate isomer was assessed in vitro using diffusion cell technology with skin samples from rats, mice and humans. The data demonstrated that the 2,3-epoxypropyl neodecanoate isomer was metabolized in vitro in skin samples from rat, mouse and humans to the corresponding diol and ester hydrolysis product. Rat skin was most permeable to the test substance isomer. Human skin samples were approximately an-order-of-magnitude less permeable to the 2,3 -epoxypropyl neodecanoate isomer than rodent skin.

The mean percent penetration of the 2,3 -epoxypropyl isomer in human skin samples was 0.24% +/- 0.06%.