Commentary to the article "Human skin penetration of the major components of Australian tea tree oil applied in its pure form and as a 20% solution in vitro".

This note summarises recent studies on skin penetration of terpinen-4-ol, which is the main component of tea tree oil [S.E. Cross, M. Russell, I. Southwell, M.S. Roberts, Human skin penetration of the major components of Australian tea tree oil applied in its pure form and as a 20% solution in vitro, Eur. J. Pharm. Biopharm. doi: 10.1016/j.ejpb.2007.10.002 (in press)]. The influence of different experimental models on obtained skin penetration results is discussed.