title: In vitro Dermal Absorption of Hydroquinone: Protocol Validation and Applicability on Illegal Skin-Whitening Cosmetics.
abstract: In Europe, hydroquinone is a forbidden cosmetic ingredient. It is, however, still abundantly used because of its effective skin-whitening properties. The question arises as to whether the quantities of hydroquinone used become systemically available and may cause damage to human health. Dermal absorption studies can provide this information. In the EU, dermal absorption has to be assessed in vitro since the Cosmetic Regulation 1223/2009/EC forbids the use of animals. To obtain human-relevant data, a Franz diffusion cell protocol was validated using human skin. The results obtained were comparable to those from a multicentre validation study. The protocol was applied to hydroquinone and the dermal absorption ranged between 31 and 44%, which is within the range of published in vivo human values. This shows that a well-validated in vitro dermal absorption study using human skin provides relevant human data. The validated protocol was used to determine the dermal absorption of illegal skin-whitening cosmetics containing hydroquinone. All samples gave high dermal absorption values, rendering them all unsafe for human health. These results add to our knowledge of illegal cosmetics on the EU market, namely that they exhibit a negative toxicological profile and are likely to induce health problems.
authors.affiliation: Division of Food, Medicines and Consumer Safety, Section Medicinal Products, Scientific Institute of Public Health (IPH), Brussels, Belgium.
authors.forename: Bart
authors.initials: B
authors.lastname: Desmedt
authors.forename: Gamze
authors.initials: G
authors.lastname: Ates
authors.forename: Patricia
authors.initials: P
authors.lastname: Courselle
authors.forename: Jacques O
authors.initials: JO
authors.lastname: De Beer
authors.forename: Vera
authors.initials: V
authors.lastname: Rogiers
authors.forename: Benoit
authors.initials: B
authors.lastname: Hendrickx
authors.forename: Eric
authors.initials: E
authors.lastname: Deconinck
authors.forename: Kristien
authors.initials: K
authors.lastname: De Paepe
mesh_terms: D000328:Adult; D004335:Drug and Narcotic Control; D005260:Female; D006801:Humans; D006873:Hydroquinones / Q000493:pharmacokinetics*; D066298:In Vitro Techniques; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012867:Skin / Q000378:metabolism; D012869:Skin Absorption; D062327:Skin Lightening Preparations / Q000493:pharmacokinetics*; D013696:Temperature
chemical_list: D006873:Hydroquinones; D062327:Skin Lightening Preparations; C031927:hydroquinone