Development and validation of a fast chromatographic method for screening andquantification of legal and illegal skin whitening agents

tDuring the last years, the EU market is flooded by illegal cosmetics via the Internet and a so-called "blackmarket". Among these, skin-bleaching products represent an important group. They contain, according tothe current European cosmetic legislation (Directive 76/768/EEC), a number of illegal active substancesincluding hydroquinone, tretinoin and corticosteroids. These may provoke as well local as systemic toxiceffects, being the reason for their banning from the EU market. To control this market there is a need fora fast screening method capable of detecting illegal ingredients in the wide variety of existing bleachingcosmetic formulations.In this paper the development and validation of an ultra high pressure liquid chromatographic (UHPLC)method is described. The proposed method makes use of a Waters Acquity BEH shield RP18 column witha gradient using 25 mM ammonium borate buffer (pH 10) and acetonitrile.This method is not only able to detect the major illegal (hydroquinone, tretinoin and six dermatologicactive corticosteroids) and legal whitening agents, the latter having restrictions with respect to concen-tration and application (kojic acid, arbutin, nicotinamide and salicylic acid), but can also quantify thesein a run time of 12 min.The method was successfully validated using the "total error" approach in accordance with the vali-dation requirements of ISO-17025.During the validation a variety of cosmetic matrices including creams, lotions and soaps were takeninto consideration.

Publication year:2013

Keywords:Illegal cosmetics, Bleaching agents, Salicylic acid, Hydroquinone, Corticosteroids, Tretinoin