Skin lightening/whitening agents in cosmetics are often used to produce a more even skin tone, usually to the face and neck, but sometimes they can be used more extensively over larger areas of skin. These products may be marketed to consumers as either a cosmetic to improve appearance, or as a therapy to treat skin conditions (i.e. a drug).

The distinction between a cosmetic and a drug is important from a regulatory and safety perspective because, among other things, a cosmetic should not contain pharmaceutical active ingredients (AIs). Otherwise they are classified as a drug according to European Commission’s No. 1223/2009 and the US FDA’s regulations on Cosmetics.

In this application note, we investigated several cosmetic products that contained prohibited pharmaceutical active ingredients such as hydroquinone, corticosteroids, and tretinoin. Samples were extracted and analyzed on the ACQUITY Arc System equipped with a 2998 Photodiode Array (PDA) Detector and the ACQUITY QDa Mass Detector. Empower 3 Chromatography Data Software (CDS) was used for data acquisition and processing. The CORTECS Column stationary phase used in the separation contained a 2.7 μm particle designed to give maximum efficiency and exceptional retention for both polar and non-polar analytes.

Several samples tested positive for prohibited skin lightening agents. The packaging labels were often misleading, and in some cases, the skin lightening agent was not listed on the enclosed product information increasing the likelihood of improper long-term use and adverse side effects to consumers.

This method could be used in the routine analysis of cosmetics to screen for skin lightening agents to ensure that they meet regulatory and safety standards.