Monitoring of clobetasol propionate and betamethasone dipropionate as undeclared steroids in cosmetic products manufactured in Korea

Some cosmetic products manufactured in Korea have been suspected to contain anti-inflammatory corticosteroids, such as clobetasol propionate and betamethasone dipropionate, for the treatment of eczema, seborrhea and psoriasis, without any indication on the label of the cosmetic products. Due to their severe side effects, such as permanent skin atopy, these two corticosteroids in cosmetic products need to be monitored from a forensic point of view. Cosmetic product samples (number of samples=47) of manufacturers charged by consumers have been collected in local and online markets of Korea, and they were validated and analyzed by a simple high performance liquid chromatography (HPLC) method with ultraviolet diode array (UV-DAD). LC–MS/MS and LC–MS were used to confirm these steroids in cosmetic samples with diagnostic ions (m/z) and isotope ratio.