Skin-depigmenting prodrugs of hydroquinone

Novel mono-1 and bis-carbonates 2, and mono-3 and bis-pivaloyloxymethyl ethers 4 (bis-POM-ethers) of hydroquinone (HQ) evaluated as skin-lightening agents, showed that: 1) they cause an initial depigmentation of the skin; 2) the depigmenting effect is not maintained over prolonged periods of time; and 3) prolonged use results in a shift of the chromatic locus, suggesting the formation of a new chemical product in the skin. HQ was a more potent depigmenting agent than any of the derivatives tested.