Introduction: Parabens are widely used in many cosmetic formulations. Although there are
some reports which correlate tumor growth with the use of parabens, available data on penetration
through human skin is still not sufficient to fully understand their potential toxicity. The aim of this report
is to investigate penetration properties of parabens through human skin. Methylparaben (MP), sodium
methylparaben (NaMP), propylparaben (PP) and sodium propylparaben (NaPP) were selected as
the most commonly used parabens in cosmetic formulations.
Methods and Materials: In addition to UPLC method, a simple and rapid method based on dispersive
liquid-liquid microextraction (DLLME) prior to capillary electrophoresis (CE) was also developed for
determination of parabens. Penetration properties of parabens through full thickness of human skin were
determined using Franz diffusion cell. For saturated solutions, the flux values for MP, PP, NaMP and
NaPP were found to be 9.36±3.36, 4.09±1.03, 121±19 and 15.4±0.2 µg/cm2h, respectively. Shampoo
formulations gave a flux value of 0.545±0.271 µg/cm2h for MP.
Results: The flux value of MP was found as 0.968±0.221 for hand cream, and MP and PP were
0.650±0.254 and 0.320±0.283 µg/cm2h, respectively for sunscreen formulations. The flux value of MP
was found as 0.677±0.273 µg/cm2h for body lotion. The amount of penetrated parabens varied depending
on the formulation. Hence, it was concluded that formulations should be investigated individually
for paraben penetration and their possible toxic effect.