Depth Profiling of Penetration of Niacinamide into the Stratum Corneum: Effect of Hydration and Oil massage

Abstract

Niacinamide is a cosmetic compound that is used in many cosmetic formulations nowadays due to its skin care properties. The present study was designed for the depth profiling of penetration of niacinamide into the skin using a control formulation. In addition, since proper amount of niacinamide penetration is necessary for skin benefit, influence of two external factors, such as skin hydration and oil massage on the penetration of niacinamide was investigated. For this study an international face cream brand was used as a test sample and the formulation was applied to eleven healthy volunteer on different sites of right and left volar forearm. The volunteers were aged between 18to 27 years. The calibration curve was formed by range of 5μg/mL to 30μg/mL. The calibration curve was found to be linear (R2>0.999). This study is conducted by tape-striping process where stratum corneum of skin was removed and amount of niacinamide content in per tape were analyzed by using UV-Spectroscopy at 262nm wavelength. The depth profile of niacinamide from control site was compared with the skin hydration and oil massaged sites. No significant difference was observed in the amount of niacinamide at any depth of skin from control to hydration or oil massage (p>0.05). In addition, the analysis was extended to observe if there any difference between male and female skin. However, like the general result, male and female skin was also failed to show any significant influence of skin hydration and oil massage in penetrating niacinamide (p>0.05). The skin was hydrated or massaged with oil for only 2 minutes. The time may not be sufficient to show any significant difference. IV