Effects of ultraviolet radiation on the kinetics of in vitro percutaneous absorption of lavender oil

The purpose of the present study is to investigate the influence of ultraviolet radiation on the rat skin absorption of lavender essential oil. The pure oil was extracted from Lavandula angustifolia by steam distillation. The chemical composition of lavender oil showed that terpenes are major compounds. In vitro, the essential oil was applied onto the rat skin. The amount of the compounds was determined using gas chromatography. Similarly, the amount of these compounds was analyzed for the skin exposed to ultraviolet radiation (UVAI) after 4, 8, 12 and 24 h. Our study demonstrated that the penetration profiles showed a cycle of charge–discharge (4 h/4 h, respectively). Our data point to the presence of reversible change in stratum corneum behavior. Interestingly, the ultraviolet radiation altered the cycle (charge–discharge) for terpenes (low lipophilicity) and increased the charge time. However, for terpenes (high lipophilicity), the ultraviolet radiation decreased the charge amplitude.