Influence of microparticles on the homogeneity of distribution of topically applied substances

The uppermost layer of the skin--the stratum corneum--represents a barrier of the human organism to the environment. It prevents the penetration of substances coming into contact with the skin into the human body. In cases of strong exposure, the skin has to be protected additionally by barrier creams. In the present study, the influence of microparticles on the homogeneity of distribution of the protection cream on the skin was investigated by laser scanning microscopy. The protection cream contained antioxidant substances with a high radical protection factor for the prevention of palmar-plantar erythema often occurring during chemotherapy with doxorubicin. In this case, the chemotherapeutic substance comes out with the sweat onto the skin surface, from which it penetrates into the skin like topically applied. It was found that particles increase the homogeneity of distribution and, thus, the protection efficacy is significantly increased. The obtained results are important, not only for the prevention of side effects during chemotherapy, but also for the development and application of sunscreens and all types of topically applied drugs and cosmetics, which should form an efficient protection film on the skin.