Cosmetic sunscreens are most often found in the form of lotions, cremes or liquid emulsions. The oil-in-water emulsions are predominant. The products with higher protection factors are often produced as water-in-oil emulsions (water-in-oil), so that the greasier consistency and low washability support the effect of the special UV filters.
Sunscreens in the form of practical pump sprays are becoming increasingly popular. These sprays are products based on low-viscosity emulsions. Overall, sun screens are characterised by a wide range of products. In addition to providing adequate sun protection, these products should also have skin-care properties, should be quickly absorbed and have the longest possible shelf life. In addition to water and light protection filters, the sunscreens therefore include glycerine, fatty acids, silicone oils and emulsifiers, moisturisers, aromas, oil components, as well as antioxidants. The main components of sunscreen products are the specific UV filters. The UV filters can be of either organic or inorganic origin, as well as physical, artificial, chemical or natural substances. These sun protection substances, which protect the skin from UV radiation by scattering, reflection or absorption, require special production processes.
In the production of sun protection products, improved efficiency of the UV filters in the finished preparation can be achieved by optimizing the design of the homogenisers. The homogenizing mixers should enable a rapid and efficient combination of the substances. In this way, several UV filters can be incorporated in a very short time. Reduction of the particle size and fine distribution by means of high-shear homogenisers ensure the best development of the effect. Fast cleaning processes, which are particularly demanding for water-repellant sun cremes with a high protection factor, should be guaranteed by special features, such as GMP-compliant and correspondingly designed CIP-systems.