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Protected skin

Nanoparticles involve active substances in sunscreen developed by UFRGS and Biolab

Artgraphic PublicidadeArtist’s drawing of polymeric nanocapsules that coat the active substances of the photo-protectorArtgraphic Publicidade

Biodegradable and water-resistant nanoparticles, made from buriti oil and other materials used by the cosmetics industry, have been incorporated in an innovative manner into a sunblock that has been developed in a partnership between the Federal University of Rio Grande do Sul (UFRGS) and Biolab Farmacêutica, from São Paulo. “The active substances are encapsulated and surrounded by a polymer that controls their release; they are subsequently totally eliminated by the skin,”  says Professor Adriana Pohlmann, from the Chemistry institute at UFRGS, who took part in the development project of the sunblock that was coordinated by Professor Silvia Guterres, from the Pharmacy School of the southern Brazilian university. “As the size of the nanoparticles varies between 240 and 250 nanometers, they are retained in the stratum corneum, which is the outermost layer of the epidermis and, therefore, of the skin,”  she points out. This means that sunblocks are not absorbed by the dermis, the layer that is immediately underneath the epidermis and that houses the nerves and blood vessels.

“Depending on the expected action of the product, the size of the particles is changed,” says Dante Alário Júnior, the technical-scientific president of  Biolab. In the range below 100 nanometers – a nanometer is the equivalent of one millimeter divided by one million – they enter the blood stream. For some products that the company is developing, such as an antifungal drug for nails, for example, the nanoparticles have to be smaller in order to penetrate the layers of keratin. The development of cosmetic products based on nanotechnology is a path that has long been trodden by international companies, such as L’Oréal and Chanel from France (read more about the subject in issue 146 of Pesquisa FAPESP).

“We prepared a formula that allows the product to remain on the skin longer, and even when in contact with water it doesn’t come off that easily,” says Alário. The composition consists mainly of chemical filters, which are organic molecules that absorb ultraviolet (UV) radiation, and also an inorganic sunblock that reflects UV rays. This association is necessary to obtain sunblock with a higher protection factor. However, what remains for most of the time on the skin are fatty acids and their non-hydrophilic derivatives, which repel water, meaning that the sunblock lasts longer after it has been applied. “The fact that the particle is on a nanometric scale helps keep the product on because, as it is small, it sticks to the natural porosity of our skin,”  says Alário.

Launched in November 2009 under the commercial name of Photoprot factor 100 sunblock, in a 40 ml. container, the product protects against types B (UVB) and A (UVA) ultraviolet radiation. The first type, UVB, of which there is more between 10 a.m. and 3 p.m., causes redness, a pricking sensation, peeling, burns and skin cancer. UVA is responsible for premature ageing and some types of cancer. The sun emits a third ultraviolet ray, UVC, which is very harmful, but does not penetrate the ozone layer.

In addition to buriti oil, an antioxidant, the formula contains the organic sunblock avobenzone and octocrilene, photostable substances that maintain the effectiveness of the blocks for several hours. “Although all the sun protection factors have been developed for the product, Biolab chose to launch the factor 100 sunblock to reach a more targeted market segment,” says Lilian Lopergolo, manager of the company’s department of research projects, development and innovation. “We chose a product that’s different because of its high protection factor, indicated for use by people who have had clinical, esthetic and surgical treatment, such as peeling, photodynamic therapy, antiwrinkle skin filling and the application of botox,” says Alário; or for use in the prevention and therapy of chloasma, better known as skin blemishes. The selling price in pharmacies is around R$70.00.

As the company has an important operation in the pharmaceutical area and only recently started working with the Cosmiatric line of cosmetic products that have a therapeutic effect, the photoprotector is being publicized among doctors at first. Still, everything indicates that in a short while Photoprot will also be in markets abroad. “We’re negotiating with a German company, which has branches in eight countries, to take not only the photoprotector but also other products based on Brazilian biodiversity outside the country,”  says Alário.

Therapeutic applications
Development of the photoprotector started back in 2005, as part of a larger project supported by the Studies and Projects Finance Agency (Finep), of the Ministry of Science and Technology. At the time, UFRGS already had a partnership with Biolab, via a project that resulted in a patent for a nano-anesthetic. “This was when the opportunity arose to do another Finep call notice project, one specifically relating to nanocosmetics,”  says Adriana. The research group from UFRGS had broad knowledge of the production and characterization of polymeric nanocapsules for use with anti-inflammatory and anti-tumor drugs and other therapeutic applications. “Since 1995, when Professor Silvia returned to Brazil, after having worked on polymeric nanoparticles for her PhD, she set up a group to work specifically in this area at UFRGS,” says Adriana, who was invited to join it. “We’ve created a lot of knowledge about this topic,” she reports. “We’ve have had some 80 works published, 70 of which have been indexed in international databanks.”

The project approved by Finep was finalized in 2007, after two years of joint work. In 2008 the tests required by the Brazilian Health Surveillance Agency (Anvisa) for registering the product were carried out. For the specific photo-protector project with nanotechnology, Finep earmarked R$600,000, the same amount put up by the company. The biodegradable nanocapsule technology was patented and registered under the brand name of  Nanophoton.