Desenvolvimento de protetores solares formulados a partir de óleo de palma, caulinita in natura e nanopartículas de ZnO, e estudo da propriedade fotoprotetora, antimicrobiana e antioxidante

Abstract

Skin cancer is one of the biggest causes of death in the world and is directly related to the high exposure to ultraviolet rays, coming mainly from the sun's rays. In this context, the demand for cosmetics with efficiency in sun protection is increasing, and studies have been carried out in order to combine several interesting properties for the skin in a single product. The sun's rays are responsible for the premature aging of the skin, because during the exposure occurs the generation of free radicals, which damage the skin and accelerate the process of skin aging. Proprietary antioxidant and antimicrobial products are interesting because they neutralize free radicals and can control the development of undesirable microorganisms in the skin, such as the microorganisms associated with the development of acne. In this sense, the present study sought to develop formulations of sunscreens that associate photoprotective, antimicrobial and antioxidant properties, from a combination of zinc oxide nanoparticles with concentrations of 0.5; 1.0; 2.0 and 3.0% w/v, 2.0% w/v kaolinite in natura and palm oil in the oil phase of the emulsion. The concentration of active principles to promote better photoprotective, antimicrobial and antioxidant activities was studied. Antimicrobial activity against Staphylococcus aureus was diffusion disc technique. Finally, the antioxidant potential of the samples was analyzed by Ferric reducing antioxidant power (FRAP) and ABTS and DPPH radicals scavenging. Formulations with good spread ability, antioxidant potential, color and odor were obtained. The results indicated the need to employ higher concentrations of the active principles in the formulations to obtain adequate photoprotection and antimicrobial activities. Another important aspect is that the combined use of the active principles (NPs‒ZnO/kaolinite) at suitable concentrations promotes properties of great interest for human skin health.