Pickering emulsions are systems composed of two immiscible fluids stabilized by organic or inorganic solid particles. These solid particles of certain dimensions (micro- or nano-particles), and desired wettability, have been shown to be an alternative to conventional emulsifiers. The use of biodegradable and biocompatible stabilizers of natural origin, such as clay minerals, presents a promising future for the development of Pickering emulsions and, with this, they deliver some advantages, especially in the area of biomedicine. In this review, the effects and characteristics of microparticles in the preparation and properties of Pickering emulsions are presented. The objective of this review is to provide a theoretical basis for a broader type of emulsion, in addition to reviewing the main aspects related to the mechanisms and applications to promote its stability. Through this review, we highlight the use of this type of emulsion and its excellent properties as permeability promoters of solid particles, providing ideal results for local drug delivery and use in Pickering emulsions.

Oils and fats have a wide range of health benefits, especially those that have a high concentration of polyunsaturated fatty acids, like fish oils. Unfortunately, oils are highly susceptible to heat, light, and oxygen degradation, causing them to lose the qualities that would make them interesting for the public. With this in mind, this study compared two methods of spray-drying, a technique that helps preserve the stability of oils in storage for longer periods of time. Emulsions made with skimmed milk powder and with maltodextrin and whey protein hydrolysate were spray-dried, resulting in 2 different microencapsulated fish oils. They were compared regarding encapsulation efficiency, water activity, moisture content, and peroxide index. The skimmed milk showed better results, with a 28.17% lower peroxide index than the non-encapsulated oil and lower water activity and moisture content compared to the emulsion using maltodextrin (2.690±0.19% vs 6.747±0.29% moisture content and 0.376±0.013 vs 0.554±0.006 water activity). Since skimmed milk powder is rather cheap, it is ideal for spray-drying, a simple and fast technique. In this way, fish oil can be safely microencapsulated in powder form, lasting longer than the oil capsules currently available, since the oil is protected from light, temperature, moisture, and oxidation. In addition, the oily odor is masked, making it more appealing to the consumer, and it may be combined with other powders, like vitamins and minerals, which opens up new possibilities for the production of supplements.

Research background. The current commercial scenario indicates an increase in the demand for natural dyes. Compared to synthetic dyes, natural ones have the advantage of being sustainable, making them of great interest for the food and cosmetic industries. The development of new natural dyes is necessary, as well as the carrying out of complementary research regarding the existing ones. Experimental approach. The present study aims to characterize the physicochemical and biological characteristics of the dye obtained from dehydrated endocarp of the genipap (Genipa americana) fruit, as well as perform the relevant stability and cytotoxicity tests. The chemical characterization was performed by HPLC-MS/MS analyses. The stability studies were carried out by spectrophotometry and cytotoxicity assays using cell culture and fluorometric methods. Results and conclusions. After dehydration and milling of the fruit endocarp, water was added to the obtained powder (in the ratio 4:1) to extract the dye. HPLC-MS/MS elucidated five compounds and confirmed the presence of the geniposide as its main compound. With the X-ray diffraction and electron microscopy analysis, we characterised the obtained powder as being amorphous and of porous structure with a variable size. The thermogravimetric analysis indicated a maximum loss of 61 % mass after exposure to a temperature range from 240 to 760 °C. The obtained blue dye was stable in the absence of light, at room temperature and had neutral pH. In the cytotoxicity assay, (95.0±1.3) % of viable human fibroblast were observed after exposure to this dye. The genipap fruit can be a viable alternative to produce a natural blue dye, since it is easy to obtain and has very low toxicity in food, pharmaceutical or cosmetic products. Novelty and scientific contribution. This study demonstrates for the first time the physicochemical and biological properties of a natural blue dye from G. americana fruit.

Cytotoxicity and antimicrobial activity of mouthwash obtained from the extract of Libidibia ferrea Mart / Citotoxicidade e atividade antimicrobiana de enxaguatório bucal obtido do extrato de Libidibia ferrea Mart