The mineral diesel oil sold in Brazil, due to environmental reasons; presents sulfur concentration of 10 ppm, which causes a deficiency of lubricity, since sulfur is one of the chemical species that gives a good lubricating characteristic. Poor lubricity affects performance and causes failure of engine parts. This study aimed to evaluate the use of glycerin as an antiwear additive by means of tribological tests of the mineral diesel S10 B7 and 10 formulations of diesel based fuels, microemulsified with 0% (distilled water), 7.5% and 15% of glycerin solution. The formulations were subjected to lubricity tests on HFRR (Hight Frequency Reciprocating Rig) under hydrodynamic lubrication conditions, according to the ASTM D-6079 standard. The results showed that the increased concentration of glycerin added to diesel S10 B7 contributes to improved lubricity and wear reduction.

Sistemas microemulsionados (MES) oferecem inúmeras vantagens como liberadores de fármacos já que favorecem a absorção do princípio ativo e são, em muitos casos, mais eficientes do que outros métodos de liberação de substâncias bioativas. Neste trabalho, um MES foi obtido visando uma formulação para uso tópico, contendo extrato etanólico de própolis (PEE). Neste estudo, Diagramas de fase pseudoternários foram utilizados para caracterização das regiões de microemulsão, bem como para definição da região de Winsor IV do sistema PEE-MES (Tween 80 como tensoativo e álcool etílico como co-tensoativo, em baixo percentual). Os resultados obtidos indicaram que o melhor sistema microemulsionado contém C/S (cotensoativo/tensoativo) na razão 1,0, fornecendo uma microemulsão do tipo O/A com ampla região de Winsor IV. A formulação PEE-MES poderá vir a ser utilizada comercialmente para uso tópico no combate a inflamações de boca e garganta. Considerando o amplo uso de própolis em formulações convencionais, onde sua solubilidade representa um dos maiores problemas, o sistema PEE-MES disponibiliza este produto natural para aplicações farmacológicas, com boa solubilidade em um sistema microemulsionado do tipo O/A. Adicionalmente, o efeito bactericida do sistema PEE-MES foi comprovado e uma nova metodologia de extração de própolis é apresentada.

Microemulsion systems (MES) offer advantages as drug delivery systems, among them favour drug absorption, being in most case more efficient than other methods in delivering of drug. In this work a new MES was obtained in order to be applied as a pressurized aerosol formulation containing bee propolis ethanolic extract (PEE). For that, pseudoternary phase diagrams were used to characterize the microemulsions boundaries and also to define the Winsor IV microemulsion region of the PEE-MES system containing Tween 80 as surfactant and the cosurfactant ethyl alcohol in small percentage. The obtained results indicated that the best MES was composed by Tween 80 and ethyl alcohol with C/S (cosurfactant/surfactant) ratio equal to 1.0, since it provided a large boundaries in the obtained O/W microemulsion region. This PEE-MES formulation, in which bee propolis consisting as oil phase, is herein designed for topical uses (PEE-MES spraying) in order to treat mouth and throat inflammatory infections. Considering the very large uses of bee propolis in conventional vehicles, MES type of delivery system has to be compatible with achieving the highest drug aim loadings, determined substantially by the specific MES application (drug solubilization in water systems) improving in this case, propolis farmacological aplications. Additionally, PEE-MES antibacterial effect was evidenced and the microemulsion system PEE-MES was also used as newest chemical approach for extraction of bee propolis material from resinous hive.