Selecting a polymer depends on its characteristics, the properties of the drug and of the remaining ingredients in the formulation. The drug, when incorporated into a polymeric matrix, can show several advantages when compared with its conventional form. In this context, this work describes the preparation and characterization of polyethylene glycol (PEG 4000) and its derivative particles loaded with benznidazole, as well as evaluates their trypanocidal activity. In this work, reactions to modify the PEG 4000 polymer and the subsequent incorporation of the benznidazole were made. The nuclear magnetic resonance (NMR) analysis confirmed the efficiency in modifying the PEG chains. The morphology of polymeric films was observed by atomic force microscopy (AFM) and showed considerable changes on the film organization. The acetylation of PEG favored the stability of the system and an increase in the zeta potential from ?14.83 to ?25.54 mV was observed. Although encapsulation efficiency values between 30.14 and 39.48% were found, the enhanced benznidazole dissolution profile by microparticles enables the use of lower drug concentrations. This fact can be proven by the increased trypanocidal effect of benznidazole when encapsulated in BP3 microparticles. Finally, the high selectivity of the formulations for trypanocidal action guarantees their safety as an alternative for the treatment of the Chagas disease.

Abstract In the present study, an innovative cultivation strategy of Rhodotorula mucilaginosa CCT 7688 to accumulate both lipids and high added value carotenoids was proposed, with the potential to contribute to the economic feasibility of microbial oils in comparison with vegetable oils. The stepwise fed-batch cultivation with crude glycerol feeding at 24 h, 96 h, and 144 h, with the addition of magnesium to the initial culture medium, resulted in a lipid content of 51.0 ± 0.3 % CDW, biomass concentration of 21.00 ± 0.48 g L-1, total lipid production of 10.72 ± 0.18 g L-1, lipid productivity of 0.037 ± 0.001 g L-1 h-1, volumetric carotenoid production of 2843.2 ± 282.0 μg L-1, and carotenoid productivity of 9.87 ± 0.98 μg L-1 h-1. These values represent a 6-fold increase in lipid content, a 19-fold increase in lipid production, and a 2-fold increase in carotenoid production compared to batch cultivation.

INTRODUÇÃO: A sibutramina tem sido descrita como um fármaco recomendado para o tratamento da obesidade, uma vez que tem a capacidade de inibir a recaptação de serotonina e noradrenalina no sistema nervoso central, aumentando assim o gasto energético. OBJETIVO: Investigar os efeitos ansiogênico e ansiolítico dos tratamentos agudo e crônico com a sibutramina em ratos Wistar submetidos à tarefa do labirinto em cruz elevado. MÉTODOS: O diazepam foi usado como controle positivo para o efeito ansiolítico, e a tarefa do labirinto em cruz elevado apresentou sensibilidade para detectar o efeito. No tratamento crônico, a sibutramina foi ingerida por um período de dois meses. RESULTADOS: Os tratamentos agudo e crônico, na dose estudada, que é descrita para produzir um efeito de antiobesidade máxima em ratos, não interferem na ansiedade. CONCLUSÕES: As administrações aguda e crônica de sibutramina não estão relacionadas aos efeitos ansiolítico ou ansiogênico.

INTRODUSTION: Sibutramine has been described as a drug recommended for treatment of obesity, since it has the ability to inhibit the reuptake of serotonin and noradrenaline in the central nervous system, thereby increasing energy expenditure. OBJECTIVE: Investigate the anxiogenic and anxiolytic effects of acute and chronic treatment with sibutramine in rats submitted to the task of the elevated plus-maze. METHODS: Diazepam was used as a positive control for the anxiolytic effect, and the task of the elevated plus-maze showed sensitivity to detect the effect. In the chronic treatment, sibutramine was ingested for a period of two months. RESULTS: The acute and chronic treatments at the studied dose, which is described to produce a maximum effect of anti-obesity in rats, did not interfere with anxiety. CONCLUSIONS: The acute and chronic administration of sibutramine is not related to anxiolytic or anxiogenic effects.

Simulations have been carried out on the bromate - oxalic acid - Ce(IV) - acetone oscillating reaction, under flow conditions, using Field and Boyd's model (J. Phys. Chem. 1985, 89, 3707). Many different complex dynamic behaviors were found, including simple periodic oscillations, complex periodic oscillations, quasiperiodicity and chaos. Some of these complex oscillations can be understood as belonging to a Farey sequence. The many different behaviors were systematized in a phase diagram which shows that some regions of complex patterns were nested with one inside the other. The existence of almost all known dynamic behavior for this system allows the suggestion that it can be used as a model for some very complex phenomena that occur in biological systems.

São relatadas, pela primeira vez, a observação de oscilações periódicas, em reator agitado de fluxo contínuo (CSTR), para o sistema bromato-ácido oxálico-Ce(IV)-acetona-ácido sulfúrico. Identificou-se que a reação entre Ce(IV) e a acetona, até então não descrita na literatura e que ocorre antes dos reagentes serem adicionados ao reator, é um fator decisivo para o aparecimento de oscilações regulares.

Periodic oscillations were observed for the first time, in a CSTR, in the system bromate-oxalic acid-Ce(IV)-acetone-sulfuric acid, in a CSTR. A reaction between Ce(IV) and acetone, until now not described in the literature and occurring before the addition of the reagents to the reactor, was identified as a decisive factor for the appearing of the regular oscillations.