[en] The aim of this work is investigate the use of a rotary dryer with inert bed for drying of microalga Spirulina platensis. The influence of air temperature, feed rate, rotation speed and inerts filling degree was quantified. The contents of main bioactive compounds were also analyzed. The results shown that the used drying system proved to be an interesting alternative for a possible use of this microalga, if performed under adequate conditions. It was identified conditions with high drying performance and with the preservation of product quality. (Author)

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[en] Dapsone (DPS) is an oral antibiotic used to treat diseases caused by microbacteria, such as tuberculosis and leprosy. It belongs to Class II of the Biopharmaceutical Classification System because it shows water solubility. This fact contributes to the reduction of its bioavailability and its therapeutic efficacy. The synthesis of novel solid drug dispersions, such as cocristates, has been a highly feasible alternative for improving the physico-chemical properties of drugs, such as increasing water solubility and improving their therapeutic efficacy. Thus, this work aimed to synthesize and characterize a new DPS cocrystal using para-aminobenzoic acid (PABA) as a conformer. For this, the synthesis of this cocrystal was carried out using the slow solvent evaporation method, where masses of DPS and PABA in the molar ratio of 1: 2 were weighed. These masses were placed in a 50 mL beaker, where 40 mL of the ethanol / acetone mixture (1: 1 v / v) was added for complete solubilization of the compounds. This solution was then allowed to stand at 8 ° C for 15 days. The final product was left in an oven with forced air circulation at 30 ° C for 2 hours to ensure complete evaporation of the solvents. For comparison purposes, the individualized starting compounds (DPS and PABA) were recrystallized by the same cocrystallization process. Subsequently, the starting compounds and the cocrystalline DPS-PABA (1: 2) were characterized by powder X-ray diffraction (PXRD) and differential scanning calorimetry (DSC). The results obtained by PXRD for the cocrystal, when compared to those obtained for the starting compounds, evidenced the formation of a new crystalline phase, whose diffractogram showed the appearance of new peaks between 2 deg and 3,5 deg (2θ) and the displacement of others. The DSC curve confirmed the formation of the cocrystal resulting from the interaction of DPS with PABA in the molar ratio of 1: 2, as this new material exhibited a single well defined endothermic peak, which was attributed to a fusion event. The enthalpy change shows the phase stability and the purity of the cocrystallization product. This event occurred at a temperature below the melting point of DPS, suggesting that the new pharmaceutical form of this drug is more soluble. Thus, the results of this study confirmed the formation of the DPS-PABA cocrystal (1: 2). This new material shows a promising alternative for improving the aqueous solubility of DPS and increasing its efficacy in the treatment of diseases. (author)

[en] X-ray multiple diffraction technique using synchrotron radiation is applied to characterize the PrAl₂ magnetocaloric compound. Renninger scans (phi-scans) of the (0 0 2) primary reflection were measured in the Brazilian Synchrotron Laboratory (LNLS). The (5 3 3-bar) (5 3 5) four-beam case provided a=8.0277(5) A and the sample surface polishing effect was clearly observed through the measurement of Bragg-surface diffraction (BSD) peak and the mapping (MBSD) of its multiple diffraction condition

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