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Braz. J. Pharm. Sci. (Online) ; 58: e18946, 2022. tab, graf
Article in English | LILACS | ID: biblio-1364411


Abstract To investigate structure-property relationship of polymer-based curcumin solid dispersion (SD), three acrylic polymers were used to formulate curcumin SD by solvent evaporation method. Curcumin Eudragit EPO SD (cur@EPO), curcumin Eudragit RS PO SD (cur@RSPO) and curcumin Eudragit RL PO SD (cur@RLPO) showed deep red, golden orange and reddish orange color, respectively. Cur@RSPO entrapped 15.42 wt% of curcumin followed by cur@RL PO and cur@EPO. FTIR spectra indicated that in cur@EPO, curcumin may transfer hydrogen to the dimethylaminoethyl methacrylate group and thus change its color to red. In contrast, curcumin may form hydrogen bonding with Eudragit RS PO and Eudragit RL. Curcumin exists in amorphous state in three SDs as proved by differential scanning calorimetry and X-Ray diffraction measurement. In vitro digestion presented that lower pH value in simulated gastric fluid (SGF) stimulates the curcumin release from cur@EPO while permeability influences the release profile in other two SDs. When in simulated intestinal fluid (SIF), first order release model governs the release behaviors of all three SDs which showed sustained release pattern. Our results are helpful to elucidate how structure of polymer may impact on the major properties of curcumin contained SD and will be promising to broaden its therapeutic applications.

Polymers , Curcumin/analysis , Methods , Solvents/administration & dosage , X-Ray Diffraction/instrumentation , In Vitro Techniques/methods , Calorimetry, Differential Scanning/methods , Evaporation/classification , Spectroscopy, Fourier Transform Infrared , Color , Citrus sinensis/classification , Hydrogen-Ion Concentration
Psicol. reflex. crit ; 33: 19, 2020. tab, graf
Article in English | LILACS-Express | LILACS, INDEXPSI | ID: biblio-1143584


Abstract Accumulating evidence over the last two decades has established the causal role of a unidirectional orthography in shaping speakers, mental representations of time. Casasanto and Bottini (Journal of Experimental Psychology: General, 143, 473-479, 2014) extended previous findings by showing that exposure to mirror-reversed orthography of speakers' native language could completely redirect their mental timelines within minutes. However, the question of whether such a causal effect of writing direction on temporal cognition can be identified in speakers whose native languages adopt bidirectional orthographies remains underexplored in the literature. To address this issue, the present study focused on Japanese which uses bidirectional writing systems, one proceeding horizontally from left to right (HLR) and one vertically from top to bottom (VTB). Two experiments were performed, and the tasks asked participants to process standard/mirror orthography prime questions about time arranged horizontally or vertically, followed by horizontal or vertical arrays of pictorial target stimuli about temporal relations. Results demonstrated that Japanese speakers encoded passage of time into a top-to-bottom linear path commensurate with the VTB writing direction, but they did not align their mental representations of time with the HLR writing orientation. Accordingly, exposure to mirror-reversed bidirectional orthographies redirected Japanese speakers' vertical but not horizontal space-time mappings. Theoretical implications concerning the causal effects of bidirectional orthographies and the generalizability of the representational flexibility of time maintained by Casasanto and Bottini (Journal of Experimental Psychology: General, 143,473-479) are discussed.