RESUMEN
To overcome the instability of pectin-Ca2+ gels based oral colon-specific drug delivery system (OCDDS) in the upper gastrointestinal tract, the chemical cross-linked pectin carriers were prepared by adding succinic anhydride and glutaric dialdehyde as the cross-linking reagents. The diclofenac sodium was employed as the water-soluble drug model to calculate the controlled release properties. The encapsulation efficiency and loading efficiency were measured and the sample PG1 shows the best efficiency of 78.81% and 7.78%, respectively. The simulative release rate was estimated and the cumulative release rate of sample PG1 reached to a maximum of 3.04, 3.66 and 79.43% in SGF, SSIF and SCF. The release data was employed to fit the First order, Higuchi, Bhaskar, and Ritger-peppas model and the goodness of the fit was calculated by the regression coefficient. The succinic anhydride and glutaric dialdehyde cross-linked pectin were characterized by FTIR to prove the cross-linking reaction. In addition, FE-SEM characterization of sample PG1 indicated the rally microsphere with smooth surface. The sample PG1 after the digestion was also characterized by the FE-SEM, and irregularly structure was obtained.
Asunto(s)
Diclofenaco/química , Portadores de Fármacos/química , Liberación de Fármacos , Pectinas/química , Cinética , Microesferas , Tamaño de la Partícula , Solubilidad , Agua/químicaRESUMEN
The pectin gel has been proved to be an effective material for methylene blue (MB) removal, but it presented low adsorption rate. To get over the vice, the pectin microgel particles (PMP) was prepared. No matter high or low initial MB concentration, the PMP presented high adsorption rate with equilibrium time of 20min. The adsorption process based on monolayer adsorption and adsorbance of 284.09mg/g was obtained. What's more, the adsorption process was electrostatic adsorption with mean free energy of 74.223kJ/mol. The pseudo-second-order kinetic model fitted perfectly to the experimental data. The MB uptake was controlled by film diffusion mechanism. Furthermore, the recovery efficiency of regenerated PMP were higher than 80% after three cycles. The present study showed the PMP presented acceptable adsorbance, high adsorption rate and recovery efficiency. Thus, we believe that the PMP was a promising candidate for MB cleanup.
Asunto(s)
Colorantes/aislamiento & purificación , Azul de Metileno/aislamiento & purificación , Pectinas/química , Contaminantes Químicos del Agua/aislamiento & purificación , Adsorción , Colorantes/toxicidad , Conservación de los Recursos Naturales , Humanos , Residuos Industriales/prevención & control , Cinética , Azul de Metileno/toxicidad , Soluciones/química , Termodinámica , Contaminantes Químicos del Agua/toxicidad , Purificación del Agua/métodosRESUMEN
The extraction of pectin from sugar beet pulp by citric acid was carried out under different conditions using Box-Behnken design for four independent variables (pH, temperature, time and liquid to solid ratio). The yield of sugar beet pulp pectin ranged from 6.3% to 23.0%, and the content of protein from 1.5% to 4.5%. All independent variables significantly affected the yield, and all variables except liquid to solid ratio significantly affected the protein content. The yield increased as decreasing pH of extracting solution, extending time and advancing temperature, and an opposite relationship of effects between variables and content of protein was obtained. The chemical composition of collected samples was determined. Moreover, from the results of emulsifying properties study, the extracted pectin from sugar beet pulp could prepare steady oil-in-water emulsions. Therefore, it was inferred that the extraction conditions could influence yield and protein content, resulting in different emulsifying property.