Microencapsulation of riboflavin with galactomannan biopolymer and F127: Physico-chemical characterization, antifungal activity and controlled release

Riboflavin (Rf) is a water-soluble vitamin essential for living beings; it acts as cofactor in various processes of oxidation-reduction in a cellular system. However it is photosensitive and may suffer reactions of degradation. In this way, the objective of this study was to perform the microencapsulation of (Rf) by spray drying with the galactomannan biopolymer (G), in order to preserve or enhance their functional properties. Microencapsulation was used as the coating matrix for the biopolymer (G) and the surfactant F127 in concentrations of 0.10% and 0.15%. The biopolymer (G), (Rf) and the microparticles produced (GRf, GRfF1 and GRfF2) were characterized by FT-IR, XRD, TGA, DSC and SEM. Biopolymer (G) was characterized by H-1 NMR and its viscosity was studied. The microparticles produced were analyzed for viscosity, antifungal activity and controlled release in vitro. The antifungal activity of the microparticles was evaluated by means of the broth microdiluition method and checkerboard test using strains of Trichophyton rubrwn e Candida albicans. Controlled release was performed with the (Rf) and the microparticles in pH 1.2 (0.1 M) and pH 6.8 (0.025 M). By means of chemical tests it was found that the efficiency of encapsulation in microparticles ranged from 87.14-88.53%. The viscometric study pointed to greater fluidity of the microparticles produced when compared with biopolymer (G). All the microparticles produced showed antifungal potential against T. rubrutn, however the (GRf) demonstrated better inhibitory capacity. In the checkboard test there was no synergistic effect of the (GRf) microparticles with ketoconazole. The release showed that the biopolymer (G) is a satisfactory matrix for the microencapsulation of (RD, since it slows the release in both acidic and basic media when compared with the isolated (Rf). These results indicate that the galactomannan can be used efficiently in the microencapsulation of (Rf), since it conserves the anti fungal potential against T.rubrwn and slows the delivery of the bioactive.