Insight into multilayered alginate/chitosan microparticles for oral administration of large cranberry fruit extract

We present a series of multilayered alginate/chitosan microparticles fabricated via combining ionic gelation with the layer-by-layer (LbL) approach to improve oral administration of large cranberry fruit extract (CFE). Sodium alginate of low (ALGlv) or medium (ALGmv) viscosity was used as a core polymer, and chitosan (CHIT) and ALGmv layers were alternately assembled to form up to seven layers' coating. Microparticles size ranged between 640 and 1120 mu m, and their morphology, moisture content, and structural integrity were affected mainly by the outermost layer's composition. Both the microgel core and shell composition of these microparticles influenced the mechanical properties determined by the parallel plates compression test. Microparticles exhibited good CFE entrapment efficiency (E.E. > 55%) and favorable release profiles in the simulated gastro-intestine environment, well described by the hybrid model of the release kinetics. Our results evidence that polysaccharide-inspired microparticles are good platforms for enhancing the oral bioavailability of poorly water-soluble therapeutic agents.