Chondroitin sulfate micro granules embedded with oligochitosan-calcium complexes for potential osteoporosis prevention

[Display omitted] •Calcium citrate and chondroitin sulfate (CS) were manufactured to edible granules.•The edible granules were reinforced in functions by oligochitosan (Och).•The composite granules provided Ca protection and multi-nutritious delivery.•The composite granules have huge potentials in sustaining bone health. Calcium citrate (CaCi) and chondroitin sulfate (CS) were renovated as edible granules by spray-drying and polymer (Eudragit) coating to develop bone-protective product. The granules were reinforced functionally with oligochitosan (Och). Characterizations of IR, DSC and XRD concluded that Ca and Och were concordantly incorporated into granules and embedded into the CS matrix. The Ca-loading CS granules achieved about 1.6% Ca loading and 25% of Ca recovery in encapsulation. CaCi and Och would chelate together during preparation of the granules. Eudragit coating enabled the granules smooth and compact, and resulted in slow Ca release in dissolution. In a 28-days of animal test, oral administration with Ca + Och/CS granules inhibited osteoporosis progression in OVX rats through increasing serum Ca/P and internal Ca retention, as well as enhancing bone density and major minerals. Therefore, the composite granules have some potential in sustaining bone health owing to its improvements in Ca protection and the multi-nutritious delivery.