A Novel Hollow Hydroxyapatite Microspheres/Chitosan Composite Drug Carrier for Controlled Release

A novel composite drug carrier with excellent sustained and pH-sensitive release performance was prepared by mixing hollow hydroxyapatite (HA) microspheres and chitosan solution with pH-sensitive characteristics. The hollow HA microspheres with mesopores filled on their multilayered spherical shell were obtained by converting borate glass with a novel composition of 19Na 2 O-17CaO-64B 2 O 3 (wt%). The structure, phase composition and morphology of HA microspheres were characterized by SEM, SEM-EDS, XRD, FTIR and N 2 adsorption-desorption measurements.