Preparation of Compositionally Graded Spherical Particles of Hydroxyapatite/Acesulfame-K by Spray Drying

Spray drying is a process in which an aqueous solution containing dissolved materials is sprayed into a high-temperature furnace in order that the materials undergo instant drying to form powder. The powder thus formed consists of tilled or hollow spherical particles. We considered internal and external compositionally graded spherical particles prepared by the spray-drying method using a solution that contained two compounds with different solubilities. In this study, we investigated the preparation of compositionally graded spherical particles by spray drying a solution containing the low-solubility material hydroxyapatite (Ca(10)(PO(4))(6)(OH)(2); HAp), and the high-solubility material acesulfame-K (C(4)H(4)KNO(4)S). We also examined the elemental mapping of the internal structure of the spherical particles by electron prove microanalysis (EPMA). The results indicate that the external structure of the spherical particles was HAp, and the internal structure of the filled spherical particles was acesulfame-K.