Effect of process parameters on the performance of spray dried hydroxyapatite microspheres

Preparation of hydroxyapatite microspheres by spray drying technology at different process parameters was investigated in this paper. The results indicated that the process parameters, such as the slurry concentration, compressed air flow rate, and liquid feed rate, played important roles in controlling the performance of hydroxyapatite microspheres, such as the specific surface area, the size distribution, etc., but had little influence on the micromorphology, phase composition and crystallinity. The spray dried particles were composed of low crystallinity and the scanning electron microscope results showed that they had good spherical structure with smooth surface. The results of the laser diffraction particle size analyzer indicated that the mean size increased with the increase of the slurry concentration and compressed air flow rate. Experimentally, most of the process parameters were crucial to the productive efficiency.