During the synthesis of different calcium phosphate phases, the pH variation of the slurry solution affects the purity, structure, and chemical composition of final products. High-capacity buffering agent solutions were used to keep the pH value constant during the synthesis procedure. Consequently, high purity and single-phase HA, b-TCP. Also, morphological evaluation of granules from plate-like to completely porous structure is another result of keeping the slurry pH constant during the synthesis step. Increasing the specific surface area of BCP granules from 10 to 38 m2/g affected the in vitro behaviour of the products. Precipitation of 20 nm hydroxyapatite phase after suspension of experimental samples for 30 days in simulation body fluid attributed to using Tris buffer solution during synthesis.