The present invention is directed to calcium phosphates in granular form having an X-ray diffraction pattern characteristic of hydroxyapatite in which a portion of the anions of the crystal lattice are substituted with carbonate anions and which have good compressibility and flow properties in direct compression applications. The invention is also directed to the methods for preparing the calcium phosphate aforesaid granules characterized in that the methods include the processing of a brushite dicalcium phosphate solution having a specified particle size distribution using a solution of an alkaline earth carbonate for a sufficient period of time to allow the transformation of the brushite calcium phosphate into hydroxyapatite calcium phosphate.