Several approaches have been developed for the preparation of calcium phosphate cements, some of them are commercially available, and they have proved very effective bone substitutes in different applications. Some of their properties, such as the ability to incorporate different molecules make them very interesting candidates as drug carriers. We were interested in this paper to the study of the hydrolysis after curing a cement composed of the tricalcium phosphate (-TCP) and monocalcium phosphate monohydrate (MCPM), in aqueous solution with a controlled pH, leading system to transform towards other calcium phosphates known by their very wide including biological and medical applications. In this study the operating conditions are chosen in order to have apatite containing molecular oxygen. Characterization by analyzes (IR, XRD etc.) show that the proposed process provides better results for oxygenated apatite containing together molecular oxygen and peroxide ions. These are removed by heating the final product at a temperature of 300 ° C.