AbstractThe formation of a biologically equivalent carbonatecontaining apatite on the surface of synthetic calcium phosphate ceramics (CPC) may be an important step leading to bonding with bone. Reactions of several single phases CPCs upon immersion into a simulated physiologic solution (SPS) with an electrolyte composition of human plasma were determined. The CPCs covered a wide range of solution stabilities from low‐soluble hydroxyapatites (HA) to metastable tricalcium phosphates (TCP) and tetracalcium phosphate (TTCP). Changes in chemical composition of SPS and infrared spectral features after CPC immersion were analyzed. New phase formation was observed on all the CPCs. However, kinetics, compositions, and structures of the new phases were significantly different. The studied CPCs can be characterized by the time to new phase formationin vitro; the minimum time for measurable precipitate formation was found to increase in the order: not‐well‐crystallized HAs