Monobasic Calcium Phosphate Monohydrate

About Monobasic Calcium Phosphate Monohydrate

Calcium phosphate (CaP) is the common name of a family of minerals containing calcium cations (Ca²⁺) together with orthophosphate (PO₄³⁻), metaphosphate (PO₃⁻), or pyrophosphate (P₂O₇⁴⁻) anions, and sometimes hydrogen (H⁺) or hydroxide (OH⁻) ions. CaP is the principal form of calcium found in bovine milk and blood. It is the major inorganic constituent of bone (~60 wt % of bone), and the main constituent of tooth enamel (ca. 90%). Calcium phosphates with a Ca/P atomic ratio between 1.5 and 1.67 are called apatites (e.g., hydroxyapatite or fluorapatite).

Calcium phosphate (CaP) bioceramics are widely used in the field of bone regeneration, both in orthopedics and in dentistry, due to their good biocompatibility, osseointegration and osteoconduction.

Calcium phosphates are commonly used in medical applications in the form of cements, coatings, scaffolds, and paste.

Individual calcium phosphate phases like monobasic calcium phosphate monohydrate are the major members of the CaP family that are of interest to biomedical applications.

Monobasic calcium phosphate monohydrate (MCPM)

MCPM is the most acidic and water-soluble CaP phase. It does not form in living organisms. Yet, it is used as a component of several self-hardening CaP cements and as sealer in dentistry. It is associated with the first acidic proton of H3PO4, and can be prepared by partial neutralization of the phosphoric acid with calcium hydroxide, followed by evaporation of water at low temperature, in acidic conditions. The hydrated monocalcium phosphate crystallizes as platelets elongated along the c-axis of the triclinic structure. MCPM-containing chewing gum was found to produce significantly greater saliva flow and lower salivary pH than a control gum. MCPM is marked as food additive E341 and is often added to toothpastes. However, pure MCPM is not biocompatible with bone due to its acidity.