Biomaterials Hydroxyapatite

Biomaterials Hydroxyapatite

Inorganic materials for the biomaterials field


  • Hydroxyapatite is basic calcium phosphate and exists naturally as a major component of bones and teeth and as an ore in nature.
  • Hydroxyapatite shows high biocompatibility and is utilized in biomaterials such as artificial bones, dental implants, and coating materials for artificial joints.
  • Tomita Pharmeceuticals’ hydroxyapatite conforms to ASTM* standards, and in addition to meeting standards for quality and impurities as raw material for medical equipment, its physical properties are strictly controlled according to the requirements of each application.
  • Since impurities are controlled and managed during production, there are few elemental and crystalline structural impurities, resulting in high purity.
  • It therefore inherently has a high degree of whiteness, making it ideal for products with a white coating.

*ASTM standards are developed and published by ASTM International (formerly known as the American Society for Testing and Materials), the world’s largest standards organization.

  • Chemical name: Hydroxyapatite (tricalcium phosphate)
  • Chemical composition: Ca10(PO4)6(OH)2 CAS.No. 1306-06-05

Product Name Use Characterstics
Hydroxyapatite C For industrial use Abrasives, materials for plasma thermal spraying,
raw materials for biomaterials
(artificial bone, dental implants, bone filler)
  • Capable of coating PEEK and Ti alloys
  • Lineup based on physical properties
  • Spherical granule type
  • ISO/ASTM compliant
Hydroxyapatite HD
Hydroxyapatite FP

Hydroxyapatite for Thermal Spraying

Our hydroxyapatite conforms to ISO13779-6. Since medical devices such as implants exist in the body for a long period of time, elemental impurities and analogous substances in their raw materials must be strictly controlled.
We strictly control hydroxyapatite from raw materials to manufacturing and quality inspection, and can provide products that qualify as raw materials for medical equipment as well as conforming to ISO.

Physical properties

Test case Example of Analysis
Hydroxyapatite C Hydroxyapatite HD Hydroxyapatite FP
Bulk density(ISO 3923-1) 0.5 g/mL 0.8 g/mL 1.0 g/mL
Particle size distribution D10 57 μm 57 μm 15 μm
D50 91 μm 93 μm 28 μm
D90 150 μm 156 μm 48 μm

SEM image

Hydroxyapatite C Hydroxyapatite HD Hydroxyapatite FP
Hydroxyapatite C Hydroxyapatite HD Hydroxyapatite FP

Example of application as a coating material

We performed plasma thermal spraying experiments to confirm the coating characteristics of our hydroxyapatite on Poly Ether Ether Ketone (PEEK), which is used as a base material for implants.

Test conditions

Test Case Conditions
Thermal Spraying Method Atmosphere Plasma Spray
Base Material PEEK
Coating Material
  • Hydroxyapatite FP
  • Competitor product
Blasting conditions Media Al2O3 (WA♯46)
Pressure 0.5 MPa
Distance 150 mm
Thermal Spray Equipment
  • GTV/MF-P
  • HVOF-K1000
  • Plasma Torch Typ F4
Working gas Ar SLPM 30
He SLPM 150
Carrier gas N2 SLPM 4
Current value A 500
Spray distance mm 100

Microscopic image of coated film

Before coating After coating
Before coating After coating

Cross-sectional image of coated film

Magnification Hydroxyapatite FP Competitor Product
×200 Hydroxyapatite FP Competitor Product

Our hydroxyapatite FP formed a film on the PEEK surface in a uniformly melted state.
In contrast, the competitor product failed to form a film.

Characteristics of Coating Film

Test case Result
Purity Crystallinity 63%
Impurity Phase α-TCP 1.40%
β-TCP 1.60%
TTCP 1.00%
CaO 0.20%
Ca/P ratio 1.67
Characteristics Vickers hardness 244 (HV0.3)
Abrasion 4.2 mg
Film thickness 170 um
Surface roughness (Ra) 4.1 um

Hydroxyapatite FPs showed little decomposition to impurity phase after thermal spraying and formed a high-strength film.
Therefore, it showed desirable properties as a surface coating material for medical equipment.


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