Overview
ISO 13175-3:2012 - "Implants for surgery - Calcium phosphates - Part 3: Hydroxyapatite and beta‑tricalcium phosphate bone substitutes" defines quality, compositional and testing requirements for synthetic hydroxyapatite (HA), β‑tricalcium phosphate (β‑TCP) and biphasic HA/β‑TCP bone substitutes supplied as blocks or granules. It is intended for manufacturers, testing laboratories and regulators. The standard is not applicable to cell‑seeded products, calcium phosphate cements or bone void fillers containing materials other than HA and β‑TCP.
Key technical topics and requirements
- Material scope: monophasic HA, monophasic β‑TCP and biphasic HA/β‑TCP in blocks or granules.
- Phase purity and composition: crystalline phases must be quantified by X‑ray diffraction (XRD) in accordance with ISO 13779‑3.
- Monophasic HA: HA mass fraction ≥ 95% of crystalline phases; CaO ≤ 1% of crystalline phases.
- Monophasic β‑TCP: β‑TCP mass fraction ≥ 95% of crystalline phases.
- Biphasic products: HA/β‑TCP ratio must be specified with ±5% absolute tolerance.
- Trace element limits and impurity control: specified maximums (e.g., Arsenic 3 mg/kg, Cadmium 5 mg/kg, Mercury 5 mg/kg, Lead 30 mg/kg, Heavy metals 50 mg/kg). Quantification methods include ICP‑AES, ICP‑MS, AAS or ISO 13779‑3 methods. Impurities >1 000 mg/kg must be identified and assessed for effects on bone healing and biocompatibility (ISO 10993‑1).
- Form, size and dimensional data: block dimensions and granule size distributions must be specified (laser diffraction ISO 13320 or sieving ISO 2591‑1; report D10/D50/D90 or min/max). Packaging must state volume.
- Porosity and pore architecture: total porosity calculation, micropore and macropore sizing (SEM or micro‑CT methods), interconnection sizing (mercury porosimetry ISO 15901‑1). Emphasis on interconnected macroporosity for bone ingrowth.
- Other tests: dissolution and pH change, mechanical strength measurement and required test reporting.
Applications - who uses this standard
- Medical device manufacturers for product specification, design control and batch release of synthetic bone substitutes.
- Quality control & analytical labs performing phase analysis, trace element testing, porosity and particle sizing.
- Regulatory affairs teams preparing technical files and safety documentation showing compliance with recognized standards.
- R&D and material scientists developing osteoconductive scaffolds and biphasic formulations.
Related standards (normative references)
Keywords: ISO 13175-3, hydroxyapatite, beta‑tricalcium phosphate, bone substitutes, porosity, XRD, trace elements, biphasic bone graft, granules, surgical implants.