ASTM F1609-23

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it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: F1609 − 08 (Reapproved 2014) F1609 − 23
Standard Specification for
Calcium Phosphate Coatings for Implantable Materials
This standard is issued under the fixed designation F1609; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This specification covers the material requirements for calcium phosphate coatings for surgical implant applications.
1.2 In particulate and monolithic form, the calcium phosphate materials system has been well-characterized well characterized
regarding biological response (1, 2) and laboratory characterization (2-4). Several publications (5-10) have documented the in
vitro and in vivo properties of selected calcium phosphate coating systems.
1.3 This specification includescovers hydroxylapatite coatings, tricalcium phosphate coatings, or combinations thereof, other
calcium phosphate (for example, octacalcium calcium phosphate, amorphous calcium phosphate, dicalcium phosphate dihydrate)
coatings, or a coating containing a combination of two or more calcium phosphate phases, with or without intentional minor
additions of other ceramic or metallic,elements or compounds (for example, fluorine, manganese, magnesium, carbonate), and
applied by methods including, but not limited to, the following: (1) mechanical capture, plasma spray deposition, (2) plasma spray
deposition, solution precipitation, (3) dipping/sintering, (4) electrophoretic deposition, and (5) porcelainizing, and (6) sputtering.
1.4 For a coating containing two or more calcium phosphate phases, one or more of which will be a major phase or major phases
in the coating, while the other phase(s) may occur as a second or minor phases, the phase composition(s) of the coating should
be determined against each corresponding crystalline phase, respectively. See X1.2.
1.5 Substrates may include smooth, porous, textured, and other implantable topographical forms.
1.6 This specification excludes organic coatings that may contain calcium and phosphate ionic species.
1.6 Warning—Mercury has been designated by EPA and many state agencies as a hazardous material that can cause central
nervous system, kidney, and liver damage. Mercury, or its vapor, may be hazardous to health and corrosive to materials. Caution
should be taken when handling mercury and mercury-containing products. See the applicable product Material Safety Data Sheet
(MSDS) for details and EPA’s website (http://www.epa.gov/mercury/faq.htm) for additional information. Users should be aware
that selling mercury or mercury-containing products, or both, in your state may be prohibited by state law.
This specification is under the jurisdiction of ASTM Committee F04 on Medical and Surgical Materials and Devices and is the direct responsibility of Subcommittee
F04.13 on Ceramic Materials.
Current edition approved March 1, 2014July 1, 2023. Published March 2014July 2023. Originally approved in 1995. Last previous edition approved in 20082014 as
F1609 – 08.F1609 – 08 (2014). DOI: 10.1520/F1609-08R14.10.1520/F1609-23.
The boldface numbers in parentheses refer to the list of references at the end of this specification.
The Joint Committee on Powdered Diffraction has established a Powder Diffraction File. The committee operates on an international basis and cooperates closely with
the Data Commission of the International Union of Crystallinity and ASTM. Hydroxylapatite data can be found on file card No. 9-432; beta tricalcium phosphate data can
be found on file card No. 9-169.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
F1609 − 23
1.7 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
E376 Practice for Measuring Coating Thickness by Magnetic-Field or Eddy Current (Electromagnetic) Testing Methods
F1044 Test Method for Shear Testing of Calcium Phosphate Coatings and Metallic Coatings
F1088 Specification for Medical-Grade Beta-Tricalcium Phosphate Raw Material for Implantable Medical Devices
F1147 Test Method for Tension Testing of Calcium Phosphate and Metallic Coatings
F1160 Test Method for Shear and Bending Fatigue Testing of Calcium Phosphate and Metallic Medical and Composite Calcium
Phosphate/Metallic Coatings
F1185 Specification for Composition of Medical-Grade Hydroxylapatite for Surgical Implants
F1854 Test Method for Stereological Evaluation of Porous Coatings on Medical Implants
F1926 Test Method for Dissolution Testing of Calcium Phosphate Granules, Fabricated Forms, and Coatings
F2024 Practice for X-ray Diffraction Determination of Phase Content of Plasma-Sprayed Hydroxyapatite Coatings
2.2 U.S. Pharmacopeia Convention Documents:
National Formulary XVI,XVI Tribasic Calcium Phosphate
United States Pharmacopeia:
U.S. Pharmacopeia (most current),USP <191> Chemical Tests: Calcium (191), Phosphorous (191), Lead <251>, Mercury
<261>, Arsenic < 211>, and Heavy Metals <231> Method (1)Tests—Calcium and Phosphorous
USP <211> Arsenic
USP <232> Elemental Impurities—Limits
USP <233> Elemental Impurities—Procedures
USP <251> Lead
USP <261> Mercury
2.3 Other Documents:
U.S. Geological Survey Method,Method Cadmium
U.S. Code of Federal Regulations Title 21 (CFR 21), Part 820 Part 820–Quality Quality System Regulation
X-Ray Diffraction Analyses
ICH Q3D ICH Harmonized Guideline for Elemental Impurities
3. Terminology
3.1 Definitions:
3.1.1 amorphous calcium phosphate—a non-crystalline calcium phosphate.
3.1.2 beta tricalcium phosphate—a calcium phosphate substance of empirical chemical formula, Ca (PO ) (see Specification
3 4 2
F1088).
3.1.3 calcium phosphate—any one of a number of inorganic chemical compounds containing calcium and phosphate ions as its
principal constituents.
3.1.4 coating—a layer of mechanically or chemically attached material covering a substrate material.
3.1.5 hydroxylapatite—a calcium phosphate crystalline compound of empirical chemical formula, Ca (PO ) OH (see Specification
5 4 3
F1185).
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Available from U.S. Pharmacopeia (USP), 12601 Twinbrook Pkwy., Rockville, MD 20852-1790, http://www.usp.org.
Crock, J. G., Felichte, F. E., and Briggs, P. H., “Determination of Elements in National Bureau of Standards Geological Reference Materials SRM 278 Obsidian and SRM
688 Basalt by Inductively Coupled Argon Plasma—Atomic Emission Spectrometry,” Geostandards Newsletter, Vol 7, 1983, pp. 335–340.
Available from Standardization Documents Order Desk, DODSSP, Bldg. 4, Section D, 700 Robbins Ave., Philadelphia, PA 19111-5098, http://dodssp.daps.dla.mil.
Available from International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH), ICH Secretariat, Route de Pré-Bois, 20,
P.O Box 1894, 1215 Geneva, Switzerland, https://www.ich.org.
F1609 − 23
4. Chemical or Crystallographic Requirements, or Both
4.1 Chemical:
4.1.1 Elemental analysis for calcium and phosphorous and intentional additions (other than trace elements)elemental impurities)
shall be consistent with the expected stoichiometry of the specific calcium phosphate compound(s). The calcium and phosphorus
content shall be determined using a suitable method such as USP <191> Identification Tests for Calcium and Phosphate, USP
<232> Elemental Impurities—Limits, and USP <233> Elemental Impurities—Procedure (see 2.2) or X-ray fluorescence.
4.1.2 Trace Element Analysis for Hydroxylapatite and Beta Tricalcium Phosphate—The concentration of trace elements in the
coating shall be limited as follows:
Element ppm, max
As 3
Cd 5
Hg 5
Pb 30
total heavy metals (as lead) 50
For reference purposes, the U.S. Pharmacopeia (most current) and U.S. Geological Survey Method, Cadmium, shall be used.
4.1.2 The analysis of other trace elements elemental impurities may be required, based on the conditions, apparatus, or
environments specific to the coating application technique used.
4.1.2.1 The significance of elemental impurities within an absorbable material is ultimately dependent on the dimensional
characteristics of the final product and the rate of release of those initially interstitial elements into the surrounding tissue and
extracellular fluid. Thus, any risk assessment of such impurities will be dependent on the final product design and intended
application. More detailed and pharmaceutical-oriented guidance regarding the appropriate means for both monitoring and
assessing relevant elemental impurities within a final product can be found in USP Chapters <232> and <233> and in the ICH
Harmonised Guideline for Elemental Impurities—Q3D.
4.1.2.2 Determine the concentration of the respective elemental impurities within the coating by utilizing inductively coupled
plasma mass spectroscopy (ICP-MS) or inductively coupled plasma atomic or optical emission spectroscopy (ICP-AES or
ICP-OES) or an equivalent alternative method as described in Chapter <233> of the U.S. Pharmacopeia. The specific 24 different
elemental impurities of interest are outlined in both USP <232> and in Table A.2.2 of the ICH Harmonised Guideline for Elemental
Impurities—Q3D. Both of these documents include risk-based approaches toward the assessment and control of elemental
impurities.
4.1.2.3 Except for intentionally added elements, assess the obtained results for compliance with the Parenteral Concentration
limits described within the Individual Component Option of USP <232>, Table 3 (derived from ICH Q3D Option 1, Table A.2.2).
If all listed elements except for those that are intentionally added can be assured to be maintained within the Parenteral
Concentration Individual Component Option limits, the material “conforms” to the USP <232> elemental impurities limits (except
for those intentionally added). If any listed element (other than those intentionally added) cannot be controlled to be maintained
within the prescribed USP <232> limits, the material does not conform with the USP <232> elemental impurities limits and the
concentration (in ppm, per USP <233> or equivalent) of each uncontrolled element shall be both monitored and reported.
4.1.2.4 The elemental impurities thresholds for the Individual Component Option of USP <232>, Table 3, provide specific
elemental daily dosage limits for parenteral drug products. These daily elemental impurity limits (including those applied to
intentionally added elements) should be considered as conservative thresholds for informational purposes only when applied to
absorbable implants. Proper application of these limits in setting material specifications should consider the amount of the coating
in the final implant product as well as its degradation and elemental elution rate into the surrounding tissue.
4.1.2.5 The elemental impurity content of the coating used in implants with a successful clinical history may also be considered
in setting limits for material specifications. For such data to be relevant, analyses shall be consistent with the methods of USP
<233> and shall be conducted on raw material lots used for clinically released product.
4.1.3 The analysis of intentional additional elements or compounds such as fluorine, manganese, magnesium, carbonate, and so
forth shall be specified (concentration in ppm, per USP <233> or equivalent) for calcium phosphate coa
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