1、Designation: F2224 09 (Reapproved 2014)Standard Specification forHigh Purity Calcium Sulfate Hemihydrate or Dihydrate forSurgical Implants1This standard is issued under the fixed designation F2224; the number immediately following the designation indicates the year oforiginal adoption or, in the cas
2、e of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This specification covers material requirements for un-fabricated and fabricated forms of h
3、ydrated calcium sulfateintended for surgical implants. Fabricated forms may includepressed and cast surgical implants in various geometric shapes.The calcium sulfate hemihydrate in the unfabricated form canbe converted with the addition of water or other water-containing solutions to a fabricated ca
4、lcium sulfate dihydrateform.1.2 The requirements of this specification apply to calciumsulfate combined with two molecules of water or two calciumsulfate molecules sharing one water molecule.Approximate chemical formulae:Calcium Sulfate DihydrateCaSO42H2OCalcium Sulfate HemihydrateCaSO41/2H2O or CaS
5、O4H2OCaSO41.3 This specification specifically excludes calcium sulfateanhydrite and calcium sulfate forms that contain additives suchas reinforcing phases, medicaments, biological agents, and soforth.1.4 The presence of processing aids does not exclude aproduct from the physical and mechanical requi
6、rements of thisspecification.1.5 Some provisions of Specification C59/C59M and TestMethods C472 apply. Special requirements that are detailed inthis specification are included to characterize the materialwhich will be used in surgical implants.1.6 The biological response to calcium sulfate in bone t
7、issuehas been well characterized by a history of clinical use (1-14)2and by laboratory studies (15-18).1.7 The following precautionary caveat pertains only to thetest method portion, Sections 4, 5, and 6, of this specification.This standard does not purport to address all of the safetyconcerns, if a
8、ny, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety andhealth practices and determine the applicability of regulatoryrequirements prior to use.2. Referenced Documents2.1 ASTM Standards:3C59/C59M Specification for Gypsum Casting Plaster an
9、dGypsum Molding PlasterC472 Test Methods for Physical Testing of Gypsum, Gyp-sum Plasters and Gypsum ConcreteF648 Specification for Ultra-High-Molecular-Weight Poly-ethylene Powder and Fabricated Form for Surgical Im-plantsF756 Practice for Assessment of Hemolytic Properties ofMaterialsF763 Practice
10、 for Short-Term Screening of Implant Materi-alsF813 Practice for Direct Contact Cell Culture Evaluation ofMaterials for Medical DevicesF895 Test Method forAgar Diffusion Cell Culture Screeningfor CytotoxicityF981 Practice for Assessment of Compatibility of Biomate-rials for Surgical Implants with Re
11、spect to Effect ofMaterials on Muscle and BoneF1088 Specification for Beta-Tricalcium Phosphate for Sur-gical ImplantationF1635 Test Method forin vitro Degradation Testing of Hy-drolytically Degradable Polymer Resins and FabricatedForms for Surgical Implants2.2 Other Documents:BS 6463-102: 2001 Quic
12、klime, Hydrated Lime and NaturalCalcium CarbonatePart 102: Methods for ChemicalAnalysis41This specification is under the jurisdiction of ASTM Committee F04 onMedical and Surgical Materials and Devices and is the direct responsibility ofSubcommittee F04.13 on Ceramic Materials.Current edition approve
13、d March 1, 2014. Published March 2014. Originallyapproved in 2003. Last previous edition approved in 2009 as F2224 09. DOI:10.1520/F2224-09 (2014).2The boldface numbers in parentheses refer to the list of references at the end ofthis standard.3For referenced ASTM standards, visit the ASTM website, w
14、ww.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.4Available from the British Standards Institution, c/o IHS Engineering/IHSInternational, 15 Inverness Way East, Englew
15、ood, CO 80112, http:/.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1US Pharmacopeia XXIV (USP 24) NF-195CFR Title 21, Part 820 Quality System Requirements6Food Chemical Codex (FCC)7European Pharmacopeia8ISO 10993-1 Biological Evalua
16、tion of Medical Devices93. Terminology3.1 Definitions:3.1.1 calcium sulfate anhydritea chemical substance hav-ing approximate molecular formula of CaSO4.3.1.2 calcium sulfate dihydratea chemical having theapproximate molecular formula of CaSO42H2O. This sub-stance is also known as gypsum.3.1.3 calci
17、um sulfate hemihydratea chemical substancehaving approximate molecular formula of CaSO41/2H2OorCaSO4H2OCaSO4. The mineral name of this substance isbassanite and the substance is also known as Plaster of Paris inthe clinical literature.3.1.4 processing aidsany constituent intentionally used inthe pro
18、cessing of the raw material to fulfill a certain techno-logical purpose during treatment or processing. Some ex-amples would be: binders, lubricants, compaction aids,disintegrants, plasticizers, deflocculants, wetting agents, waterretention agents, antistatic agents, antifoam agents, foamstabilizers
19、, chelating or sequestering agents, phase stabilizers,and so forth.3.1.4.1 DiscussionUse of a processing aid may result inthe unintentional but technically unavoidable presence ofresidues of the substance or its derivatives in the final product.3.1.5 set timefor a mixture of calcium sulfate hemihydr
20、ateand an aqueous solution, set time is defined as the elapsed timebetween the onset of mixing and the development of sufficientmechanical properties to meet a specific criteria (for example,hardness or resistance to indentation).4. Chemical Requirements4.1 Calcium sulfate for surgical implants (raw
21、 material)shall have a purity of not less than 98 % for calcium sulfate(absent of water) when measured by USP 24 NF 19. (Thispurity measurement method may not be applicable to thefabricated forms containing substantial quantities of additives.)4.2 The total concentration of heavy metals (for example
22、,lead, arsenic, cadmium, antimony, bismuth, and mercury) inthe calcium sulfate raw material shall be limited to less than 10ppm. Other trace elements, such as iron, may also affectimplant performance and should be kept to a minimum. Forexample, for calcium sulfate to meet USP grade, the ironconcentr
23、ation should not be higher than 100 ppm. Methods formeasuring these trace elements are described in SpecificationF1088 (Coupled PlasmaAtomic Absorption Spectrometry),the United States Pharmacopeia (USP), EuropeanPharmacopeia, or Food Chemical Codex (FCC). A secondmethod that may be used to analyze a
24、cid insoluble impuritiesis described in BS 6463-102.4.2.1 When calcium sulfate dihydrate is converted intocalcium sulfate hemihydrate, the mass of the material isreduced by approximately 15 % due to dehydration. Dependingon the conversion process, the quantities (total mass) of mostor all of the tra
25、ce elements present in the dihydrate are notaffected. Therefore, the concentration of those trace elementsin the resulting hemihydrate material can be expected toincrease by approximately 15 %. This should be taken intoaccount when setting acceptance criteria for a calcium sulfatedihydrate raw mater
26、ial that will be used to produce a hemihy-drate final product that is expected to conform to this specifi-cation.5. Physical and Mechanical Characterization5.1 The following physical and mechanical characterizationmay be applicable to calcium sulfate for surgical implantapplications in either the fa
27、bricated form or intra-operativefabricated form. When characterization test results are reportedin labeling, the test methods associated with these results shallbe referenced. Labeling can be defined as but is not limited tothe product label, brochures, technical monographs, and otherrelated documen
28、tation.5.2 Set TimeIf set time is an applicable property, it shouldbe reported along with the method by which it was determinedin order to inform the final user. Test Methods C472 asdescribed in Specification C59/C59M can be used to define atypical set time. The actual method used for set time deter
29、mi-nation shall be described or referenced in labeling.5.3 Compressive StrengthCalcium sulfate dihydrate in afabricated final form is intended to be used in non-load bearingapplications. If applicable to implant performance, documen-tation of typical compressive strength and the methods used todeter
30、mine it should be reported in order to inform the final user.Test Methods C472 as described in Specification C59/C59Mcan be used for the typical compression strength determination.The actual method used shall be described or referenced inlabeling.5.4 In vitro DegradationFor calcium sulfate dihydrate
31、 in afabricated final form, weight loss from dissolution may bereported. If reported, the method used should be described orreferenced. Additional information is given in Appendix X1.4.6. Test Specimen Fabrication6.1 Prepare test specimens from material(s) produced ac-cording to the same manufacturi
32、ng procedures and processesemployed in fabricating the implant device.7. Quality Program Requirements7.1 The manufacturer shall conform to Quality SystemsRegulations (see Title 21, part 820, of the U.S. Code of FederalRegulations) or its equivalent.5Available from U.S. Pharmacopeia (USP), 12601 Twin
33、brook Pkwy., Rockville,MD 20852, http:/www.usp.org.6Available from U.S. Government Printing Office Superintendent of Documents,732 N. Capitol St., NW, Mail Stop: SDE, Washington, DC 20401, http:/www.access.gpo.gov.7Available from National Academies Press, 500 Fifth St., NW, Lockbox 285,Washington, D
34、C 20055, http:/www.nap.edu.8Available from EDQM, European Pharmacopeia, Council of Europe, B.P. 907,F-67029, Strasbourg, France, http:/www.edqm.eu.9Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.F2224 09 (2014)28. Keyword
35、s8.1 bone; calcium sulfate; gypsum; implant; plasterAPPENDIX(Nonmandatory Information)X1. RATIONALEX1.1 The biocompatibility of calcium sulfate may dependupon processing conditions and source material, both whichmay not be identified by the compositional requirements of thisspecification. The biocom
36、patibility of these products should beensured by a combination of preclinical testing and processcontrols. Material derived under the desired process conditionsshould be tested in accordance with the recommendations ofPractices F756, F763, F813, and F981; Test Methods F895 andF1635; Specification F6
37、48; and ISO 10993-1, and manufactur-ing controls put in place to ensure that process variationsoutside of acceptable tolerances do not occur. Substantialchanges in process conditions or source material parameterswill necessitate additional biocompatibility or preclinical func-tional testing to ensur
38、e maintenance of an acceptable tissueresponse.X1.2 X-ray powder diffraction (XRD) analysis of the ma-terial provides differentiation between calcium sulfate dihy-drate and calcium sulfate hemihydrate. The International Cen-tre for Diffraction Data (ICDD) designation of calcium sulfatehemihydrate for
39、 surgical implants is ICDD # 41-0224(Bassanite, syn). A typical calcium sulfate dihydrate XRDpattern will show the peaks from ICDD #s 33-0311 (Gypsum,syn), 37-1496 (Anhydrite syn), and 41-0224 (Bassanite, syn).X1.3 The setting time measurement in Section 5 is usefulfor the calcium sulfate hemihydrat
40、e since the hemihydrate mustbe hydrated to a calcium sulfate dihydrate before surgical use.Likewise, the calcium sulfate hemihydrate and dihydrate rawmaterial powders do not have the compressive strength ordegradation attributes that are needed for surgical applicationswithout being converted by hyd
41、ration to calcium sulfatedihydrate or with the dihydrate form pressed into a geometricshape.X1.4 The mechanism of resorption of calcium sulfate invivo is complex and involves both physical dissolution and cellmediated resorption. As a result, in vitro dissolution experi-ments should not be expected
42、to accurately predict in vivoresorption rates. In addition, it has been shown that the choiceof simulated body fluid can radically alter in vitro resorptionrates. For example, calcium sulfate dihydrate pellets immersedin a phosphate buffered saline solution (PBS) can develop ashell of recrystallized
43、 hydroxyapatite on their surface whichsignificantly slows the process of dissolution (19). This behav-ior has not been observed in vivo. Similarly, the use of distilledor deionized water for in vitro testing has been shown toaccelerate the rate of degradation relative to rates observedclinically and
44、 in pre-clinical animal studies (19).REFERENCES(1) Alexander, D. I., et al, “Efficacy of Calcium Sulfate Plus Decompres-sion Bone in Lumbar and Lumbosacral Spinal Fusion: PreliminaryResults in 40 Patients,” Can. J. Surg., 44(4), 2001, pp. 262-266.(2) Kelly, C. M., et al, “The Use of a Surgical Grade
45、 Calcium Sulfate asa Bone Graft Substitute,” Clin. Orthop. Rel. Res., 382, 2001, pp.42-50.(3) Mirzayan, R., et al, “The Use of Calcium Sulfate in the Treatment ofBenign Bone Lesions,” J. Bone Joint Surg., 83A(3), 2001, pp.355-358.(4) Peltier, L. F., “The Use of Plaster of Paris to Fill Defects in Bo
46、ne,”Clin. Orthop. Rel. Res., 21, 1961, pp. 1-31.(5) Peltier, L. F. and Speer, D. P., “Calcium Sulfate,” Bone Grafts andBone Substitutes, Habal, M. B. and Reddi,A. H., eds., W. B. SaundersCompany, 1993, pp. 243-246.(6) Damien, et al, “Bone Grafts and Bone Graft Substitutes,” J. AppliedBiomat., 2, 1991, pp. 187-208.(7) Bahn, S., “Plaster: A Bone Substitute,” Oral Surg. Oral Med. or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).F2224 09 (2014)4
