ASTM F2064-00(2006)e1
(Guide)Standard Guide for Characterization and Testing of Alginates as Starting Materials Intended for Use in Biomedical and Tissue-Engineered Medical Products Application
Standard Guide for Characterization and Testing of Alginates as Starting Materials Intended for Use in Biomedical and Tissue-Engineered Medical Products Application
SIGNIFICANCE AND USE
This guide contains a listing of those characterization parameters that are directly related to the functionality of alginate. This guide can be used as an aid in the selection and characterization of the appropriate alginate for a particular application. This guide is intended to give guidance in the methods and types of testing necessary to properly characterize, assess, and ensure consistency in the performance of a particular alginate. It may have use in the regulation of these devices by appropriate authorities.
The alginate covered by this guide may be gelled, extruded, or otherwise formulated into biomedical devices for use in tissue-engineered medical products or drug delivery devices for implantation as determined to be appropriate, based on supporting biocompatibility and physical test data. Recommendations in this guide should not be interpreted as a guarantee of clinical success in any tissue engineered medical product or drug delivery application.
To ensure that the material supplied satisfies requirements for use in TEMPS, several general areas of characterization should be considered. These are: identity of alginate, physical and chemical characterization and testing, impurities profile, and performance-related tests.
SCOPE
1.1 This guide covers the evaluation of alginates suitable for use in biomedical or pharmaceutical applications, or both, including, but not limited to, tissue-engineered medical products (TEMPS).
1.2 This guide addresses key parameters relevant for the functionality, characterization, and purity of alginates.
1.3 As with any material, some characteristics of alginates may be altered by processing techniques (such as molding, extrusion, machining, assembly, sterilization, and so forth) required for the production of a specific part or device. Therefore, properties of fabricated forms of this polymer should be evaluated using test methods that are appropriate to ensure safety and efficacy and are not addressed in this guide.
1.4 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.
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
´1
Designation: F2064 − 00(Reapproved 2006)
Standard Guide for
Characterization and Testing of Alginates as Starting
Materials Intended for Use in Biomedical and Tissue-
Engineered Medical Products Application
This standard is issued under the fixed designation F2064; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
´ NOTE—Mercury warning was editorially added in April 2008.
INTRODUCTION
Alginatehasfoundusesinavarietyofproductsrangingfromsimpletechnicalapplicationssuchas
viscosifiers to advanced biomedical matrices providing controlled drug delivery from immobilized
living cells. As for most hydrocolloids, the functionality of alginate is related to its chemical and
structural composition. The aim of this guide is to identify key parameters relevant for the
functionalityandcharacterizationofalginatesforthedevelopmentofnewcommercialapplicationsof
alginates for the biomedical and pharmaceutical industries.
1. Scope tion. Users should be aware that selling mercury or mercury-
containingproducts,orboth,inyourstatemaybeprohibitedby
1.1 Thisguidecoverstheevaluationofalginatessuitablefor
state law.
use in biomedical or pharmaceutical applications, or both,
1.5 This standard does not purport to address all of the
including, but not limited to, tissue-engineered medical prod-
safety concerns, if any, associated with its use. It is the
ucts (TEMPS).
responsibility of the user of this standard to establish appro-
1.2 This guide addresses key parameters relevant for the
priate safety and health practices and determine the applica-
functionality, characterization, and purity of alginates.
bility of regulatory limitations prior to use.
1.3 As with any material, some characteristics of alginates
2. Referenced Documents
may be altered by processing techniques (such as molding,
extrusion, machining, assembly, sterilization, and so forth)
2.1 ASTM Standards:
required for the production of a specific part or device.
D2196Test Methods for Rheological Properties of Non-
Therefore, properties of fabricated forms of this polymer
Newtonian Materials by Rotational (Brookfield type)
should be evaluated using test methods that are appropriate to
Viscometer
ensure safety and efficacy and are not addressed in this guide.
F619Practice for Extraction of Medical Plastics
F748PracticeforSelectingGenericBiologicalTestMethods
1.4 Warning—Mercury has been designated by EPA and
for Materials and Devices
many state agencies as a hazardous material that can cause
F749Practice for Evaluating Material Extracts by Intracuta-
central nervous system, kidney, and liver damage. Mercury, or
neous Injection in the Rabbit
its vapor, may be hazardous to health and corrosive to
F756Practice for Assessment of Hemolytic Properties of
materials.Cautionshouldbetakenwhenhandlingmercuryand
Materials
mercury-containing products. See the applicable product Ma-
F763Practice for Short-Term Screening of Implant Materi-
terial Safety Data Sheet (MSDS) for details and EPA’s website
als
(http://www.epa.gov/mercury/faq.htm) for additional informa-
F813Practice for Direct Contact Cell Culture Evaluation of
Materials for Medical Devices
This guide is under the jurisdiction ofASTM Committee F04 on Medical and
Surgical Materials and Devices and is the direct responsibility of Subcommittee
F04.42 on Biomaterials and Biomolecules for TEMPs. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved March 1, 2006. Published April 2006. Originally contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
approved in 2000. Last previous edition approved in 2000 as F2064–00. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/F2064-00R06E01. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
´1
F2064 − 00 (2006)
F895TestMethodforAgarDiffusionCellCultureScreening DHHS, July 15, 1991
for Cytotoxicity 2.6 ANSI Documents:
F981Practice for Assessment of Compatibility of Biomate- ANSI/AAMI/ISO 11737-1: 1995:Sterilization of Medical
rials for Surgical Implants with Respect to Effect of Devices—Microbiological Methods—Part 1: Estimation
Materials on Muscle and Bone of Bioburden on Product.
F1251Terminology Relating to Polymeric Biomaterials in ANSI/AAMI/ISO 11737-2: 1998:Sterilization of Medical
Medical and Surgical Devices (Withdrawn 2012) Devices—MicrobiologicalMethods—Part2:TestsofSte-
F1439Guide for Performance of Lifetime Bioassay for the rilityPerformedintheValidationofaSterilizationProcess
Tumorigenic Potential of Implant Materials 2.7 AAMI Documents:
F1903Practice for Testing For Biological Responses to AAMI/ISO 14160—1998:Sterilization of Single-Use Medi-
Particles In Vitro cal Devices Incorporating Materials of Animal Origin—
F1904Practice for Testing the Biological Responses to Validation and Routine Control of Sterilization by Liquid
Particles in vivo Chemical Sterilants
F1905Practice For Selecting Tests for Determining the AAMI ST67/CDV-2: 1999: Sterilization of Medical
Propensity of Materials to Cause Immunotoxicity (With- Devices—Requirements for Products Labeled “Sterile”
drawn 2011) AAMI TIR No. 19—1998:Guidance for ANSI/AAMI/ISO
F1906Practice for Evaluation of Immune Responses In 10993-7: 1995, Biological Evaluation of Medical
BiocompatibilityTestingUsingELISATests,Lymphocyte Devices—Part 7: Ethylene Oxide Sterilization Residuals
3 9
Proliferation, and Cell Migration (Withdrawn 2011) 2.8 prEN Documents:
prEN 12442-1Animal Tissues and their Derivative Utilized
2.2 USP Document:
in the Manufacture of Medical Devices—Part 1:Analysis
USP Monograph USP 24/NF 19<719>Sodium Alginate
and Management of Risk
2.3 ISO Documents:
prEN –12442 Part 3:Validation of the Elimination and/or
ISO 10993Biological Evaluation of Medical Devices:
Inactivation of Virus and Transmissible Agents
ISO 10993-1Biological Evaluation of Medical Devices—
2.9 Other Documents:
Part 1: Evaluation and Testing
21CFR184.1724 Listing of Specific SubstancesAffirmed as
ISO 10993-3Part 3:Tests for Genotoxicity, Carcinogenicity
GRAS–Sodium Alginate
and Reproductive Toxicity
ISO 10993-9—Part 9:Framework for Identification and
3. Terminology
Quantification of Potential Degradation Products
ISO 10993-17—Part 17:Methods for Establishment of Al- 3.1 Definitions of Terms Specific to This Standard: (see also
Terminology F1251):
lowable Limits for Leachable Substances Using Health-
Based Risk Assessment 3.1.1 alginate, n—a polysaccharide substance containing
calcium, magnesium, sodium, and potassium salts obtained
ISO 13408-1: 1998:Aseptic Processing of Health Care
Products—Part 1: General Requirements. from some of the more common species of marine algae.
Alginate exists in brown algae as the most abundant
2.4 ICH Documents:
polysaccharide, mainly occurring in the cell walls and inter-
International Conference on Harmonization (ICH) S2B
cellularspacesofbrownseaweedandkelp.Itsmainfunctionis
Genotoxicity:A Standard Battery for Genotoxicity Test-
to contribute to the strength and flexibility of the seaweed
ing of Pharmaceuticals (July 1997)
plant. Alginate is classified as a hydrocolloid. The most
International Conference on Harmonization (ICH) Q1A
commonly used alginate is sodium alginate.
ICHHarmonizedTripartite Guidance for StabilityTesting
of New Drug Substances and Products (September 23,
3.1.2 decomposition, n—structural changes of alginates due
1994)
to exposure to environmental, chemical or thermal factors,
2.5 FDA Documents:
such as temperatures greater than 180°C. Decomposition can
FDA Guidelineon Validation of the Limulus Amebocyte result in deleterious changes to the alginate.
Test as an End-Product Endotoxin Test for Human and
3.1.3 degradation, n—change in the chemical structure,
AnimalParenteralDrugs,BiologicalProductsandHealth-
physical properties, or appearance of a material. Degradation
care Products. DHHS, December 1987
of polysaccharides occurs by means of cleavage of the glyco-
FDA.Interim Guidance for Human and Veterinary Drug
sidic bonds, usually by acid catalyzed hydrolysis. Degradation
Products and Biologicals. Kinetic LAL techniques.
can also occur thermally. It is important to note that degrada-
tion is not synonymous with decomposition. Degradation is
3 often used as a synonym for depolymerization when referring
The last approved version of this historical standard is referenced on
www.astm.org. to polymers.
AvailablefromU.S.Pharmacopeia(USP),12601TwinbrookPkwy.,Rockville,
MD 20852.
5 8
Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St., AssociationfortheAdvancementofMedicalInstrumentation1110NorthGlebe
4th Floor, New York, NY 10036. Rd., Suite 220, Arlington, VA 22201–4795.
6 9
Available from ICH Secretariat, c/o IFPMA, 30 rue de St-Jean, P.O. Box 758, Available from European Committee for Standardization CEN, Management
1211 Geneva 13, Switzerland. Centre 36, rue de Stassart B-1050 Brussels, Belgium.
7 10
Available from U. S. Food and Drug Administration, 5600 Fishers Lane, Available from Superintendent of Documents, U.S. Government Printing
Rockville MD 20857-0001. Office, Washington, DC 20402.
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F2064 − 00 (2006)
3.1.4 depolymerization, n—reductioninlengthofapolymer 5. Chemical and Physical Test Methods
chain to form shorter polymeric units. Depolymerization may
5.1 Identity of Alginate—The identity of alginates can be
reducethepolymerchaintooligomericormonomericunits,or
establishedbyseveralmethodsincluding,butnotlimitedtothe
both. In alginates, hydrolysis of the glycosidic bonds is the
following:
primary mechanism.
5.1.1 Sodium alginate monograph USP 24/NF19.
3.1.5 Endotoxin, n—a high-molecular weight lipopolysac- 5.1.2 Fourier Transform Infrared Spectroscopy (FT-IR)—
charide (LPS) complex associated with the cell wall of
Almost all organic chemical compounds absorb infrared radia-
gram-negative bacteria that is pyrogenic in humans. Though tion at frequencies characteristic for the functional groups in
endotoxins are pyrogens, not all pyrogens are endotoxins.
the compound. A FT-IR spectrum will show absorption bands
relatingtobondstretchingandbendingandcanthereforeserve
3.1.6 hydrocolloid, n—a water-soluble polymer of colloidal
asauniquefingerprintofaspecificcompound.Castanalginate
nature when hydrated.
filmfroma0.25%(w/v)solutionofsodiumalginatebydrying
3.1.7 molecular mass average (molecular weight average),
approximately 500 µLof the sample onto a disposable IR card
n—thegivenmolecularweight(Mw)ofanalginatewillalways
for3to4hat 60°C. Record a background spectrum between
–1 –1
represent an average of all of the molecules in the population.
4000 and 400 cm using 128 scans at a resolution of 4 cm .
The most common ways to express the Mw are as the number
Record the IR spectrum of a dried blank IR card, then record
¯ ¯
average ~M ! and the weight average ~M !. The two averages
n w the IR spectrum of the sample using 128 scans at a resolution
–1
are defined by the following equations:
of4cm , % transmission mode. Label the peaks. Typical
–1
frequencies (cm ) for sodium alginate are 3375-3390 (b),
N M w M N M
(i i i (i i i (i i i
¯ ¯
1613 (s), 1416 (s), 1320 (w), 1125, 1089, 1031 (s), 948 (m),
M 5 and M 5 5 (1)
n w
N w N M
(i i (i i (i i i
903 (m), and 811 (m). The peak designators are: sh: sharp; s:
strong; m: medium; w: weak; and b: broad.
where:
5.2 Physical and chemical characterization of alginate:
N = number of molecules having a specific molecular
i
5.2.1 The composition and sequential structure of alginate
weight, M, and
i
w = weightofmoleculeshavingaspecificmolecularweight can be a key functional attribute of any alginate. Variations in
i
M the composition or the sequential structure, or both, may, but
i
notnecessarily,causedifferencesinperformanceofanalginate
Inapolydispersemolecularpopulationtherelation M¯ >M¯
w n
inaparticularenduse.Thisinformationmaybedeterminedby
is always valid. The coefficient M¯ /M¯ is referred to as the
w n
1 13
the following method: High-resolution H and C-nuclear
polydispersityindex,andwilltypicallybeintherangefrom1.5
magnetic resonance spectroscopy (NMR). Sodium alginate
to 3.0 for commercial alginates.
should be dissolved in D O and partially degraded to a degree
3.1.8 pyrogen, n—any substance that produces fever when
of depolymerization of 20 to 30 using mild acid hydrolysis
administered parenterally.
before recording proton or carbon NMR spectra (Grasdalen,
H., Larsen, B., and Smidsrød, O., Carbohydr. Res., 68, 23-31,
4. Significance and Use
1979). Techniques have been developed to determine the
monadfrequenciesF (fractionofguluronateresidues)andF
4.1 This guide contains a listing of those characterization G M
(fraction of mannuronate residues), the four nearest neighbor-
parameters that are directly related to the functionality of
ing(diad)frequencies(F ,F ,F ,andF )andtheeight
alginate. This guide can be used as an aid in the selection and GG GM MG MM
next nearest neighboring (triad) frequencies (F ,F ,
characterization of the appropriate alginate for a particular
GGG GGM
F ,F ,F ,F ,F , and F ). A typical
application. This guide is intended to give guidance in the GMM GMG MGM MGG MMG MMM
H-NMR spectrum of alginate is shown as follows.Alginate is
methods and types of testing necessary to properly
characterized by calculating parameters such as M/G ratio,
characterize,assess,andensureconsistencyintheperformance
G-content, consecutive number of G monomers (that is, G>1),
of a particular alginate. It may have use in the regulation of
and average length of blocks of consecutive G monomers.
these devices by appropriate authorities.
5.2.2 Molecularmass(molecularweight)ofanalginatewill
4.2 The alginate covered by this guide may be gelled,
define certain performance characteristics such as viscosity or
extruded, or otherwise formulated into biomedical devices for
gel strength, or both.As such and depending on the sensitivity
use in tissue-engineered medical products or drug delivery
of a particular end use to these variations, determination of
devicesforimplantationasdeterminedtobeappropriate,based
molecular mass directly or indirectly may be necessary. Com-
on supporting biocompatibility and physical test data. Recom-
mercial alginates are polydisperse with respect to molecular
mendations in this guide should not be interpreted as a
weight (M ). Molecular weight may be expressed as the
w
guarantee of clinical success in any
...
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