ASTM_F_2259_-_10_2012e1.pdf

Designation:F225910(Reapproved 2012)1Standard Test Method forDetermining the Chemical Composition and Sequence inAlginate by Proton Nuclear Magnetic Resonance(1H NMR)Spectroscopy1This standard is issued under the fixed designation F2259;the number immediately following the designation indicates the year oforiginal adoption or,in the case 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.1NOTEEditorial changes were made to subsections 2.2 and 4.2 in November 2012.1.Scope1.1 This test method covers the determination of the com-position and monomer sequence of alginate intended for use inbiomedical and pharmaceutical applications as well as inTissue Engineered Medical Products(TEMPs)by high-resolution proton NMR(1H NMR).A guide for the character-ization of alginate has been published as Guide F2064.1.2 Alginate,alinearpolymercomposedof-D-mannuronate(M)and its C-5 epimer-L-guluronate(G)linkedby-(14)glycosidic bonds,is characterized by calculatingparameters such as mannuronate/guluronate(M/G)ratio,gu-luronic acid content(G-content),and average length of blocksof consecutive G monomers(that is,NG1).Knowledge ofthese parameters is important for an understanding of thefunctionality of alginate in TEMP formulations and applica-tions.This test method will assist end users in choosing thecorrect alginate for their particular application.Alginate mayhave utility as a scaffold or matrix material for TEMPs,in celland tissue encapsulation applications,and in drug deliveryformulations.1.3 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.4 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2E386 Practice for Data Presentation Relating to High-Resolution Nuclear Magnetic Resonance(NMR)Spec-troscopyF2064 Guide for Characterization and Testing of Alginatesas Starting Materials Intended for Use in Biomedical andTissue Engineered Medical Product Applications2.2 United States Pharmacopeia Document:USP 35-NF30 Nuclear Magnetic Resonance33.Terminology3.1 Definitions:3.1.1 alginate,npolysaccharide obtained from some ofthe more common species of marine algae,consisting of aninsoluble mix of calcium,magnesium,sodium,and potassiumsalts.3.1.1.1 DiscussionAlginate exists in brown algae as itsmost abundant polysaccharide,mainly occurring in the cellwalls and intercellular spaces of brown seaweed and kelp.Alginates main function is to contribute to the strength andflexibility of the seaweed plant.Alginate is classified as ahydrocolloid.The most commonly used alginate is sodiumalginate.Sodium alginate and,in particular,calcium cross-linked alginate gels are used in Tissue Engineered MedicalProducts(TEMPs)as biomedical matrices,controlled drugdelivery systems,and for immobilizing living cells.3.1.2 degradation,nchange in the chemical structure,physical properties,or appearance of a material.Degradation1This test method is under the jurisdiction ofASTM Committee F04 on Medicaland Surgical Materials and Devices and is the direct responsibility of SubcommitteeF04.42 on Biomaterials and Biomolecules for TEMPs.Current edition approved Oct.1,2012.Published November 2012.Originallyapproved in 2003.Last previous edition approved in 2010 as F2259 10.DOI:10.1520/F2259-10R12E01.2For referenced ASTM standards,visit the ASTM website,www.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.3Available from U.S.Pharmacopeia(USP),12601 Twinbrook Pkwy.,Rockville,MD 20852-1790,http:/www.usp.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 of polysaccharides occurs via cleavage of the glycosidic bonds.It is important to note that degradation is not synonymous withdecomposition.Degradation is often used as a synonym fordepolymerization when referring to polymers.3.1.3 depolymerization,nreduction in the length of apolymer chain to form shorter polymeric units.4.Significance and Use4.1 The composition and sequential structure of alginatedetermines the functionality of alginate in an application.Forinstance,the gelling properties of an alginate are highlydependent upon the monomer composition and sequentialstructure of the polymer.Gel strength will depend upon theguluronic acid content(FG)and also the average number ofconsecutive guluronate moieties in G-block structures(NG1).4.2 Chemical composition and sequential structure of alg-inate can be determined by1H-and13C-nuclear magneticresonance spectroscopy(NMR)