ASTM_F_2260_-_03_2012e1.pdf

Designation:F226003(Reapproved 2012)1Standard Test Method forDetermining Degree of Deacetylation in Chitosan Salts byProton Nuclear Magnetic Resonance(1H NMR)Spectroscopy1This standard is issued under the fixed designation F2260;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 2.2,2.3,and 4.5 in November 2012.1.Scope1.1 This test method covers the determination of the degreeof deacetylation in chitosan and chitosan salts intended for usein biomedical 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 chitosan salts has been published as Guide F2103.1.2 The test method is applicable for determining the degreeof deacetylation(%DA)of chitosan chloride and chitosanglutamate salts and is valid for%DAvalues from 50 up to andincluding 99.It is simple,rapid,and suitable for routine use.Knowledge of the degree of deacetylation is important for anunderstanding of the functionality of chitosan salts in TEMPformulations and applications.This test method will assist endusers in choosing the correct chitosan for their particularapplication.Chitosan salts may have utility in drug deliveryapplications,as a scaffold or matrix material,and in cell andtissue encapsulation applications.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:2F386 Test Method for Thickness of Resilient Flooring Ma-terials Having Flat SurfacesF2103 Guide for Characterization and Testing of ChitosanSalts as Starting Materials Intended for Use in Biomedicaland Tissue-Engineered Medical Product Applications2.2 United States Pharmacopeia Document:USP 35-NF30 Nuclear Magnetic Resonance32.3 European Pharmacopoeia Document:European Pharmacopoeia Monograph 2008:1774 ChitosanChloride43.Terminology3.1 Definitions:3.1.1 chitosan,na linear polysaccharide consisting of(14)linked 2-acetamido-2-deoxy-D-glucopyranose(Glc-NAc)and 2-amino-2-deoxy-D-glucopyranose(GlcN).Chito-san is a polysaccharide derived by N-deacetylation of chitin.3.1.2 degradation,nchange in the chemical structure,physical properties,or appearance of a material.Degradationof 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 degree of deacetylation,nthe fraction or percentageof glucosamine units(GlcN:deacetylated monomers)in achitosan polymer molecule.3.1.4 depolymerization,nreduction in the length of apolymer chain to form shorter polymeric units.4.Significance and Use4.1 The degree of deacetylation of chitosan salts is animportant characterization parameter since the charge density1This 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 2008 as F2260 03(2008).DOI:10.1520/F2260-03R12E01.2For 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.4Available from European Directorate for the Quality of Medicines(EDQM),Publications and Services,European Pharmacopoeia,BP 907,F-67029 Strasbourg,France.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 of the chitosan molecule is responsible for potential biologicaland functional effects.4.2 The degree of deacetylation(%DA)of water-solublechitosan salts can be determined by1H nuclear magneticresonance spectroscopy(1H NMR).Several workers havereported on the NMR determination of chemical compositionand sequential arrangement of monomer units in chitin andchitosan.The test method described is primarily based on thework of Vrum et al.(1991),5which represents the firstpublication on routine determination of chemical compositionin chitosans by solution state1H NMR spectroscopy.This testmethod is applicable