EN ISO 10993-12:2007

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Biological evaluation of medical devices - Part 12: Sample preparation and reference materials (ISO 10993-12:2007)Evaluation biologique des dispositifs médicaux - Partie 12: Préparation des échantillons et des matériaux de référence (ISO 10993-12:2007)Biologische Beurteilung von Medizinprodukten - Teil 12: Proben-vorbereitung und Referenzmaterialien (ISO 10993-12:2007)Ta slovenski standard je istoveten z:EN ISO 10993-12:2007SIST EN ISO 10993-12:2008en11.100.20ICS:SIST EN ISO 10993-12:20051DGRPHãþDSLOVENSKI
STANDARDSIST EN ISO 10993-12:200801-april-2008

EUROPEAN STANDARDNORME EUROPÉENNEEUROPÄISCHE NORMEN ISO 10993-12November 2007ICS 11.100.20Supersedes EN ISO 10993-12:2004
English VersionBiological evaluation of medical devices - Part 12: Samplepreparation and reference materials (ISO 10993-12:2007)Évaluation biologique des dispositifs médicaux - Partie 12:Préparation des échantillons et matériaux de référence(ISO 10993-12:2007)Biologische Beurteilung von Medizinprodukten - Teil 12:Proben-vorbereitung und Referenzmaterialien (ISO 10993-12:2007)This European Standard was approved by CEN on 30 September 2007.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the CEN Management Centre or to any CEN member.This European Standard exists in three official versions (English, French, German). A version in any other language made by translationunder the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the same status as theofficial versions.CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMITÉ EUROPÉEN DE NORMALISATIONEUROPÄISCHES KOMITEE FÜR NORMUNGManagement Centre: rue de Stassart, 36
B-1050 Brussels© 2007 CENAll rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN ISO 10993-12:2007: E

Relationship between this European Standard and the Essential Requirements of EU Directives 93/42/EEC on medical devices and 90/385/EEC on active implantable medical devices
This European Standard has been prepared under a mandate given to CEN by the European Commission and the European Free Trade Association to provide a means of conforming to Essential Requirements of the New Approach Directives 93/42/EEC on medical devices and 90/385/EEC on active implantable medical devices.
Once this standard is cited in the Official Journal of the European Communities under that Directive and has been implemented as a national standard in at least one Member State, compliance with the clauses of this standard given in Table ZA.1 confers, within the limits of the scope of this standard, a presumption of conformity with the corresponding Essential Requirements of that Directive and associated EFTA regulations.
Table ZA.1 — Correspondence between this International Standard and Directives 93/42/EEC on medical devices and 90/385/EEC on active implantable medical devices
Clause(s)/sub-clause(s) of this International Standard Essential Requirements (ERs) of Directives 93/42/EEC and 90/385/EEC
Qualifying remarks/Notes 1, 7, 8, 9, 10 93/42/EEC: Annex I, 11.7
1, 7, 8, 9, 10 90/385/EEC: Annex I.1 and 11.9
WARNING — Other requirements and other EU Directives may be applicable to the product(s) falling within the scope of this standard.

Reference numberISO 10993-12:2007(E)© ISO 2007
INTERNATIONAL STANDARD ISO10993-12Third edition2007-11-15Biological evaluation of medical devices — Part 12: Sample preparation and reference materials Évaluation biologique des dispositifs médicaux — Partie 12: Préparation des échantillons et matériaux de référence

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ISO 10993-12:2007(E) © ISO 2007 – All rights reserved iiiContents Page Foreword.iv Introduction.vi 1 Scope.1 2 Normative references.1 3 Terms and definitions.1 4 General requirements.3 5 Reference materials.4 5.1 General.4 5.2 Certification of RMs for biological safety testing.4 6 Use of RMs as experimental controls.4 7 Test sample selection.5 8 Test sample and RM preparation.5 9 Selection of representative portions from a device.5 10 Preparation of extracts of samples.6 10.1 General.6 10.2 Containers for extraction.6 10.3 Extraction conditions and methods.6 10.4 Extraction conditions for hazard identification and risk estimation in the exaggerated-use condition.8 11 Records.9 Annex A (informative)
Experimental controls.10 Annex B (informative)
General principles on and practices of test sample preparation and sample selection.12 Annex C (informative)
Principles of test sample extraction.14 Bibliography.17

ISO 10993-12:2007(E) iv © ISO 2007 – All rights reserved Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 10993-12 was prepared by Technical Committee ISO/TC 194, Biological evaluation of medical devices. This third edition cancels and replaces the second edition (ISO 10993-12:2002), which has been technically revised. ISO 10993 consists of the following parts, under the general title Biological evaluation of medical devices: ⎯ Part 1: Evaluation and testing ⎯ Part 2: Animal welfare requirements ⎯ Part 3: Tests for genotoxicity, carcinogenicity and reproductive toxicity ⎯ Part 4: Selection of tests for interactions with blood ⎯ Part 5: Tests for in vitro cytotoxicity ⎯ Part 6: Tests for local effects after implantation ⎯ Part 7: Ethylene oxide sterilization residuals ⎯ Part 9: Framework for identification and quantification of potential degradation products ⎯ Part 10: Tests for irritation and delayed-type hypersensitivity ⎯ Part 11: Tests for systemic toxicity ⎯ Part 12: Sample preparation and reference materials ⎯ Part 13: Identification and quantification of degradation products from polymeric medical devices ⎯ Part 14: Identification and quantification of degradation products from ceramics ⎯ Part 15: Identification and quantification of degradation products from metals and alloys

ISO 10993-12:2007(E) © ISO 2007 – All rights reserved v⎯ Part 16: Toxicokinetic study design for degradation products and leachables ⎯ Part 17: Establishment of allowable limits for leachable substances ⎯ Part 18: Chemical characterization of materials ⎯ Part 19: Physico-chemical, morphological and topographical characterization of materials [TS] ⎯ Part 20: Principles and methods for immunotoxicology testing of medical devices [TS] Future parts will deal with other relevant aspects of biological testing.

ISO 10993-12:2007(E) vi © ISO 2007 – All rights reserved Introduction This part of ISO 10993 specifies methods of sample preparation and the selection of reference materials in the biological evaluation of medical devices. Sample preparation methods should be appropriate for both the biological evaluation methods and the materials being evaluated. Each biological test method requires the selection of materials, extraction solvents and conditions. This part of ISO 10993 is based on existing national and international specifications, regulations and standards wherever possible. It is periodically reviewed and revised.

INTERNATIONAL STANDARD ISO 10993-12:2007(E) © ISO 2007 – All rights reserved 1Biological evaluation of medical devices — Part 12: Sample preparation and reference materials 1 Scope This part of ISO 10993 specifies requirements and gives guidance on the procedures to be followed in the preparation of samples and the selection of reference materials for medical device testing in biological systems in accordance with one or more parts of the ISO 10993 series. Specifically this part of ISO 10993 addresses: ⎯ test sample selection; ⎯ selection of representative portions from a device; ⎯ test sample preparation; ⎯ experimental controls; ⎯ selection of and requirements for reference materials; ⎯ preparation of extracts. This part of ISO 10993 is not applicable to materials or devices containing live cells. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 10993-1:2003, Biological evaluation of medical devices — Part 1: Evaluation and testing ISO 14971, Medical devices — Application of risk management to medical devices 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 blank extraction vehicle not containing the test material, retained in a vessel identical to that which holds the test sample and subjected to identical conditions to which the test sample is subjected during its extraction NOTE The purpose of the blank is to evaluate possible confounding effects due to the extraction vessel, extraction vehicle and extraction process.

ISO 10993-12:2007(E) 2 © ISO 2007 – All rights reserved 3.2 certified reference material (CRM) reference material, accompanied by a certificate, one or more of whose property values are certified by a procedure which establishes its traceability to an accurate realization of the unit in which the property values are expressed, and for which each certified value is accompanied by an uncertainty at a stated level of confidence [ISO Guide 30, definition 2.2] 3.3 experimental control substance with well characterized responses, which is used in a specific test system to assist in evaluating if the test system has responded in a reproducible and appropriate manner 3.4 extract liquid that results from extraction of the test sample or control 3.5 homogeneous property of a material and its relationship to a biological endpoint such that it is of uniform structure or composition to consistently render or not a specific biological response NOTE A reference material is said to be homogeneous if the biological response to a specific test is found to lie within the specified uncertainty limits of the test, irrespective of the batch or lot of material from which the test sample is removed. 3.6 negative control any well characterized material and/or substance, which, when tested by a specific procedure, demonstrates the suitability of the procedure to yield a reproducible, appropriately negative, non-reactive or minimal response in the test system NOTE In practice, negative controls are reference materials but may include blanks and extraction vehicles/solvents. 3.7 positive control any well characterized material and/or substance, which, when evaluated by a specific test method, demonstrates the suitability of the test system to yield a reproducible, appropriately positive or reactive response in the test system 3.8 reference material (RM) material with one or more property values that are sufficiently reproducible and well established to enable use of the material or substance for the calibration of an apparatus, the assessment of a measurement method, or for the assignment of values to materials [ISO Guide 30, definition 2.1] NOTE For the purpose of this part of ISO 10993, a reference material is any well characterized material or substance, which, when tested by the procedure described, demonstrates the suitability of the procedure to yield a reproducible, predictable response. The response may be negative or positive. 3.9 stability 〈of property values〉 ability of a material, when stored under specified conditions, to maintain a specific stated biological response, within specified limits, for a specific period of time NOTE Adapted from ISO Guide 30, definition 2.7.

ISO 10993-12:2007(E) © ISO 2007 – All rights reserved 33.10 test sample material, device, device portion, component, extract or portion thereof that is subjected to biological or chemical testing or evaluation 3.11 simulated-use extraction extraction to demonstrate compliance with the requirements of this part of ISO 10993, by evaluating leachable material levels available to the patient or user from devices during the routine use of a device using an extraction method that simulates product use NOTE The burden of validation on the analytical laboratory is to demonstrate that the simulated-use extraction is carried out under conditions that provide the greatest challenge to the intended use. Product-use simulation is carried out assuming the device is assigned to the most stringent category probable for duration of exposure and takes into consideration both tissue(s) exposed and temperature of exposure. 3.12 exaggerated extraction any extraction that is intended to result in a greater amount of a chemical constituent being released as compared to the amount generated under the simulated conditions of use NOTE Exaggerated extraction might result in a chemical change of the material or the substances being extracted. 3.13 accelerated extraction extraction that provides a measure of the leachable materials of the device or material using conditions that shorten the time for leaching of the substances into the extraction vehicle but do not result in a chemical change of the substances being extracted NOTE Examples of accelerated extraction conditions are as follows: elevated temperature, agitation, changing of the extraction vehicle, etc. 3.14 exhaustive extraction extraction until the amount of leachable material in a subsequent extraction is less than 10 % of that detected in the initial extraction, or until there is no analytically significant increase in the cumulative leachable material levels detected NOTE As it is not possible to demonstrate the exhaustive nature of residual recovery, the definition of exhaustive extraction adopted is as above. See also Annex C. 4 General requirements 4.1 As described in ISO 14971, in the identification of hazard and risk estimation for medical devices, hazards that arise from changes in the manufacturing process, or insufficient control of the manufacturing process, shall be considered in the design and preparation of samples for test and preparation of extracts of those devices. Particular attention shall be given to residues, e.g., trace elements and cleaning and disinfection agents, of those manufacturing processes. 4.2 Because ISO 10993 describes many different biological assay systems, the individual standards shall be consulted to ascertain if these recommendations are appropriate for specific test systems. 4.3 Experimental controls shall be used in biological evaluations to validate a test procedure and/or to compare the results between materials. Depending on the biological test, negative controls, blanks and/or positive controls shall be used as is appropriate to the test. NOTE The same type of control can be applicable to different tests and may allow cross-reference to other established materials and test methods. Additional guidance on the selection of experimental controls is given in Annex A. Use of positive controls for in-vivo testing may be affected by animal welfare regulations.

ISO 10993-12:2007(E) 4 © ISO 2007 – All rights reserved 5 Reference materials 5.1 General Reference materials (RMs) are established by individual laboratories. The extent of chemical, physical and biological characterization is determined by the individual laboratory. Commercially available articles may be used as reference materials. NOTE 1 See also ISO Guide 35. Certified reference materials (CRMs) are selected for their high purity, critical characteristics, suitability for the intended purpose and general availability. The critical chemical, physical and biological characteristics shall be determined by collaborative testing in three or more laboratories, and made available to the investigator by the distributor. NOTE 2 It is desirable for users to obtain a commitment from suppliers of RMs or CRMs that these materials will be available to the user for at least five years. A second, but less desirable, option is for the source of the RM or CRM to publish an “open formulation” for the material, i.e., publication of the source materials and details of the processing needed to ensure uniform batches of the RM. 5.2 Certification of RMs for biological safety testing 5.2.1 Qualification of an RM is a procedure that establishes the numerical or qualitative value of the biological response of the material under specified test conditions, ensuring reproducibility of the response within and/or between laboratories. The range of biological responses associated with the material shall be established through laboratory tests. NOTE See also ISO Guide 34. 5.2.2 Suppliers of RMs shall certify the materials. The supplier determines the extent of chemical and physical characterization that is performed. The individual laboratories that use the RMs shall identify the biological characterization necessary to qualify an RM for a specific test or procedure. Commercially available materials may be used as RMs provided they are certified and qualified. 5.2.3 Certification of an RM is a procedure that establishes the numerical or qualitative value of the biological response of the material under the specified test conditions. This process serves to validate the testing of the material for that particular response and results in the issuance of a certificate. The biological response of the material shall be established through interlaboratory tests. 6 Use of RMs as experimental controls 6.1 RMs or CRMs shall be used in biological tests as control materials to demonstrate the suitability of a procedure to yield a reproducible response, such as either positive and/or negative. Any material used in this way shall be characterized with each biological test procedure for which the use of the material is desired. A material characterized and then certified for one reference test method or response, e.g., delayed-type hypersensitivity, shall not be used as an RM for another, e.g., cytotoxicity, without additional validation. NOTE Use of an RM will facilitate the comparability of the response between laboratories and assist in assessing reproducibility of test performance within individual laboratories. For comparison of the biological response, it is desirable to use RMs having a range of responses, e.g., minimum, intermediate or severe. 6.2 RMs used as experimental controls shall meet the established quality assurance procedures of the manufacturer and test laboratory. They shall be identified as to source, manufacturer, grade and type. RMs are processed as described in Clause 8.

ISO 10993-12:2007(E) © ISO 2007 – All rights reserved 56.3 When RMs are used as experimental controls, they shall be in the same material class as the test sample, i.e., polymer, ceramic, metal, colloid, etc. However, pure chemicals may be used as experimental controls for mechanistically-based test procedures, e.g., genotoxicity and immune delayed-type hypersensitivity assays. 7 Test sample selection 7.1 Testing shall be performed on the final product, or representative samples from the final products or materials processed in the same manner as the final product (see ISO 10993-1) or on appropriate extracts of any of these. The choice of test sample shall be justified. NOTE In the case of materials that cure in-situ, different test samples representative of the cured material versus the uncured state of the material might be needed. 7.2 The same test sample selection procedure applies when an extract is required. 8 Test sample and RM preparation 8.1 Test samples and RMs shall be handled with care to prevent contamination. Any residues from the manufacturing processes shall be considered to be integral to the device, device portion or component. NOTE For additional guidance on preparation see Annex B. a) Test samples from sterilized devices and RMs shall be handled aseptically if appropriate to the test procedure. b) Test samples from a device which is normally supplied non-sterile, but which requires sterilization prior to use, shall be sterilized by the method recommended by the manufacturer and handled aseptically if appropriate to the test procedure. c) If test samples are cleaned prior to sterilization, the influence of the cleaning process and cleaning agent shall be considered in the selection and handling of the test sample. 8.2 If sterile test samples are required for the test procedure, the effect of the sterilization or resterilization process on the test sample and RMs shall be considered. 8.3 When test samples and RMs need to be cut into pieces as described in 10.3.3 b), the influence of previously unexposed surfaces, e.g., lumens or cut surfaces, shall be considered. Tools used for cutting medical devices into representative portions for testing shall be cleaned between uses to prevent contamination. 9 Selection of representative portions from a device 9.1 If a device cannot be tested as a whole, each individual material in the final product shall be represented proportionally in the
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