1、Designation: F2808 17Standard Test Method forPerforming Behind-the-Knee (BTK) Test for Evaluating SkinIrritation Response to Products and Materials That ComeInto Repeated or Extended Contact with Skin1This standard is issued under the fixed designation F2808; the number immediately following the des
2、ignation 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.1. Scope1.1 The Behind-the-Knee (BTK) met
3、hod, using thepopliteal fossa of human volunteers as a test site, simultane-ously evaluates the inherent chemical irritation, and the poten-tial for mechanical irritation of substrates and products that aredesigned to come into repeated or extended close contact withthe skin (see validation referenc
4、es 1-7).2This is a bilateral testcomparing a test material to a reference material with a knownsafety profile.1.2 This test method shall be used by qualified health careprofessionals experienced in good clinical practice (GCP)procedures.1.3 This test method can be performed using human sub-jects on
5、either intact or compromised skin. Testing should beperformed on intact skin for test substrates or products ex-pected to have contact with normal, intact skin, or for directcomparison to products with a known skin irritation profile.Testing can be performed on compromised skin for testsubstrates or
6、 products that may commonly come into contactwith damaged skin (for example, skin with diaper rash, orchapped skin) or skin that is expected to be hydrated.1.4 Visual scoring of erythema and dryness is performed bya trained skin grader on a pre-defined scale.1.5 Prior to use in this test, materials
7、shall undergo overallfavorable biocompatibility testing consistent with the approachoutlined in protocol Practice F748 or ISO 10993-1:2009. As apart of this series of testing, irritation per Practice F719 or ISO10993-10 shall be conducted.1.6 The values stated in inch-pound units are to be regardeda
8、s standard. No other units of measurement are included in thisstandard.1.7 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 th
9、e applica-bility of regulatory limitations prior to use.1.8 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations iss
10、ued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:3D6355 Test Method for Human Repeat Insult Patch Testingof Medical GlovesF719 Practice for Testing Biomaterials in Rabbits for Pri-mary Skin IrritationF748 Practice for Selecting
11、Generic Biological Test Methodsfor Materials and Devices2.2 ISO Standards:4ISO 10993-1:2009 Biological Evaluation of MedicalDevicesPart 1: Evaluation and Testing Within a RiskManagement ProcessISO 10993-10 Biological Evaluation of Medical DevicesPart 10: Tests for Irritation and Delayed-type Hyperse
12、nsi-tivity3. Terminology3.1 Definitions:3.1.1 chemical irritation, nirritation caused by a physi-ological response to the chemical nature of a material. Suchphysiological responses may include: oxidation or reductionreactions, dehydration, disruption of the keratin ultra-structureor direct injury to
13、 cellular macromolecules or organelles.1This test method is under the jurisdiction ofASTM Committee F04 on Medicaland Surgical Materials and Devices and is the direct responsibility of SubcommitteeF04.16 on Biocompatibility Test Methods.Current edition approved Nov. 1, 2017. Published November 2017.
14、 Originallyapproved in 2010. Last previous edition approved in 2010 as F2808-10. DOI:10.1520/F2808-17.2The boldface numbers in parentheses refer to the list of references at the end ofthis standard.3For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service
15、at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.4Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.Copyright ASTM International, 100 Ba
16、rr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom
17、mendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.13.1.2 compromised skin, nskin that is treated with re-peated application of surgical tape prior to the first sampleapplication.3.1.3 edema, nobservable swelling from abnormal accu-mulation of fluid in conn
18、ective tissue.3.1.4 erythema, nredness of the skin.3.1.5 mechanical irritation, nirritation caused by move-ment and friction of products intended to remain in contactwith the skin for extended periods of time.3.1.6 popliteal fossa, nthe area at the back of the knee.3.1.7 reference material, na mater
19、ial similar in form andcomposition to the test material. The reference material shouldhave a known safety and irritation profile.3.1.8 skin grades, nvisual assessments of erythema anddryness according to a defined scale (see 10.3).3.1.9 test material, nany material or product expected tocome into co
20、ntact with skin.3.1.10 trained skin grader, npersonnel who have beentrained to reliably recognize erythema and dryness reactions byusing reference examples, and by performing side-by-sidescoring with an experienced skin grader.4. Summary of Test Method4.1 Samples are applied to the back of the knee
21、using anelastic knee band or brace. As the subjects go about theireveryday activities, normal movements generate friction be-tween the test sample and the skin at the test site, therebyadding the element of mechanical irritation. Thus, the BTK testprotocol evaluates a combination of mechanical irrit
22、ation andthe inherent chemical irritation potential of materials andproducts that come into contact with the skin.4.2 This is a randomized, controlled, double blind study inwhich both the subjects and skin grader are unaware of thetreatment assignments. Test and reference materials are appliedfor 6
23、h per day, for 5 days. Skin reactions are graded forerythema and dryness prior to the first sample application (thatis, at baseline), each morning prior to subsequent sampleapplications, and upon the removal of the sample at the end ofeach period.4.3 Test materials are applied, once each test day to
24、 normal,intact skin to evaluate potential reactions to products thatnormally come into contact with intact skin. To evaluatepotential reactions to products that normally come into contactwith damaged skin, the skin can be compromised by using tapestripping prior to the first sample application.5. Si
25、gnificance and Use5.1 This test method is intended to assess a combination ofinherent chemical irritation and mechanical irritation for prod-ucts and materials expected to come into contact with the skin.It is a comparative approach whereby the potential irritation ofa test material is compared to t
26、hat of a reference materialsimilar in form and composition. The reference material shouldhave a known safety and irritation profile.6. Interferences and Precautions6.1 Possible protocol deviations that could interfere with oraffect the outcome of the study include the fit of the elasticknee band and
27、 the activity level of the subjects. As in anyclinical study, adherence to the protocol conditions will offsetany potential confounding issues.6.2 The use of lotions, powders, creams, or skin careproducts in the skin area at the test sites during the course ofthe study may impact the study results.
28、In addition, shaving theskin behind the knee, exposing the test sites to tanning or thesun, or swimming or hot tub use during study participationshould not be permitted, since these practices and activitiesmay produce low levels of skin irritation in some persons.6.3 Anti-inflammatory medications ma
29、y interfere with thenormal development of the skin irritation reaction and shouldnot be used during the study.6.4 Normal showering or bathing cannot be allowed duringthe sample application of 6 h per day, but can be allowedduring the 18 h each day when the test samples are not in place.6.5 Some pers
30、ons will experience some degree of skinirritation at the test sites. In addition, some persons mayexperience slight discomfort from the manner in which thesamples are applied (that is, an elastic knee band). In mostcases, these effects are anticipated to be reversible whensample application conclude
31、s.7. Apparatus7.1 An artificial light source, with a 100 W incandescentdaylight blue bulb or an alternate light source with a similarColoring Rendering Index (CRI), is used to illuminate theapplication areas for erythema grading and an illuminated 10magnifying lens is used to grade dryness.8. Reagen
32、ts and Materials8.1 Elastic knee bands or braces are used to hold thesamples in place.8.2 Test materials include substrates and products that aredesigned to come into repeated or extended close contact withthe skin. The appropriate reference sample is a similar materialor product that has been demon
33、strated through biocompatibil-ity testing to be a non-irritant.8.3 If testing is to be conducted on compromised skin, anappropriate surgical tape is required.9. Hazards9.1 No specific hazards have been identified for this testprotocol. However, if any of the test materials tested should fallunder bi
34、ohazard then all used test materials should be handledand discarded by the test site staff following BiohazardStandard Operating Procedures (SOPs).10. Calibration and Standardization10.1 No calibration of specific equipment is required.10.2 Skin graders shall be trained to recognize the degreesof se
35、verity of the irritation reactions described in the gradingscales given in Appendix X7.F2808 17210.3 The Skin Irritation Grading Scales for Erythema andDryness (Appendix X7) are similar to those scales used bycontract testing facilities in a variety of skin testing protocols,including single patch t
36、ests placed on the upper arm, multiplepatch tests in cumulative irritation testing, forearm controlledapplication testing, nasal irritation, and Human Repeat InsultPatchTesting (as outlined inTest Method D6355). Skin gradersshould be trained to recognize erythema and dryness reactionsby performing s
37、ide-by-side scoring of patch tests or BTK testswith an experienced skin grader until the trainee can reliablyrecognize the reactions.11. Institutional Review and Informed Consent11.1 Institutional Review:11.1.1 The method for this study and qualification of per-sons conducting the study shall be rev
38、iewed by an appropriateInstitutional Review Board (IRB) or equivalent ethics reviewboard or committee.11.2 Informed Consent:11.2.1 An informed consent document should be read,understood, and signed by the subjects prior to initiating thestudy.12. Procedure12.1 SubjectsEach experiment should include
39、a generalsample size calculation done by a statistician to determine thenumber of subjects in the study (see 13.3). A sufficient numberof subjects should be recruited give the study sufficient powerto achieve a statistically significant difference between thereference and test samples, and to allow
40、for a dropout rateconsistent with the norms for the test facility. In the course ofrecruitment, demographic information (age, sex, ethnicity,height, and weight) should be collected on each subject.Subjects should be healthy adults between 18 and 65 years ofage, who meet the inclusion/exclusion crite
41、ria and preferablywith Fitzpatrick skin type I to IV mixture.12.1.1 Specific inclusion/exclusion criteria are as follows(see Appendix X1):12.1.1.1 Inclusion CriteriaSubjects who:(1) Have read, understood, and signed the informed con-sent;(2) Are at least 18 years old;(3) Are no more than 65 years ol
42、d;(4) Are in general good health (self-declared);(5) Are Fitzpatrick skin type I to IV (see Appendix X2);(6) Agree to refrain from using lotions, creams, powders,or other skin preparations on the skin in the area behind theknee during participation in the study;(7) Agree to refrain from shaving the
43、skin in the areabehind the knee during participation in the study;(8) Agree to refrain from swimming or hot tub use duringparticipation in the study;(9) Agree to refrain from fitness training during sampleapplication;(10) Agree to refrain from tanning or sun exposure to thetest area during participa
44、tion in the study;(11) Agree to refrain from taking anti-inflammatory medi-cation such as acetylsalicylic acid (aspirin), acetaminophen,ibuprofen, and naproxen;(12) Agree to comply with all study protocol requirements.12.1.1.2 Exclusion Criteria:(1) Fitzpatrick skin type V to VI (see Appendix X2) du
45、e todifficulties in scoring visible erythema on highly pigmentedskin;(2) Cuts, scratches, rashes, sunburn, acne, abrasions, scartissue, tattoos, or any other skin abnormality at the test sites;(3) Psoriasis, eczema, skin cancer, or any active dermatitisthat could potentially interfere with interpret
46、ation of test resultsat the test sites;(4) Use of corticosteroids (oral or topical) or other types ofdrugs that may interfere with the normal development ofirritation, inflammation, or immune reactions;(5) Participation in a behind-the-knee study within the lastfour weeks;(6) Known irritancy or disc
47、omfort in the area behind theknee which would prevent the subject from wearing a kneebrace for 6 h each day during study participation;(7) Current pregnancy or lactation (self-reported);(8) Diabetes or kidney disease (self-reported) which maybe associated with potential circulatory problems;(9) Hear
48、t or circulatory disease (including blood clots)(self-reported) which may be exacerbated by wearing an elasticknee band for 6 h each day during study participation;(10) Leg varicosities which would interfere with the sub-jects wearing a knee brace for 6 h each day during studyparticipation;(11) Arth
49、ritis in the lower extremities;(12) Known allergies to tape(s) and/or adhesives;(13) History of edema in the lower extremities;(14) Knee circumference greater than 21 in. (since 21 in. isthe maximum size that can be accommodated by manycommercial elastic knee bands).12.1.2 Once eligibility is confirmed, the areas behind theknees are screened for cuts, scratches, rashes, sunburn, acne,abrasions, scar tissue, tattoos, or any other condition that couldprevent a clear assessment of their skin during the test portionof the study.12.1.3 At the enrollment visit, subjects are
