1、Designation: F720 13Standard Practice forTesting Guinea Pigs for Contact Allergens: Guinea PigMaximization Test1This standard is issued under the fixed designation F720; the number immediately following the designation indicates the year of originaladoption or, in the case of revision, the year of l
2、ast revision. A number in parentheses indicates the year of last reapproval. A superscriptepsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice is intended to determine the potential for asubstance, or material extract, to elicit contact dermal alle
3、rge-nicity.1.2 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.3 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 est
4、ablish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2F619 Practice for Extraction of Medical Plastics2.2 ISO Standards:2ISO 1099310 Biological evaluation of medical devicesPart 10: Tests for
5、 irritation and skin sensitization3. Summary of Practice3.1 After a two-stage induction employing Freunds com-plete adjuvant and sodium lauryl sulfate, the substance orextract is placed on patches and then placed on the skin ofguinea pigs. After 24 h, the patches are removed and the skinexamined for
6、 allergic reaction, and the intensity of the reactionscored at the time of removal and 24 and 48 h subsequent toremoval.4. Significance and Use4.1 In selecting a new material for human contact in medicalapplications, it is important to ensure that the material will notstimulate the immune system to
7、produce an allergic reaction.The reaction would be due to substances which could leach outof a material. Therefore, this practice provides for usingmaterial extracts. The rationale for this practice is based on thefact that the guinea pig has been shown to be the best animalmodel for human allergic
8、contact dermatitis. The use ofFreunds complete adjuvant and sodium lauryl sulfate tends toenhance the potential of a material to cause an allergy.Therefore, this test, while not guaranteeing that a material isnonallergenic, is the most severe animal test in common usetoday.5. Materials and Manufactu
9、rer5.1 Hartley Strain Guinea Pigs, male, 300 to 500 g.5.1.1 Ten animals are used for each test material.5.2 Freunds Complete Adjuvant.5.3 Occlusive Surgical Tape, 3.75 cm in width.5.4 Elastic Bandage.5.5 Sodium Lauryl Sulfate (10 weight %) in USP petroleumjelly.5.6 Positive Control Substance.5.6.1 5
10、 % formaldehyde for water-soluble test substances.6. Preparation of Test Samples6.1 Samples for Intradermal Injection:6.1.1 Water-Soluble Constituents or Water Extract Liquids:6.1.1.1 Dissolve the water-soluble constituent up to itsmaximum solubility, not to exceed a concentration of 10weight %, or
11、obtain a water extraction liquid as described inPractice F619.6.1.1.2 Combine equal volumes of the liquid described in6.1.1.1 and Freunds complete adjuvant. Homogenize by con-tinuous and vigorous vortex mixing for a minimum of 5 min.Emulsification is complete when a drop placed on the surfaceof a wa
12、ter-ice bath remains intact.6.1.1.3 Also prepare the constituent or extract to the sameconcentration in water without Freunds complete adjuvant.6.1.2 Oil Soluble Constituents:6.1.2.1 Dissolve oil-soluble constituents in Freunds com-plete adjuvant to a concentration of 10 weight %.1This practice is u
13、nder the jurisdiction ofASTM Committee F04 on Medical andSurgical Materials and Devices and is the direct responsibility of SubcommitteeF04.16 on Biocompatibility Test Methods.Current edition approved June 1, 2013. Published July 2013. Originally approvedin 1981. Last previous edition approved in 20
14、12 as F720 81 (2012). DOI:10.1520/F0720-13.2For 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 In
15、ternational Organization for Standardization (ISO), 1, ch. de laVoie-Creuse, CP 56, CH-1211 Geneva 20, Switzerland, http:/www.iso.org.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States16.1.2.2 Combine equal volumes of the 10 % Freunds ad
16、ju-vant solution with an equal volume of water by slowly addingthe water to the adjuvant while homogenizing with a rotatingstirrer. Homogenize by continuous and vigorous mixing for aminimum of 5 min. Emulsification is complete when a dropplaced on the surface of a water-ice bath remains intact.6.1.2
17、.3 Also prepare the constituent to an equal concentra-tion without Freunds complete adjuvant.6.1.3 Vegetable Oil Extract Liquids:6.1.3.1 Mix equal volumes of oil extract liquid obtained inaccordance with Practice F619 with an equal volume ofFreunds complete adjuvant.6.1.3.2 Also prepare extract to a
18、n equal concentration inwater without Freunds complete adjuvant.6.1.4 Alternative Sample Preparation: As an alternativemethod for sample extraction, the method described in ISO1099310, Annex E is recommended for consideration for theextraction of polymeric materials.6.1.5 Prepare control substances
19、consistent with6.1.1-6.1.3.2.NOTE 1If the final concentration of the suspected allergen results indeleterious effects such as ulceration, necrosis, or systemic toxicity, usethe maximum tolerable concentration.6.2 Samples for Topical Application:6.2.1 LiquidsFor all liquids, use highest concentration
20、 notcausing excessive irritation or deleterious to general health oftest animals. (See Note 1.)6.2.1.1 For oil-miscible liquids, dilute with petroleum jellyif necessary.6.2.1.2 For water-miscible liquids, dilute with water ifnecessary.7. Procedure for Test and Control Substances7.1 Induction:7.1.1 I
21、ntradermal Injection:7.1.1.1 Clip the shoulder region of each guinea pig free ofhair, exposinga4by6-cm area.7.1.1.2 Three injection sites on each side of the spine shouldbe identified with at least 1.5 cm between sites. Intradermalinjections are then made as indicated below, with Site 1 beingclosest
22、 to the animals head.(1) Site 10.1 mL of adjuvant without test sample(2) Site 20.1 mL of test sample without adjuvant(3) Site 30.1 mL of test sample emulsified in completeadjuvant7.1.2 Topical Application:7.1.2.1 One week after the intradermal injections, clip thetest area of the guinea pigs.7.1.2.2
23、 If the test sample is non-irritating, treat each test areawith 10 % sodium lauryl sulfate (SLS) in petroleum jelly, 24 hbefore applying the test patches. Massage the SLS into the skinwith a glass rod.7.1.2.3 Apply the test sample toa2by4-cm patch ofqualitative filter paper. Apply the test agent in
24、petroleum jellyto the filter in a thick, even layer. Apply the test liquid to thetest paper until saturated.7.1.2.4 Apply filter paper to the injection site of the guineapigs. Cover with 3.75-cm occlusive surgical tape and wrap anelastic bandage around the torso to secure the tape.7.1.2.5 Leave in p
25、lace for 48 h.7.2 Challenge:7.2.1 Two weeks following the induction described in 7.1,perform the following:7.2.2 Shavea5by5-cm area on theanimals flank.7.2.3 Delivery of Test Sample:7.2.3.1 Test solids as a 25 % concentration (providing thisconcentration is not irritating) in petroleum jelly by weig
26、ht.Apply ona2by2-cm piece of filter paper as outlined in7.1.2.3.7.2.3.2 Test liquids in undiluted form consistent with 6.1.5.Apply ona2by2-cm piece of filter paper as outlined in7.1.2.3.7.2.4 Cover the filter paper and sample with occlusivesurgical tape and an elastic bandage as described in 7.1.2.4
27、.7.2.5 Leave the samples in place for 24 h.8. Interpretation of Results8.1 Read the challenge sites within 1 h after removing thepatches and at 24 and 48 h after removing the patches. Gradeeach site for erythema and edema in accordance with Table 1.8.2 Prepare a tabular listing of the reactions at 1
28、, 24, and 48h. Any animal showing a reaction at 24 or 48 h of two orgreater for erythema and edema shall be considered sensitized.8.3 Rate the allergenicity of the test material in accordancewith Table 2.8.3.1 If a significant number (more than 50 %) of animalsshow a reaction score of one, repeat th
29、e test with an additionalten animals.8.3.2 If 60 % of the animals in the positive control group donot show a reaction of two or greater, repeat the test.9. Report9.1 The report shall include the following:9.1.1 Test material description, generic name, productname, and lot number.9.1.2 Method of prep
30、aration, that is, extraction liquid used,and form of exposure.TABLE 1 Scoring Criteria for Test ReactionsReaction Description ScoreErythema erythema and escharno erythema 0very slight erythema (barely perceptible) 1well-defined erythema (pale red in color) 2moderate to severe erythema (red and area
31、well de-fined)3severe erythema (beet redness to slight eschar for-mation)4Edema edema formationno edema 0very slight edema (barely perceptible) 1slight edema (edges of area well-defined by definiteraising)2moderate edema (edges raised approximately 1 mm) 3severe edema (raised more than 1 mm and exte
32、ndingbeyond the area of exposure)4F720 1329.1.3 Any necessary dilutions due to severe reactions.9.1.4 General conditions of animal health.9.1.5 Scoring of erythema and edema for each animal.9.1.6 Rating of sensitization response.10. Keywords10.1 acute toxicity tests; allergenicity; biocompatibility;
33、guinea pigs; sensitization; test animalsASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the
34、 riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of
35、 this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldm
36、ake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained
37、 by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).TABLE 2 Rating of Sensitization Response% Sensitized Grades Classification0 to 8 I no different than control9to28 II mild29 to 64 III moderate65 to 80 IV strong81 to 100 V extremeF720 133
