1、Designation: F 720 81 (Reapproved 2007)e1Standard Practice forTesting Guinea Pigs for Contact Allergens: Guinea PigMaximization Test1This standard is issued under the fixed designation F 720; the number immediately following the designation indicates the year oforiginal adoption or, in the case of r
2、evision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.e1NOTEFormatting and grammar were corrected editorially throughout in April 2007.1. Scope1.1 This practice i
3、s intended to determine the potential for asubstance, or material extract, to elicit contact dermal allerge-nicity.1.2 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
4、safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2F 619 Practice for Extraction of Medical Plastics3. Summary of Practice3.1 After a two-stage induction employing Freunds com-plete adjuvant and sodium lauryl
5、 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 allergic reaction, and the intensity of the reactionscored at the time of removal and 24 and 48 h subsequent toremoval.4. Significance and Us
6、e4.1 In selecting a new material for human contact in medicalapplications, it is important to ensure that the material will notstimulate the immune system to produce an allergic reaction.The reaction would be due to substances which could leach outof a material. Therefore, this practice provides for
7、 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 contact dermatitis. The use ofFreunds complete adjuvant and sodium lauryl sulfate tends toenhance the potential of a material to cause an alle
8、rgy.Therefore, this test, while not guaranteeing that a material isnonallergenic, is the most severe animal test in common usetoday.5. Materials and Manufacturer5.1 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 Occl
9、usive 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 % formaldehyde for water-soluble test substances.6. Preparation of Test Samples6.1 Samples for Intradermal Injection:6.1.1 Water-Soluble Cons
10、tituents 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 obtain a water extraction liquid as described inPractice F 619.6.1.1.2 Combine equal volumes of the liquid described in6.1.1.1 and Freunds com
11、plete adjuvant. Homogenize bycontinuous and vigorous vortex mixing for a minimum of 5min. Emulsification is complete when a drop placed on thesurface of a water-ice bath remains intact.6.1.1.3 Also prepare the constituent or extract to the sameconcentration in water without Freunds complete adjuvant
12、.6.1.2 Oil Soluble Constituents:6.1.2.1 Dissolve oil-soluble constituents in Freunds com-plete adjuvant to concentration of 10 weight %.6.1.2.2 Combine equal volumes of the 10 % Freunds adju-vant solution with an equal volume of water by slowly addingthe water to the adjuvant while homogenizing with
13、 a rotating1This practice is under 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 Feb. 1, 2007. Published February 2007. Originallyapproved in 1981. La
14、st previous edition approved in 2002 as F 720 81 (2002)e1.2For 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.1Co
15、pyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.stirrer. 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.6.1.2.3 Also pre
16、pare 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 F 619 with an equal volume ofFreunds complete adjuvant.6.1.3.2 Also prepare extract to an equal co
17、ncentration inwater without Freunds complete adjuvant.6.1.4 Prepare control substances consistent with 6.1.1-6.1.3.2.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
18、 Samples for Topical Application:6.2.1 LiquidsFor all liquids, use highest concentration 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
19、with water ifnecessary.7. Procedure for Test and Control Substances7.1 Induction:7.1.1 Intradermal 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
20、 sites. Intradermalinjections are then made as indicated below, with Site 1 beingclosest 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
21、 One week after the intradermal injections, clip testarea of guinea pigs.7.1.2.2 If the test sample is non-irritating, treat each test areawith 10 % sodium lauryl sulfate (SLS) in petroleum jelly, 24 hbefore applying test patches. Massage the SLS into the skinwith a glass rod.7.1.2.3 Apply test samp
22、le toa2by4-cm patch of qualitativefilter paper. Apply test agent in petroleum jelly to the filter ina thick, even layer. Apply the test liquid to the test paper untilsaturated.7.1.2.4 Apply filter paper to the injection site of guinea pigs.Cover with 3.75-cm occlusive surgical tape and wrap an elast
23、icbandage around the torso to secure the tape.7.1.2.5 Leave in place 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 animals flank.7.2.3 Delivery of Test Sample:7.2.3.1 Test solids as a 25 % concentration (providing th
24、isconcentration is not irritating) in petroleum jelly by weight.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 occlusiv
25、esurgical tape and elastic bandage as described in 7.1.2.4.7.2.5 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 T
26、able 1.8.2 Prepare a tabular listing of the reactions at 1, 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 th
27、an 50 %) of animalsshow a reaction score of one, repeat the 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, gene
28、ric name, productname, and lot number.9.1.2 Method of preparation, that is, extraction liquid used,and form of exposure.9.1.3 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 re
29、sponse.10. Keywords10.1 acute toxicity tests; allergenicity; biocompatibility;guinea pigs; sensitization; test animalsTABLE 1 Scoring Criteria for Test ReactionsReaction Description ScoreErythema erythema and escharno erythema 0very slight erythema (barely perceptible) 1well-defined erythema (pale r
30、ed in color) 2moderate to severe erythema (red and area 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 approxima
31、tely 1 mm) 3severe edema (raised more than 1 mm and extendingbeyond area of exposure)4F 720 81 (2007)e12ASTM 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
32、determination of the validity of any such patent rights, and the 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 reapprove
33、d or withdrawn. Your comments are invited either for revision of 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
34、 that your comments have not received a fair hearing you shouldmake 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 repri
35、nts (single or multiple copies) of this standard may be obtained 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).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 extremeF 720 81 (2007)e13
