ASTM_F_720_-_13.pdf

Designation:F72013Standard 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 last revision.Anumber in parentheses indicates the year of last reapproval.Asuperscriptepsilon()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 allerge-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 establish 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:3ISO 1099310 Biological evaluation of medical devicesPart 10:Tests for 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 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 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 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 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 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%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 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 water-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:1This 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 June 1,2013.Published July 2013.Originally approvedin 1981.Last previous edition approved in 2012 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 International Organization for Standardization(ISO),1,ch.dela Voie-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 States1 6.1.2.1 Dissolve oil-soluble constituents in Freunds com-plete adjuvant to a 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 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.6.1.2.3 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 Al