Skin Sensitization test (GPMT: Guinea pig maximization test of Magnusson y Kligman). UNE-EN ISO 10993-10: 2013. Biological evaluation of medical devices. Test for irritation and skin sensitization; OPPTS 870.2600: 1998, “Office of Prevention, Pesticides and Toxic Substances (OPPTS), United States Enviromental Protection Agency”; and Directive 92/69/EEC, July 31, 1992, paragraph B.6.
Test Accredited by ENAC (National Accreditation Entity).
Test with the Certificate of Good Laboratory Practices (GLPs).
This test aims to detect the ability of a product to trigger a process of sensitization (hypersensitivity) in which cellular immune mechanisms are involved, induced by a substance with the capacity to induce in a different way (cellular hypersensitivity) to the immune system. Sensitization is triggered after single or multiple exposures. The inducing substance, after penetrating and binding to plasma proteins, induces the T cell response. The test is developed in two phases: induction phase and trigger phase. The product, or its extract obtained with polar solvents (physiological saline solution, distilled water, hydroalcoholic solution 5%, polyethylene glycol 400), or with non-polar solvents (vegetable oil), during the induction phase, is used both incorporated in complete Freund adjuvant (to increase the sensitizing capacity), as without adjuvant. During the induction phase, the product (or its extract) is applied in two different ways, one of them, initial, intradermally, and another after 7 days, topically, in the same area of the skin in which was performed initially by intradermal route. On day 21, the triggering phase (exposure) is carried out by topical application of the substance for 24 hours in another part of the skin to that used for the initial and 7-day induction. After removing the dressing from the trigger induction, the reading is made at 24, 48 and 72 hours. At the same time a group of animals should be used as a negative control (not exposed to the test substance), and a group of animals as a positive control, which are induced with a substance (2,4-dinitrochlorobenzene) which is a known sensitizer. The animals used are albino guinea pigs.