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Assessment of sensitising properties on albino guinea pig

ISO 10993-10

Maximisation test according to MAGNUSSON and KLIGMAN

Guinea pigs are initially exposed to the test product by intradermal injections and epidermal application (induction exposure). Following a rest period of a least 14 days (induction period), during which an immune response may develop, the animals are exposed to a challenge dose. The extent and degree of skin reaction to the challenge exposure in the test animals is compared with that demonstrated by control animals which undergo sham treatment during induction and receive the challenge exposure.

Test extract preparation

Usually polar and non-polar extracts are requested.
The test extracts are prepared in accordance with the standard NF EN ISO 10993 part 12.

Determination of surface area

Surface area calculations will be used for samples which can be considered as resembling simple geometric shapes. Porous samples such as gauze, woven articles or spongy materials with simple geometric shapes will be regarded and measured as solid objects.

Mass

For materials with an irregular shape whose surface area cannot easily be determined, a mass/volume of extracting fluid shall be used.
The standard surface areas and extract liquid volumes are defined in the following table:

Thickness

 

(mm)

Extraction ratio

(Surface area or mass/volume)

± 10%

Examples of forms of materials

< 0.5

6 cm2/mL

film, sheet, tubing wall

0.5 to 1.0

3 cm2/mL

tubing wall, slab, small moulded items

>1.0

3 cm2/mL

larger moulded items

>1.0

1.25 cm2/mL

elastomeric closures

Irregularly shaped solid devices

0.2 g sample/mL

powder, pellets, foam, non-absorbent moulded items

Irregularly shaped porous devices (low density materials)

0.1 g/mL

membranes

NOTE While there are no standardized methods available at present for testing absorbents and hydrocolloids, the following is a suggested protocol.

Determine the volume of extraction vehicle that each 0.1 g or 1.0 cm2 of material absorbs. Then, in performing the material extraction, add this additional volume to each 0.1 g or 1.0 cm2 in an extraction mixture.

 

Observations -treated and control groups

  • Approximately 21 hours after removing the patch the challenge area is cleaned and closely-clipped and/or shaved or depilated if necessary;
  • Approximately 3 hours later (approximately 48 hours from the start of the challenge application) the skin reaction is observed and recorded according to the grades shown below;
  • Approximately 24 hours after this observation a second observation (72 hours) is made and once again recorded.

TABLE: MAGNUSSON AND KLIGMAN GRADING SCALE FOR THE EVALUATION OF CHALLENGE PATCH TEST REACTIONS

  • 0 = no visible change
  • 1 = discrete or patchy erythema
  • 2 = moderate and confluent erythema
  • 3 = intense erythema and swelling

Interpretation of results

 The test item will be regarded as a sensitiser if 30% or more of the test animals show a sensitisation response.

Price

€€

Turnaround

6 weeks

€ : < 1500 € €€ : between 1500 and 4000 € €€€ : between 4000 and 20000 € €€€€ : > 20000 €
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