The method is found in an informative annex of the document.
There is an exemption statement that test articles are excluded when the pH is less than or equal to 2 or greater than or equal to 11.5 or if it is already known as an irritant in other tissues.
If the test material is a solid, then it should be extracted, and if it is a liquid it can be dosed directly. Extraction should be performed using both polar and non-polar vehicles. All test material preparation should be performed according to the appropriate associated annexes.
The animals used should be female, albino rabbits.
A total of six animals should be used. Three animals for each of the test and control (material or solvent) articles, separate groups for each extract vehicle.
In order to be qualified for testing, the animals should be evaluated before the test for signs of discharge, swelling, infection, or irritation. Those animals with findings should not be used.
If the results of the initial test are questionable, more animals may be necessary.
At each of the doses, 2 mL of the test or control article should be administered to the rectum. The procedure should be repeated daily for 5 days for an acute exposure and if the total length should be longer than 5 days, it should mimic clinical exposure.
The dosed tissue should be observed 24 hours after the previous exposure.
Macroscopic grading is assessed on a 5 point scale ranging from no(0), very slight(1), well-defined(2), moderate(3), to severe(4) for erythema. 24 hours after the last dose, the animals are scored macroscopically and then the rectums are harvested, fixed and processed histologically.
Macroscopic evaluation:
The average score for each animal in the test group is compared to the treated control group. A consideration is made to the potential presence of procedural related irritation in the final study evaluation.
Microscopic evaluation:
An overall average per group score is determined with the maximum score being 16. Four different microscopic categories are individually evaluated with grading ranges from 0 to 4 for epithilium, leukocyte infiltration, vascular congestion and edema. The final evaluation is a 5 range category scale ranging from not an irritant to a severe irritant.
There is an exemption statement that test articles are excluded when the pH is less than or equal to 2 or greater than or equal to 11.5 or if it is already known as an irritant in other tissues.
If the test material is a solid, then it should be extracted, and if it is a liquid it can be dosed directly. Extraction should be performed using both polar and non-polar vehicles. All test material preparation should be performed according to the appropriate associated annexes.
The animals used should be female, albino rabbits.
A total of six animals should be used. Three animals for each of the test and control (material or solvent) articles, separate groups for each extract vehicle.
In order to be qualified for testing, the animals should be evaluated before the test for signs of discharge, swelling, infection, or irritation. Those animals with findings should not be used.
If the results of the initial test are questionable, more animals may be necessary.
At each of the doses, 2 mL of the test or control article should be administered to the rectum. The procedure should be repeated daily for 5 days for an acute exposure and if the total length should be longer than 5 days, it should mimic clinical exposure.
The dosed tissue should be observed 24 hours after the previous exposure.
Macroscopic grading is assessed on a 5 point scale ranging from no(0), very slight(1), well-defined(2), moderate(3), to severe(4) for erythema. 24 hours after the last dose, the animals are scored macroscopically and then the rectums are harvested, fixed and processed histologically.
Macroscopic evaluation:
The average score for each animal in the test group is compared to the treated control group. A consideration is made to the potential presence of procedural related irritation in the final study evaluation.
Microscopic evaluation:
An overall average per group score is determined with the maximum score being 16. Four different microscopic categories are individually evaluated with grading ranges from 0 to 4 for epithilium, leukocyte infiltration, vascular congestion and edema. The final evaluation is a 5 range category scale ranging from not an irritant to a severe irritant.
