Vaginal Irritation Test (UNE-EN ISO 10993-23: 2021. Biological evaluation of medical devices - Part 23: Tests for irritation; Anexo D6. Vaginal irritation test).
Test with the Certificate of Good Laboratory Practices (GLPs).
This test is intended to evaluate materials/substances that are going to be in contact with the vaginal tissue and if safety data cannot be determined by other methods. Materials or substances that have been shown to cause skin or eye irritation, or with a pH ≤ 2.0 or ≥ 11.5 should not be tested and shall be labelled as potential vaginal irritant.
The test is performed on six female rabbits (three for the test group and three for the control group), which are free of signs of vaginal inflammation, vaginal discharge, or other signs of vaginal infection. If there were equivocal results with this number of rabbits, the test should be done with more animals. The sample to be inoculated must be liquid. Non-soluble solid medical devices must be analyzed using their extracts in polar and non-polar solvents, requiring twice as many animals to perform the test. The animals are dosed with 1 mL of the test sample vaginally applied every 24 hours, for a minimum of five consecutive days, and are evaluated every 24 hours to detect the presence of discharge, erythema or oedema. Other treatment schedules (e.g. based on clinical use) shall be justified and documented. For prolonged repeated-exposure tests, the number of applications their duration and their interval on the exposure time should be based on the clinical situation.
The complete evaluation of the effect is made after the humanized sacrifice, 24 hours after the last dose, and the necropsy to observe the macroscopic findings after the vaginal opening to detect signs of irritation, epithelial layer injury or necrosis. In addition, a histopathological study should be performed to detect signs of microscopic inflammation in three different regions of the vagina exposed to the test sample in each of the three animals and from control animals (18 histopathological tests, 36 test if a test with extracts of the medical device is required).
According to the ISO 10993-23 standard, the mucosal tissue reactions observed in the animals exposed to the test sample and control are evaluated and the Irritation Index of the test sample is determined. The irritation index will determine whether the test sample does not cause irritation, or causes a minimal, slight, moderate or severe vaginal irritation response.