An alternative predictor of eye irritation that utilizes potential parameters of the human corneal epithelium model calculated based on Hansen solubility parameters.

Eye irritation predictions are very important in the development of cosmetics and pharmaceuticals. For animal protection, alternative tests are being developed to replace the Draize test, which involves the use of rabbits to test eye irritation. The Vitrigel-eye irritancy test (Vitrigel-EIT), is one such alternative. As a preliminary study, we evaluated if Hansen solubility parameter (HSP) values can be used to predict Vitrigel-EIT results. An Hansen sphere was created based on the HSP values and Vitrigel-EIT results from 61 substances. Substances inside and outside of the sphere were designated as dangerous and safe substances, respectively. The safety of each test substance was predicted by comparing the center point (Ro) of the sphere with the relative energy difference, i.e., the ratio of each test substance (Ra). The accuracy, false negativity, and false positivity of the "irritant" and "nonirritant" designations, as determined by the Vitrigel-EIT results and Hansen sphere, were 91.8% (56/61), 2.3% (1/43), and 22.2% (4/18), respectively. These results indicated that HSP values can be used to predict Vitrigel-EIT results with high reproducibility, and thus are useful for evaluating the safety of substances.

Highly accurate predictor of eye irritation utilizing potential parameters of a reconstructed human cornea epithelium model calculated based on Hansen solubility parameters.

Concerns regarding animal welfare have led to the need for alternatives to animal eye irritation tests. The reconstructed human cornea-like epithelium (RhCE) test is described in the OECD TG 492 as an alternative to animal eye irritation tests. However, the accuracy and labor investment of this method can be improved if the results can be predicted before the experiment. In this study, we evaluated whether Hansen solubility parameter (HSP) values can be used to predict the results of RhCE method using the LabCyte CORNEA-MODEL for 65 test substances. We found that HSP values can predict the RhCE method with high correlation (accuracy 84.6% (55/65), false-negative rate of 16.2% (7/43), and false-positive rate of 13.6% (3/22). These results indicate that HSP values can be used to predict the results RhCE method using LabCyte CORNEA-MODEL with high reproducibility, and thus are useful for evaluating the safety of substances.

Investigation of Pelvic Injuries on Eighteen Post Mortem Human Subjects Submitted to Oblique Lateral Impacts.

The aim of this study was to investigate the sacroiliac joint injury mechanism. Two test configurations were selected from full scale car crashes conducted with the WorldSID 50th dummy resulting in high sacroiliac joint loads and low pubic symphysis force, i.e. severe conditions for the sacroiliac joint. The two test conditions were reproduced in laboratory using a 150-155 kg guided probe propelled respectively at 8 m/s and 7.5 m/s and with different shapes and orientations for the plate impacting the pelvis. Nine Post Mortem Human Subject (PMHS) were tested in each of the two configurations (eighteen PMHS in total). In order to get information on the time of fracture, eleven strain gauges were glued on the pelvic bone of each PMHS. Results - In the first configuration, five PMHS out of nine sustained AIS2+ pelvic injuries. All five presented sacroiliac joint injuries associated with pubic area injuries. In the second configuration, four specimens out of nine sustained AIS2+ pelvic injuries. Two of them presented sacroiliac joint fractures associated with pubic area injuries. The other two presented injuries at the pubic area and acetabulum only. The strain gauges signals suggested that the pubic fractures occurred before the sacroiliac joint fractures in the great majority of the cases (five cases out of seven). Conclusions - Even in the oblique impact conditions of the present study, the pubic symphysis area was observed to be the weakest zone of the pelvis and its failure the predominant cause of sacroiliac joint injuries. It was hypothesized that the failure of the pubic rami allowed the hemi-pelvis to rotate inward, and that this closing-book motion induced the failure of the sacroiliac joint.