2.8. Irwin Test (Neurobehavioral Activity)

In this test, an examination is done whether or not drugs induce behavioural and physiologically relevant effects. Effects were determined for three different doses of Pep19-2.5 after a single i.v. administration versus one dose of a positive (chlorpromazine) control item and a negative control item (saline), respectively, in male Wistar rats using the modified Irwin test. The modified Irwin test was performed under GLP conditions and was comprised of a standard observation battery of tests addressing various parameters of the central nervous, autonomic nervous, peripheral motor, and sensory systems.

Details of the performed Irwin test are depicted in Scheme 1.

Experimental approach used for the Irwin test.

The study comprised five treatment groups with six male animals each. The experimental groups and doses are shown in the Table 2.

Modified Irwin test, comprised of standard observation battery addressing various parameters, such as central nervous and autonomic nervous systems, as well as peripheral motor and sensory systems + mortality, body weight, clinical observations.

The following investigations were made at the following time points:

Statistical analyses of the data were performed for each group separately. Group mean values (means) with standard deviation (SD) were calculated for body weights, each parameter of the Irwin Test, and each investigation time point.

For Irwin Test parameters, statistical differences between the positive control group and the vehicle control group and between the test item groups and the vehicle control group were evaluated by the Mann–Whitney U-test, using an MS Excel^® statistics tool developed and validated in-house; p < 0.05 was accepted as the level of significance.

No relevant neurobehavioral effects of Pep19-2.5 were calculated.