This study was conducted to assess the acute oral toxicity of TI-435 in fasted rats. Groups of five male and five female fasted rats were given TI-435 as a single dose by oral gavage at dose levels of 1758, 2283, 2965, 3850, and 5000 mg/kg body weight. The test article was dispersed in 5% m/v aqueous gum arabic and administered at a dose volume of 10 ml/kg on Day 1. All animals suntiving treatment were killed on Day 15 and subsequently underwent a full necropsy. Single female rats were found dead on Day 2 and on Day 4 alter oral administration of 2965 or 5000 mg/kg of the test article, respectively. Two rats were killed on humane grounds on Day 12. A male (no. 800; 5000 mg/kg) and female (no. 821; 3850 mg/kg) had showed progressive losses of body weight, during the observation period, and were considered to be moribund. The principal treatment-related clinical signs were palpebral closure, decreased activity, and tremor, followed at later stages of the observation period by a wasted appearance and hair loss. Less common clinical signs, apparent at all dose levels, included ataxia and hunched posture.