In vivo and in vitro experimental toxicity study of titanium diisopropoxide bis (2–4‐pentanedionate) in rat

The toxicity of an organic titanium salt, titanium diisopropoxide bis (2–4 pentanedionate) was tested in rats and mice. After acute oral intoxication this compound is poorly absorbed and titanium is slowly eliminated in the faeces. After acute inhalation of an oily aerosol of the compound, faecal excretion is more important than urinary elimination but the latter is significantly higher than after oral administration. Irritation of mucous membranes and pulmonary difficulties are the major clinical signs of the intoxication. Repeated inhalation (6 hours per day, 5 days per week) over 4 weeks leads to an important pulmonary deposit. Later on, because of its ability to combine with tissue proteins, the titanium accumulated in the lungs slowly diffuses and remains for a long time in the body. Titanium toxicity was also demonstrated in primary rat hepatocyte cultures. IC50 values for the four tests used were closed to 65 μg ml−1. Therefore comparison of these in vitro results with the in vivo data appears diff...