[Toxicity of oxythioquinox (Morestan) administered in a lipid solution]

Administered to rats by stomach tubing oxythioquinox (Morestan) toxicity is very strongly increased after solubilisation in olive oil. The oxythioquinox DL50, in this case, is 500 mg/kg although we can reach 2.8 g/kg in aqueous suspensions. When it is administered (1 g/kg) in aqueous suspension, the decrease in body weight is the same as these observed with a 5 fold lower dose in oil. Conversion rate feed and weight of differents organs decrease when animals are daily submitted to oxythioquinox in oil, during 16 days, compared with animals treated with an equivalent dose in aqueous suspension. Potentiation, in oil solutions, of the decrease of oxythioquinox intestinal transit, promoting its absorption, could explain the increase of oxythioquinox toxicity in oil solution.