Toltrazuril is a triazinon derivative and an antiprotozoal agent. It has coccidiocidal activity against all intracellular development stages of the genera Cystoisospora, that is, merogony (asexual multiplication) and gamogony (sexual phase).

Iron is an essential micronutrient. It plays a major role in the transport of oxygen via haemoglobin and myoglobin, as well as having a key role in enzymes, such as cytochromes, catalases, and peroxidases. Injectable iron-carbohydrate complexes, such as gleptoferron, are established haematinic agents in veterinary medicine and are effective in significantly increasing the haemoglobin levels in piglets raised under intensive farming conditions in which an all milk diet for several weeks does not provide an adequate source of iron. Following intramuscular injection, gleptoferron is absorbed and metabolised to release the iron for use and/or storage in accordance with the nutritional status of the animal. Excess iron is stored principally in the liver.

After intramuscular administration of 1.5 ml/piglet of Forceris, maximal concentrations of 7 mg/l of toltrazuril were reached about 6 days after administration (Tmax ranging from 4 to 7 days), and the AUC was about 57 day.mg/l.

Toltrazuril is primarily metabolised into toltrazuril sulfone. After intramuscular administration of 1.5 ml/piglet of Forceris the maximal concentration of 10 mg/l for toltrazuril sulfone was reached about 13 days after administration (Tmax ranging from 10 to 19 days), and the AUC was about 183 day.mg/l.

Toltrazuril and toltrazuril sulfone were eliminated slowly with a half-life of 3 days each. The principal route of excretion is via the faeces.

After intramuscular injection of 1.5 ml/piglet of Forceris, iron is absorbed rapidly from the injection site into the capillaries and the lymphatic system and a maximal concentration of 645 μg/ml was reached after approximately 0.5 day, the AUC was about 699 day.μg/ml. Since iron is recycled in the body little of the absorbed iron is excreted. Very small losses occur in the faeces, sweat and urine.