Sorbifer Durules Mechanism of Action

Pharmacology: Pharmacodynamics and Pharmacokinetics: Iron is regularly and incompletely absorbed from the gastrointestinal tract, the main sites of absorption being the duodenum and jejunum. Absorption is aided by the acid secretion of the stomach and by some dietary acids (such as ascorbic acid) and occurs more readily when the iron is in the ferrous state or is part of the haem complex (haem-iron). Absorption is also increased in conditions of iron deficiency or in the fasting state but is decreased if the body stores are overloaded. Normally, only about 5% to 15% of the iron ingested in food is absorbed.
Most absorbed of the iron is bound to transferrin and transported to the bone marrow where it is incorporated into haemoglobin; the remainder is contained within the storage forms, ferritin or haemosiderin, or as myoglobin with smaller amounts occurring in haem-containing enzymes or in plasma bound to transferrin.
Only very small amounts of iron are excreted as the majority released after the destruction of haemoglobin molecule is re-used. This conservation of body iron, and lack of an excretory mechanism for excess iron, is the reason for the development of iron overload with excessive iron therapy or repeated transfusions.
Properties: Durules provide continuous release of active substance. Studies using the double-isotope technique have shown that iron administered in the form of Ferrous Sulfate Durules is better utilized by the body than iron in ordinary tablets. This good absorption does not result in increased side effects. The occurrence of nausea and gastric pain is less with Ferrous Sulfate Durules than with conventional tablets.