Mucoadhesive microspheres of ferrous sulphate - A novel approach for oral iron delivery in treating anemia

Ferrous sulphate is a widely used oral iron supplement with low bioavailability and substantial side effects. In this study ferrous sulphate has been coated with highly mucoadhesive polymers such as hydroxypropylmethyl cellulose (HP), chitosan (CS) and carbopol (CP) by spray drying technique to produce mucoadhesive polymer coated microspheres with good yield and high encapsulation efficiency. Mucoadhesive coating may allow these microspheres to get attached to the intestine and hence better absorption of ferrous sulphate may be achieved. in vitro release studies from the microspheres show that the release follows non-Fickian zero order drug release. CP and CSHP coated microspheres showed good swelling(similar to 1200 to 2400 %) and mucoadhesion properties (58-95 %) indicating that they can swell and get attached to the intestine for longer time period as compared to free ferrous sulphate. All the microspheres were found to be non-cytotoxic in Caco2 cell lines and fibroblast cell lines. Cell uptake studies conducted on Caco2 cell lines showed that uptake of microspheres containing ferrous sulphate has an increased and sustained release to the cell as compared to free ferrous sulphate. Though cell uptake studies showed an increase in uptake for ferrous sulphate microspheres, comparable efficacy was observed upon administering ferrous sulphate microspheres and ferrous sulphate to phenyl hydrazine induced anemic rats.