V. Batra et al., SUSTAINED-RELEASE OF FERROUS SULFATE FROM POLYMER-COATED GUM ARABICA PELLETS, Journal of pharmaceutical sciences, 83(5), 1994, pp. 632-635
Sustained release of ferrous sulfate (FeSO4) from gum arabica pellets
has been achieved for 7 h. Release is further sustained for 12 to 600
h by coating the pellets with polyvinyl acetate and ethylene vinyl ace
tate, respectively. An increase in the amount of gum arabica in the pe
llets decreases the rate of release due to the gelling property of gum
arabica. The gel layer acts as a barrier and retards the rate of diff
usin of FeSO4 through the pellet. In coated pellets, an increase in th
ickness of membrane helps to sustain the release of FeSO4 for a longer
duration. Thus, the release of FeSO4 can be sustained for the require
d duration by adjusting the amount of gum arabica in the pellet and th
e composition and thickness of polymeric coat. The mechanism of releas
e accordingly varies from Fickian to zero-order and super case II tran
sport.