Full Natural Hydrogel Beads for Controlled Release of Acetate and Disodium Phosphate Derivatives of Betamethasone.

Highly practical conditions were accomplished to prepare new ionically crosslinked polymer network hydrogel beads (Caralgi) composed of polysaccharides carrageenan and sodium alginate. Disodium phosphate and the acetate derivatives of betamethasone were simultaneously loaded while the hydrogel network was being formed. A maximum loading efficiency of 91% was achieved at pH 4.8 and temperature 75°C. The morphology of the Caralgi hydrogels with and without drug was investigated using SEM analysis. A more regulated morphology was observed when the drug was incorporated into the hydrogel. The in vitro release behaviour of the drugloaded Caralgi samples prepared under various conditions was also studied. The full natural system has exhibited release behaviour with no burst effect. No major difference was found in the loading and release when a highly water-soluble derivative of the drug, i.e., betamethasone disodium phosphate was used.