Calcium alginate hydrogel beads

Figure 9.6 Image of the calcium alginate hydrogel beads/DMSO system. (Reproduced with permission from [51]. Copyright (2009) Taylor Francis).

This vibration system involves a Turbotak air-atomizer in which a pressurized air is injected to mix with the sodium alginate solution. Pressurized air forces the minute liquid droplets out through the orifice of a nozzle and is sprayed into the calcium chloride solution. When these droplets come in contact with calcium chloride solution, calcium ions diffuses into the droplets of sodium alginate, which leads to form microgel droplets. Hydrogel particles thus formed can be further reinforced by poly-L-lysine or chitosan to form a membrane on the droplets. The particle size of hydrogel beads can be obtained in the range of 5 and 15 pm by the use of air atomization technique. ... 

Hydrogel beads composed of calcium alginate and crosslinked polyisopropylacrylamide were prepared based on a simultaneous IPN process. The themially reversible formation of the core-shell structure in the hydrogel was applied to temperature modulated drug release using indomethacin. 12 refs. 

Carboxyl loaded alginate based beads were used by Isiklan [152],Various hydrogel bead formulations were prepared by the ionotropic crosslinking of sodium alginate with calcium and nickel ions. Bead characteristics such as carbaryl entrapment efficiency, particle size, equilibrium swelling degree, and carbaryl releases kinetics were determined. 

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