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2581713 
Journal Article 
Effects of Drying Methods on the Release Kinetics of Vitamin B-12 in Calcium Alginate Beads 
Abubakr, N; Lin, SX; Chen, XD 
2009 
Yes 
Drying Technology
ISSN: 0737-3937 
27 
11 
1258-1265 
WOS:000274667700013 
The aim of this article was to investigate the morphology, swelling properties, and respective drug release kinetics of vitamin B12-loaded calcium alginate beads prepared by oven (air), vacuum, and freeze drying. The initial particle size was 1mm. The mean bead sizes of dried Ca-alginate beads were 0.7, 0.8, and 0.9mm for oven-, vacuum-, and freeze-dried beads, respectively. The surface morphology of the dried beads was affected by the different drying methods applied. Oven- and vacuum-dried beads shrank in size, and more cracks appeared on the surface of oven-dried beads. Freeze-dried beads almost retained the same size prior to drying; however, the surface was rougher and highly porous. The swelling profiles were also affected by the drying methods, whereby freeze-dried beads showed the fastest solvent uptake at the start of the experiment. The release data of the dried Ca-alginate beads were treated with first-order, Higuchi, Korsmeyer, and Peppas kinetic models. The data for oven and vacuum seemed to follow a combination of diffusion and swelling controlled release, whereas data from freeze-dried beads seemed to follow more diffusion-dominated controlled release. 
Calcium alginate; Drug release; Freeze drying; Kinetics; Oven drying; Vacuum drying; Water-soluble drug