Release study of sodium alginate beads prepared via lonotropic gelation method

In this study, a macrosphere with different average diameter (dAve) of bead size from sodium alginate, brown algae (Phaeophyceae) were prepared using an ionotropic gelation method. The release study of model drug from the beads was also carried out. Calcium alginate bead was used as the immobilisation matrix and the effect of sodium alginate concentration, calcium chloride concentration, feeding rate and needle size on the bead formation size were investigated. Four type of analysis was conducted on the alginate bead which is size, structural, morphology and release profile. Scanning electron microscope (SEM) was used to characterize the bead structure and morphology while UV-Vis Spectrophotometer was used to observe the release profile for the model drug (Methylene Blue) encapsulated in the beads. The results indicated that increase in sodium alginate concentration at 5 wt% will decrease the average bead size (dAve = 4.08mm) on the fixed 18G, needle size. At higher calcium chloride concentration (5 wt%), hardness increase and the bead produced are decrease (dAve = 4.32mm). Increasing the diameter of needle (18G = 1.20mm) resulting in increasing of average bead size (dAve = 4.20mm). Furthermore, size of alginate bead also dependant on feeding rate. By increasing the feeding rate to 5.0 ml/min resulted in increasing of average bead size (dAve = 5.22mm). The release study of methylene blue (MB) was tested on two types of beads which is alginate beads and agar/alginate beads. The release profile showing that MB was released slower from agar/alginate beads rather than from alginate beads. Hence, from the study it shows that varies in bead size can be used in varies application also the release of active substance can be improve by blending alginate with other polymers.