Investigating the Unexpected Behavior for the Release Kinetics of Brilliant Blue Encapsulated into Calcium Alginate Beads

This work is focused on investigating the unexpected behavior for the release kinetics of brilliant blue (BB) encapsulated into calcium alginate beads. By increasing the alginate concentration from 1 - 3 % (w/v), the release of BB over time was found to follow two different behaviors. For the first two hours, the order was 1 % > 2 % > 3 %, after which it was as follow: 1 % > 3 % > 2 %! The unanticipated increase in BB release using 3 % (w/v) alginate beads after two hours over that of 2 % (w/v) alginate was examined by the swelling and bursting tests. The results were showing clear evidences by data and image the unusual behavior of 3 % (w/v) alginate beads at two hours of swelling. This unexpected behavior for the 3 % (w/v) alginate beads might be due to the higher osmotic pressure inside the beads. Overall, 2 % (w/v) calcium alginate beads were considered to be the optimum formulation showing an excellent carrier for targeting drugs to the intestine, where the swelling of the beads were 60 % in the acidic medium, it was 5000 % in the alkaline medium.