Molecules (Nov 2007)

The Drug Release Profile from Calcium-induced Alginate Gel Beads Coated with an Alginate Hydrolysate

  • Susumu Kawashima,
  • Kyouko Kofuji,
  • Takshi Isobe,
  • Dongchun Liu,
  • Daisaku Jinno,
  • Yoshifumi Murata

DOI
https://doi.org/10.3390/12112559
Journal volume & issue
Vol. 12, no. 11
pp. 2559 – 2566

Abstract

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Calcium-induced alginate gel bead (Alg-Ca) coated with an alginate hydrolysate(Alg), e.g. the guluronic acid block (GB) was prepared and the model drug, hydrocortisonerelease profiles were investigated under simulated gastrointestinal conditions. Theirmolecular weights were one sixth or one tenth that of Alg and the diffraction patterns of thehydrolysates resembled that of Alg. The drug release rate from Alg-Ca coated with GBapparently lowered than that of Alg-Ca (coating-free) in the gastric juice (pH1.2). And thecoating did not resist the disintegration of Alg-Ca in the intestinal juice (pH 6.8) and thegel erosion accelerated the drug release. On the other hand, for the coated Alg-Cacontaining chitosan, the drug release showed zero-order kinetics without rapid erosion ofAlg-Ca. The drug release rate from Alg-Ca was able to be controlled by the coating andmodifying the composition of the gel matrix.

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