Al+3 ion cross-linked and acetalated gellan hydrogel network beads for prolonged release of glipizide

作者：Maiti Sabyasachi^*; Ranjit Somdipta; Mondol Ranjit; Ray Somasree; Sa Biswanath

来源：Carbohydrate Polymers, 2011, 85(1): 164-172.

DOI：10.1016/j.carbpol.2011.02.010

• Gellan gum
• Hydrogel bead
• Ionotropic gelation
• Entrapment efficiency
• Swelling
• Drug release

Considering relatively fast drug release rate of Ca+2/gellan beads in phosphate buffer solution, a novel glipizide-loaded bead system was developed through ionotropic gelation of gellan with trivalent Al+3 ions and covalent cross-linking with glutaraldehyde (GA). Following GA-treatment, spherical Al+3/gellan beads contracted leaving wrinkles on bead surface. A maximum of 97.67% drug entrapment efficiency was achieved; however GA-treatment reduced the same by 11.89%. All the beads released only 10% drug in acidic medium in 2 h; however it was found 38-47% for Al+3/gellan beads and only 15% for GA-treated beads in weakly alkaline medium. The drug release did correlate well with their swelling behaviors. The anomalous drug transport mechanism shifted to super case II transport for GA-treated beads, where the polymer relaxation phenomenon was dominant. The drug was relatively stable, amorphous in the beads. Thus both GA-treated and -untreated Al+3/gellan beads could be useful carriers for the controlled oral delivery of glipizide.

• 出版日期2011-4-22