Related Experiment Video
Updated: Oct 19, 2026

Synthesis of Thermogelling Poly(N-isopropylacrylamide)-graft-chondroitin Sulfate Composites with Alginate Microparticles for Tissue Engineering
Published on: October 26, 2016
In situ-gelling gellan formulations as vehicles for oral drug delivery
S Miyazaki1, H Aoyama, N Kawasaki
1Faculty of Pharmaceutical Sciences, Health Science University of Hokkaido, Ishikari-Tohbetsu, Hokkaido 061-0293, Japan.
Abstract:
Gels formed in situ following oral administration of 1% (w/v) aqueous solutions of gellan to rats and rabbits were evaluated as sustained-release vehicles. The formulation contained calcium ions in complexed form, the release of which in the acidic environment of the stomach caused gelation of the gellan gum. The in vitro release of theophylline from the rigid gellan gels followed root-time kinetics over a period of 6 h. Plasma levels of theophylline after oral administration of gellan solutions and a commercial oral sustained-release liquid dosage form containing an identical drug concentration were compared in both rats and rabbits. Bioavailability of theophylline from gellan gels formed by in situ gelation in the animal stomach was increased by four-fivefold in rats and threefold in rabbits compared with that from the commercial oral formulation. There was no significant difference in the mean residence times of theophylline when administered by these two vehicles.
Related Concept Videos
Oral Drug Delivery Systems: Introduction
Oral Drug Delivery Systems: Delayed-Release Systems
Bioavailability Enhancement: Drug Stability Enhancement and GI Retention
Oral Drug Delivery Systems: Continuous-Release Systems
Drug Delivery: Enteral Route
Drugs in...
Site-Targeted Drug Delivery Systems: Polymeric Carriers
