Gelrich can be used to produce easy-to-swallow solid dosage forms, such as gels and coated tablets, and to modify the rate of release of active ingredients from tablets and capsules. Gelrich is also conveniently used for controlled or sustained release of various drugs and also for micro-encapsulation preparation. The bioavailability of theophilline from the gellan gels increases 4-5 folds in rats and 3 folds in rabbits compared to a commercial sustained release liquid dosage form.