GELLAN IN SUSTAINED-RELEASE FORMULATIONS - PREPARATION OF GEL CAPSULES AND RELEASE STUDIES

The ability of gellan to form gels in the presence of calcium ions ena bled us to prepare capsules by gelation of this polysaccharide around a core containing starch, calcium chloride and a model drug. Release f rom the dried capsules was studied in vitro by means of the rotating b asket technique (USP) in different environmental conditions (distilled water, pH=2.0, pH=6.8) and the effects of the presence of increasing amounts of drug in the formulation were also investigated. The behavio ur of the gellan capsules was compared with that of beads prepared wit h the same polysaccharide but containing different additives. Results obtained indicate that gellan is suitable for the formulation of susta ined release capsules and that solvent uptake by the dried capsules is most likely the main factor capable of affecting the rate of delivery from the tested preparations. (C) 1996 Elsevier Science Limited.