A novel co-crosslinked polysaccharide: studies for a controlled delivery matrix.
J Control Release
; 55(1): 57-66, 1998 Oct 30.
Article
in En
| MEDLINE
| ID: mdl-9795015
ABSTRACT
The formulation of a new controlled delivery system, based on a novel type of matrix obtained by the chemical reaction carried out in an aqueous medium on a mixed physical gel of gellan and scleroglucan, is described in this paper. The preparation yielded a new co-crosslinked polysaccharide (CCP) hydrogel, bearing carboxylic groups, that showed a sustained release behaviour that can be modulated by means of calcium ions. For the characterization of CCP, diffusion experiments through the swelled hydrogel were carried out in different environmental conditions and the release from tablets prepared with CCP and a model drug was evaluated. The addition of CaCl2 in the formulation of the dosage forms allowed a further marked reduction in delivery rate to be obtained; this effect is to be related to the free ionized carboxylic groups still present in the gellan moiety of CCP. The different behaviour of Ca+2 and Na+ ions is discussed.
Search on Google
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Polysaccharides
/
Cross-Linking Reagents
/
Delayed-Action Preparations
Type of study:
Prognostic_studies
Language:
En
Journal:
J Control Release
Year:
1998
Document type:
Article