In situ gelling xyloglucan/alginate liquid formulation for oral sustained drug delivery to dysphagic patients

Background: The oral administration of liquid dosage forms of suitable consistency and with sustained release characteristics may provide a means of improving the compliance of geriatric patients who experience difficulties in swallowing conventional solid dosage forms. Aim: We have designed and evaluated liquid preparations for administration to dysphagic patients, composed of aqueous mixtures of xyloglucan, which has thermally reversible gelation characteristics, and sodium alginate, which has ion-responsive gelation characteristics. Method: The gelation and in vitro and in vivo release characteristics of liquid formulations containing appropriate concentrations of xyloglucan and sodium alginate with mannuronate/guluronate ratios of either 0.5 or 0.8 were assessed. Results: Aqueous mixtures of 1.5% xyloglucan and 0.5% alginate had suitable viscosities for ease of swallowing and appropriate gelation temperatures (∼33°C) to ensure in situ gelation following oral administration. The in vitro release of par...