Daily ingestion of alginate reduces energy intake in free-living subjects

Sodium alginate is a seaweed-derived fibre that has previously been shown to moderate appetite in models of acute feeding. The mechanisms underlying this effect may include slowed gastric clearance and attenuated uptake from the small intestine. In order to assess whether alginate could be effective as a means of appetite control in free-living adults, 68 males and females (BMI range: 18.50-32.81 kgl M-2) completed this randomised, controlled two-way crossover intervention to compare the effects of 7 day daily ingestion of a strong-gelling sodium alginate formulation against a control. A sodium alginate with a high-guluronate content was chosen because, upon ingestion, it forms a strong gel in the presence of calcium ions. Daily preprandial ingestion of the sodium alginate formulation produced a significant 134.8 kcal (7%) reduction in mean daily energy intake. This reduced energy intake was underwritten by significant reductions in mean daily carbohydrate, sugar, fat, saturated fat and protein intakes. The absence of any significant interaction effects between the main effect of preload type and those of gender, BMI classification and/or timing of preload delivery indicates the efficacy of this treatment for individuals in different settings. These findings suggest a possible role for a strong-gelling sodium alginate formulation in the future management of overweight and obesity. (C) 2008 Elsevier Ltd. All rights reserved

Feasibility of a bioadhesive drug delivery system targeted to oesophageal tissue

This contribution examines the feasibility of utilising an oesophageal-adhesive alginate layer to support model drug particles. Such a bioadhesive system offers the prospect of local drug delivery to the oesophagus, which in turn has applications in the treatment of conditions including gastro-oesophageal reflux disease and oesophageal cancer. Surface-modified (amine, carboxylate and sulfate) as well as neutral fluorescent beads were investigated as model drug particles. A fluorescence assay technique was utilised to quantify the extent and duration of adhesion of a fixed dose of these particles to excised porcine oesophageal tissue. Retention of the particles was investigated both from aqueous systems and within an adhesive alginate solution. After 30 min significantly higher adhesion of neutral beads was recorded from the alginate solution as compared to the aqueous suspension (n=6, P0.05)