Adsorption of Bile Acid by Chitosan-Orotic Acid Salt and Its Application as an Oral Preparation

New chitosan salt in gastro-resistant oral formulation could interfere with enteric bile salts emulsification of diet fats: preliminary laboratory observations and physiologic rationale

Chitosan (CH) is a polymer of glucosamine that is extracted from the shells of several sea fruits. It is well recognized as a nutritional supplement that is used to reduce body weight and blood lipid levels, but its clinical efficacy has not been clearly demonstrated. The true mechanism of action and physiological processes involved in these properties of CH are not yet understood or explained. The most accepted theories assume that CH reduces dietary fat absorption by trapping the fat in the gastric lumen. The very low pH of the gastric lumen induces CH jellification and, therefore, entrapment of the fats. This article describes the most plausible mechanism by which CH interferes with fat absorption in the first part of the enteric tract while interacting with cholic acids. We emphasize the weak points of the classic CH-containing formulations, which are unable to prove this theory. We also report preliminary experimental data of a new CH salt-containing formulation that is capable of effectively interfering with bile salt emulsification processes and, as a result, reducing dietary fat absorption.

Sulindac loaded alginate beads for a mucoprotective and controlled drug release

Ionotropic gelation was used to entrap sulindac into calcium alginate beads as a potential drug carrier for the oral delivery of this anti-inflammatory drug. Beads were investigated in vitro for a possible sustained drug release and their use in vivo as a gastroprotective system for sulindac. Process parameters such as the polymer concentration, polymer/drug ratio, and different needle diameter were analysed for their influences on the bead properties. Size augmented with increasing needle diameter (0.9 mm needle: 1.28 to 1.44 mm; 0.45 mm needle: 1.04 to 1.07 mm) due to changes in droplet size as well as droplet viscosity. Yields varied between 87% and 98% while sulindac encapsulation efficiencies of about 88% and 94% were slightly increasing with higher alginate concentrations. Drug release profiles exhibited a complete release for all formulations within 4 hours with a faster release for smaller beads. Sulindac loaded alginate beads led to a significant reduction of macroscopic histological damage in the stomach and duodenum in mice. Similarly, microscopic analyses of the mucosal damage demonstrated a significant mucoprotective effect of all bead formulation compared to the free drug. The present alginate formulations exhibit promising properties of a controlled release form for sulindac; meanwhile they provide a distinct tissue protection in the stomach and duodenum.