In vitro validation of colon delivery of vitamin B2 through a food grade multi-unit particle system

Colon target delivery of active ingredients is frequently applied in pharmaceutical products. However, in functional food and beverage applications, dietary supplements, and medical nutrition, formats targeting colonic delivery to improve human health are rare. Nevertheless, there is emerging evidence for beneficial effects of colonic delivered nutrients on gut microbiota and host health which increases the demand for sustainable food grade materials that are regulatory approved for application. In this paper, we describe a double layer coated multi-unit particle system (MUPS) with a diameter of approximately 730 microns consisting of food grade materials: shellac as outer layer, alginate as inner layer, cellulose as a core and riboflavin as active ingredient. The suitability of the MUPS for colonic delivery was tested in three well-established in vitro digestion and fermentation models: the USP Apparatus 3 and the TNO Intestinal Models 1 and 2 (TIM-1 and TIM-2). All systems confirmed the integrity of the MUPS under simulated upper gastrointestinal tract conditions with approximately 90% of the active ingredient being released under simulated ileal-colonic conditions. The TIM-2 model also showed the effects of riboflavin loaded MUPS on the microbiome composition with an increase in the production of short-chain fatty acids, acetate and butyrate. The results of these experiments provide a reliable basis for validation of this vitamin-loaded food grade MUPS in future human clinical trials. In addition, following the recent announcement of the European Commission to restrict intentionally added microplastics to products, the materials used in the described formulation offer an environmentally friendly alternative to often applied methyl acrylate based coatings.