In recent years, functional foods have attracted increasing attention due to growing health consciousness. When functional food ingredients are poorly water-soluble, they largely fail to be absorbed due to their low solubility in the digestive tract, limiting their ability to exert their functions. To develop poorly water-soluble compounds into viable functional food ingredients, it is important to increase their gastrointestinal absorption so that they can fully exert their functions, and to ensure their safety and efficacy through ADMET research. β-Carotene exerts physiological activities including antioxidant effects, and functions as a source of vitamin A, but it is completely insoluble in water, so it is poorly absorbed from the digestive tract, rendering it difficult to use efficiently as a functional food ingredient. To overcome this problem, we are conducting research on drug delivery system to improve β-carotene solubility and thereby improve its digestive absorption by applying our unique amorphous solid dispersion production technology. To date, we have produced amorphous solid dispersions with dramatically improved water solubility by adding polymers and emulsifiers to β-carotene and kneading these mixtures under heat. The resultant amorphous solid dispersion showed unprecedentedly high gastrointestinal absorption, enhanced inhibition of allergic dermatitis, and enhanced amelioration of cognitive impairment. No major safety issues associated with long-term continuous administration were observed. In this paper, we introduce our efforts to effectively deliver poorly water-soluble compounds such as β-carotene in functional foods.
Keywords: amorphous solid dispersion; functional food; β-carotene.