Novel micellar system for Vitamin D3 oral delivery: Assessment of enteric absorption through a digestion-like in vitro model

Vitamin D3 (cholecalciferol) is a lipophilic vitamin universally recognized as the calcium-absorbing factor. This vitamin plays a pivotal role in the maintenance of calcium homeostasis but also represents a fundamental factor to sustain immune function. Despite the widespread use of Vitamin D3 in form of supplements and drugs the issue of its overall bioavailability, after oral assumption, is frequently misjudge and taken for granted. Because of the large interindividual differences in enteric absorption, bile secretion and comorbidity such as intestinal malabsorption syndromes, enteric villi atrophy and others, Vitamin D3 bioaccessibility and as consequence its enteric absorption can vary dramatically. In this study we compared the enteric bioaccessibility of Vitamin D3 from an oily not formulated form versus a novel micellar liquid system in which Vitamin D3 is finely dispersed. The assessment has been carried out through an in vitro enteric model coupled with a gastro-enteric digestion simulating machine. DLS characterization of Vitamin D3 micellar system and its dispersion in fasted state simulated intestinal fluid has been assessed as well. The data collected overall confirm that sole bile is not much effective in dispersing Vitamin D3, especially in enteric fasted state and that a finely dispersed water-based Vitamin D3 micellar system can effectively improve it. Experiments assessed substantially confirmed that micellar system herewith described is able of improving Vitamin D3 enteric bioaccessibility and significantly enhance its enteric permeation rate in comparison with Vitamin D3 unformulated oil. [Display omitted]