Impact of Delivery System Type on Curcumin Bioaccessibility: Comparison of Curcumin-Loaded Nanoemulsions with Commercial Curcumin Supplements

Abstract

In this study, nanoemulsion-based delivery systems fabricated using three different methods were compared with three commercially available curcumin supplements. Powdered curcumin was dispersed into the oil-in-water nanoemulsions using three methods: the conventional oil-loading method, the heat-driven method, and the pH-driven method. The conventional method involved dissolving powdered curcumin in the oil phase (60 °C, 2 h) and then forming a nanoemulsion. The heat-driven method involved forming a nanoemulsion and then adding powdered curcumin and incubating at an elevated temperature (100 °C, 15 min). The pH-driven method involved dissolving curcumin in an alkaline solution (pH 12.5) and then adding this solution to an acidified nanoemulsion (pH 6.0). The three commercial curcumin products were capsules or tablets purchased from an online supplier: Nature Made, Full Spectrum, and CurcuWin. Initially, the encapsulation efficiency of the curcumin in the three nanoemulsions was determined and decreased in the following order: pH-driven (93%) > heat-driven (76%) > conventional (56%) method. The different curcumin formulations were then subjected to a simulated gastrointestinal tract (GIT) model consisting of mouth, stomach, and small intestine phases. All three nanoemulsions had fairly similar curcumin bioaccessibility values (74−79%) but the absolute amount of curcumin in the mixed micelle phase was highest for the pH-driven method. A comparison of these nanoemulsions and commercial products indicated that the curcumin concentration in the mixed micelles decreased in the following order: CurcuWin ≈ pH-driven method > heat-driven method > conventional method ≫ Full spectrum > Nature Made. This study provides valuable information about the impact of the delivery system type on curcumin bioavailability. It suggests that encapsulating curcumin within small lipid particles may be advantageous for improving its absorption form the GIT.

Formulation of More Efficacious Curcumin Delivery Systems Using Colloid Science: Enhanced Solubility, Stability, and Bioavailability

“…At pH values around and above the pK a values of its hydroxyl groups, curcumin undergoes rapid hydrolytic degradation, which has been attributed to cleavage of the α, β-unsaturated β-diketone moiety. As a result, the original curcumin molecule is transformed into trans-6-(4′-hydroxy-3′-methoxyphenyl)-2,4-dioxo-5-hexanal, which itself undergoes cleavage reactions to form ferulic acid, feruloylmethane, and vanillin [ 4 , 13 , 53 , 54 ] ( Figure 2 ). The color of curcumin fades due to this alkaline degradation reaction.…”

Potential of Nanomaterial Applications in Dietary Supplements and Foods for Special Medical Purposes

“…Zheng et al [77] subjected CUR loaded oil-in-water (O/W) NEs prepared using the conventional oil-loading method, the heat-driven method, and the pH-driven method and three commercial CUR supplements (Nature Made, Full Spectrum, and CurcuWin) to a simulated GI tract model consisting of mouth, stomach, and small intestine phases and found that the three tested NEs showed similar CUR bioaccessibility (74–79%) with the highest absolute amount of CUR in the mixed micelle phase of the NE fabricated by the pH-driven method. The concentration of CUR in mixed micelles decreased as follows: CurcuWin ≈ pH-driven method > heat-driven method > conventional method >> full spectrum > nature made, and CUR encapsulated in small lipid particles had an improved absorption in GI tract.…”

Oxidatively stable curcumin‐loaded oleogels structured by β‐sitosterol and lecithin: physical characteristics and release behaviour in vitro

“…Various delivery and encapsulation systems had been developed for curcumin. Among these, lipidbased system allowed a higher loading capacity, such as nanoemulsion, liposomes and nanoparticles (Wang et al, 2013;Martin et al, 2017;Silva et al, 2017;Zheng et al, 2018). Although these investigations have improved the solubility and bioactivity of curcumin to some extent, their preparation technique is relatively complex and they are prone to polymorphic rearrangements and changes in crystallinity which affect the stability of bioactives (Tadros et al, 2004;O'Sullivan et al, 2016).…”