α-Tocopherol-loaded Ca-pectinate microcapsules: Optimization, in vitro release, and bioavailability

Vitamin E Encapsulation within Oil-in-Water Emulsions: Impact of Emulsifier Type on Physicochemical Stability and Bioaccessibility

The influence of plant-based (gum arabic and quillaja saponin) and animal-based (whey protein isolate, WPI) emulsifiers on the production and stability of vitamin E-fortified emulsions was investigated. Their impact on lipid digestibility and vitamin bioaccessibility was also studied utilizing an in vitro gastrointestinal tract. WPI and saponin produced smaller emulsions than gum arabic. All emulsions had good storage stability at room temperature (4 weeks, pH 7). Saponin- and gum arabic-emulsions were resistant to droplet aggregation from pH 2 to 8 because these emulsifiers generated strong electrosteric repulsion. WPI-coated droplets flocculated around pH 5 due to a reduction in charge near their isoelectric point. Lipid digestion was slower in saponin-emulsions, presumably because the high surface activity of saponins inhibited their removal by bile acids and lipase. Vitamin bioaccessibility was higher in WPI- than in saponin- or gum arabic-emulsions. This information may facilitate the design of more efficacious vitamin-fortified delivery systems.

The efficacy of microemulsion-based delivery to improve vitamin E properties: evaluation of the antinociceptive, antioxidant, antidepressant- and anxiolytic-like activities in mice

Objectives

A microemulsion-based delivery system was designed to improve vitamin E (VE) properties, and its antinociceptive, antioxidant, antidepressant- and anxiolytic-like activities in mice were evaluated.

Methods

Male Swiss mice received, by intragastric route, canola oil (20 ml/kg), blank microemulsion (B-ME) (20 ml/kg), VE free (VE-F) (200 mg/kg) or VE microemulsion (VE-ME) (200 mg/kg). In acute treatment, a single dose of treatments was administrated and 30 min after behavioural tests were performed. In the subchronic treatment, mice received such treatments, once a day, for 8 days. On the eighth day, behavioural tests were performed.

Key findings

In the subchronic treatment, VE-ME increased entries and spent time in the open arms in the elevated plus-maze test and decreased the immobility time in the tail suspension test, but no change was found after acute treatment. Acute and subchronic treatments with VE-ME increased response latency to thermal stimulus in the hot-plate test. VE-ME decreased the thiobarbituric acid reactive species levels in the acute and subchronic protocols. Additionally, in subchronic treatment, VE-ME increased renal catalase activity, but VE-F reduced its activity.

Conclusions

Vitamin E-microemulsions showed antioxidant, antinociceptive, antidepressant- and anxiolytic-like actions; thus, ME-based delivery improved pharmacological properties of VE.

The influence of droplet size on the stability, in vivo digestion, and oral bioavailability of vitamin E emulsions

Vitamin E (α-tocopherol) is a nutraceutical compound, which has been shown to possess potent antioxidant and anticancer activity.

Bioavailability of Orally Delivered Alpha-Tocopherol by Poly(Lactic-Co-Glycolic) Acid (PLGA) Nanoparticles and Chitosan Covered PLGA Nanoparticles in F344 Rats

It is hypothesized that the bioavailability of αT (alpha-tocopherol), an antioxidant, can be improved when delivered by poly(lactic-co-glycolic) acid (PLGA) nanoparticles (NPs) and chitosan covered PLGA nanoparticles (PLGA-Chi NPs), and that the mucoadhesive properties of chitosan may enhance absorption of αT. PLGA and PLGA-Chi NPs were characterized by measuring entrapment efficiency, size, polydispersity, and zeta potential. Nanoparticle physical stability, chemical stability of entrapped αT, and release kinetics were also measured. Pharmacokinetic studies were conducted by administering PLGA (αT) NPs, PLGA-Chi (αT) NPs, and free αT via oral gavage in rats. The size and zeta potential of the two particle systems were 97.87 ± 2.63 nm and -36.2 ± 1.31 mV for PLGA(αT) NPs, and 134 ± 2.05 nm and 38.0 ± 2.90 mV for PLGA-Chi (αT) nanoparticles in DI water. The particle systems showed to be stable during various in vitro assays. Bioavailability of nanodelivered αT was improved compared to the free αT, by 170% and 121% for PLGA and PLGA-Chi NPs, respectively. It was concluded that while chitosan did not further improved bioavailability of αT, PLGA NPs protected the entrapped drug from the GI environment degradation and proved to be an effective delivery system for αT.

Design and characterization of controlled-release edible packaging films prepared with synergistic whey-protein polysaccharide complexes

This paper describes an investigation into the properties of a doubly emulsified film incorporated with protein-polysaccharide microcapsules, which serves as a multifunctional food packaging film prepared using common edible materials in place of petroleum--based plastics. The relationships between the microstructural properties and controlled release features of a series of water-in-oil-in-water (W/O/W) microcapsulated edible films prepared in thermodynamically incompatible conditions were analyzed. The hydrophilic riboflavin (V(B2)) nano-droplets (13-50 nm) dispersed in α-tocopherol (V(E)) oil phase were embedded in whey protein-polysaccharide (WPs) microcapsules with a shell thickness of 20-56 nm. These microcapsules were then integrated in 103 μm thick WPs films. Different polysaccharides, including gum arabic (GA), low-methoxyl pectin (LMP), and κ-carrageenan (KCG), exhibited different in vitro synergistic effects on the ability of both films to effect enteric controlled release of both vitamins. GA, which showed a strong emulsifying ability, also showed better control of V(E) than other polysaccharides, and the highly charged KCG showed better control of V(B2) than GA did.

Preparation and characterization of zein/chitosan complex for encapsulation of α-tocopherol, and its in vitro controlled release study

Chitosan (CS) nanoparticles coated with zein has been newly demonstrated as a promising encapsulation and delivery system for hydrophilic nutrient with enhanced bioactivities in our previous study. In this study, a hydrophobic nutrient, α-tocopherol (TOC), was successfully encapsulated into zein/CS complex. The fabrication parameters, including zein concentration, zein/CS weight ratio, and TOC loading percentage, were systematically investigated. The physicochemical and structural analysis showed that the electrostatic interactions and hydrogen bonds were major forces responsible for complex formation. The scanning electron microscopy study revealed the spherical nature with smooth surface of complex. TOC encapsulation was also evidenced by differential scanning calorimetry. The particle size and zeta potential of the complex varied from 200 to 800 nm and +22.8 to +40.9 mV, respectively. The kinetic release profile of the TOC showed burst effect followed by slow release. Compared with zein nanoparticles, zein/CS complex provided better protection of TOC release against gastrointestinal conditions, due to CS coatings. Zein/CS complex is believed to be a promising delivery system for supplementation or treatment of hydrophobic nutrients or drugs.

Characteristics and antioxidant activity of Elsholtzia splendens extract-loaded nanoparticles

Elsholtzia splendens extract-loaded chitosan nanoparticles prepared by ionic gelation were characterized by particle size, zeta potential, entrapment efficiency, and loading efficiency. As the initial concentration of E. splendens extract was increased, the loading efficiency and zeta potential significantly increased, whereas the entrapment efficiency and particle size significantly decreased. The optimum concentration of E. splendens extract for maximum loading efficiency was found to be 0.8 mg/mL. Both free E. splendens extract and E. splendens extract-loaded chitosan nanoparticles showed concentration-dependent antioxidant activity. However, the lipid peroxidation inhibitory activity of E. splendens extract was effectively enhanced when it was entrapped within chitosan nanoparticles. Chitosan nanoparticle encapsulation is therefore a potentially valuable technique for improving the antioxidant activity of E. splendens extract.